Source: WEST VIRGINIA UNIVERSITY submitted to
FEED EFFICIENCY AND FEEDING BEHAVIOR IN CATTLE AND SHEEP
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
0206823
Grant No.
2006-38881-03483
Project No.
WVA00186
Proposal No.
2006-06247
Multistate No.
(N/A)
Program Code
UI
Project Start Date
Jul 1, 2006
Project End Date
Jun 30, 2008
Grant Year
2006
Project Director
Warren, Jr., J. E.
Recipient Organization
WEST VIRGINIA UNIVERSITY
PO BOX 6108
MORGANTOWN,WV 26506
Performing Department
ANIMAL & VETERINARY SCIENCE
Non Technical Summary
Feed cost is the most significant cost in most livestock production systems. Although moderately to highly heritable, feed efficiency is generally not a variable measured in cattle and sheep performance testing programs because feed consumed is difficult and time consuming to measure on an individual basis. This project examines the effectiveness of an automated system to measure individual feed consumption and feeding frequency of animals self-feeding during the course of various feeding trials. Factors which affect feed efficiency of bulls, cows, calves, and rams will be evaluated along with the relationship of feeding frequency with estrous behavior.
Animal Health Component
50%
Research Effort Categories
Basic
50%
Applied
50%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
3013310102010%
3023310101050%
3023610101010%
3033310101020%
3033610101010%
Goals / Objectives
Feed cost, estimated at 64 percent of total cow-calf unit operating costs in the eastern upland region of the United States, is the most significant cost item in most livestock production systems. In beef and sheep production systems the weight of the animal is the single most important component in determining value. Thus, the ability to identify and propagate animals that are efficient in converting feed into weight gain should be an important component of overall operational efficiency and result in enhanced profit potential for producers. Altjough moderately to highly heritable, feed conversion is generally not a variable measured in performance testing programs because feed consumption is difficult and time consuming to measure on an individual basis. However, technological advances in electronic identification of animals and recording of individual feed consumption in computer data bases presents an opportunity to measure individual feed consumption during the course of performance trials. Consistent with the objectives of a previous grant, we are utilizing the GrowSafe 4000E to identify each animal, record each feeding event, and complile individual feed consumption. We now use this system to determine individual feed consumption and efficiency in the feedlot environment of the West Virginia Bull Test Evaluation Program. In late spring and summer months when bulls are not being evaluated, we utilize the system to evaluate factors which affect feed efficiency of cows and heifers with emphasis on maternal conversion of feed resources to pounds of calf produced. The influence of maternal breed, age, offspring sex, and body condition at various stages of lactation on efficiency of feed conversion has and will continue to be studied. Additionally, these cows and heifers will be observed for estrus and bred artificially while feeding frequency and feed consumption is being measured. We will determine if the onset and duration of estrus can be predicted by changes in feeding frequency. In another experiment, we will conduct a ram performance test utilizing the existing hardware and software of the GrowSafe system. Information from these studies will aid livestock producers throughout West Virginia and the nation in increasing their competitive edge in an ever-growing world market. The specific objectives of this proposal are: The specific objectives of this proposal are: 1)to determine residual feed intake as a measure of feed efficiency in beef bulls and length of feeding tests required to accurately assess feed efficiency, 2)to investigate factors affecting feed efficiency of beef matriarchs, 3)to determine if the onset and duration of estrus in cattle is associated with changes in the frequency of feeding, 4)to determine residual feed intake in a ram performance test program, 5)to determine the feed efficiency of offspring from high and low feed efficiency bulls.
Project Methods
GrowSafe 4000E System is integrated hardware/software consisting of feed nodes (troughs) mounted on load cells. An animal feeding at a trough is scanned every five seconds and feed available in every feed trough is sampled every second with accuracy within 5 grams. Data on animal feeding frequency and feed disappearance are compiled by computer software. Bulls are weighed on test and feed consumption and weight gained are measured for 84 days. Bulls are weighed at 14 day intervals and fed ad libitum a total-mixed-ration containing 13.0% crude protein and 64% TDN. Residual feed intake (RFI) is the difference in expected intake versus actual intake. RFI is calculated based upon linear regression of the experimental group body weights and gains. By this method animals of different physiological age, breed, and mature size can be accurately compared in terms of metabolic efficiency of energy use. A multi-year approach has been initiated to understand factors affecting maternal feed efficiency. First calf heifers (calving as two year olds: 16), pregnant three year olds (16) and mature cows (16) of either Angus, Hereford or crossbred breeding with equal representation of either heifer or bull calves at side will be used for two 45-day experimental periods. Individual feed intake data will be collected on each matriarch by the GrowSafe system. A single hay based diet will be fed to all animals during each period. Matriarchs and calves will be weighed on two consecutive days at the beginning and end of each experimental period with single day intermittent weights being taken at two-week intervals. These weights along with individual feed intakes will be used in the calculation of feed efficiency. Cows and heifers under objective two will be observed for estrus and artificially inseminated. The relationship of feeding frequency and estrous behavior will by evaluated by correlation analysis. To assess objective four, ram lambs will be fed with the GrowSafe system, individual intake measured, and RFI calculated. For objective five a random half of WVU herds and cooperator herds will be mated to high and low efficiency bulls, feed consumption of offspring from these matings will be measured in RFI calculated. Thus.we hope to demonstrate that significant progress may be made through selection for feed efficiency.

