Metabolizable energy levels in the rations of Santa Ines sheep: weight of internal organs and digestive tract

Abstract

It was evaluated the effect of different levels of metabolizable energy in the rations on the weight of internal organs, gastrointestinal compartments and content of the gastrointestinal tract (CGT). Twenty growing Santa Ines sheep were used, with age and body weight of 50 days and 13.00 kg, respectively. The animals were allotted into four experimental treatments with different levels of metabolizable energy (2.08, 2.28, 2.47 and 2.69 Mcal/kgDM) in a randomized block design with five replications. There was no influence of the metabolizable energy (ME) levels on the weights of the heart, lungs and CGT, expressed in kg and %, as well as kidney and spleen, expressed in %. There was linear increase for the weights in kg and % of the liver. Quadratic and linear effects were observed for the weights, in kg, of kidneys and spleen, respectively. However, there was no influence of the energy levels of experimental rations on weight, in kg, of rumen-reticulum and omasum as well as to the abomasum, in kg and %, and to the small intestine, expressed in %. As for the weight of the rumen-reticulum and omasum, expressed in %, it was observed linear decrease, of the weight of these organs, with increased levels of ME. The weight of the small intestine, in kg, was positively influenced depending on the levels of ME of the experimental diets. As for the weight, in kg and %, of the large intestine, it was observed linear and quadratic increases, respectively, with the levels of ME in the experimental rations. In this study, no significant effect was observed for the weights, in kg and %, of the pelvic, mesenteric and heart fats. Increased levels of metabolizable energy of the rations influences the weight of internal organs of growing Santa Inês sheep.