Effect of energy source and level, and animal age and sex on meat characteristics of sheep

Abstract

Trial 1 was designed to identify meat quality differences due to sheep age (n = 16 ewe lambs, n = 16 yearling ewes, and n = 16 mature ewes) and diet (ad libitum alfalfa pellets (AP), and ad libitum whole shelled corn (WSC100)). Mature ewes had greater (P ≤ 0.02) lean CIELAB a* values when compared with yearling ewes and ewe lambs. Offering WSC100 resulted in a greater (P ≤ 0.05) CIELAB a* value from the fat of sheep carcasses. Longissimus thoracis (LT) cook loss and slice shear force (SSF) values decreased (P ≤ 0.01) with postmortem aging from 1 d to 14 d. Trial 2 was designed to identify meat quality differences due to diet (AP, WSC100, and 85% restricted intake of WSC; WSC85), lamb sex (n = 48 ewes and n = 48 wethers), and lamb age (n = 48 short-fed and n = 48 long-fed). Short-fed lambs had greater LT ultimate pH (P ≤ 0.05) and lean CIELAB L* values (P ≤ 0.01) when compared with long-fed lambs. Long-fed lambs had greater (P ≤ 0.05) CIELAB L* values from the fat of the carcass when compared with short-fed lambs. Lambs offered WSC100 produced carcass fat with greater (P ≤ 0.03) CIELAB a* values when compared with lambs offered AP. Long-fed lambs had a greater percentage of lipid in the LT (P ≤ 0.01) and the whole, boneless ground shoulder (P ≤ 0.01) and greater shoulder patty cook loss (P ≤ 0.01) when compared with samples from shorter-fed lambs. Offering WSC100 resulted in a greater (P ≤ 0.01) percentage of lipid in the shoulder patty when compared with offering AP and WSC85. Percent cook loss and SSF values decreased (P ≤ 0.05) in the LT when aged for 14 days when compared with 1 day. Across the two trials, indicators of sheep meat quality were not largely influenced by diet, age of the sheep, or sex of the sheep.