SUSTAINABLE BEEF SUPPLY, MT

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: SPECIAL GRANT
• Reporting Frequency: Annual
• Accession No.: 0219808
• Grant No.: 2009-34411-20190
• Proposal No.: 2009-05552
• Project Start Date: Sep 1, 2009
• Project End Date: Aug 31, 2011
• Grant Year: 2009
• Program Code: [OL]- Sustainable Beef Supply, MT

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

Performing Department
Animal & Range Sciences

Non Technical Summary
Montana's cattle industry consists mainly of seedstock and cow-calf producers, and is the sixth largest cow/calf producing state in the United States. Research from Canada and Australia has shown that selecting bull sires and dams for a negative RFI (more efficient) can reduce maintenance requirements by 10 percent, reduce feed intake by 11 percent, but has no effect on average daily gain of offspring or increased mature body size, and improves feed conversion ratio by 9 to 15 percent. In addition, selecting cows with a negative (efficient) RFI has improved calf-weight-per-cow feed intake by 15 percent. From an environmental standpoint, animals with a lower RFI reduce methane emission by 17 percent and manure N, P, and K production by 16 percent. A potential outcome of RFI research is a reduction in the emission of greenhouse gases. The nation's largest bull testing station, Midland Bull Test, in Columbus, MT, has recognized the commercial applications of determining residual feed intake (RFI) and feed conversion ratio. The data from Midland will be analyzed by the MBN to determine if negative RFI bulls have a higher incidence of failing breeding soundness exams. Hopefully, bulls identified with a negative RFI will sire heifer calves that have these negative RFI traits with no impact on reproductive efficiency. This facility has begun screening bulls to generate additional sale value for breeders and commercial cattlemen. By practicing the BQA and biosecurity lessons demonstrated at hands on BQA workshops, MT ranchers will be able to apply these new or improved skills to improve the overall productivity and value of their feeder calves. Another expected outcome of this BQA education and research is more MT herds free of disease which results in increased value to the operation. As the beef export business continues to grow, in addition to age and source verification, many producers have also requested NHTC (Non Hormone Treated Cattle) certification; required to export beef to Europe. To meet the demands of these producers, the previous age and source verification database will be modified to handle NHTC verification. Verification services will also be available to producers for age, source, NHTC, NE3 (Natural), and Grass Fed certifications. An outcome of this work is that by expanding these verifications, the MBN will assist in opening global markets to MT beef producers. Because producers want instant access to information, continued development of the MarketManager website is an important part of this grant.

Animal Health Component

50%

Research Effort Categories

Basic

30%

Applied

50%

Developmental

20%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
308	3310	1010	50%
308	3310	1080	50%

Knowledge Area
308 - Improved Animal Products (Before Harvest);

Subject Of Investigation
3310 - Beef cattle, live animal;

Field Of Science
1010 - Nutrition and metabolism; 1080 - Genetics;

Keywords

beef cattle

food safety

biosecurity

residual feed intake

Goals / Objectives
Research aimed at measuring phenotypic and genetic effects of reducing feed intake in beef heifers and cows will be measured. Reducing feed intake without negatively impacting reproduction, calf weaning weights and bull fertility is the main focus with measurements of greenhouse gas (methane, carbon dioxide and nitrous oxide) production the secondary focus. The hypothesis is that feed intake can be reduced 15 percent and greenhouse gases can be reduced 17 percent without affecting productivity. A third goal of this grant is producer research and education which will help producers document and ensure feeder calf quality and consistency through source, age, and process verification. By using county extension agents to assist with producer training, beef producers are educated on methods to reduce beef quality defects; age and source verify weaned calves and subsequently improve the value of cattle and carcasses. A database that documents age and source verification of calves, and facilitates and streamlines the transfer of carcass data from the packing plant to the producer is a fourth goal of this grant. As part of a regional project, carcass data collected over the past five years will be analyzed to determine if production practices have changed with regard to carcass quality and yield. The starting point for this research is accomplished by a series on hands on courses demonstrating best management practices. The Montana Stockgrowers Association (MSGA) and MSU will provide beef quality assurance education throughout the state. Finally as a component of the educational focus, a cooperative effort between MSU, MSGA, and Montana Grain Growers Association, the Montana MarketManager web site will be implemented.

