Location:2011 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 meat quality attributes for the pasture-based beef production system. 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.
1b. Approach (from AD-416)
Researchers in several disciplines will work together and will include soil scientists, agronomists, ruminant nutritionists, animal physiologist, agricultural economist and extension specialists. Experiments will be conducted in the field on stocker and heifer development systems as well as on the soil fertility, pasture production and management components. Residual feed intake and forage-use efficiency will be estimated from data under controlled conditions. Continuous-flow fermentation will be utilized to compare digestive kinetics and fermentation with products and byproducts of forages consumed during finishing. Data from experiments will be used to estimate and calibrate risk-profitability decision tools for producers. Potential revenues will be assessed under various live cattle market conditions to predict scenarios that favor marketing harvested grass-fed beef. Data will be obtained in grocery stores to determine consumers’ response to visual and taste characteristics, and their willingness to buy the product.
3. Progress Report
Angus-cross steers (n = 96) were used to determine the effects of frame size (medium, MED or small, SM) and animal age on beef carcass quality and tenderness in a forage finishing system. Steers grazed mixed pastures (bluegrass/white clover) and were slaughtered at 16.6, 18.6, and 20.3 mo of age in a 2-yr study. Hot carcass weight, fat thickness, and skeletal maturity scores increased with animal age. Marbling scores, quality grades, and yield grades were greater for 20.3 than 16.6 mo. Hot carcass weight and ribeye area were greater (P < 0.05) for MED than SM. Frame size did not alter other carcass parameters. At 14 d postmortem, steaks from 16.6 and 18.6 mo were more tender than 20.3 mo. In pasture-based beef finishing systems, increasing animal age results in larger carcasses with more external fat and marbling; however tenderness of ribeye steaks decreases with advanced age such that longer postmortem aging times are required to achieve similar tenderness level. Angus heifers (n = 40) were used to evaluate the effect of finishing on endophyte-free tall fescue (TF), TF with grain (TF+G), or alfalfa (AL) on carcass and meat quality, and lipid oxidation during storage. Heifers were finished on TF or AL to two time endpoints, which corresponded to 161 or 189 d of grazing. The TF+G heifers also grazed TF for 161 or 189 d and after adaptation were offered corn grain ad libitum for a total of 56 or 84 d prior to slaughter. Supplementation with corn grain on tall fescue increased concentration of n-6 polyunsaturated fatty acids and the ratio of n-6 to n-3 fatty acids, and reduced conjugated linoleic acid percentage. Finishing heifers on alfalfa resulted in greater carcass weights, fat thickness, KPH, marbling score and quality grades. Lipid oxidation in fresh ground beef was higher in ground beef for grain supplemented than tall fescue only or alfalfa. For frozen ground beef samples, non-vacuum packaging (i.e. chub packaging) increased lipid oxidation 3-fold higher during frozen storage compared to vacuum packaged. Finishing heifers on tall fescue with grain increased omega-6 PUFA levels and lipid oxidation rates in fresh ground beef. 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.