Inclusion of crude glycerin in partial replacement of corn on performance and metabolism of sheep

Abstract

Due to the incentive that drives the production of biodiesel, the wide availability of crude glycerin drew attention and today is also applied in animal nutrition. To evaluate its use in diets for sheep three experiments will be performed. Experiment 1: Fifty intact Santa Ines ram lambs will be used to determine the effects of including crude glycerin to partially replace corn in high concentrate diets on performance, carcass characteristics and meat quality. The experimental diets will be composed of 90% concentrate and 10% hay. The levels of replacement will be: 0, 5, 10, 15 and 20% crude glycerin, corresponding to the treatments G0, G5, G10, G15 and G20, respectively. The variables analyzed will be: average daily gain, dry matter intake, feed efficiency, blood parameters ( activity of aspartate aminotransferase - AST and GGT gamma-GT ), carcass traits (hot and cold carcass yield, ribeye area, back fat thickness and body wall thickness) and meat characteristics ( pH, color , shear force, cooking weight loss, water holding capacity, lipid content and fatty acid profile ). Experiment 2: Five Santa Inês lambs, cannulated in the rumen, will be used in a 5x5 Latin Square design to determine the effects of using the diets of Exp. 1 on nutrient digestibility, ruminal fermentation, blood (insulin and glucose) and water consumption. Experiment 3: 118 ewes will be used at 90 days of pregnancy and will be randomly divided into two treatments. Diets will consist of 70% concentrate and 30% roughage, with 0 (no addition of glycerin) or 10% crude glycerin replacing corn. Every 2 weeks, blood samples will be withdrawn from the animals for subsequent determination of plasma glucose, non-esterified fatty acid and insulin. In addition, from the ewes that started the trial, 16 ewes from each treatment will be selected to determine lactation performance and offspring growth. The variables analyzed will be: ewe and lambs dry matter intake, ewe's milk production and composition, ewe's weight and body condition score, blood parameters (glucose , non-esterified fatty acid and insulin ) and offspring average daily gain. (AU)