Project Methods
Residual feed intake (RFI equals expected versus actual intake) research will be accomplished as follows. Pregnant cows (15/sire) which were previously (2008) determined to have positive or negative RFI (efficient or inefficient feed intakes) will be transported to MSU-Bozeman and randomly placed into one of eight pens equipped with GrowSafe System feeders (Model 4000 E). These devices measure individual feed intake and feeding behavior. RFI will be calculated by regressing actual DM intake against ADG and metabolic midweight daily gains to match Montana environmental conditions will be programmed to be 1.0 to 1.5 lbs/d using hay based diets. Feed intake and feeding behavior will be recorded daily. The first outcome of this research will be to determine if the ranking from last year's experiment for RFI will be repeatable and highly correlated with the results of this experiment. During the time period of 2008-2010, we will measure adjusted calf weaning weight, cow weight at weaning, cow body condition score, cow weight change from calf birth to weaning, changes in cow body fat, and reproductive efficiency. A secondary outcome of this work is measurement of greenhouse gases. The breakdown or decomposition of biological materials such as manure or feed can produce carbon dioxide (as a natural by-product), methane (under anaerobic conditions), and nitrous oxides (mainly from the nitrification/denitrification processes). By determining digestibile dry matter consumption calculations can be made which estimate carbon dioxide, methane and nitrous oxide production on a daily and yearly basis for cows which have differing average dry matter intakes. In the Montana Beef Network(MBN)Extension programs, producer education will emphasize waste management legislation based on RFI research results. During 2009 and 2010, the Montana Stockgrowers Association (MSGA) will work with MSU and continue to organize BQA demonstrations around the state. A database that documents age and source verification of calves produced by Montana ranchers, and facilitates and streamlines the transfer of carcass data from the packing plant to the producer is a goal. It meets all the requirements of age and source verification (export eligibility and USDA's PVP), and it has the capability to store information related to cattle production, from the producer through the consumer. As a cooperative effort between MSU, MSGA, and Montana Grain Growers Association, a livestock component to the Montana MarketManager will be implemented via a website. This site serves as the information hub of the Montana MarketManager program and includes Montana specific news, pricing, weather, education, references, and links to other marketing resources.

Progress 09/01/09 to 08/31/11

Outputs
OUTPUTS: Producer education was conducted in the following areas: Beef Quality Assurance (BQA), food safety, nutrition, reproduction and the principles of marketing management. Included was an enhanced feeder calf certification program that applies management protocols for BQA-trained producers with an additional focus of emphasizing ranch biosecurity issues. Aspects of this objective are carried out through a subcontract by the MSGA. Continued development of an electronic identification/tracking system to trace calves through various production channels and return production information back to the cow-calf producer. Information necessary to maximize profits from different beef marketing strategies through the integration of workshops, marketing clubs, and on-line market information was provided to Montana beef producers. From 1999 through 2006, MSU/MBN conducted a research and development project to address viability of electronic animal identification technologies and procedures for sourcing cattle from the ranch to the end carcass product. This research assessed and identified the use of radio frequency identification (RFID) tags as the preferred traceability tool for source and carcass data collection. Data collection efforts are streamlined when the RFID tag is linked to the carcass data at the packer level. When the data is captured electronically, the transaction cost of transferring data from one party to another is minimized. In the earlier years, MSU/MBN researched multiple RFID tag manufacturers including: AllFlex USA; Digital Angel/Destron USA; Dalton EU; API USA; VeriLogic USA; Y-Tex USA; and Farnam/Z-Tag USA. The conclusions from the MSU/MBN research indicated the AllFlex tag was superior to the others in the study. This research effort was the seminal undertaking in the industry. The MSU/MBN RFID tag and associated database research was soon put into action when the detection of bovine spongiform encephalopathy (BSE) threatened the profitability of the U.S. beef industry. PARTICIPANTS: John Paterson, MSU Co-PI 1999-present; Jim Peterson, MSGA/MSU Collaborator/Co-PI 1999-2007; Steve Pilcher, MSGA Collaborator 2003-2006; Errol Rice, MSGA Collaborator 2006-Present; Myles Watts, MSU Co-PI 2008-Present; Leif Anderson, MSU Staff 1999-2002; Lisa Duffey, MSU Staff 2002-2006; Andy Kellom, MSU Staff 2005-2007; Mo Harbac, MSU Staff 2006- Present; Clint Peck, MSU Staff 2006-present; Ryan Clark, MSU Staff 2006-2008; Lindsey Wallace, MSU Staff 2007-2008. TARGET AUDIENCES: 160,000 head of cattle were tested for BVD as part of the Beef Quality Assurance education program. Over 1,000,000 calves have been age and source verified as part of the Montana Beef Network/Verified Beef program. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Dr. Paterson had the foresight to provide industry leadership in the early stages of the cattle verification movement and initiated an added value for beef cattle in Montana. The effort has provided significant (millions of dollars annually) added value for Montana producers. Dr. Paterson and his crew created in the early years, a prototype or proof of concept (Montana Beef) that has withstood the test of time and has become a standard for excellence in the industry. Verified Beef has been privileged to transition the early efforts of Dr. Paterson into a business that continues to provide a venue for Montana Beef producers (approximately 20% of the Montana Beef production) to add value to their product and thereby significantly increasing their net margins. Currently it is estimated that Verified Beef returns about eight million dollars in added value to the Montana Beef industry.

