FEED EFFICIENCY IN CATTLE

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: SPECIAL GRANT
• Reporting Frequency: Annual
• Accession No.: 0213845
• Grant No.: 2008-34502-18980
• Proposal No.: 2008-03171
• Project Start Date: Jul 1, 2008
• Project End Date: Jun 30, 2010
• Grant Year: 2008
• Program Code: [UY]- (N/A)

Recipient Organization
UNIVERSITY OF FLORIDA
G022 MCCARTY HALL
GAINESVILLE,FL 32611

Performing Department
NORTH FLORIDA RESEARCH & EDUCATION CENTER

Non Technical Summary
Approximately 55 to 75% of the total costs associated with beef cattle production are feed costs. A 5% decrease in feed efficiency could have an economic impact four times greater than a 5% improvement in average daily weight gain. Studies in feedlot cattle showed that 10% improvement in average daily gain (ADG) as a result of a 7% increase in appetite improved profitability 18%, whereas, a 10% improvement in feed efficiency returned a 43% increase in profits. Improving the efficiency of feed/forage use will have a large impact on reducing input costs of beef production. For example, in Florida alone with approximately 1.83 million cattle on inventory, a 10% increase in feed/forage efficiency could reduce production costs by at least $36 million annually. This research will apply to most of the United States and thus would have a dramatic impact on US cattle production. From an immune status standpoint, cattle undergo a variety of stressors within normal production processes. In general, these stressors may be grouped into two broad categories, 1) psychological stress such as co-mingling, restraint, and novel exposure, and 2) physical stress such as hunger, injury, disease, and environmental pressure. Vaccination and castration are two normal beef production practices that may also lead to stress and subsequent production of the acute phase reaction. Impacts of castration on the acute phase reaction and daily dry matter feed intake have been reported previously; however, water intake and individual animal feeding behavior were not correlated to measures of inflammatory stress. These data will lead to a clearer understanding of stress management in cattle and may improve our ability to enhance animal welfare while improving overall heath and productivity. By-product feeds from numerous agricultural commodity and industrial processes has altered the diets of numerous nutrition programs. For example, dry milling corn co-products are excellent sources of energy and protein, but by virtue of the fact that they concentrate nutrients, other nutrients such as sulfur (S) are also concentrated at levels that dictate proper diet management to prevent effects of their excesses. In fact, a recent review of mineral concentrations in corn co-products revealed that some samples may reach concentrations of S as high as 1.5%, particularly in wet distillers grains (DGS) and/or condensed distillers solubles. Indeed, one of the main limitations in incorporating DGS in feedlot diets is S concentration of DGS. Under experimental conditions, feeding DGS to feedlot cattle reached an inclusion level maximum due to S concentration effects on animal health, and not because of any other nutrient attribute (protein, moisture or energy content) of DGS.

Animal Health Component

60%

Research Effort Categories

Basic

40%

Applied

60%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
306	3310	1010	40%
306	3310	1020	30%
306	3310	1090	30%

Knowledge Area
306 - Environmental Stress in Animals;

Subject Of Investigation
3310 - Beef cattle, live animal;

Field Of Science
1090 - Immunology; 1010 - Nutrition and metabolism; 1020 - Physiology;

Keywords

residual feed intake

feed efficiency

immune status

reproductive efficiency

puberty

by-product feeds

Goals / Objectives
Residual feed intake (RFI) measures the variation in feed intake beyond that needed to support maintenance and growth requirements, and is calculated as the difference between actual feed intake and the feed an animal is expected to consume based on its body weight and average daily gain. When cattle consume less feed than expected for their body weight and average daily gain they have a negative RFI, which equates to an improvement in feed efficiency. Understanding the interactions of feed efficiency or RFI on biological processes and management procedures is critical to utilizing RFI as a tool for cattle selection by beef producers. Feed and forage efficiency improvement will increase ranch profit through reduced input costs and reduce potential environment disruption through reduced animal nutrient waste. This is especially critical when the cost of feed resources continues to increase, the availability of forages continues to decrease, and our need to consider the effects of the cattle industry on environmental impacts. Therefore, our objectives of the current project aim to resolve both biological and management interventions that may be related to feed efficiency and RFI. Objective 1. Determine the relationship between reproductive efficiency of growing heifers and RFI, specifically focusing on the onset of puberty and subsequent fertility. This project has a specific interest in cattle of both Bos taurus and Bos indicus genotypes fed high forage diets. Objective 2. Characterization and quantification of the acute phase response and feed and water intake of growing calves presented with the stress of vaccination or castration. Objective 3. Establish whether the negative effects of hydrogen sulfide can be reduced in cattle fed high grain diets containing high sulfur concentrations from milling by-products.

