Location:2010 Annual Report
1a. Objectives (from AD-416)
Grassland is an extensive natural resource in Appalachia. Basing beef production on pasture, from conception to slaughter, will add value to small farm production in the Appalachian area. Three cooperating institutions (West Virginia University, Virginia Tech, and Clemson University) and the ARS Appalachian Farming Systems Research Center are together providing production information by cooperatively studying soil, plant, animal and economics. Each institution is responsible for research on particular phases of the production stream. The objective of this agreement is to provide information on winter stocker and heifer development pasture-based production systems. The Agreement has three specific goals: 1) Produce a 12-month supply of pasture-based beef by expanding the harvest window with retention of acceptable meat quality, 2) Develop criteria for pasture raised beef that define “the window of acceptability”, and 3) Develop tools for pasture-based beef producers to assess and manage risk. Fieldwork to be conducted at Virginia Tech will emphasize on production systems from cow-calf through backgrounding, risk reduction of pasture-based systems and economic evaluation of consumer preferences. Objective 1. Produce a 12-month supply of pasture-based beef by expanding the harvest window with retention of acceptable meat quality. Subobjective 1.1. Evaluate the use of variation in frame scores of sire and dams and different creep grazing systems to expand the harvest window of grass-fed beef. Subobjective 1.2.3. Alternative forage species and nitrogen sources. Objective 2. Develop criteria for pasture raised beef that define “the window of acceptability”. Subobjective 2.1. Quantify performance efficiency of cattle in pasture-based forage systems. Subobjective 2.1.1. Estimate residual feed intake (RFI) of forage-fed cattle. Subobjective 2.1.2. Quantify actual intake of grazing cattle during finishing. Subobjective 2.1.5. Identify life cycle risk factors relevant to meat quality. Subobjective 2.2. Define “window of acceptability” by relating animal production systems, meat quality and consumer parameters. Objective 3. Identify management and nutritional strategies for minimizing weaning stress in calves. Subobjective 3.1. Evaluate ability of high quality forage to minimize post weaning weight gain. Subobjective 3.2. Evaluate the effect of alternative weaning techniques on cattle behavior and stress markers. Subobjective 3.3. Characterize relationship between cattle behavior and carcass quality. Objective 4. Develop tools for pasture-based beef producers to assess and manage risk. Subobjective 4.1. Establish the impact of continuous-use pasture on disease incidence and weight gain of young stock.
1b. Approach (from AD-416)
Systems for the different segments of beef production will be evaluated. The Virginia Tech team will include scientists, graduate students and technicians from the Departments of Agricultural and Applied Economics, Animal and Poultry Sciences and Crop and Soil Environmental Sciences in the College of Agriculture and Life Sciences and the Departments of Biomedical Sciences and Pathobiology and Large Animal Clinical Sciences in the College of Veterinary Medicine. Experiments will be conducted in the field on cow-calf production systems, weaning systems, and backgrounding systems. Risk reduction in pasture-based livestock production will be evaluated relative to forage species and nitrogen sources. Potential production losses from internal parasites on continuous-use pastures will be estimated from data under controlled conditions. Economic data from ethnic demand for pasture-finished products will be evaluated. Weaned calves will be provided to the other cooperators for completion of their phases of the project.
3. Progress Report
In FY 10, calves from the designated creep system weighed 63 lbs more than calves from the forward creep system and calves from large frame cows weighed 15 lbs more than calves from the moderate frame cows. Steers were backgrounded on site and gained approximately 1.1 lb/d during the period. Pasture quality for backgrounding was less than desired due to lack of rain. Steers were shipped in November to WVU for winter stockering. Cows produced the fourth calf crop which will be weaned in fall ’10. Plants contain cuticular wax compounds that may be used to estimate intake and diet composition of grazing cattle. Grass, legume and weed species in the forage system were evaluated to quantify their n-alkane and long chain alcohol (LCOH) concentrations, and to investigate changes in concentrations over the grazing season. Plants differed in n-alkane and LCOH profiles. Plant LCOH concentration was more consistent than n-alkane concentration, suggesting greater utility to delineate plant species. Plant cuticular wax profiles were fairly static over the grazing season, which will be important for investigating foraging patterns in cattle. A separate group of 45 steers and heifers were utilized to compare immunological responses to alternate weaning techniques. Fecal cortisol metabolites were lower 1 day post weaning in fenceline weaned calves as compared to abruptly weaned calves. A difference in lymphocyte phenotypes and leukocyte gene expression was not detected. The calves utilized were approximately 30 days younger than past years’ calves, thus weaning will be delayed in FY-11 to evaluate older calves. Cattle may express stress or anxiety behaviors during routine management. These behaviors have been associated with reduced animal performance and decreased profitability. Our objectives were to develop reliable measures of calf behavior, and to determine whether these measures change under repeated handling. Forty heifers post-weaning were randomly assigned to either a regular or irregular measurement protocol. Heifers were routinely handled at three recording periods, one month apart. In the regular measurement protocol, heifers were handled on three consecutive days each period; with the irregular protocol, they were handled just once. A series of subjective behavioral scores and objective physiological measures were collected. With repeated handling, signs of stress and anxiety were reduced. Chute scores indicated anxiety and could be quickly assessed. A similar set of behavioral and physiologic measures were collected on steers post-weaning. These will be continued during the stockering/finishing phases, and used to characterize the relationships among behaviors post-weaning with growth and carcass attributes at harvest. The database manager position was filled in May 2010. A project server, including security, backup and surge protection, was set-up. Database software was installed and tested (Microsoft SQL Server). The manager’s focus in FY-11 will be to develop the scheme for a project-wide database, and establish and implement procedures for data entry and validation. Monitoring was done through email communication.