Publications

• A.Kellom, J.A. Paterson, J. Vanek, M.Watts, and Mo Harbac. 2008. The effects of age and source verification of calves on value received on Superior Livestock Video Auction. Proc. Of West. Sec. of Am. Soc. Of Anim. Sci. No 34.
• M. Harbac, C. Peck, J. Paterson and B. Hoffman. 2008. The Montana BVD-PI biosecurity project. Proc. Of West. Sec. of Am. Soc. Of Anim. Sci. No. 36.
• L. Wallace, J.A. Paterson, L. Gagnon, R. Clark, K. Davis, and M. Miller. 2008. Evaluation of implantable RFID microchips for readability and measurement of body temperature in mature horses. Proc. Of West. Sec. of Am. Soc. Of Anim. Sci. No. 43.
• A.N. Haffla, S.D. Cash. L.M.M. Surber, J.A. Paterson, A. Lenssen, A.L. Todd and M.S. Huffman. 2008. Evaluation of winter cereals for pasture in Montana. Proc. Of West. Sec. of Am. Soc. Of Anim. Sci. No. 43.
• Paterson, J.A. 2008. ASAS Centennial Presentation: History of extension. Symposium: Extension Education: From 40 Acres and a Mule to Today: Historical Perspective of Extension Programming Amer. Soc. Of Anim. Sci. (INVITED).
• J. C. Whittier*, R. W. Ellis, D. Colburn, M. J. Fisher, M. Jarosz, S. P. Porter, and Western Beef Resource Committee. 2008. CSUbeef.Com as a Web Resource for Disseminating Beef Battle Educational Information and for On-line Access to the Cattle Producer's Library. Proc. Of West. Sec. of Am. Soc. Of Anim. Sci. #33.
• Lardy, G.P., B.A. Loken, V.L. Anderson, D.M. Larson, K.R. Maddock-Carlin, B. R. Ilse, R. Maddock, R. Clark, J.A. Paterson, and M.L. Bauer. 2008. Field Pea Inclusion in Finishing Diets: Increasing field pea (Pisum sativum) level in high concentrate diets. 2. Effects on growth performance and carcass traits in finishing steers and heifers. J.Anim. Sci. (co-PI from 4-State Backgrounding Grant).
• Loken, B.A., G.P. Lardy, T.C. Gilbery, V.L. Anderson , R. Clark, J.A. Paterson, and M.L. Bauer. 2008. Field Pea Inclusion in Finishing Diets. Increasing field pea (Pisum sativum) level in high concentrate diets. 1. Effect on intake, ruminal fermentation, digestibility, and in situ disappearance in high concentrate diets fed to steers and wether lambs. J. Anim. Sci.
• R. C. Waterman T. W. Geary, J. A. Paterson, and R. J. Lipsey. 2008. Early weaning in Northern Great Plains beef cattle production systems: I. Performance and reproductive response in range beef cows. J. Anim. Sci.
• R. C. Waterman, T. W. Geary, J. A. Paterson, and R. J. Lipsey. 2008. Early weaning in Northern Great Plains beef cattle production systems: II. Development of replacement heifers either early or normal weaned. J.Anim. Sci. (Collaborator).
• Paterson, J.A., W. Green, A.B. Johnson. 1999. Role of Trace Minerals in the Life Cycle of the Beef Cow. Proceedings of the Minnesota and Pacific Northwest Nutrition Conferences.
• Ansotegui, R.P., J.D. Bailey, J.A. Paterson, P.G. Hatfield, and C.K. Swenson. 1999. Effects of supplemental trace mineral form on copper status, estrus, ovulation rate, and fertility in beef heifers. Proc. West. Sec. Amer. Soc. Anim. Sci.
• Bailey, J.D., R.P. Ansotegui, J.A. Paterson, J.G. Berardinelli, and A.B. Johnson. 1999. Effects of supplemental trace mineral form on trace mineral status and performance of beef heifers. Proc. West. Sec. Amer. Soc. Anim. Sci.
• Kim Skinner. 2006. M.S. Thesis. Effects of a compromised immune system on the fecal shedding of E.coli O157:H7 by recently weaned calves.
• Travis Standley. M.S. Thesis. 2007. Effects of an Experimental Vaccine to Prevent Shedding of E. coli O157:H7 in the neonatal calf.