Project Methods
Experiment 1: This work will utilize calves of Angus or Brahman crossbred genetics produced at the NFREC from the 2008 and 2009 calf crops, which will result in about 100 heifer calves per calving season. At 8 to 10 months of age heifers will enter the FEF and will have ad libitum access to a diet high in forage to reflect a similar diet to that received on pasture. While in the facility heifers will undergo a 14-d adaptation period, followed by a 70-d data collection period that will include the collection of data for residual feed intake, feed to gain ratio, and various measurements of temperament. Puberty in heifers will be assessed by collection of blood samples weekly for analysis of progesterone. Collection of blood samples will continue until the heifer has attained puberty or the initiation of the breeding season. Subsequent fertility (conception and pregnancy rates) will be assessed after breeding by the use of transrectal ultrasonography. Experiment 2: Two experiments will be completed. Exp. 2a will utilize twenty weaned steer calves assigned to a completely randomized design to two treatments: 1) vaccinated (Mannheima haemolytica), and 2) saline control. In Exp. 2b twenty weaned bull calves will be utilized in a completely randomized design with two treatments: 1) castrated (knife cut), and 2) non-castrated control. All animals will be allowed free choice access to a complete diet in the FEF. The feeding system will measure daily individual animal feed and water intake; therefore, animals will act as the experimental unit in the statistical model. Prior to vaccination, steers will be allowed to acclimate to the pens and feeding system for 7 d. Following vaccination, blood samples, for determination of the acute phase reaction and antibody titer, will be collected on d 0, 3, 6, 9, 12, and 15. Individual BW will be determined following a 12-hr feed and water withdrawal on d 0 (day of vaccination) and d 16 (end of study). Experiment 3: In two experiments (Exp. 3a will utilize rumen-cannulated steers in a 4 x 4 Latin square design and Exp. 3b will utilize 40 steers randomly assigned to treatments) steers will be adapted to an 85% corn grain diet over a 21 d period. After adaptation, steers will be assigned randomly to one of four treatments: 1) no manganese oxide and dietary S content of 0.25%; 2) manganese oxide and dietary S content of 0.25%; 3) no manganese oxide and dietary S content of 0.65%; and 4) manganese oxide and dietary S content of 0.65%. Steers will be fed for ad libitum intake throughout the experiment, and feed and water intake will be measured daily. For Exp. 3a rumen hydrogen sulfide gas and fluid sulfide concentrations will be measured at pre-feeding, 1, 2, 4, and 6 h post-feeding for each of the three days of collection. Rumen fluid will be collected at these times to determine rumen ammonia and volatile fatty acid concentrations. For Exp. 3b arterial blood pressure will be measured and acute phase proteins, haptoglobin and ceruloplasmin, associated with stress. Additional blood samples will be collected for haptoglobin and ceruloplasmin.

