This experiment was developed at the Animal Science Department, at Federal University of Santa Maria, Brazil with the aim of determining the growth of the organs and other body constituents of lambs, and their proportion in the live weight (LW) and empty body weight (EBW). Twenty-two intact male lambs, from crossbreed Texel x Ideal dams sired by Texel males were used. Four lambs were slaughtered at the beginning of the experiment (24 hours after birth) and groups of six lambs were slaughtered at weaning and when reaching 28 or 33kg of body weight. To study the relative growth of the different body constituents, the halometric equations between the log of the weight of each component, and of the log of the EBW were fitted. The proportions of alimentary tract (AT), other internal organs (GOI), internal fat (IF) and carcass increased with increasing LW and EBW (P<0.05), whereas heart, liver, spleen, kidney, lung with trachea, blood, feet and head decreased (P<0.05). One group of constituents was early maturity (heart, kidney, lung with trachea, feet, blood and head), and another was of late maturity (rumen- reticulum- omasum and abomasum ), AT and IF). The remaining ones (liver, spleen, intestine, skin and carcass) had the same growth rate as EBW.
allometry; body weight components; carcass; empty body weight; live weigh
