NUTRITIONAL MANAGEMENT OF RANGE BEEF COWS AND CALVES

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 0164209
• Project Start Date: Oct 1, 2011
• Project End Date: Sep 30, 2016
• Program Code: [(N/A)]- (N/A)

Recipient Organization
MONTANA STATE UNIVERSITY
(N/A)
BOZEMAN,MT 59717

Performing Department
Animal & Range Sciences

Non Technical Summary
Beef cattle production on Montana farms and ranches provided $905 million of gross income to the state in 2009. These operations rely heavily on forages to supply nutrients for both cows and calves. For much of the cow-calf production cycle, requirements for protein and energy can be met with low to medium quality forages. These forages are usually high in fiber and may be deficient in both protein and energy, especially for cows during late gestation and lactation. When forage quantity or quality is limited, feeding supplements may be necessary to maintain the desired level of animal performance. In cow-calf operations in the Northern Great Plains, $319.70 is spent yearly per cow on feed costs. This purchased feed is the largest single production expense for cow-calf producers, making up 63.8% of the total operating costs. Increasing the utilization of Montana's most important natural resources, forages, via strategic supplementation practices, could reduce production input costs substantially and improve the profitability of cow-calf operations. The primary goal in a forage-based livestock production system is to obtain maximum animal performance while effectively utilizing the forage resource base. Providing supplements to range cattle and sheep during times of low forage quality can improve animal performance and provide increased economic returns. The effectiveness of supplementation programs is based on a target supplement intake per animal; however, individual supplement intake may vary with animal preferences, supplement palatability and formulation, delivery method, social interactions, and forage availability. Variation in individual supplement intake may explain inconsistent responses to supplementation.Supplement formulation and delivery method are believed to play an important role in animal response to supplementation. Self-fed supplements have the potential to increase pasture utilization and decrease labor costs. However, scientific literature indicates that self-fed supplements generally result in higher variation in individual supplement intake, which may impact performance. Individual intake variation is generally lower when hand-feeding supplements, but labor costs are increased and there is the potential to disrupt grazing patterns. Effects of competition may also be greater with hand-fed supplements, which could increase the proportion of non-feeders. Most literature relating to supplementation strategies have a number of limitations that make it difficult to apply results to current beef production systems. Supplementation of forages has been and continues to be an active research area. Protein supplementation of low quality forages will generally improve forage intake and animal performance, however, individual performance measures are needed to assist in evaluating the effectiveness of supplementation. Our research project will incorporate measurements of individual forage and supplement intake, and animal performance to provide a realistic evaluation of range supplementation programs.

Animal Health Component

(N/A)

Research Effort Categories

Basic

(N/A)

Applied

(N/A)

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
302	3310	1010	40%
302	3310	1060	10%
307	3310	1010	40%
307	3310	1060	10%

Knowledge Area
302 - Nutrient Utilization in Animals; 307 - Animal Management Systems;

Subject Of Investigation
3310 - Beef cattle, live animal;

Field Of Science
1060 - Biology (whole systems); 1010 - Nutrition and metabolism;

Keywords

beef cattle

supplementation

forage intake

forage digestion

grazing

supplement delivery

Goals / Objectives
The objectives of this project are to: evaluate the interactions between level of supplement consumption, supplement delivery method, and forage intake and utilization by beef cows and calves; integrate feeding strategies to improve forage intake and utilization by beef cows; and investigate the variation in individual animal consumption of supplement. The intent of the proposed research is to determine how the basic processes controlling forage intake and utilization by ruminants can be manipulated by supplementation, and how supplement delivery methods affect variation in individual animal consumption of supplement. In addition, the intent is to develop management strategies that result in improved nutritional efficiencies of forage-based diets for livestock. Expected ouputs: data; collaborations; technology, methods, or techniques; information, skills, and technology for individuals, communities, and programs; and students graduated in agricultural sciences.

Project Methods
Three hundred-sixty pregnant crossbred cows will be randomly allocated to one of six rangeland pastures. Three dietary treatments will be replicated twice using the six pastures, resulting in 30 cows per pasture and 60 cows per treatment. The treatments will be varying stocking rates on liquid supplement lick tanks: 1) 30 cows per lick tank; 2) 20 cows per lick tank; and 3) 10 cows per lick tank. The same liquid supplement formulation will be provided in all lick tanks. The liquid supplement will be a commercially available product, and will consist of a mixture of 50% cane and 50% beet molasses, with 84% of the CP provided by urea. Supplementation will begin approximately November 1 and will continue until approximately January 10. Cow body weight and body condition score will be taken initially and at the end of the supplementation period. Two ruminally-cannulated cows will be randomly assigned to each of the six pastures. Samples of forage consumed on winter range will be obtained by removing freshly grazed forage from the rumen after rumen evacuation. Extrusa samples will be analyzed for DM, N, NDF, ADF and acid detergent lignin. Dried and ground winter range extrusa will be placed in nylon bags and rate and extent of DM and NDF digestion measured in situ in the ruminally-cannulated cows. All cows will be dosed with an indigestible external marker, and random fecal grab samples will be taken and composited for each cow over three days to determine fecal output. Forage indigestibility as determined from in situ incubation will be used along with fecal output to estimate forage intake of each individual cow. Intake (kg/d) = fecal output (kg/d)/Indigestibility. The liquid supplement will be marked with TiO3, and the Ti concentration of the fecal samples from individual cows used to estimate the supplement consumption by individual cows. Carboxymethylcellulase (CMCase) activity will be used as a marker for the measurement of microbial colonization of fiber particles. CMCase is a particle-bound microbial enzyme that has been used as an index of the particle-associated, fiber-degrading population of rumen microorganisms. Forage intake, supplement intake, weight change, and body condition change will be analyzed as a replicated completely randomized design with individual cows as the experimental units.

Progress 10/01/11 to 09/30/16

Outputs
Target Audience:Western Section of the American Society of Animal Science, Montana and Western regional sheep producers, Montana and Western regional beef producers, Ruminant Nutrition scientists, and Extension professionals. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Field work for 5 graduate students and 8 undergraduate students. Lab analyses at the ARS facility in Miles City, MT, and at the USFWS, Bozeman Fish Technology Center. Statistical analysis and summarization of the data. Written theses for 3 graduate students. Posters and oral reports at theannual Montana Nutrition Conference, and theannual Western Section of the American Society of Animal Science. How have the results been disseminated to communities of interest?These data were reported as posters and oral presentationsat the Montana Nutrition Conference, and the Western Section of the American Society of Animal Science. 3published thesis, and4 published journal articles, 3 conference papers. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Previous research has reported high variation in intake of self-fed protein and/or energy supplements by individual animals, however little is known about variation in consumption of mineral supplements. In this study, variation in individual ewe intake of mineral supplement was large in both grazing ewes and ewes fed hay in confinement. This study found a large variation in mineral supplement intake by individual ewes (CV of 34-67%), and indicated there may be up to 10% of ewes in a flock which consume only trace amounts. A better understanding of the factors that regulate mineral supplement intake could possibly improve the effectiveness of mineral supplement programs. Objectives: 1. To evaluate the interactions between level of supplement consumption, supplement delivery method, and forage intake and utilization by beef cows and calves. Supplementation programs rely on the assumption that animals consume a targeted amount of supplement. If animals consume less than the target amount, then the formulated nutrient intake is not received. If animals consume more than the target amount, supplementation costs are increased, and there can be potential negative impacts on forage intake and digestibility. Deviation from the targeted supplement intake can negatively impact animal production. Intake of supplement is usually measured by dividing the supplement disappearance by the number of animals. This method does not consider variation in intake by individual animals. To demonstrate the importance of variation in individual animal supplement consumption, consider the following example of the calculation of consumption as a percent of target intake. If 10 kg of supplement with a target intake of 1 kg per animal per day is fed to a group of 10 animals, average supplement consumption is 1 kg, and it is assumed that the target consumption is met. However, if supplement consumption by individual animals is measured, and there are three animals that consume no supplement, and two animals that consume 0.5 lb/d, then only 50% of the animals consumed at least the target amount. Mulholland and Coombe (1979) used disappearance of supplement to estimate intake and found this method resulted in 100% of target intake by grazing wethers for molasses and molasses-urea liquid supplements, whereas only 55 and 40% of sheep consumed the target amount or more of molasses and molasses-urea liquid supplements, respectively, when individual supplement consumption was measured. Common parameters used to measure intake variation include: the proportion of animals that consume no or a low level of supplement (non-feeders), the coefficient of variation (CV) for individual animal supplement intake, and the percentage of animals consuming the desired or target amount of supplement. 2. Integration of feeding strategies to improve forage intake and utilization by beef cows. The objectives of these studies were to investigate the effects of feeding highlinoleic cracked safflower seeds on reproductive and performance outcomes in pubertal beef heifers. Three experiments were conducted at Montana State University research facilities (Exp. 1, n = 48, BW = 370 ± 24.8 kg; Exp. 2, n = 40, BW = 396.5 ± 31.7 kg; Exp. 3, n = 63, BW = 404.4 ± 26.14 kg). Angus and Angus crossbred heifers were stratified by BW and allocated randomly to the following experimental treatments; 1) fed 1.8 kg/d barley grain concentrate (Barley); or, 2) fed 1.8 kg/d of high linoleic cracked safflower seed (Safflower). Heifers were fed 35 and 29 d, Exp. 1, Exp. 2 and 3. Following the feeding period, heifers (Exp. 1 and 2) were artificially inseminated (AI) 12 h after the onset of estrus, and heifers that did not show estrus were administered 25 mg of PGF2α and time AI. A 7-d CO-synch + CIDR and TAI protocol was used for heifers in Exp. 3. Performance variables included initial and final BW, live wt gain, ADG, and DMI (Exp. 1 and 2). Biweekly blood samples were assayed for progesterone (P4) and PGF2α metabolites (PGFM) concentrations (Exp. 1). Estrus responses were observed using Estrotect tags, heifers with progesterone (P4) < 1 ng/mL were not included in the calculation. Pregnancy rates were determined 40 d post breeding. Performance variables did not differ between barley and safflower treatments with the exception of DMI in Exp. 2. Heifers supplemented with barley consumed 21% more (P < 0.001) DM per d than heifer fed safflower. In Exp. 1, overall pregnancy rates were greater in safflower supplemented heifers than in barley supplemented heifers (P = 0.036). Pooled PGFM concentrations differed by day (P < 0.05) in Exp. 1. Results suggest supplemental high linoleic safflower seed does not appear to influence estrus response or PGFM concentrations in pubertal beef heifers. 3. To investigate the variation in individual animal consumption of supplement. Previous research has reported high variation in intake of self-fed protein and/or energy supplements by individual animals, however little is known about variation in consumption of mineral supplements. Sixty mature range ewes (non-pregnant, non-lactating) were used in a completely randomized design repeated 2 years to determine if feeding method of intercropped field pea (Pisum sativum L.) and spring barley (Hordeum vulgare L.) forage (swath grazed or fed as hay in confinement) affected individual ewe mineral consumption. Thirty ewes were allocated to 3 confinement pens (10 ewes/pen) and 30 ewes were allocated to 3 grazing plots (10 ewes/plot). Ewes had ad libitum access to feed, water, and a mineral supplement containing 1% titanium dioxide as an external marker. Forage dry matter intake (DMI) was calculated using estimates of fecal output, and in vitro 48-h forage DM digestibility. Ewe supplement intake was determined from fecal and supplement Ti concentrations, and fecal output. Forage and mineral intakes were analyzed using ewe as the experimental unit, and plot or pen as the experimental unit for intake variation. A year x treatment interaction (P<0.01) existed for DM forage and mineral intake. Ewes in confinement consumed more forage DM than grazing ewes in 2010, but less than grazing ewes in 2011. Mean mineral intake was highest (P<0.01) by grazing ewes in 2011 and 2010 (average 69 g/day), intermediate by confinement ewes in 2010 (57 g/day), and lowest by confinement ewes in 2011 (31 g/day). A year x treatment interaction (P=0.05) existed for mineral intake CV which was higher (P=0.04) for confinement ewes in 2011 (67 vs. 34%), but was not different (P>0.05) between treatments in 2010. In this study, variation in individual ewe intake of mineral supplement was large in both grazing ewes and ewes fed hay in confinement.

