EFFECTS OF ADDITIONAL FEEDING REGIMEN FOR THE OFF-THE PASTURE LAMBS ON CARCASS TRAITS AND MEAT QUALITY

Two hundred eighty weaned Targhee lambs were grazed on annual grass-subclover pastures for 84 d under continuous and rotational defoliation grazing system. At the end of the grazing season, twenty lambs weighing 44 kg were slaughtered directly off the pasture, whereas two groups of 20 lambs each were fed either a alfalfa pellet or a 50% alfalfa/50 concentrate pellet for additional 6 wk until they reached an average live weight of 50 kg. Carcass traits and loin chop palatability were compared. Lambs slaughtered directly off the pasture were lighter than desirable market weight and some lambs had less than adequate fat cover and approximately half of them were graded U.S. Good in quality. Overall conformation and leg muscling was inferior and loin chops were less tender, less juicy and less flavorful. The lambs on alfalfa pellets for 6 wk appeared to be ideal in terms of carcass quality (all Choice except one), fat cover and yield grade. They had better taste panel scores in all palatability traits than off-the-pasture lambs, and most loin chops were acceptable. The lambs on a 50% concentrate diet for 6 wk had a higher conformation score and a greater muscling in the legs. Loin chops had more marbling and better palatability than other groups. However, some lambs had an excessive fat cover and lower yield of retail cuts. It was concluded that additional feeding for 6 wk on alfalfa pellets until the live weight reached 50 kg(for Targhee lambs) was the best way of finishing lambs at the end of grazing season in the California rangeland.