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

Outputs
OUTPUTS: In beef production systems the weight of the animal is the single most important component in determining value. Thus, the ability to identify and propagate cattle that are efficient in converting feed into weight gain becomes an important component of a successful cow-calf unit. A one pound improvement in dry matter feed conversion of feeder calves reduces feed cost by $50 per head. Improved feed efficiency in cow-calf operations will reduce input cost and enhance profit potential for beef producers. Furthermore, the production of offspring is the driving force behind most cow/calf operations. Improved utilization of forage by beef cows, stocker cattle and steers and heifers in forage fed beef programs will provide additional economic impact and increase the number of animal units that can be produced per acre. From this project residual feed intake was determined utilizing the GrowSafe System in sire evaluations programs for beef bulls, rams, and bucks. Additionally, behavioral studies were conducted to determine feeding behaviors and perfomance measurements in bulls, rams and bucks. A study was conducted with beef heifers utilizing both the GrowSafe System and Heat Watch system to determine if differences in feed intake and behavior existed in association with estrus. PARTICIPANTS: Principle investigators Warren and Felton wrote the proposal, led the investigative work, analyzed and reported the data on the objectives of the project. Collaborators include Dr. Monty Kerley, University of Missour-Columbia, where calves utilized in pasture studies were fed to marked weight in the feed intake selecton experiment. West Virginia University Extension personnel provide leadership for organizing the sire evaluation programs and working directly with seedstock consignors and commercial producers buying seedstock from sales following the completion of the sire evaluation programs. This project has provided data for three Master of Science Theses (one completed and two in progress). TARGET AUDIENCES: Target audiences include livestock producers (beef, sheep and goat) who consign animals to the respective sire evaluation programs. As a result they obtain valuable data residual feed intake (RFI) for individual animals consigned and knowledge of performance of their animals relative to those of other consignors. Also, the RFI data is available and useful to commercial producers purchasing bulls, rams and bucks to use in their herds and flocks. Thus, overall feed efficiency may be improved which is the ultimate goal. Additionally, results of sire evaluations and experiment are shared through meeting proceedings, publication in scientific journals, and popular press articles with the scientific community and livestock producers both nationally and worldwide. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Six Angus bulls with known residual feed intakes (RFI) were used to breed three beef cow herds in the spring of 2005. Bulls were selected as pairs possessing similar expected progeny differences, growth performance but approximately equal but opposing RFI values. Forty-eight steer calves, 24 from +RFI sires(POS) and 24 from -RFI(NEG)sires, were selected based on similarity in bodyweight and winter growth performance and utilized for a pasture-season experiment and subsequent feedlot finishing. In the pasture experiment animal weight-gain and pasture forage disappearance/utilization measurements were collected. Results from measurements taken from the beginning of the experiment to late June (Period of excess forage) indicate that POS stocked pastures have more forage disappearance than NEG stocked pastures with no difference in animal performance. Results from late June to early August (Period of limiting forage) have not been fully analyzed but raw means show a 1.3 fold improvement in daily growth of NEG vs. POS steers. Steers were transported to the University of Missouri in mid October 2007 and worked up on full feed. All steers were treated equally and slaughtered in early February averaging an 832 lb carcass with a SM60 amount of marbling, 0.41 in of backfat, 13.0 sq. in. ribeye and a yield grade of 2.9. POS sired calves outperformed NEG sired calves by 0.57 lb/d over the 72 day finishing period with no difference in slaughter or hot carcass weight or standard carcass measurements. Although not statistically different, feed costs from the time steers entered the feedlot till slaughter averaged 21.63 dollars more per head for positive RFI sired steers. These results may indicate that when forage is plentiful, offspring sired by positive RFI sires are able to have a greater intake of energy than negative RFI sired offspring and therefore compensate for poorer metabolic efficiency yielding similar performance. However, under a limited forage environment, less efficient, positive RFI sired offspring are more likely to have poorer performance and create greater risk for the producer. The reduction in gain experienced by the positive sired offspring while on limited pasture allowed for them to have compensatory gain while finishing. However, the efficiency of the positive RFI sired steers was still compromised and resulted in them having an overall higher feed costs. These results are based on a limited number of offspring from six different sires, however results indicate that selection for RFI can be made with positive results. In analysis of feeding behaviors of rams, bucks and bulls in performance evaluation programs, more efficient animals generally have fewer feeding bouts than less efficient animals. Most feeding bouts occurred during the daylight hours for all species.

