Studies on the Criollo goat of Northern Mexico: Part 2-Physical and chemical characteristics of the musculature.

Groups of castrate male Criollo goats were slaughtered at 12, 16, 20 and 24 kg liveweights after being reared on natural rangeland with concentrate supplementation. After slaughter the carcasses were chilled for 24 h at 2°C, and the total lean was dissected from the left halves of the carcasses. The total lean was subjected to a proximate analysis. M. biceps femoris and M. longissimus dorsi muscles were dissected out of the right halves of the carcasses. Various physical and chemical quality parameters, such as Warner-Bratzler shear values and tristimulus colour values, were measured on these muscles in addition to hydroxy proline analysis, for the estimation of collagen content. The moisture content of the total lean decreased steadily with increasing slaughter weight to a level of approximately 76% in the heaviest group. Ash and protein content tended to fall, with intramuscular fat increasing to approximately 16% of the wet tissue weight. The ultimate pH of the two muscles was high in all the slaughter groups, being usually higher than 6·0. Generally, shear values did not change between the slaughter groups in the two muscles. The data indicate that slaughtering castrate male Criollo goats at 24 kg instead of 8 kg does not exert deleterious effects on the parameters of physical and chemical quality investigated.