Progress 07/01/08 to 06/30/10

Outputs
OUTPUTS: We determined whether supplementation of anti-phospholipase A2 antibody (aPLA2; BIG BEEF, Aova Technologies, Madison, WI) for growing beef cattle would alter voluntary DM feed intake and feed efficiency of growing calves. Individual performance and daily DMI was measured on 70 crossbred weaned calves (53 steers and 17 heifers) during a 70-d period using a GrowSafe system (GrowSafe Systems Ltd., Alberta, Canada) at the University of Florida NFREC Feed Efficiency Facility. We concluded that the supplementation of anti-phospholipase A2 (BIG BEEF) for growing beef cattle decreased daily DMI while maintain ADG, therefore, improving feed efficiency. We determined the correlation between Residual Feed Intake (RFI) measured as post-weaned growing heifers (phase 1) and RFI measured as lactating beef cows (phase 2) in the same cohort. Individual performance and daily DMI were evaluated in 74 yearling heifers, and were subsequently reevaluated upon the birth of their second calf. We concluded that ECM and BF are important sources of variation affecting evaluation of RFI in lactating beef cows and heifers ranked as more efficient subsequently consumed less as cows. We also established that DMI and performance of suckling calves was not related to feed efficiency, feed intake, and performance of their dam as a growing heifer or lactating cow. We examined the effect of castration technique on daily feed intake (DFI), daily water intake (DWI), growth performance, residual feed intake (RFI), and inflammatory response in weaned beef calves. Calves castrated pre-weaning had improved d 0 to 14 ADG, feed intake, and inflammation response compared to calves castrated at weaning. Banding elicited a delayed negative response in ADG, DWI, and inflammation. In weaned calves, castration method did not impact performance, DFI, DWI, or inflammatory response long-term. We determined the fraction of additive genetic variance explained by the SNP from the Illumina Bovine3k chip, to compare the ranking of animals evaluated with genomic-polygenic, genomic, and polygenic models, and to assess trends in predicted values from these 3 models for residual feed intake (RFI), daily feed intake (DFI), feed conversion ratio (FCR), and postweaning weight gain (PWG) using phenotypic data and genotypes from 620 bulls, steers, and heifers ranging from 100% Angus to 100% Brahman (B). Genomic-polygenic, genomic, and polygenic predictions for all traits tended to decrease as B fraction increased, indicatiing that calves with higher B fraction were more efficient, but grew more slowly than calves with higher A fraction. Predicted SNP values were small for all traits and those above and below 2 SNP standard deviations were in multiple chromosomes supporting the contention that quantitative traits are determined by large numbers of alleles with small effects located throughout the genome. PARTICIPANTS: John Arthington - University of Florida; Chad Chase - USDA ARS STARS, Brooksville; Sam Coleman - USDA ARS STARS, Brooksville; Mauricio Elzo - University of Florida; Todd Thrift - University of Florida; Matt Hersom - University of Florida; Nicolas DiLorenzo - University of Florida TARGET AUDIENCES: Beef cattle producers; Cattle feed allied industry; State and County Extension educators. PROJECT MODIFICATIONS: No significant changes made.

Impacts
It costs $0.75 to $1.50 per day to raise one post-weaned calf and 70% of the cost ($0.53 to $1.05 per day) is feed related. In addition, a calf is usually backgrounded for 90 to 120 days. If the BIG BEEF Supplement during the backgrounding period does not exceed $0.05 per day and use of the supplement results in a 7% to 8% reduction in feed with no reduction in performance, then cattle producers will save between $3.65 to $9.24 per head during the backgrounding phase (90 to 120 days) or $1.9 to $7.0 million savings to the state of Florida cattle industry each year! Initial data indicate that efficient cows consumed 30.3 lbs of feed daily compared to average cows that consumed 36.1 lbs of feed daily and inefficient cows consumed 43.1 lbs of feed daily (19% to 42% improvement). No differences existed in cow performance, milk production, or calf performance. Therefore, $0.13 to $0.36 per head per day, or $47.4 to $131.4 per head per year savings in feed costs is realized, resulting in $44.3 million to $125.4 million savings to the state of Florida cattle industry. When managing weaned beef calves early post-castration in sub-tropical environments, our data indicates that the short-term response to the banding procedure may not be as advantageous to some producers due to the delayed suppression of growth rate and feed intake observed in the current experiment. In addition, the Henderson castrating tool appears to not be any more or less stressful than other surgical methods of castration. Calves castrated prior to weaning had greater initial growth rates, feed intake, water intake, and feed efficiency. Genomic-polygenic, genomic, and polygenic predictions tended to decrease as Brahman fraction increased for all traits, indicating that calves with larger Brahman fractions tended to use feed more efficiently, eat less, and gain less weight postweaning than animals with larger Angus fractions.