Publications

• Type: Journal Articles Status: Published Year Published: 2016 Citation: Nix, Erin E., Devon L. Ragen, Janice G. P. Bowman, Rodney W. Kott, Mark K. Petersen, Andrew W. Lenssen, Patrick G. Hatfield and Emily C. Glunk. 2016. Forage Intake and Wastage by Ewes in Pea/Hay Barley Swath Grazing and Bale Feeding Systems. American Journal of Experimental Agriculture 12(3):1-6.
• Type: Journal Articles Status: Published Year Published: 2016 Citation: Anderson, Robin C., Laura H. Ripley, Jan G. P. Bowman, Todd R. Callaway, Kenneth J. Genovese, Ross C. Beier, Roger B. Harvey and David J. Nisbet. 2016. Ruminal Fermentation of Anti-Methanogenic Nitrate- and Nitro-Containing Forages In Vitro. Front. Vet. Sci. 3:62.

Progress 10/01/14 to 09/30/15

Outputs
Target Audience:Western Section of the American Society of Animal Science Montana and Western regional sheep producers Montana and Western regional beef producers Ruminant Nutrition scientists Extension professionals Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?These data werereported at the 2014Montana Nutrition Conference, and the 2014 Western Section of the American Society of Animal Science. Kaitlyn Spence received a MS degree. How have the results been disseminated to communities of interest?These data were reported at the Montana Nutrition Conference, and the Western Section of the American Society of Animal Science. 1 published thesis, and 1 published journal article. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Previous research has reported high variation in intake of self-fed protein and/or energy supplements by individual animals, however little is known about variation in consumption of mineral supplements. In this study, variation in individual ewe intake of mineral supplement was large in both grazing ewes and ewes fed hay in confinement. This study found a large variation in mineral supplement intake by individual ewes (CV of 34-67%), and indicated there may be up to 10% of ewes in a flock which consume only trace amounts. A better understanding of the factors that regulate mineral supplement intake could possibly improve the effectiveness of mineral supplement programs.

Publications

• Type: Journal Articles Status: Published Year Published: 2015 Citation: Ragen, D. L., E. E. Nix, R. L. Endecott, P. G. Hatfield, M. K. Petersen, and J.G.P. Bowman. 2015. Individual mineral supplement intake by ewes swath grazing or confinement fed pea-barley forage. Anim. Feed Sci. Technol. 200:107111.

Progress 10/01/13 to 09/30/14

Outputs
Target Audience: Formal classroom instruction, graduate students and undergraduate students Researchers and scientists Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? OUTPUTS: There is no literature on individual mineral intake in sheep and no literature on the variation in sheep mineral intake. This research adds to the literature and the body of knowledge. It is also biological research that becomes the foundation for economic evaluation and will aid feed companies in formulating mineral rations that meet sheep requirements. In this study, both swath grazing ewes and ewes in confinement consumed more mineral than recommended by the mineral manufacturer and the NRC. More research is needed to develop a better understanding of the factors that regulate and impact mineral intake so the appetite of over-eaters can be curbed reducing mineral costs for producers. These data were reported at the 2012 Montana Nutrition Conference, and the Western Section of the 2012 American Society of Animal Science. Devon Ragen and Erin Nix, both graduate students associated with this project, received MS degrees in 2012 from Montana State University. PARTICIPANTS: PIs/PDs - Janice Bowman, Pat Hatfield M.S. Graduate students - Devon Ragen, Erin Nix; The Bair Ranch Foundation - partner organization, provided sheep and funding. TARGET AUDIENCES: Western Section of the American Society of Animal Science Montana and Western regional sheep producers. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period. How have the results been disseminated to communities of interest? These data were reported at the 2012 Montana Nutrition Conference, and the Western Section of the 2012 American Society of Animal Science. 1 published thesis, and 1 accepted journal article. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Experiment 1 - The objectives of these studies were to investigate the effects of feeding highlinoleic cracked safflower seeds on reproductive and performance outcomes in pubertal beef heifers. Three experiments were conducted at Montana State University research facilities (Exp. 1, n = 48, BW = 370 ± 24.8 kg; Exp. 2, n = 40, BW = 396.5 ± 31.7 kg; Exp. 3, n = 63, BW = 404.4 ± 26.14 kg). Angus and Angus crossbred heifers were stratified by BW and allocated randomly to the following experimental treatments; 1) fed 1.8 kg/d barley grain concentrate (Barley); or, 2) fed 1.8 kg/d of high linoleic cracked safflower seed (Safflower). Heifers were fed 35 and 29 d, Exp. 1, Exp. 2 and 3. Following the feeding period, heifers (Exp. 1 and 2) were artificially inseminated (AI) 12 h after the onset of estrus, and heifers that did not show estrus were administered 25 mg of PGF2α and time AI. A 7-d CO-synch + CIDR and TAI protocol was used for heifers in Exp. 3. Performance variables included initial and final BW, live wt gain, ADG, and DMI (Exp. 1 and 2). Biweekly blood samples were assayed for progesterone (P4) and PGF2α metabolites (PGFM) concentrations (Exp. 1). Estrus responses were observed using Estrotect tags, heifers with progesterone (P4) < 1 ng/mL were not included in the calculation. Pregnancy rates were determined 40 d post breeding. Performance variables did not differ between barley and safflower treatments with the exception of DMI in Exp. 2. Heifers supplemented with barley consumed 21% more (P < 0.001) DM per d than heifer fed safflower. In Exp. 1, overall pregnancy rates were greater in safflower supplemented heifers than in barley supplemented heifers (P = 0.036). Pooled PGFM concentrations differed by day (P < 0.05) in Exp. 1. Results suggest supplemental high linoleic safflower seed does not appear to influence estrus response or PGFM concentrations in pubertal beef heifers. Experiment 2 - Previous research has reported high variation in intake of self-fed protein and/or energy supplements by individual animals, however little is known about variation in consumption of mineral supplements. Sixty mature range ewes (non-pregnant, non-lactating) were used in a completely randomized design repeated 2 years to determine if feeding method of intercropped field pea (Pisum sativum L.) and spring barley (Hordeum vulgare L.) forage (swath grazed or fed as hay in confinement) affected individual ewe mineral consumption. Thirty ewes were allocated to 3 confinement pens (10 ewes/pen) and 30 ewes were allocated to 3 grazing plots (10 ewes/plot). Ewes had ad libitum access to feed, water, and a mineral supplement containing 1% titanium dioxide as an external marker. Forage dry matter intake (DMI) was calculated using estimates of fecal output, and in vitro 48-h forage DM digestibility. Ewe supplement intake was determined from fecal and supplement Ti concentrations, and fecal output. Forage and mineral intakes were analyzed using ewe as the experimental unit, and plot or pen as the experimental unit for intake variation. A year x treatment interaction (P<0.01) existed for DM forage and mineral intake. Ewes in confinement consumed more forage DM than grazing ewes in 2010, but less than grazing ewes in 2011. Mean mineral intake was highest (P<0.01) by grazing ewes in 2011 and 2010 (average 69 g/day), intermediate by confinement ewes in 2010 (57 g/day), and lowest by confinement ewes in 2011 (31 g/day). A year x treatment interaction (P=0.05) existed for mineral intake CV which was higher (P=0.04) for confinement ewes in 2011 (67 vs. 34%), but was not different (P>0.05) between treatments in 2010. In this study, variation in individual ewe intake of mineral supplement was large in both grazing ewes and ewes fed hay in confinement.

Publications

• Type: Journal Articles Status: Accepted Year Published: 2014 Citation: Ragen et al., 2014. Individual mineral supplement intake by ewes swath grazing or confinement fed pea-barley forage. Anim. Feed Sci. Technol.
• Type: Theses/Dissertations Status: Published Year Published: 2014 Citation: Spence, K. C. 2014. The effects of feeding high-linoleic safflower seeds on estrus synchronization in beef heifers. MS Thesis, Montana State Univ., Bozeman.

