This study had the objective of verifying the differential growth of carcass organs and visceras in relation to the empty body weight of Santa Ines and Bergamacia lambs. Thirty-six non-castrated male lambs, 24 Santa Ines breed and 12 Bergamacia breed, slaughtered at 15, 25, 35 and 45 kg of live weight under feedlot system receiving a diet with forage:concentrate ratio of 20:80 were used. The study of the relative growth of internal organs, fats, carcass non-integrant parts, carcass parts and components of the abdominal and thoracic cavities was carried out by means of the non-linear model of the potency equation Y = αXβ, linearly transformed into a linear model, lnY = lnα + βlnX. Liver, pancreas, abomasum, small intestine, large intestine and thoracic cavity are parts of the empty body of the animals that presented early development, while spleen, abdominal cavity, carcass integrant and non-integrant parts presented isogonic growth (β=1); the fat stores presented negative heterogonic growth (β<1). The omasum and rumen/reticulum of Santa Inês lambs growth early, while in Bergamácia lambs, it grows late. Liver, pancreas, abomasum, small intestine, large intestine and thoracic cavity in both breeds present early development and spleen, abdominal cavity, carcass integrant and non-integrant parts present isogonic growth in relation to the weight of the empty body.
allometry; growth; sheep
