2009 Annual Report
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.
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.
A pilot group of 12 heifer calves were utilized to compare immunological responses to alternate weaning techniques. Several analytes showed promise, which included fecal cortisol analysis, IgG isotyping into IgG1 and IgG2 and serum gamma interferon. Analysis of lymphocyte gamma interferon production via ELISPOT was not promising and IL4 concentrations could not be detected in serum samples.
With input from IT specialists, the specifications for computer hardware (server) and software (Microsoft SQL Server 2008) necessary to develop a project-wide database was developed. Funding for a database manager position was secured, with plans to advertise, interview and fill the position by early 2010.
Beef cattle undergo routine management to maintain their health and productivity. For some animals, these procedures may cause stress and fear, and affect growth and carcass quality. Two groups of calves were either handled irregularly (monthly for 3 months) or regularly (3 consecutive days each month). Calf behavior was assessed using subjective (chute and pen score) and objective measures (exit velocity), as well as physiological measures of stress. With regular handling, both subjective scores and physiological measures suggested that calves became accustomed to routine management with reduced stress. Chute and pen scores were useful indicators of calf stress. These results imply planned management strategies can be used to reduce stress and enhance well-being in calves.
The ADODR communicates with the project collaborators on a regular basis by telephone, internet and in person. Two scientists from each of the collaborating institutions serve as members of the project¹s executive committee that develops project policy and plans execution as well as insuring accountability to the project plan. Quarterly meetings of the executive committee are held via conference call. Project meetings for all participants are held twice a year. The ADODR interacts frequently in person at the USDA-ARS location in Beaver, WV and at the collaborators¹ sites. The ADODR provides guidance and oversight to administer the specific cooperative agreement and insuring project accountability.