Progress 01/01/13 to 09/30/13

Outputs
Target Audience: Formal classroom instruction, graduate students and undergraduate students Researchers and scientists Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? OUTPUTS: There is no literature on individual mineral intake in sheep and no literature on the variation in sheep mineral intake. This research adds to the literature and the body of knowledge. It is also biological research that becomes the foundation for economic evaluation and will aid feed companies in formulating mineral rations that meet sheep requirements. In this study, both swath grazing ewes and ewes in confinement consumed more mineral than recommended by the mineral manufacturer and the NRC. More research is needed to develop a better understanding of the factors that regulate and impact mineral intake so the appetite of over-eaters can be curbed reducing mineral costs for producers. These data were reported at the 2012 Montana Nutrition Conference, and the Western Section of the 2012 American Society of Animal Science. Devon Ragen and Erin Nix, both graduate students associated with this project, received MS degrees in 2012 from Montana State University. PARTICIPANTS: PIs/PDs - Janice Bowman, Pat Hatfield M.S. Graduate students - Devon Ragen, Erin Nix; The Bair Ranch Foundation - partner organization, provided sheep and funding. TARGET AUDIENCES: Western Section of the American Society of Animal Science Montana and Western regional sheep producers. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period. How have the results been disseminated to communities of interest? Disseminated via 2 theses, and 2 submitted journal articles. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Sixty mature ewes (non-pregnant, non-lactating) were used in a completely randomized design to determine if feeding method of pea-barley forage (swath grazing or hay in confinement) had an effect on individual ewe mineral consumption. Thirty ewes were randomly allocated to 3 confinement pens and 30 ewes were randomly allocated to 3 grazing plots. The study was conducted during Sept. 25 to Oct. 15, 2010 and repeated Sept. 6 to 19, 2011. Targhee ewes (65.4 kg BW) were used in 2010. Rambouillet ewes (61.9 kg BW) were used in 2011. Ewes had ad libitum access to food, water, and a mineral supplement containing 12% salt with 2% titanium dioxide (TiO2) added as an external marker to estimate individual mineral intake. On d 1 of the study, mineral was weighed and placed in covered feeders in pens and plots. Mineral was weighed and added as needed and at the end of the collection period, remaining mineral was weighed to provide an estimate of total mineral intake via disappearance. Forage DMI was calculated using estimates of fecal output, obtained by dosing gelatin capsules containing 2 g chromic oxide (Cr2O3) every day for 14 d, and in vitro 48 h forage DM digestibility. Fecal grab samples were collected from each individual ewe for 7 d and composited by ewe. Forage and mineral intakes were analyzed using individual ewe as the experimental unit, while plot or pen was used as the experimental unit for intake CV. A year x treatment interaction (P 0.001) existed for forage and mineral DMI. Ewes in confinement pens consumed more forage than grazing ewes in 2010 (2.60 vs. 1.86 kg per day, respectively), but less than grazing ewes in 2011 (1.99 vs. 2.49 kg per day, respectively). Mean mineral intake was highest (P 0.001) by grazing ewes in 2011 and 2010 (average 69 g per day), intermediate by ewes in pens in 2010 (57 g per day), and lowest by ewes in pens in 2011 (31 g per day). A year x treatment interaction (P = 0.05) existed for mineral DMI CV which was higher (P = 0.004) for the pen treatment in 2011 (67 vs. 34%) but not different (P > 0.05) between treatments in 2010. In this study, both swath grazing ewes and ewes in confinement consumed more mineral than recommended by the mineral manufacturer and the NRC indicating that more research is needed to develop a better understanding of the factors that regulate and impact mineral intake.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Helmecke, P., S. J. Moreaux, J. Weeding, J.G.P. Bowman, and J. G. Berardinelli. 2013. Effects of psyllium supplementation on protein, triglycerides, serum electrolytes and packed cell volume in grazing horses. J. Equine Vet. Sci. 33:336.
• Type: Journal Articles Status: Published Year Published: 2012 Citation: Abdel-Haleem, H., J.G.P. Bowman, L. Surber, and T. Blake. 2012. Variation in feed quality traits for beef cattle in Steptoe x Morex barley population. Molecular Breeding 29:503-514.

Progress 01/01/12 to 12/31/12

Outputs
OUTPUTS: There is no literature on individual mineral intake in sheep and no literature on the variation in sheep mineral intake. This research adds to the literature and the body of knowledge. It is also biological research that becomes the foundation for economic evaluation and will aid feed companies in formulating mineral rations that meet sheep requirements. In this study, both swath grazing ewes and ewes in confinement consumed more mineral than recommended by the mineral manufacturer and the NRC. More research is needed to develop a better understanding of the factors that regulate and impact mineral intake so the appetite of over-eaters can be curbed reducing mineral costs for producers. These data were reported at the 2012 Montana Nutrition Conference, and the Western Section of the 2012 American Society of Animal Science. Devon Ragen and Erin Nix, both graduate students associated with this project, received MS degrees in 2012 from Montana State University. PARTICIPANTS: PIs/PDs - Janice Bowman, Pat Hatfield M.S. Graduate students - Devon Ragen, Erin Nix; The Bair Ranch Foundation - partner organization, provided sheep and funding. TARGET AUDIENCES: Western Section of the American Society of Animal Science Montana and Western regional sheep producers. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Sixty mature ewes (non-pregnant, non-lactating) were used in a completely randomized design to determine if feeding method of pea-barley forage (swath grazing or hay in confinement) had an effect on individual ewe mineral consumption. Thirty ewes were randomly allocated to 3 confinement pens and 30 ewes were randomly allocated to 3 grazing plots. The study was conducted during Sept. 25 to Oct. 15, 2010 and repeated Sept. 6 to 19, 2011. Targhee ewes (65.4 kg BW) were used in 2010. Rambouillet ewes (61.9 kg BW) were used in 2011. Ewes had ad libitum access to food, water, and a mineral supplement containing 12% salt with 2% titanium dioxide (TiO2) added as an external marker to estimate individual mineral intake. On d 1 of the study, mineral was weighed and placed in covered feeders in pens and plots. Mineral was weighed and added as needed and at the end of the collection period, remaining mineral was weighed to provide an estimate of total mineral intake via disappearance. Forage DMI was calculated using estimates of fecal output, obtained by dosing gelatin capsules containing 2 g chromic oxide (Cr2O3) every day for 14 d, and in vitro 48 h forage DM digestibility. Fecal grab samples were collected from each individual ewe for 7 d and composited by ewe. Forage and mineral intakes were analyzed using individual ewe as the experimental unit, while plot or pen was used as the experimental unit for intake CV. A year x treatment interaction (P < 0.001) existed for forage and mineral DMI. Ewes in confinement pens consumed more forage than grazing ewes in 2010 (2.60 vs. 1.86 kg per day, respectively), but less than grazing ewes in 2011 (1.99 vs. 2.49 kg per day, respectively). Mean mineral intake was highest (P < 0.001) by grazing ewes in 2011 and 2010 (average 69 g per day), intermediate by ewes in pens in 2010 (57 g per day), and lowest by ewes in pens in 2011 (31 g per day). A year x treatment interaction (P = 0.05) existed for mineral DMI CV which was higher (P = 0.004) for the pen treatment in 2011 (67 vs. 34%) but not different (P > 0.05) between treatments in 2010. In this study, both swath grazing ewes and ewes in confinement consumed more mineral than recommended by the mineral manufacturer and the NRC indicating that more research is needed to develop a better understanding of the factors that regulate and impact mineral intake.

Publications

• Nix, E.E. 2012. Effect of swath grazing on forage intake and wastage by ewes. M.S. Thesis, Montana State University.
• Nix, E.E., D.L. Ragen, J.G.P. Bowman, R.W. Kott, and P.G. Hatfield. 2012. Effect of Swath Grazing on Forage Intake and Wastage by Ewes. Proc. West. Sec. Am. Soc. Anim. Sci. 63:58-61.
• Ragen, D.L. 2012. Individual mineral supplement intake by ewes swath grazing or confinement fed pea-barley forage. M.S. Thesis, Montana State University.
• Ragen, D.L., E.E. Nix, R.K. Endecott, P.G. Hatfield, M.K. Petersen, and J.G.P. Bowman. 2012. Individual Mineral Supplement Intake by Ewes Swath Grazing or Confinement Fed Pea-Barley Forage. Proc. West. Sec. Am. Soc. Anim. Sci. 63:103-107.

Progress 01/01/11 to 12/31/11

Outputs
OUTPUTS: A 26-day study will be conducted in the fall of 2010, and again in 2011, using Bair Ranch ewes at the Fort Ellis Experiment Station. The number of ewes will depend on annual forage production and hay availability. Ewes will be assigned to one of six experimental units, and units will be randomly assigned to swath grazed pea/hay barley or confinement-fed baled pea\hay barley. Response variables will include body weight gain during the flushing period, lambing percentage, individual ewe forage and mineral intake, hay and swath wastage, and forage quality changes from harvest (swathed and baled) through the fall. We have finished both years of field data collection. This includes field work on forage wastage and intake on the swath grazing portion of the study, individual ewe supplement intake, and the data collection on flushing. Erin and Devon are finishing the lab analysis for determination of forage and mineral intake, and forage quality. Samples have been analyzed at the nutrition lab at the ARS facility in Miles City, and at the USFWS, Bozeman Fish Technology Center in cooperation with Dr. Sealey. Statistical analysis and summarization of the data will begin as soon as the laboratory analysis is finished. Both graduate students have completed rough drafts of the Literature Reviews for their theses, and are working on the Materials and Methods sections. PARTICIPANTS: Dr. Jan Bowman is the PI/PD. Dr. Pat Hatfield was a collaborator, and there were 2 MS graduate students conducting the field research. TARGET AUDIENCES: Audiences for planned delivery of results include not only ranch and farm operators, but also industry professionals, such as nutritionists, veterinarians, extension educators, and farm business consultants. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Substantial variation in individual animal intake of protein and energy supplements in loose, liquid, and block form has been reported. The type of supplement offered to cattle and sheep, the conditions under which it is fed, previous experience with supplements, social interactions, and forage quality and availability has been shown to influence the amount of supplement consumed by individual animals. In this study, both swath grazing ewes and ewes in confinement consumed more mineral than recommended by the mineral manufacturer and the NRC. This indicates that more research is needed to develop a better understanding of the factors that regulate and impact mineral intake. There is no literature on individual mineral intake in sheep and no literature on the variation in sheep mineral intake. This research adds to the literature and the body of knowledge. It is also biological research that becomes the foundation for economic evaluation and will aid feed companies in formulating mineral rations that meet sheep requirements. In this study, both swath grazing ewes and ewes in confinement consumed more mineral than recommended by the mineral manufacturer and the NRC. More research is needed to develop a better understanding of the factors that regulate and impact mineral intake so the appetite of over-eaters can be curbed reducing mineral costs for producers.