Publications

• Elzo, M. A., G. C. Lamb, D. D. Johnson, M. G. Thomas, I. Misztal, D. O. Rae, J. G. Wasdin, and J. D. Driver. 2011. Genomic evaluation of Angus-Brahman multibreed cattle for feed efficiency and postweaning growth using the Illumina 3k chip. J. Anim. Sci. 89(E-Suppl. 1): 553 (Abstr.).
• Lamb, G.C., T.E. Black, K.M. Bischoff, V.R.G. Mercadante. 2011. Implications of Selection for RFI. 60th Beef Cattle Short Course, Gainesville FL pp37-46.
• Lamb, G.C., K. M. Bischoff, T.E. Black,V.R.G. Mercadante. 2011 The Impact of Selection for Feed Efficiency Growing in Heifers on Subsequent Mature Cow Performance. The Florida Cattlemen and Livestock Journal 75(7):39-42.
• Mercadante, V. R. G, K. M. Bischoff, T. E. Black, G. H. L. Marquezini, N. DiLorenzo, and G. C. Lamb. 2011. Inclusion of anti-phospholipase A2 antibody (aPLA2) to backgrounding diet enhanced feed efficiency in growing beef calves. J. Anim. Sci. 89(E-Suppl. 1): 601 (Abstr.).
• Warnock, T., T. Thrift, M. Irsik, M. Hersom, T. Maddock, G.C. Lamb, J.D. Arthington. 2011. Effect of Castration Technique on Beef Calf Performance, Residual Feed Intake, and Inflammatory Response. Proc. 2011 Florida Beef Report. Gainesville, FL. (http://www.animal.ifas.ufl.edu/extension/beef/beef_cattle_report/201 1).
• Arthington, J.D., T.D. Maddock, and G.C. Lamb. 2011. Effects of Mannheima Haemolytica Vaccination (One Shot) on Feed Intake, Feed Efficiency, and the Acute-phase Protein Response of Heifers. Proc. 2011 Florida Beef Report. Gainesville, FL.. (http://www.animal.ifas.ufl.edu/extension/beef/beef_cattle_report/201 1).
• Bischoff, K.M., T.E. Black, G.C. Lamb. 2011. Maternal feed efficiency as growing heifers and lactating cows does not alter subsequent feed intake and performance of their suckling offspring. NFREC News 13(8):1-2.
• Bischoff, K. M., T. E. Black, V. R. G. Mercadante, G. H. L. Marquezini, C. C. Chase, S. W. Coleman, and G. C. Lamb. 2011. Effect of maternal feed efficiency as growing heifers and lactating cows on feed intake and performance of their suckling offspring. J. Anim. Sci. 89(E-Suppl. 1): 601 (Abstr.).
• Black, T.E., K. M. Bischoff, V. R. G. Mercadante, G. H. L. Marquezini, C. C. Chase Jr., S. W. Coleman, and G. C. Lamb. 2011. Relationship of feed efficiency of replacement beef heifers to subsequent feed efficiency as 3-year old suckled beef cows. J. Anim. Sci. 89(E-Suppl. 1): 501 (Abstr.).
• Black, T., K. Bischoff, G. Marquezini, V. Mercadante, T. Maddock, N. DiLorenzo, C. Chase, S. Coleman, and G. C. Lamb. 2011. Feed Efficiency of 3-Year Old Suckled Beef Cows after Establishment of Feed Efficiency as Replacement Heifers. Proc. 2011 Florida Beef Report. Gainesville, FL. (http://www.animal.ifas.ufl.edu/extension/beef/beef_cattle_report/201 1). Elzo, M.A., D.D. Johnson, G.C. Lamb, T.D. Maddock, R.O. Myer, D.G. Riley, G.R. Hansen, J.G. Wasdin, and J.D. Driver. 2011. Additive genetic parameters for postweaning growth, feed intake, and ultrasound traits in angus-brahman multibreed cattle. Proc. 2011 Florida Beef Report. Gainesville, FL. (http://www.animal.ifas.ufl.edu/extension/beef/beef_cattle_report/201 1).

