Influence of Age and Diet on Carcass Characteristics and Meat Quality in Rambouillet Ewes

Abstract

Adults or cull ewes may represent an economical option in sheep production systems if the selling price could be based on the carcass weight and number of edible tissues. Therefore, it is relevant to know carcass characteristics of cull ewes and for farmers this could result in a viable option for the sale of this type of animals. Thus, this study determined the effect of age and diet on carcass characteristics and meat quality parameters of Rambouillet ewes. Forty ewes with different ages (n=20 yearling ewes and n=20 cull ewes) were fed with alfalfa hay (AH) or 100% concentrate diet (CD). Treatments were as follows: a) ten cull ewes were fed only with AH, b) ten yearling ewes were fed only with AH, c) ten cull ewes were feed with CD, d) ten yearling ewes were fed CD. Productive performance, carcass characteristics, and meat quality were recorded. Animals had 10 days of adaptation and 35 days for data collection. Dry matter intake was grater (P < 0.05) for CD. Feed conversion had no differences. The pH at 45 min and 24 h, carcass length, leg length, leg width, thorax width, and thorax perimeter were similar between treatments. Hot carcass weight was heavier (P < 0.05) in cull ewes, cold carcass weight was increased (P < 0.05) by CD. Carcass yield (CY) was heavier in CD (P < 0.05). Cull ewes had greater (P < 0.05) lean CIELAB L*, a*, b*, c*, and h* values compared with yearling ewes. The color changes increased by age at five days (P < 0.05), but a decrease (P < 0.05) by diet was observed at ten days. Cathepsins B, B+L, and Lowry protein content were similar among treatments. Our results suggested that feeding cull ewes with concentrate diets could improve body weight gain and carcass yield with respect to feeding only with alfalfa hay.

Keywords: cull ewes, diet, wool ewes, meat quality, yearling, carcass, meat color, tenderness