Publications

• Moreaux, S.J.J., J. L. Nichols, J.G.P. Bowman, and P. G. Hatfield. 2011. Psyllium Lowers Blood Glucose and Insulin Concentrations in Horses. Journal of Equine Veterinary Science 31:160-165.
• Blake, T., V. C. Blake, J.G.P. Bowman, and H. Abdel-Haleem. 2011. Barley feed uses and quality improvement. Page 522 in Barley: Production, Improvement, and Uses. Steven E. Ullrich, ed. Blackwell Publishing Ltd., West Sussex, UK.
• Surber, L., H. Abdel-Haleem, J. Martin, P. Hensleigh, D. Cash, J. Bowman, and T. Blake. 2011. Mapping quantitative trait loci controlling variation in forage quality traits in barley. Mol. Breeding 28:189-200.

Progress 01/01/10 to 12/31/10

Outputs
OUTPUTS: Many cattle producers in Montana rely on supplementation programs to correct nutritional deficiencies, improve forage utilization and animal performance, and increase economic returns. Limited research is available concerning how different supplement formulations and delivery methods may impact animal performance in grazing beef cattle. In addition, few studies have taken individual animal performance measurements. Therefore, the intent of this project is to evaluate the effects of supplement delivery methods on individual supplement intake, forage intake and digestibility, and associated performance factors of beef cows grazing native rangeland pastures. This research is aimed at defining and explaining potential differences between supplement delivery methods on forage and supplement intake, which will assist producers in utilizing an optimal supplementation strategy. Identification of characteristics that determine barley grain feed quality. Description of the genetic control of barley grain feed quality for beef cattle. Description of the genetic control of hay barley forage quality and nitrate accumulation. Demonstration that barley is the equal of corn as a back grounding and finishing feed. Release of Valier, the first feed barley variety selected for improved feed quality, improved yield potential, and regional adaptation. Release of H3860224 barley, with improved feed quality, and yield. Release of Haxby barley, with improved test weight, feed quality, and yield. Release of Hays forage barley. Use of barley gene mapping and feedlot studies to develop regionally adapted barley varieties with improved feed quality. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Supplementation programs rely on the assumption that animals consume a targeted amount of supplement. If animals consume less than the target amount, then the formulated nutrient intake is not received. If animals consume more than the target amount, supplementation costs are increased, and there can be potential negative impacts on forage intake and digestibility. Deviation from the targeted supplement intake can negatively impact animal production. Intake of supplement is usually measured by dividing the supplement disappearance by the number of animals. This method does not consider variation in intake by individual animals. To demonstrate the importance of variation in individual animal supplement consumption, consider the following example of the calculation of consumption as a percent of target intake. If 10 kg of supplement with a target intake of 1 kg per animal per day is fed to a group of 10 animals, average supplement consumption is 1 kg, and it is assumed that the target consumption is met. However, if supplement consumption by individual animals is measured, and there are three animals that consume no supplement, and two animals that consume 0.5 lb/d, then only 50% of the animals consumed at least the target amount. Mulholland and Coombe (1979) used disappearance of supplement to estimate intake and found this method resulted in 100% of target intake by grazing wethers for molasses and molasses-urea liquid supplements, whereas only 55 and 40% of sheep consumed the target amount or more of molasses and molasses-urea liquid supplements, respectively, when individual supplement consumption was measured. Common parameters used to measure intake variation include: the proportion of animals that consume no or a low level of supplement (non-feeders), the coefficient of variation (CV) for individual animal supplement intake, and the percentage of animals consuming the desired or target amount of supplement.

Publications

• Blake, T., V. C. Blake, J.G.P. Bowman, and H. Abdel-Haleem. 2011. Barley feed uses and quality improvement. Page 522 in Barley: Production, Improvement, and Uses. Steven E. Ullrich, ed. Blackwell Publishing Ltd., West Sussex, UK.
• Abdel-Haleem, H., J.G.P. Bowman, M. Giroux, V. Kanazin, H. Talbert, L.M.M. Surber, and T. K. Blake. 2010. Quantitative trait loci of acid detergent fiber and grain chemical composition in hulled x hull-less barley population. Euphytica 172:405-418.
• Abdel-Haleem, H., J.G.P. Bowman, V. Kanazin, L.M.M. Surber, H. Talbert, P. M. Hayes, and T. K. Blake. 2010. Quantitative trait loci of dry matter digestibility and particle size traits in two-rowed x six-rowed barley population. Euphytica 172:419-433.
• Surber, L., H. Abdel-Haleem, J. Martin, P. Hensleigh, D. Cash, J. Bowman, and T. Blake. 2010. Mapping quantitative trait loci controlling variation in forage quality traits in barley. Mol. Breeding http://www.springerlink.com/content/01632620w07u3607/fulltext.pdf

Progress 01/01/06 to 12/31/06

Outputs
Oral administration of barley beta-glucan has been shown to stimulate the mammalian immune system. Beta-glucans are assumed to be completely digested in the rumen and few researchers have evaluated the effects of oral beta-glucan administration on immune response in cattle. The objective of the current study was to estimate the in situ and in vivo digestibility of beta-glucan from different barley varieties in beef cattle. Valier (feed barley, 3.62% beta-glucan), Harrington (2-row malting barley, 4.59% beta-glucan), Hockett (2-row malting barley, 4.23% beta-glucan), Legacy (6-row malting barley, 4.46% beta-glucan), and Viscofiber (purified beta-glucan from barley, 67.2% beta-glucan) were incubated in situ for 0, 3, and 6 h. Diet and fecal samples collected at 42- and 107-d on feed from steers fed a finishing diet containing 80% Valier were analyzed for beta-glucan in order to calculate in vivo beta-glucan digestibility. At 3 h of incubation, in situ beta-glucan disappearance was lowest (P < 0.10) for Valier and Legacy (average 31.2%), intermediate for Harrington and Hockett (average 60.7%), and highest for Viscofiber (95.1%). At 6 h of incubation, in situ beta-glucan disappearance was lowest (P < 0.10) for Valier (44.2%), intermediate for Legacy, Harrington, and Hockett (average 78%), and highest for Viscofiber (98.5%), with beta-glucan disappearance from Harrington also being similar to Viscofiber. Total tract in vivo beta-glucan digestibility from a Valier barley-based finishing diet was lower (P < 0.0001) at 42- than 107-d on feed (91.6 vs 98.7%). We recovered 0.06 to 0.25 g beta-glucan/kg body weight from the feces of mature cattle consuming Valier barley-based finishing diets at 42 d on feed. Other researchers have stimulated the mammalian immune system with oral beta-glucan doses ranging from 0.06 to 0.24 g beta-glucan/kg body weight. By feeding Valier, it may be possible to get enough beta-glucan through the rumen early in the finishing period in order to stimulate the immune system of ruminants.

Impacts
Barley beta-glucan digestibility varied between barley varieties. By feeding Valier it may be possible to get enough beta-glucan through the rumen early in the finishing period in order to stimulate the immune system of ruminants. This is the most critical and stressful time for feedlot cattle and would be the best time to stimulate the immune system.

Publications

• Swan, C. G., J.G.P. Bowman, J. M. Martin, and M. J. Giroux. 2006. Increased puroindoline levels slow ruminal digestion of wheat (Triticum aestivum L.) starch by cattle. J. Anim Sci. 84:641-650.
• Grove, A. V., J.G.P. Bowman, D. L. Boss, and T. K. Blake. 2006. Feeding value of corn, Haxby, Valier, and H3 barley varieties for finishing steers. Proc. West. Sec. Am. Soc. Anim. Sci. 57:370-373.
• Grove, A. V., J.G.P. Bowman, L.M.M. Surber, and T. K. Blake. 2006. Feeding value of corn, Valier barley, and corn/Valier combinations for finishing steers. Proc. West. Sec. Am. Soc. Anim. Sci. 57:378-381.
• Grove, A. V., J.G.P. Bowman, L.M.M. Surber, D. L. Boss, and T. K. Blake. 2006. Feeding value of Haxby, Valier, MT960099, and Eslick barley varieties for finishing steers. Proc. West. Sec. Am. Soc. Anim. Sci. 57:374-377.
• Grove, A. V., C. R. Kaiser, N. Iversen, A. Hafla, B. L. Robinson, and J.G.P. Bowman. 2006. Digestibility of barley beta-glucan in cattle. Proc. West. Sec. Am. Soc. Anim. Sci. 57:367-369.
• Iversen, N. L., J.G.P. Bowman, A. V. Grove, B. Robinson, and T. K. Blake. 2006. Feeding value of corn and Valier barley for finishing steers. Proc. West. Sec. Am. Soc. Anim. Sci. 57:363-366.
• Turuspekov, Y., T. Blake, Y. Darlington, M. Giroux, J. Bowman,and B. Beecher. 2006. Genetic variation of Hina gene in barley (Hordeum vulgare L.). Proc. West. Soc. Crop Sci., June, 2006.

Progress 01/01/05 to 12/31/05

Outputs
One hundred twenty-one pregnant Angus cross cows (average weight 636 kg) grazing native range pastures (Agropyron spicatum, Festuca idahoensis) were used in a 2 x 7 factorial design with individual animal as the experimental unit to determine effects of herd size (large = 76 cows and small = 45 cows) and cow age (3 to 9 yr) on individual intake of hand-fed supplement. Each herd was assigned to one of two native range pastures to achieve equal stocking rates (0.4 AU/ha). Titanium dioxide was added to the supplement at 1% as an external marker to estimate individual supplement intake. Forage intake was calculated using estimates of fecal output obtained using chromium boluses and in situ 48 h DM digestibility. Individual fecal samples were collected on d 23, 36, 38, 40, and 61 and analyzed for Ti to give five estimates of supplement intake per cow. Forage intake was higher (P < 0.001) for cows in the large herd vs. cows in the small herd (19.8 vs. 18.3 kg/cow/d). Herd size did not affect ADG (P = 0.11; average 1.06 kg/d); however, ADG was lowest (P < 0.001) for 3-year-old cows (0.72 kg/d) and highest for 7-yr-olds (1.33 kg/d). Supplement DMI was higher (P = 0.03) for the large herd compared to the small herd on d 36 (0.99 vs. 0.82 kg/cow/d, respectively); however, herd size did not affect (P > 0.10) supplement DMI for the other four sampling dates. Average DM supplement intake was 33% lower (P < 0.001) for 3- and 4-yr-old cows compared to 8- and 9-yr-olds (0.72 vs. 1.07 kg/d, respectively). Supplement DMI CV was not different (P = 0.35) between herds (avg. 21%). Results of this study indicate that cow age may have more influence on individual supplement intake than herd size.