• Wallace, L. L. 2007. MS. Readability of thirteen different RFID ear tags by three different multi-panel reader systems for use in beef cattle (Midland Bull Test).
• Ty McDonald. 2010. Economic consequences of selecting for residual feed intake in bulls and heifers.
• Dennis Fennewald. 2001. MS Thesis. The Effects of Preweaning Management Strategies on Postweaning Morbidity of Calves.
• Brian Rainey. 2004. MS Thesis. The influence of dry rolling lightweight barley on digestibility by calves and cows.
• Travis Choat. 2005. PhD Dissertation. Effect of an Experimental Vaccine on Fecal Shedding of E. coli 0157:H7 in feeder cattle.
• Bryan Nichols. 2010. MS. Comparison of source of degradable protein and residual feed intake on performance of pregnant heifers.
• Paterson, J.A., G. Lardy, R. Funston and R.Carlstrom. 2000. Drought management strategies for beef producers. Cow-calf Handbook.
• Olson, B.E., R.T. Wallander and J.A. Paterson. 2000. Do windbreaks minimize stress on cattle grazing foothill winter range Can. J. Anim. Sci. 265-272.
• Anderson, L.P., J.A. Paterson, R.P. Ansotegui, M. Cecava and W. Schmutz. 2000. The effects of degradable and undergradable intake protein on the performance of lactating first calf heifers. J. Anim. Sci. 79:2224-2232.
• Bailey, J.D., R.P. Ansotegui, J.A. Paterson, C.K. Swenson and A.B. Johnson. 2000. Effects of supplementing combinations of inorganic and complexed copper and zinc on performance and liver mineral status of heifers. J. Anim. Sci. 79:2926-2934.
• Funston, R.N., T.W. Geary, R.P. Ansotegui, R.J. Lipsey and J.A. Paterson. 2002.Supplementation with whole sunflower seeds before artificial insemination in beef heifers. Prof. Anim. Scientist. 18 (2002) 254-257.
• Rainey, B.M., J.A. Paterson, R.J. Lipsey, K.Skinner, T. Standley and T. Choat. 2005. Effects of beef cattle age and barley processing method on diet digestibility. Prof. Anim. Scientist.
• Choat, T., J. Paterson, G. Smith, K. Belk, M. King and B. Rainey. 2005. Effects of beef cattle gender on tenderness of steaks. J. Anim. Sci.
• Duffey, Lisa; Paterson, John; King, Marc; Rolfe, Kelse. 2008. Ranch Management Practices of Beef Quality Assurance (BQA) and Non-BQA Certified Producers in Montana J. of Exten. No. 5RIB7.
• T. Standley, J. Paterson, K. Skinner, B. Rainey, A. Roberts, T. Geary, G. Smith, and R. White. 2008. The Use of an Experimental Vaccine in Gestating Beef Cows to Reduce the Shedding of Escherichia coli O157:H7 in the Newborn Calf. Prof. Anim. Sci. :. 260-263 (Major Professor).
• L. E. Wallace, J. A. Paterson, R. Clark, M. Harbac, and A. Kellom. 2008. Readability of Thirteen Different Radio Frequency Identification Ear Tags by Three Different Multi- Panel Reader Systems for Use in Beef Cattle. Prof. Animal Sci . 2008 24:384-391.
• Bailey, J.D., R.P. Ansotegui, J.A. Paterson and C.K. Swenson. 2000. Feedlot performance and hepatic trace mineral status of beef heifers previously consuming dietary copper antagonists. Proc. West. Sec. Amer. Soc. Anim. Sci.
• Fennewald, D.J., J.A. Paterson, R.J. Lipsey, P.J. Burfening, R.N. Funston, J.E. Peterson and L.P. Anderson. 2001. A systems approach for reducing morbidity of feeder calves. J. Anim. Sci. 79 (2) abstract.
• Reisenauer, V.L., M.W. Tess, D.A. Griffith and J.A. Paterson. 2001. Evaluation of calving seasons and marketing strategies in Northern Great Plains cow-calf enterprises. J. Anim. Sci. 79:(2) abstract.
