Performance, carcass characteristics and meat quality of Nelore cattle fed on high levels of high moisture corn and low fiber

Abstract

Abstract: In the nutrition of confined cattle, the starch is given by feeding with different kind of processed corn to attempt the animal energy requirement. In Brazil, the high moisture corn grain is the processing that is most likely to digestibility of the corn flakes, which is the most used source of starch in the nutrition of cattle in feedlots. This project is due to evaluate yield traits and carcass quality of Nelore cattle fed on a high level of high moisture corn grain and low fiber. It will be used 56 2 years old Nelore bulls and an average of 380kg of yearling weight. They will be confined in individual pens, divided by yearling weight and be evaluated during 90 days including 21 days of adaptation. The animals will be fed on a high level of high moisture corn grain and low fiber diets. The ration will be given twice a day (in the morning and in the afternoon) and the bunks' left overs will be collected weekly. Based on the dry matter intake and the bunks' left overs, the feed efficiency will be calculated. The animal will be weighted every 21 days and the weight record will be used to calculate the average daily gain. The animals will be slaughtered in a commercial slaughterhouse and only 28 carcasses will be evaluated and they will to be weighted to get the hot carcass weight and kidney, pelvic and heart fat weight. Twenty four hours after the slaughter the 28 half carcass (half of each treatment) chosen randomly will be cut between the 12th and 13th rib to determinate the rib eyed area and fat thickness. To determinate these traits, a digital image of the cuts will be taken and later they will be evaluated using the software Lince®. With samples of the Longissimus (2,5cm of thickness) in the 12th rib it will be determinate the meat tenderness using the share force and exudative water loss by cooking, based on the American Meat Science Association - AMSA method. It will also be evaluated the exudative water loss and cooking water loss. The analysis will be made in the Laboratório de Avaliação Animal e Qualidade de Carne of University of São Paulo - FZEA. The effect of treatments will be assessed by analysis of variance, considering complete ramdomized design using the MIXED methos of SAS (2002).