Ganho de peso antes e após os sete meses no desenvolvimento e características quantitativas da carcaça de novilhos Nelore abatidos aos dois anos

Abstract

The objective of the experiment was to study the development and carcass characteristics of Nellore steers, slaughtered at two years of age classified in four groups according to the average daily weight gain (ADG) pre and post seven months: high-high = steers with ADG ≥ .44 kg from birth to slaughter, low-low = steers with ADG < .44 kg from birth to slaughter, high-low = steers with ADG ≥ .44 kg before seven months, and ADG < .44 kg from seven months to slaughter, and low-high = animals with ADG < .44 kg before seven months and ADG ≥ .44 kg from seven months to slaughter. At seven months, the animals with lower weight gain (low-high and low-low) showed, in average, 109 kg versus 154 kg for high-low and high-high steers. High-high and high-low animals showed higher live weight at 18 months than the other groups, but at slaughter high-high (396 kg) and high-low (382 kg) steers were only heavier than low-low (335 kg) steers, the same was verified with the carcass weight, wich was 221, 207 and 182 kg, in the same order. Sidecut percentage was higher for high-high steers (13.8%) than low-high (12.7%) and low-low (12.1%) steers, but sawcut percentage was lower for high-high (48.4%) than low-low (50.2%) steers. Contrast analysis comparing pre and post seven months ADG, showed that only pre seven months ADG effect was important for characteristics like weight at twelve and eighteen moths, subcutaneous fat thickness, sidecut percentage, carcass length and leg length. Both effects, ADG pre and post seven months, affected slaughter and carcass weight, sawcut percentage and arm length.