Impacts
This is the first study to investigate the effects of herd size on supplement intake by a mixed-age group of cows. Supplement intake between herds was statistically different for only one out of five sampling dates; however, three-year-old cows consumed the least supplement of all age groups for all sampling dates. The results of this trial suggest that it may be beneficial to manage 3-year-old cows separately from older cows in order to obtain maximum benefit from supplementation. The CV for hand-fed supplement in this trial (avg. 21%) was lower than reports of CV found in the literature for self-fed supplements, indicating that hand-fed supplements may minimize variation in supplement intake.

Publications

• Surber, L.M.M., J. A. Pugh, K. K. Krausz, S. D. Cash, A. L. Todd, B. L. Robinson, and J.G.P. Bowman. 2005. Forage quality and agronomic characteristics of spring barley core collection lines compared to commercial barley cultivars. Proc. West. Sec. Am. Soc. Anim. Sci. 56:283-285.
• Surber, L.M.M., J. Pugh, K. Krausz, D. Cash, A. Todd, B. Robinson, and J. Bowman. 2005. Forage quality and agronomic characteristics of spring barley core collection lines compared to commercial barley cultivars. West. Soc. Crop Sci., June 19-23, 2005 (Abstract).
• Boles, J. A., J.G.P. Bowman, D. L. Boss, and L.M.M. Surber. 2005. Meat color stability affected by barley variety fed in finishing diet to beef steers. Meat Sci. 70:633-638.
• Boss, D. L., G. C. Carlson, P. L. Bruckner, R. N. Stougaard, P. F. Lamb, S. D. Cash, T. K. Blake, and J.G.P. Bowman. 2005 Row spacing, plant population and maturity stage effects on barley forage when using air drill technology. Proc. West. Sec. Am. Soc. Anim. Sci. 56:303-306.
• Bowman, J.G.P., J. J. Kincheloe, L.M.M. Surber, A. V. Grove, V. Raboy, J. A. Dorsch, and T. K. Blake. 2005. Phytic acid levels in barley for beef cattle. Proc. West. Sec. Am. Soc. Anim. Sci. 56:426-429.
• Fox, G., J. Bowman, K. Onley-Watson, A. Skerman, G. Bloustein, A. Kelly, A. Inkerman, D. Poulsen, and R. Henry. 2005. Breeding for malt and feed quality in northern Australia. Presented at the 18th North American Barley Researchers Workshop, July 17-20, 2005, Red Deer, Alberta, Canada. (Abstract). http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/fcd10134
• Fox, G., J. Bowman, K. Onley, Waterson, A. Skerman, G. Bloustein, A. Kelly, E. Mace, A. Inderman, D. Poulsen, and R. Henry. 2005. Breeding for malt and feed quality barley. Aust. Barley Tech. Symp. (Abstract).
• Hafer, J., M. Eggers, G. Whiteman, J.G.P. Bowman, B. F. Sowell, M. Frick, and V. Smith. 2005. Team teaching agricultural sciences at 1994 land grant institutions. Proc. West. Sec. Am. Soc. Anim. Sci. 56:471-473.
• Surber, L.M.M., J. Bowman, D. Cash, B. Sowell, J. Martin, and T. Blake. 2005. Is there a genetic basis for forage quality traits in barley? West. Soc. Crop Sci., June 19-23, 2005 (Abstract).

Progress 01/01/04 to 12/31/04

Outputs
One hundred twenty-one pregnant Angus cross cows (average weight 636 +/- 50 kg) grazing native range pastures (Agropyron spicatum, Festuca idahoensis) were used in a 2 x 7 factorial design with individual animal as the experimental unit to determine effects of herd size (large = 76 cows and small = 45 cows) and cow age (3 to 9 yr) on individual intake of hand-fed supplement. Each herd was assigned to one of two native range pastures to achieve equal stocking rates (0.4 AU/ha). Titanium dioxide was added to the supplement at 1% as an external marker to estimate individual supplement intake. Forage intake was calculated using estimates of fecal output obtained using chromium boluses and in situ 48 h DM digestibility. Individual fecal samples were collected on d 23, 36, 38, 40, and 61 and analyzed for Ti to give five estimates of supplement intake per cow. Forage intake was higher (P < 0.001) for cows in the large herd vs. cows in the small herd (19.8 vs. 18.3 kg/cow/d). Herd size did not affect ADG (P = 0.11; average 1.06 kg/d); however, ADG was lowest (P < 0.001) for 3-year-old cows (0.72 kg/d) and highest for 7-yr-olds (1.33 kg/d). Supplement DMI was higher (P = 0.03) for the large herd compared to the small herd on d 36 (0.99 vs. 0.82 kg/cow/d, respectively); however, herd size did not affect (P > 0.10) supplement DMI for the other four sampling dates. Average DM supplement intake was 33% lower (P < 0.001) for 3- and 4-yr-old cows compared to 8- and 9-yr-olds (0.72 vs. 1.07 kg/d, respectively). Supplement DMI CV was not different (P = 0.35) between herds (avg. 21%). Results of this study indicate that cow age may have more influence on individual supplement intake than herd size.

Impacts
Feeding an awned variety, Valier, did not impact DMI, ADG, or FE. MT 981060 had superior feeding value for backgrounding steers and is scheduled for release by the Montana Agricultural Experiment Station.

Publications

• Abdel-Haleem, H., Giroux, M., Talbert, H., Bowman, J., Kanazin, V., and Blake, T. 2004. Identification of QTLs controlling the feed quality of barley. Plant & Animal Genome XII Conf., Jan. 10-14, 2004, San Diego, CA. p. 468. (Abstract)
• Boles, J. A., Bowman, J. G., Surber, L. M. M., and Boss, D. L. 2004. Effects of barley variety fed to steers on carcass characteristics and color of meat. J. Anim Sci. 82: 2087-2091.

Progress 01/01/03 to 12/31/03

Outputs
Barley harvested as hay is a significant source of winter forage for livestock producers in Montana. Limited data is available using hay barley as a roughage source for backgrounding steers. Ninety-six Angus cross steers were allotted to 16 pens in a randomized complete block design. The objectives of this study were to 1) determine the effects of four barley varieties on animal performance and diet digestibility, and 2) determine the effects of feeding awned vs. hooded head type barley. MT 981060, Westford, and Haybet are all hooded forage barley varieties while Valier is an awned feed barley variety. Steers were given ad libitum access to their roughage source, 2.6 kg/head/day of cracked feed barley, and 0.45 kg/head/day of a commercial 32% CP supplement. All roughage was chopped to 5.1 cm. Pen was the experimental unit in the 60 d trial. Steers were weighed and diet, ort, and fecal samples were obtained on d 28 and upon completion (d 60) of the trial. Diet and fecal samples were composited by pen and analyzed for DM, OM, N, NDF, ADF, and AIA. Acid insoluble ash was used to estimate fecal output. Steers fed MT981060 and Valier had 55% greater (P < 0.01) ADG when compared to steers fed Haybet and Westford barley (avg 3.29 vs. 2.75 kg/d, respectively). Dry matter intake was greatest (P < 0.01) for steers fed MT 981060 and Valier, intermediate for Haybet and least for Westford (avg 10.06 vs. 9.61 and 8.08 kg/d, respectively). Steers fed MT 981060, Valier, and Westford barley had 14.4% improvement (P < 0.01) in feed efficiency (FE) when compared to steers fed Haybet barley (avg 15.07 vs. 12.9 kg gain/100 kg feed, respectively). Feeding an awned variety did not impact DMI, ADG, or FE. MT 981060 had superior feeding value for backgrounding steers and is scheduled for release by the Montana Agricultural Experiment Station.

Impacts
Feeding an awned variety, Valier, did not impact DMI, ADG, or FE. MT 981060 had superior feeding value for backgrounding steers and is scheduled for release by the Montana Agricultural Experiment Station.

Publications

• McDonnell, M. F., J.G.P. Bowman, L.M.M. Surber, J. J. Kincheloe, M. A. Thompson, K. A. Anderson, and T. K. Blake. 2003. Effects of barley processing, bulk density, and oil type on feedlot performance and carcass characteristics of finishing beef steers. Proc. West. Sec. Am. Soc. Anim. Sci. 54:49-52.
• Sowell, B. F., and J.G.P. Bowman. 2003. Written assignments to improve critical thinking. Proc. National Conf. on Student Writing and Critical Thinking in Agriculture. April 3-5, 2003, Jackson, WY. http://wac.colostate.edu/proceedings
• Surber, L.M.M., S. D. Cash, J.G.P. Bowman, and M. C. Meuchel. 2003. Nitrate concentration of cereal forage species at three stages of maturity. Proc. West. Sec. Am. Soc. Anim. Sci. 54:203-205.
• Surber, L.M.M., S. D. Cash, J.G.P. Bowman, and K. M. Rolfe. 2003. Stage of maturity, time of sampling, and method of drying effects on forage quality of Haybet barley. Proc. West. Sec. Am. Soc. Anim. Sci. 54:206-209.
• Todd, A. L., J.G.P. Bowman, L.M.M. Surber, M. A. Thompson, J. J. Kincheloe, M. F. McDonnell, and P. F. Hensleigh. 2003. Effect of barley varieties harvested for forage on backgrounding steer performance and diet digestibility. Proc. West. Sec. Am. Soc. Anim. Sci. 54:389-392.
• Bhatti, S. A., J.G.P. Bowman, A. V. Grove, and C. W. Hunt. 2003. Effect of feed intake level and forage source on kinetics of fiber digestion and particle passage in beef cattle. Proc. West. Sec. Am. Soc. Anim. Sci. 54:173-176.
• Boss, D. L., J.G.P. Bowman, L.M.M. Surber, D. G. Sattoriva, and T. K. Blake. 2003. Effects of barley processing and bulk density when fed to backgrounding calves. Proc. West. Sec. Am. Soc. Anim. Sci. 54:351-353.
• Kincheloe, J. J., J.G.P. Bowman, L.M.M. Surber, D. L. Boss, K. A. Anderson, and T. K. Blake. 2003. Effects of barley or corn on performance and digestibility in finishing diets. Proc. West. Sec. Am. Soc. Anim. Sci. 54:362-365.
• Bowman, J.G.P., and B. F. Sowell. 2003. Technology to complement forage-based beef production systems in the West. J. Anim. Sci. 81(E. Suppl. 1):E18-E26.
• Sowell, B. F., J.G.P. Bowman, E. E. Grings, and M. D. MacNeil. 2003. Liquid supplement and forage intake by range beef cows. J. Anim Sci. 81: 294-303.