• Funston. R.N., T.W. Geary, R.P. Ansotegui, R.J. Lipsey, M.D. MacNeil and J.A. Paterson. 2001, Supplementation of whole sunflower seeds before AI in beef heifers.. J. Anim. Sci. 79:(2) abstract.
• Kruse, R.E. , M.W. Tess, R.K. Heitschmidt, J. P. Paterson, and K. Clement. 2002. Evaluation of Drought Management Strategies for Cow-Calf Enterprises: A Practical Predictor of Growing Season Forage Production. Proc. West, Sec. Amer. Soc of Anim. Sci.
• Rainey, B.M., J.A. Paterson, R.J. Lipsey, R.N. Funsotn, G.W. Brester and W.T. Choat. 2002. Effect of age and grain processing method on diet digestibility by beef cattle. Proc. West. Sec. Amer. Soc. of Anim. Sci.
• Choat, T. J.Paterson, M King, G.C. Smith and K. Belk. Effects of beef cattle gender on tenderness. 2003. Midwest ASAS. Des Moines, IA.
• L.M. Duffey, J. A. Paterson, J.E. Peterson, M.C. King and K.M. Rolfe. 2004. Comparison of beef cattle management practices for planning beef quality assurance education. Proceedings of the Western Section of the American Society of Animal Science.
• Rainey., B.M., J.A. Paterson, M.C. King and W.T. Choat. 2004. Effect of high starch vs. high fiber on daily gain and carcass characteristics of early-weaned calves. Proceedings of the Western Section of the American Society of Animal Science.
• Roberts, A.J., R. P. Ansotegui, J. A. Paterson, and R. N. Funston. 2004. Efficacy of an intravaginal progesterone insert and an injection of PGF2α to advance date of breeding in postpartum beef cows while utilizing natural service. Proceedings of the Western Section of the American Society of Animal Science.
• Duffey, L. M., J.A. Paterson, J.E. Peterson, M.C. King, W.T. Choat and K.M. Rolfe. 2004 Comparison of management practices between beef quality assurance certified and non-certified producers in Montana. Midwest Section of the American Society of Animal Science (Abstract).
• B. M. Rainey, J. A. Paterson, T. T. Standley, L. M. Duffey, and W. T. Choat. 2004 Effect of age gender and barley grain processing method on performance and diet digestibility of beef cattle. Midwest Section of the American Society of Animal Science (Abstract).
• L. Duffey, J.A. Paterson, J. Peterson, B. Rainey, K. Skinner, T. Standley and M.King. 2004. The Montana Beef Network. Proceedings of the Western Section of the American Society of Animal Science.
• K.D. Skinner, J.A. Paterson, T.T. Standley, anand B.M. Rainey. 2005. Effect of trace mineral nutritional status on fecal shedding of E.coli O157:H7 in calves. Proceedings of the Western Section of the American Society of Animal Science.
• Standley, T.T., J.A. Paterson, K.D. Skinner, B.M. Rainey, A.J. Rainey, A,J. Roberts, T. Geary and R. White. 2005 The use of an experimental vaccine in gestating beef cows to reduce the shedding of E. coli O157:H7 in the newborn calf. Proceedings of the Western Section of the American Society of Animal Science.
• Choat, W.T., J.A. Paterson, B.M. Rainey, K.E. Belk and G.C. Smith. 2005. Vaccination as an Intervention Strategy for Reduction of Escherichia coli O157:H7 in Cattle Feces Proceedings of the Western Section of the American Society of Animal Science.
• Paterson, J.A., L.M. Duffey, R.M. Kott, J.E. Peterson, S. Pilcher and M. Bridges. 2005. Tracking cattle from the ranch to the packer: The Montana Beef Network and National ID. Proceedings of the Western Section of the American Society of Animal Science.
• Leupp, J.L, G.P. Lardy, R. Daly, C.L. Wright and J.A. Paterson. 2008. Factors influencing price of North Dakota, South Dakota and Montana feeder calves. Proc. Of West. Sect. of Am Soc. Of Anim. Sci. No. 32.

