Development of carcass tissues of growing Pantaneiro lambs

One of the most important aspects of the exploitation of animals producers of meat is the standard growth and their development, since these physiological characteristics determine the carcass tissues deposition pattern. Therefore, the study of the allometric growth would be the first step to determine an ideal slaughter weight, providing a greater quality of carcass in relation to the composition of the comestible portion, that is the relation muscle: fat. The purpose of the study was to determine tissue growth rate: bone, muscle and carcass fat of Pantaneiro's lambs that are growing, to explore their productive potential. Forty-five no castrated males were used, with initial weight 12.7 kg ? 2.03 kg, divided randomly into 5 treatments with nine animals each, receiving 80% concentrate and 20% of roughage in their diet to again 300 g/day according to NRC (2007) guidelines. Lambs were slaughtered at predetermined weights: 15, 20, 25, 30 and 35 kg. After the slaughter and cooling, the carcasses were separated by cuts and then dissected. To determine the tissue growth, it was used the equation log10 Y: log10 ? + ? log10 X, where Y is the tissue weight, X the whole organism weight, ? is the intercept of the log-linear regression of Y and ?, where ? is the allometry coefficient for bone tissue, muscle and adipose in relation to the carcass weight of the Pantaneiro lambs. The allometry coefficients of the tissues were b = 0.810, b = 0.933 and b = 2.148 to bone, muscle and fat, respectively. Based on the results we verify that bone and muscle tissue has negative heterogonic growth b < 1 in relation to the adipose tissue that has a positive heterogonic growth b >1 of the Pantaneiro lambs in the growth, which implies that the adipose tissue is more late in relation to other tissues, that demonstrates that as the animal grows, the amount of fat in the carcass increases.