Progress 01/01/02 to 12/31/02

Outputs
Annual forage barley has become an important winter feed for Montana livestock producers. The objectives of this study were to examine the variation in forage quality of commonly grown forage barley varieties, grain barley varieties, and experimental lines. Fourteen lines were grown in 1999 and 12 lines were grown in 2000 in a replicated (r = 4) field trial near Bozeman, MT. Forage samples were collected at soft dough stage of maturity. Agronomic data collected included plant height, lodging index, heading date, and yield (t/ha). In 1999, in situ DM digestibility (ISDMD) at 48 h was determined. A sub-sample of each line was evaluated for NDF, ADF, CP, and NO3-N. In 2000, samples were divided into heads and forage components, which were analyzed for NDF, ADF, CP and NO3-N. Head and forage data were reconstituted to form whole plant data. Six varieties were in common between 1999 and 2000. In 1999, the range in ISDMD was 62.3 to 74.3% (CV = 3.8%), CP ranged from 10.5 to 15.8% (CV = 9.0%), and NO3-N from 0.12 to 0.56% (CV = 38.0%). All forage quality characteristics were affected by variety (P < 0.10). In 2000, the % heads ranged from 19.8 to 41.1% (CV = 20.1%), % forage from 58.9 to 80.2% (CV = 7.7%), head NO3-N from 0.01 to 0.33% (CV = 96.0%), and forage NO3-N from 0.02 to 0.92% (CV = 51.9%). Barley variety affected forage NO3-N (P < 0.01), however, head NO3-N was not affected (P > 0.10). Whole plant CP ranged from 10.5 to 18.3% (CV = 12.3%), NDF from 50.0 to 66.8% (CV = 5.8%), ADF from 24.1 to 44.1% (CV = 11.0%), and NO3-N from 0.08 to 0.73% (CV = 50.8%). Year affected NDF and ADF (P < 0.002) when common variety data was combined, however, CP and NO3-N were not affected (P > 0.10). Neutral detergent fiber was 13% lower (P < 0.001) and ADF was 7% lower (P < 0.01) in 2000 than 1999 (53.5 vs. 61.7%, 31.0 vs. 33.4, respectively). Haybet barley had 8.8 % lower NDF (P < 0.01), 15.9% lower ADF (P < 0.001), and 28.6% lower NO3-N (P < 0.001) when compared to Westford barley. Considerable forage quality variation is available to develop improved forage barley varieties.

Impacts
Considerable forage quality variation is available to develop improved forage barley varieties, and forage quality should be used as a selection criterion in forage barley breeding programs.

Publications

• Beecher, B., J. Bowman, J. Martin, A. Bettge, C. F. Morris, T. K. Blake, and M. J. Giroux. 2002. Hordoindolines are associated with a major endosperm texture QTL in barley (Hordeum vulgare L.). Genome 45:584-591.
• Bergner, C. J., J. A. Boles, J.G.P. Bowman, D. L. Boss, L.M.M. Surber, T. Spinner and K. Groenlund. 2002. Effects of corn and barley based diets on meat characteristics. Proc. West. Sec. Am. Soc. Anim. Sci. 53:274-276.
• Blake, T. K., J.G.P. Bowman, P. Hensleigh, G. Kushnak, G. Carlson, L. Welty, J. Eckhoff, K. Kephart, and D. Wichman. 2002. Registration of `H3860224' barley. Crop Sci. 42:1747-1748.
• Blake, T. K., J.G.P. Bowman, P. Hensleigh, G. Kushnak, G. Carlson, L. Welty, J. Eckhoff, K. Kephart, D. Wichman, and P. M. Hayes. 2002. Registration of `Valier' barley. Crop Sci. 42:1748-1749.
• Bowman, Jan, and Bok Sowell. 2002. Feeding the beef cow herd. Chapter 17 In: Richard O. Kellems and D. C. Church (Ed.) Livestock Feeds & Feeding. Prentice Hall, Upper Saddle River, New Jersey. Pp. 341- 360.
• Bowman, J.G.P., and B. F. Sowell. 2002. Self-fed supplements for beef cattle on grasslands. Proc. 1st Global Conference on Organic Beef Production, Brazil.
• Kincheloe, J. J., J.G.P. Bowman, L.M.M. Surber, D. L. Boss, K. A. Anderson, and T. K. Blake. 2002. Feeding value of barley vs. corn in finishing diets. Proc. West. Sec. Am. Soc. Anim. Sci. 53:596-599.
• Surber, L.M.M., J.G.P. Bowman, W. L. Bengochea, P. F. Hensleigh, and T. K. Blake. 2002. Evaluation of barley from the core collection of the USDA National Small Grains Collection for forage quality and yield. Proc. West. Sec. Am. Soc. Anim. Sci. 53:333-336.
• Taylor, N., P. G. Hatfield, B. F. Sowell, J.G.P. Bowman, J. S. Drouillard, and D. V. Dhuyvetter. 2002. Pellet and block supplements for grazing ewes. Anim. Feed Sci. Technol. 96:193-201.

Progress 01/01/01 to 12/31/01

Outputs
Thirty-two pregnant crossbred cows individually fed chopped hay (6.9% CP) ad libitum in Calan gates were used to determine the effects of four levels of liquid supplement on forage and nutrient intake and digestibility. Eight cows were assigned by weight to one of four treatments: 0, 0.45, 0.91, or 1.36 kg (as-fed) of a molasses-based liquid supplement, which supplied 0, 100, 203, or 303 g CP daily in a randomized complete block design. All four supplement levels were represented in each of eight pens. Cows were individually fed hay and supplement at 0700 daily, hay at 1600, and feed refusals were weighed to determine forage intake. There was no effect of supplement level on hay DMI (P > 0.13), hay DM digestibility (P > 0.78), or hay digestible DMI (P > 0.15). There was a linear increase in total diet DMI (P = 0.03) due to supplement level, but there were no differences in total diet DMI on a %BW basis (P > 0.19). Total diet digestible DMI (P = 0.004) increased linearly due to supplement level. There was no effect (P > 0.13) of supplement level on diet DM digestibility. There were no treatment differences (P > 0.13) in hay nutrient intake for OM, CP, NDF, or ADF or digestibility for OM, NDF, or ADF. Total diet CP intake, CP digestibility, and digestible CP intake were increased linearly (P < 0.001) by supplement level. In this study, increasing CP supplement level had no effect on hay intake or digestibility, probably because forage quality as indicated by DMI as %BW (avg 2.6%) and ADG (avg 1.1 kg) was too high for supplemental CP to elicit a response.

Impacts
Cows fed crested wheatgrass hay (6.9% CP) with a DOM:CP ratio of 7 showed no increase in forage intake or digestibility when supplemented with increasing levels of CP, probably because forage quality as indicated by DMI as %BW (avg 2.6%) and ADG (avg 1.1 kg) was too high for supplemental CP to elicit a response.

Publications

• Surber, Lisa, Jan Bowman, Tom Blake, Dennis Cash, Kim Anderson, Pat Hensleigh, Kris Robison, Rachel Endecott, Janna Kincheloe, Miriah Stowe, and Brenda Robinson. 2001. Forage barley for beef cattle. Proc. 50th Montana Nutrition Conf., College of Ag., Agric. Exp. Stat., Extension Service, Bozeman, MT, pp. 41-49.
• Surber, L.M.M., J.G.P. Bowman, T. K. Blake, K. N. Robison, R. L. Endecott, and B. L. Robinson. 2001. Identification of genetic markers associated with forage quality characteristics in Lewis x Karl barley lines. West. Sec. Am. Soc. Anim. Sci. 52:292-295.
• Surber, L.M.M., M. T. Stowe, J.G.P. Bowman, S. D. Cash, P. F. Hensleigh, and T. K. Blake. 2001. Variation in forage quality characteristics of barley. West. Sec. Am. Soc. Anim. Sci. 52:353-356.
• Taylor, N., J.G.P. Bowman, K. A. Anderson, L.M.M. Surber, T. K. Blake, V. Raboy, J. A. Dorsch, and J. G. Broyles. 2001. Phytic acid levels in barley for beef cattle. West. Sec. Am. Soc. Anim. Sci. 52:492-495.
• Taylor, N., J.G.P. Bowman, B. F. Sowell, and J. G. Broyles. 2001. Influence of supplement level on forage intake and digestibility for beef cows. West. Sec. Am. Soc. Anim. Sci. 52:517-520.
• Robison, K. N., J.G.P. Bowman, L.M.M. Surber, S. D. Cash, K. A. Anderson, R. L. Endecott, J. J. Kincheloe, and B. L. Robinson. 2001. Effects of fibrolytic enzyme addition on forage barley varieties for backgrounding steers. West. Sec. Am. Soc. Anim. Sci. 52:336-339.
• Bowman, J.G.P., T. K. Blake, L.M.M. Surber, D. K. Habernicht, and H. Bockelman. 2001. Feed-quality variation in the barley core collection of the USDA national small grains collection. Crop Sci. 41:863-870.
• Endecott, R. L., J.G.P. Bowman, L.M.M. Surber, D. L. Boss, K. N. Robison, and T. K. Blake. 2001. Feeding value of Lewis and Baronesse barley lines for finishing steers. West. Sec. Am. Soc. Anim. Sci. 52:551-554.
• Quimby, W. F., B. F. Sowell, J.G.P. Bowman, M. E. Branine, M. E. Hubbert, and H. W. Sherwood. 2001. Application of feeding behaviour to predict morbidity of newly received calves in a commercial feedlot. Can. J. Anim. Sci. 81:315-320.
• Bowman, Jan. 2001. Barley for Beef Cattle. In: Cow-Calf Management Guide, Western Beef Resource Committee, Cooperative Extension System. Pp. 332-1 to 332-5.
• Kincheloe, J. J., J.G.P. Bowman, L.M.M. Surber, K. A. Anderson, K. N. Robison, R. L. Endecott, B. L. Robinson, and T. K. Blake. 2001. Feeding value of Morex, Steptoe, and two experimental backcross barley lines for finishing steers. West. Sec. Am. Soc. Anim. Sci. 52:555-558.