Progress 09/01/09 to 08/31/10

Outputs
OUTPUTS: : In 2008, primiparous Angus and Simmental x Angus heifers (age = 2 yr, n = 120, initial BW = 448 kg) were used to measure the effects of metabolizable protein level and dry matter intake on beef cow production. Individual feed intakes were determined using a GrowSafe feeding system. Dietary treatments were based on approximately 85% grass hay and 15% supplement. Supplements contained whole soybeans plus corn (102% MP) or dried distillers grains plus soybean meal (119% MP). After 35 d of intake measurement, heifers were placed into adjacent pens and fed their diets for an additional 50 or 82 d. Upon completion of the feeding trial, heifers were transported back to the ranch, managed as a single group, and production data were measured. These findings have been presented at the Western Section of the American Society of Animal Science and at the Montana Nutrition Conference and published in SimTalk the American Simmental Asociation magazine PARTICIPANTS: Brian Nichols and Ty McDonald and Tess Norvell. Graduate Students Mo Harbac. Research Associate John Paterson. Professor or Animal Science Andy Roberts. ARS Research Physiologist Jerry Lipsey. American Simmental Association Bair Ranch Foundation TARGET AUDIENCES: Peer scientists Ranchers PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Level of dietary MP had no effect (P > 0.17) on calf birthweight, adjusted 205-d weight, preweaning ADG, age at weaning, cow BW at calving, proportion of cows cycling at bull exposure, or proportion of cows to conceive. Dry matter intake per unit of BW0.75 did not differ because of treatment and had no effect (P > 0.17) on any variables measured. In 2009, 24 of these heifers that had the highest and lowest DMI/BW0.75 were selected to be fed a similar diet as in 2008 to determine the correlation of DMI per BW0.75 between heifers (2008) and later as cows (2009). Cows were adapted to the diet for 10 d followed by a 70 d trial to determine individual feed intakes, weight gain, and calculate residual feed intake. Dry matter intake per BW0.75 was highly correlated (r = 0.71, P < 0.01) between first and second parities. For 5 d following the feeding trial, fecal samples were collected twice daily and indigestible ADF was determined to estimate DM digestibility. Residual feed intake ranged from -4.58 to 4.46 kg/d and was negatively correlated with DM digestibility (r = -0.51, P = 0.03). Production traits from 2008 were analyzed to determine if cows found to be either high or low RFI in 2009 had similar levels of production. Low and high RFI cows did not differ (P > 0.45) in cow BW at calving, calf birthweight, calf ADG, 205-d weaning weight, or weaning age. Feeding excess metabolizable protein did not improve reproductive efficiency while DMI/BW0.75 had no relationship to cow production. Variation in residual feed intake was partially attributed to differences in DM digestibility.

Publications

• B. M. Nichols. B.M.0 J. A. Paterson, T. J. McDonald, M. M. Harbac, T. M. Norvell, and A. J. Roberts. 2010. Effects of metabolizable protein level and intake on beef cow production, and the relationship between residual feed intake and digestibility. J. Anim. Sci. (submitted).
• B. M.Nichols. 2010. Effects of metabolizable protein level and intake on beef cow production, and the relationship between residual feed intake and digestibility. MS Thesis. Montana State University.
• T. J. McDonald, B. M. Nichols, M. M. Harbac, T.M. Norvell, and J. A. Paterson. 2010. Dry Matter Intake is Repeatable over Parities and Residual Feed Intake is Negatively Correlated with Dry matter digestibility in beef cows. Proc. Western Sec. of American Soc. of Animal Sci.