Progress 07/01/08 to 06/30/09

Outputs
OUTPUTS: During the first year of this project (2008-2009) data for five experiments have been completed with the following objectives in mind: 1) to observe if the vaccination of calves with a commercially-available vaccine (One-Shot; Mannheima haemolytica) will illicit an acute phase inflammatory response resulting in the reduction of voluntary feed intake, voluntary water intake, and gain performance; 2) the relationship between reproductive efficiency of growing heifers and FRI, specifically focusing on the onset of puberty and subsequent fertility in Bos Taurus and Bos indicus genotypes; 3) determining the differences in feed efficiency and reproductive status in lactating beef cows previously evaluated for feed efficiency post-weaning; 4) The relationship between sub-clinical stress as measured by pulmonary arterial pressure and RFI and changes in body composition; 5) establish whether the negative effects of hydrogen sulfide can be reduced in cattle fed high grain diets containing high sulfur concentrations from milling by-products. Laboratory and statistical analyses are completed and reports have been written for Exp. 1, whereas analyses are being conducted on all remaining studies and reports will be summarized after completion of analyses. Reports on feed efficiency in cattle have been written and published as abstracts, research reports, conference proceedings and in popular press as a result of some of the work obtained form the studies completed by this project. PARTICIPANTS: G. Cliff Lamb - PI (University of Florida) Mauricio Elzo - CoPI (University of Florida) John Arthington - CoPI (University of Florida) Travis Maddock - Research Associate (University of Florida Don Jones - Biological Scientist (University of Florida) Harvey Standland - Biological Scientist (University of Florida) TARGET AUDIENCES: Data collected and reported is aimed for the improvement of productivity of beef cattle operations. Therefore, the primary audience is for university personnel (including county extension faculty), beef allied industry, and ultimately beef cattle producers. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
In January, 2009 the number of cows and heifers that calved in the United States reported by the National Agricultural Statistics Service was 31,671 million head, with the states represented in the SE and Gulf Coast regions accounting for 48% of all beef cattle in the U.S. By understanding the biological mechanisms responsible for feed efficiency, which could allow beef producers to alter the feed and forage input costs in their operations has the potential to impact the region significantly. Improving efficiency of cattle by 10% will reduce input costs associated with feed, thereby potentially impacting producers in the SE and Gulf Coast regions significantly. State cow/calf enterprise reports estimate that the cost of feed ranges from $170 to $330 (mean $250) per cow. Therefore, a 10% decrease in feed cost could result in a $25 per cow annual savings or, collectively, producers in the SE and Gulf Coast regions $380 million per year. To date, RFI studies have been primarily conducted with Bos taurus cattle adapted to temperate climates, while limited data is available on subtropically adapted breeds. We determined that that RFI was moderately heritable in Brangus cattle, indicating that genetic variation in RFI of Bos indicus influence cattle is comparable to Bos taurus cattle. The NRC (2000) indicates that Bos indicus breeds require about 10% less NE for maintenance than Bos taurus beef breeds. However, when a comparison of the energy requirements of Tuli, Angus, Brahman, Boran, and Hereford growing steers fed a high concentrate diet concluded that Brahman cattle have similar energy needs to their Bos taurus contemporaries. Our preliminary work conducted at the University of Florida indicates that Brahman cattle have lower RFI values than Angus contemporaries (Figure 1). Beef cattle that ranged in parentage from 100% Angus to 100% Brahman were tested after weaning for RFI at the UF-FEF over a three year period. Cattle were classified as either high RFI (> 0.50 SD, less efficient); low RFI (> -0.50 SD, more efficient); or medium RFI. Results indicate that more fullblood Brahman cattle were classified as low RFI than Brahman x Angus and fullblood Angus contemporaries

Publications

• Lamb, G.C. and T. D. Maddock 2009. Feed Efficiency in Cows. In: Proc. 2009 Florida Beef Cattle Short Course. Pp 35-41.
• Maddock, T. D., J. L. Foster, M. A. Elzo, and G. C. Lamb. 2009. Changes in temperament scores of cattle handled frequently failed to enhance feed intake. J. Anim. Sci. 87(E-Suppl. 2):6.
• Arthington, J. D., T. D. Maddock, G. C. Lamb. 2009. Effects of Mannheima haemolytica vaccination (One Shot) on feed intake, feed efficiency, and the acute-phase protein response of heifers. J. Anim. Sci. 87(E-Suppl. 1):27.