Progress 01/01/00 to 12/31/00

Outputs
Despite the importance of forage quality to animal performance, barley forage quality has not been used as a selection criterion in barley breeding programs. Our objectives were to evaluate the Steptoe/Morex doubled haploid (DH) population for forage quality, identify Quantitative Trait Loci (QTLs) for forage quality, and determine if there is a genetic basis for nitrate accumulation. The 145 DH lines were grown in a replicated field trial under irrigated conditions in Bozeman, MT. Forage samples were collected at plant anthesis. A 0.15 m clip sample of one row was cut at stubble height and dried at 60C for 48 h. Dry matter forage yield (FY) was determined. Forage samples were ground to pass a 5-mm screen. In situ DM digestibility (ISDMD) at 48 h was determined. A sub-sample of each line was evaluated for NDF, ADF, N, and NO3-N. Data was analyzed using the GLM procedure of SAS. Genetic variation was present between lines for NDF, ADF, ISDMD, N and NO3-N (P < 0.04). Population ISDMD ranged from 68.6 to 84.2% (CV = 3.2%), ADF ranged from 21.3 to 35.1% (CV = 6.3%), N ranged from 2.3 to 4.1% (CV = 9.3%), and NO3-N ranged from 0.22 to 1.1% (CV = 22.2%). Correlation analysis indicated that ISDMD was positively correlated (r = 0.70, P < 0.001) with N and negatively correlated with ADF (r = -0.57, P < 0.001) and NDF (r = -0.69, P < 0.001). Nitrogen was positively correlated (r = 0.52, P < 0.001) with NO3-N and negatively correlated (r = -0.69, P < 0.001) with ADF. Forage ISDMD could be predicted from ADF, NDF and N (R2 = 0.54, P < 0.001). Major QTL markers were identified for all traits. Molecular markers associated with ISDMD, ADF and N were identified on chromosome 2, 4, and 5. Results suggest that genetic differences among Steptoe/Morex DH lines have an impact on forage digestion in the rumen, and this information could be used to select improved forage-quality barley varieties.

Impacts
We have identified characteristics that can be used in a selection program for superior forage quality barley. In addition, we have developed the first datasets thoroughly describing the genetic control of forage quality and nitrate accumulation in forage barley. We intend to develop a program of molecular marker-assisted selection for forage quality and low-nitrate potential characteristics in forage barley. This research has provided the identification and mapping of Quantitative Trait Loci for barley forage quality based on North American Barley Genome Mapping Project populations, and will allow deployment of genes for improved forage quality via marker-assisted selection.

Publications

• Taylor, N., P. G. Hatfield, B. F. Sowell, J.G.P. Bowman, J. S. Drouillard, and D. V. Dhuyvetter. 2000. Supplement and forage intake by grazing ewes fed either a block or pelleted supplement. Proc. West. Sec. Am. Soc. Anim. Sci. 51:26-29.
• Bowman, J.G.P., and D. W. Sanson. 2000. Energy supplementation considerations for grazing ruminants. In: T. DelCurto (Ed.) Optimal Supplementation Strategies with Beef Cattle Consuming Low Quality Forage in the US. Oregon Agric. Exp. Station Special Report, Oregon State University Printing, Corvallis.
• Surber, L.M.M., J.G.P. Bowman, T. K. Blake, V. E. Nettles, A. L. Grindeland, M. T. Stowe, R. L. Endecott, K.N. Robison, B. L. Robinson, and D. R. See. 2000. Determination of genetic markers associated with forage quality of barley for beef cattle. Proc. West. Sec. Am. Soc. Anim. Sci. 51:295-298.
• Surber, L.M.M., J.G.P. Bowman, T. K. Blake, and D. R. See. 2000. Determination of genetic markers associated with forage quality for beef cattle. Proc. 8th International Barley Genetic Symposium, 22-27 October, 2000, Adelaide, South Australia.
• Daniels, J. T., P. G. Hatfield, D. E. Burgess, R. W. Kott, and J.G.P. Bowman. 2000. Evaluation of ewe and lamb immune response when ewes were supplemented with vitamin E. J. Anim. Sci. 78:2731-2736.
• Sowell, B. F., J. C. Mosley, and J.G.P. Bowman. 2000. Social behavior of grazing beef cattle: Implications for management. J. Anim. Sci. Available at: http://www.asas.org/jas/symposia/proceedings/0923.pdf.

Progress 01/01/99 to 12/31/99

Outputs
One hundred and one Angus cows (average weight 614 kg) and their bull calves (average weight 213 kg) grazing improved summer pastures were used to determine cow and calf intake of liquid supplement, and its effect on forage intake and performance. Forty-seven pairs had access to a 410 g CP/kg DM molasses-based liquid supplement in an open feeder and 54 pairs were not supplemented. The study was conducted in southwestern Montana from July 28 to October 3, 1997. Cows consumed significantly more supplement (0.3 kg/day) than calves (0.1 kg/day) but both consumed 0.5 g/kg bodyweight per day. Supplemented cows gained 0.12 kg/day more (p<0.05) than unsupplemented cows; however, there was no difference (p>0.10) in body condition score change. Average daily gain by supplemented calves was 30% greater (p<0.01) than average daily gain by unsupplemented calves. Forage intake (g/kg body weight) by both supplemented cows and calves was 64% greater (p<0.01) than forage intake by unsupplemented cows and calves. There was no difference (p>0.10) in milk intake between supplemented and unsupplemented calves. There was no difference (p>0.10) in time spent at the supplement feeder between cows and calves, averaging 5.0 min/day. Time at the feeder was lowest for 7-year-old cows, intermediate for 6- and 8-year-old cows, and highest for 9-year-old cows (p<0.10). There was no difference (p>0.10) in supplement feeding bouts/day between age groups of cows. Calf liquid supplement intake (g/kg body weight) and time spent at the supplement feeder were similar to intake and time spent at the feeder by cows. Liquid supplementation increased forage intake and average daily gain by cows and calves grazing improved forages in late summer. The cost for additional weight gained by the supplemented calves was US$ 0.33/kg and October cattle prices in Montana were US$ 1.64/kg. Liquid supplementation was cost effective under the conditions of this study.

Impacts
Late summer supplementation improved performance of suckled calves and was economical under conditions of this study. Social dominance by a mixed-age group of cows at an open liquid supplement feeder was similar to social dominance exhibited by supplemented cows at lick-wheel feeders and by cows that were hand-fed with supplements.

Publications

• Bowman, J.G.P., B. F. Sowell, D. L. Boss, and H. Sherwood. 1999. Influence of liquid supplement delivery method on forage and supplement intake by grazing beef cows. Anim. Feed Sci. Technol. 78:273-285.
• Earley, A. V., B. F. Sowell, and J.G.P. Bowman. 1999. Liquid supplementation of grazing cows and calves. Anim. Feed Sci. Technol. 80:281-296.

Progress 01/01/98 to 12/31/98

Outputs
Twenty-eight heifers were individually fed on low quality hay ad libitum along with one of seven levels of liquid supplement (0, 0.23, 0.45, 0.68, 0.90, 1.13, and 1.36 kg/day) during a 24-day trial to evaluate the use of YbCl3 and Cr2O3 as external markers to estimate forage and supplement intake. A linear relationship was found between supplement DM intake predicted by the dual marker technique and actual supplement DM fed (P < 0.001; r2 = 0.92). Sixty crossbred 2- and 3-yr-old pregnant cows were assigned to one of three native range pastures to evaluate forage and supplement intake, and supplement feeding behavior as affected by cow age (2 vs 3 years) and liquid supplement delivery method. Treatments were: 1) no supplement (Control); 2) ad libitum access to a liquid supplement feeder (ADLIB); and 3) ad libitum access to Regulate Liquid Feed Delivery System (REGULATE; Agri-Beef, Boise, Idaho, USA). Liquid supplement (28.5% CP as-fed) used in both feeders contained ytterbium chloride. Chromic oxide boluses were used to estimate fecal output (FO). Forage intake was estimated from FO, and 48 hour DM indigestibility of extrusa samples collected using ruminally cannulated cows, and incubated in situ. Forage 48 hour DM and NDF digestibility values were greater (P < 0.01) for ADLIB and REGULATE than for Control (average 67.1 vs 49.4% for DM; average 63.7 vs 42.7% for NDF). Three-year-old cows consumed 11% more (P < 0.05) forage DM than 2-year-old cows (15.3 vs 13.8 kg/d), but no differences (P > 0.10) were significant when expressed on a g/kg body weight basis. Cows receiving REGULATE and ADLIB consumed 49% more (P < 0.01) forage DM than Control cows (average 16.3 vs 11.0 kg/d). Individual supplement DM consumption ranged from 0.002 to 2.54 kg/day. A cow age by treatment interaction was detected for supplement consumption. Two- and 3-year-old cows on REGULATE and 2-year-old cows on ADLIB consumed less (P < 0.01) supplement DM than 3-year-old cows on ADLIB. Liquid supplement increased forage intake and digestibility by cows grazing fall native range. A computer controlled liquid supplement feeder equalized supplement intake by 2- and 3-year-old cows.