Publications

  • Chavez,S., Baptiste Q., and Felton,E.E.D. 2008. Relationship between feeding behaviors in Boer bucks. Midwest Section American Society of Animal Science Meeting. DeMoine, IA. March 17-19,2008. Abstract 7,P.19.
  • Chavez,S., 2008, Feeding behaviors and performance measurements in bucks, rams and bulls. Master of Science in Animal and Nutritional Sciences Thesis, West Virginia University, Morgantown, WV.
  • Gulas,J., Warren,J, and Felton,E.E.D. 2008. Residual feed intake as a measure of feed efficiency of beef bulls in a test station. JAS-accepted with revision.
  • Felton, Gene, 2008. Effects of resdiual feed intake selection:from conception to slaughter. Proceeding of Beef Research and Teaching Farm Field Day, University of Missouri-Columbia. Sept. 2008.


Progress 07/01/06 to 06/30/07

Outputs
Six Angus bulls with known residual feed intakes (RFI) were used to breed two West Virginia University (Wardensville and Reedsville) and one private producer's beef cow herds in the spring of 2005. Bulls were selected as pairs possessing similar expected progeny differences, growth performance but approximately equal but opposing RFI values within the test groups in which they were determined. Forty-eight steer claves (24 from +RFI sires and 24 from -RFI sires) from these three herds were selected based on similarity in bodyweight and winter growth performance and utilized for a pasture-season experiment beginning March 30, 2007 and is still ongoing. In this experiment, steers were allotted to 1 of 4 treatments, with treatment group being randomly assigned to 1 of 4, one-hectare plots (subdivided into 4 subplots for rotational grazing) located in 3 areas of differing terrain (bottomland, slight slope, and steep slope). Thus, steers were stocked at a rate of 4 hd per hectare with 4 treatments equally represented within each terrain classification. Based on 4 yrs of previous experiments on these sites utilizing this approach, with similar stocking rates, no interaction between terrain and treatment have been identified and would not be expected. Treatments tested were 4 positive RFI steers per pasture (POS), 4 negative RFI steers per pasture (NEG), 2 positive RFI steers per pasture lead grazing with 2 negative RFI steers follow grazing (+/-), and 2 negative RFI steers per pasture lead grazing with 2 positive RFI steers follow grazing (-/+). Animal weight-gain and pasture forage disappearance/utilization measurements are being collected. Data is being analyzed as two separate experiments: Experiment 1, POS vs. NEG, Experiment 2, +/- vs. -/+. Statistically analyzed results from measurements taken from the beginning of the experiment to late June (Period of excess forage) indicate that POS stocked pastures have more forage disappearance than NEG stocked pastures with no difference in animal performance. There was also no difference in pasture disappearance between +/- and -/+ stocked pastures. Although not significant, numerical differences in gain indicate that negative RFI sired steers are better able to utilize material left by forward grazed positive sired steers while no difference was seen in weight gain when positive RFI sired steers followed negative RFI sired steers. Results from late June to early August (Period of limiting forage) have not been fully analyzed but raw means show a 1.3 fold improvement in daily growth of NEG vs. POS steers. Raw means of the -/+ vs. +/- treatment showed similar better use of forage as seen in the earlier period with 1.6 fold greater ADG. These results may indicate that when forage is plentiful, offspring sired by positive RFI sires are able to have a greater intake of energy than negative RFI sired offspring and therefore compensate for poorer metabolic efficiency yielding similar performance. However, under a limited forage environment, less efficient, positive RFI sired offspring are more likely to have poorer performance and create greater risk for the producer.

Impacts
In beef production systems the weight of the animal is the single most important component in determining value. Thus, the ability to identify and propagate cattle that are efficient in converting feed into weight gain becomes an important component of a successful cow-calf unit. A one pound improvement in dry matter feed conversion of feeder calves reduces feed cost by $50 per head. Improved feed efficiency in cow-calf operations will reduce input cost and enhance profit potential for beef producers. Furthermore, the production of offspring is the driving force behind most cow/calf operations. Improved utilization of forage by beef cows, stocker cattle and steers and heifers in forage fed beef programs will provide additional economic impact and increase the number of animal units that can be produced per acre.

Publications

  • No publications reported this period