Weight and yield of non-carcass components of Morada Nova lambs fed with different levels of metabolizable energy

Abstract

The objective of this study was to evaluate the effect of different metabolizable energy (ME) levels on weight of gastrointestinal content, weight and yield of the internal organs and gastrointestinal compartments of Morada Nova growing lambs. Thirty-two animals, non-castrated, with average body weight of 12.12 ± 1.69 kg and two months old approximately, were used. The animals were distributed into four different metabolizable energy (1.28; 1.72; 2.18 and 2.62 Mcal/kg DM) levels, in randomized block design with eight replicates per treatment. Tifton 85 hay was used as roughage. There was no effect of energy levels (P > 0.05) on weight of gastrointestinal content. Increased linear effect (P < 0.05) was observed for the weights of heart, "LTET" (lungs, trachea, esophagus and tongue), liver and spleen, expressed in kg. Regarding the compartments of the gastrointestinal tract, it was observed increased linear effect (P < 0.05) only for rumen-reticulum, in %, and small intestine, in kg. The perirenal, omental and mesenteric fats were also influenced by the ME levels (P < 0.05) with linear increase when expressed in kg and %. Increased levels of ME influence weight and yield of internal organs, viscera and fats of Morada Nova lambs during the growing period.