Impacts
(N/A)

Publications

• Daniels, T.K., Bowman, J.G.P, Sowell, B.F., Grings, E.E. and MacNeil, M.D. 1998. The effects of cow age and supplement delivery method on forage and liquid supplement intake. Proc. West. Sec. Am. Soc. Anim. Sci. 49:145-148.
• Earley, A.V., Sowell, B.F. and Bowman, J.G.P. 1998. Forage and supplement intake by range cows and calves. Proc. West. Sec. Am. Soc. Anim. Sci. 49:141-144.
• Sowell, B.F., Bowman, J.G.P., Sherwood, H.W. and Grings, E.E. 1998. Radio frequency technology for supplement feeding behavior by range cows. Soc. Range Manage. Ann. Mtg. 51:13.
• Earley, A.V. 1998. Liquid supplementation of grazing cows and calves. M.S. Thesis, Montana State University.

Progress 01/01/97 to 12/31/97

Outputs
One hundred eighty crossbred cows were assigned to one of six native range pastures during two winters to evaluate forage and supplement intake as affected by cow age and liquid supplement delivery method. Treatments were: 1) no supplement (Control); 2) a lickwheel feeder containing liquid supplement (UNREG); and 3) a computer-controlled lickwheel feeder that dispensed 1 kg/head/d of liquid supplement (REG). A treatment x year interaction was found for DMI, with both REG and UNREG cows having higher DMI than Control cows the first year, and REG cows having higher DMI than UNREG and Control cows in year two. Forage DMI was similar for all age groups (avg 3.2% BW). Forage digestibility was increased by supplementation both years. Blood urea nitrogen was highest for UNREG (8.7 mg/dL), intermediate for REG (6.2 mg/dL), and lowest for Control (2.3 mg/dL). Supplemented cows lost less body condition (1-9 scale) than Control cows (-.3 vs -.5 BCS). Supplement intake (as-fed) was higher by cows on UNREG (1.83 kg/d) than those on REG (.72 kg/d). Supplement intake (as-fed) was lowest for 2-year-old cows (.82 kg/d), intermediate for 3-year-olds (1.16 kg/d), and greatest for 4-, 5-, and 6-year-olds (avg 1.46 kg/d). Liquid supplementation increased forage intake, and forage digestibility, and reduced cow body condition score change.

Impacts
(N/A)

Publications

• BOWMAN, J.G.P., and B.F. SOWELL. 1997. Delivery method and supplement consumption by grazing ruminants: A review. J. Anim. Sci. 75:543-550.
• BOWMAN, J.G.P., and B.F. SOWELL. 1997. Feeding the Beef Cow Herd. In: R. O. Kellems, and D. C. Church (Eds) Livestock Feeds and Feeding, 4th Edition, Prentice Hall Publishing, NJ.
• SOWELL, B.F., J.G.P. BOWMAN, M.E. BRANINE, and M.E. HUBBERT. 1998. Radio frequency technology to measure feeding behavior and health of feedlot steers. Appl. Anim. Behav. Sci. (In press)
• SURBER, L.M.M., and J.G.P. BOWMAN. 1998. Monensin effects on digestion of corn or barley high concentrate diets. J. Anim. Sci. (In

Progress 01/01/96 to 12/30/96

Outputs
We grew and harvested over 40 tons each of four barley genotypes (Baronesse, Lewis, Morex, Steptoe) that were selected to test hypotheses regarding impact of genotype on feedlot performance by beef steers. One-hundred sixty steers are currently on feed in large scale feedlot experiments at the Northern Agricultural Research Center, Havre, MT and at the Montana State University, Bozeman, MT. These experiments will run for a time period of approximately 160 days. We published the first significant paper demonstrating that the gene on barley chromosome 4 and another on barley chromosome 3 have impacts on digestibility and milling quality of barley feed to beef cattle (Bowman and Blake, 1996).

Impacts
(N/A)

Publications

• Bowman, J.G.P. and T.K. Blake (1996) Barley feed quality for beef cattle. In: GRAHAM SCOLES, AND BRIAN ROSSNAGEL (Eds.) PROC. 5TH INTERNATIONAL OAT CONFERENCE& 7TH INTERNATIONAL BARLEY GENETICS SYMPOSIUM, SASKATOON, SASKATCHEWAN. pp. 82-90
• Boss, D.L. and J.G.P. Bowman (1996) Barley varieties for finishing steers: I. Feedlot performance, in vivo diet digestion, and carcass characteristics. J. ANIM. SCI. 74:1967-1972.
• Boss, D.L., and J.G.P. Bowman (1996) Barley varieties for finishing steers: II. Ruminal characteristics, and rate, site and extent of digestion. J. ANIM. SCI. 74:1973-1981.
• Bowman, J.G.P., T.K. Blake, L.M.M. Surber, D.K. Habernicht, T.K. Daniels, and J.T. Daniels (1996) Genetic factors controlling digestibility of barley for ruminants. PROC. WEST. SEC. AM. SOC. ANIM. SCI. 47:257-260.
• Milner, T.J., J.G.P. Bowman, L.M.M. Surber, S.D. McGinley, T.K. Daniels, and J.T. Daniels (1996) Feedlot performance and carcass characteristics of beef steers fed corn or barley. PROC. WEST. SEC. AM. SOC. ANIM. SCI. 47:32-35.

Progress 01/01/95 to 12/30/95

Outputs
A technique to estimate individual cow consumption of liquid supplement was developed using YbCl and Cr2O3 boluses. A linear relationship was found between supplement DM intake predicted by the dual marker technique and actual supplement DM fed (P < .001; R2 = .92). This technique appears to have the potential to estimate liquid supplement consumption by individual animals and would be useful under grazing conditions. Cows grazing native rangeland and receiving liquid supplement consumed 49% more (P < .01) forage DM than control cows (avg 16.3 vs 11.0 kg/d). Individual supplement DM consumption, as estimated from fecal Yb concentration, ranged from .002 to 2.54 kg/d. Liquid supplement increased forage intake and digestibility by cows grazing fall native range. Approximately 29% of the cows having access to liquid supplement consumed only a trace amount based on visual observations and Yb marker techniques. Coefficients of variation for supplement use based on fecal Yb concentrations and observational data averaged 85%. Two-yr-old cows visited the lick feeders less frequently (P < .001) and spent less time at the feeder (P < .001) than 3-yr-old cows.

Impacts
(N/A)

Publications

• Bowman, J.G.P., and B. F. Sowell. 1995. Delivery method and supplement consumption by grazing ruminants. Presented at a symposium entitled "Supplementation Strategies for Grazing Ruminants", Ann. Mtg. Am. Soc. Anim. Sci., Orlando, FL.
• Bowman, J.G.P., and B. F. Sowell. 1995. Liquid supplement use by beef cows grazing native rangeland. Proc. Liquid Feed Symposium, Sept. 11-13, Dallas, TX. pp. 13-23.
• Bowman, J.G.P., and B. F. Sowell. 1995. Liquid supplementation for beef cattle. Proc. International Beef Symposium, Jan. 18-20, Great Falls, MT. SR58:163-175.
• Bowman, J.G.P., B. F. Sowell, and D. L. Boss. 1995. Effect of liquid supplement delivery method on forage intake and digestibility by cows on native range. Proc. West. Sec. Am. Soc. Anim. Sci. 46:391-394.
• Bowman, J.G.P., B. F. Sowell, and J. A. Paterson. 1995. Liquid supplementation for ruminants fed low-quality forage diets: a review. Anim. Feed Sci. Technol. 55:105-138.
• Gibson, L. A., J.G.P. Bowman, and B. F. Sowell. 1995. Dual marker technique for measurement of individual animal liquid supplement intake. Proc. West. Sec. Am. Soc. Anim. Sci. 46:21-23.
• Sowell, B. F., J.G.P. Bowman, D. L. Boss, and H. W. Sherwood. 1995. Feeding behavior of range cows receiving liquid supplements. Proc. West. Sec. Am. Soc.

Progress 01/01/94 to 12/30/94

Outputs
Twenty-eight yearling heifers (avg wt 428 kg) were randomly allocated to one of four treatments to determine the effects of increasing level of nonstructural carbohydrate (NSC) supplementation on intake and digestibility of low-quality hay. Supplements were formulated to provide 0, .32, .63, or .95 kg of NSC/d while supplying .34 kg CP.d and 5.1 Mcal ME/d. Treatments were: 1) control, no supplement; 2) 2.04 kg/d soybean hulls and soybean meal(15.5% CP, 55.1% NDF; LOW); 3) 1.93 kg/d wheat middlings (15.9% CP, 41.1% NDF; MED); and 4) 1.91 kg/d barley and soybean meal (15.7% CP, 14.1% NDF; HIGH). Heifers were individually fed a low-quality hay (5.5% CP, 71.3% NDF) ad libitum and their respective supplements in 8 pens containing Calan gates for 21 d. Sustained release Cr2)3 boluses were used to determine fecal output for calculation of total tract digestibility. Forty-eight h in situ DM, OM and NDF disappearance of supplements were used to correct fecal output estimates to calculate hay DM, OM and NDF digestibilities. Treatment sums of squares were partitioned into linear and quadratic components. Intake and digestibility of hay DM, OM, and NDF responded quadratically (P<.05) to increasing level of NSC supplementation. Total diet NDF digestibility was 14.4% greater (P<.05) for LOW & MED than C or HIGH. Hay DM digestibility was 13.6% greater (P<.05) for LOW and MED than C or HIGH. Hay NDF digestibility was increased (P<.05) by supplementation with LOW or MED, but not by HIGH. intermediate levels of.

Impacts
(N/A)

Publications

• BOWMAN, J.G.P., B.F. SOWELL, AND J.M. NICOL. 1994. Effects of increasing level of nonstructural carbohydrate suypplementation on intake and digestion of low quality hay by yearling heifers. Proc. West. Sec. Am. Soc. Anim. Sci. 45:126-128.
• MILNER, T.J., J.G.P. BOWMAN, AND B.F. SOWELL. 1994. Effects of forage type, barley level, management system, and pen composition on replacement heifer performance. Proc. West. Sec. Am. Soc. Anim. Sci. 45:71-73.
• PATERSON, J.A., R.L. BELYEA, J.G. P. BOWMAN, M.S. KERLEY, AND J.E. WILLIAMS. 1994. The impact of forage quality and supplementation regimen on ruminant animal intake and performance. In: G.C. Fahey, Jr., L.E. Moser, D.R. Mertens, and M. Col
• BOWMAN, J.G.P., AND J.L. FIRKINS. 1993. Effects of forage species and particle size on bacterial activity and colonization in situ. J. Anim. Sci. 71:1623-1633.