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| Author(s): |
Rodrigo da Costa Gomes
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Pirassununga. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Zootecnica e Engenharia de Alimentos (FZE/BT) |
| Defense date: | 2006-01-25 |
| Examining board members: |
Paulo Roberto Leme;
Luís Carlos Vinhas Itavo;
José Carlos Machado Nogueira Filho
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| Advisor: | Paulo Roberto Leme |
| Abstract | |
A recent concern about anti-microbial resistance by microorganisms has increased the interest for studies of new feed additives for ruminants, alternatively to ionophores utilization. In this way, It was aimed with this work to evaluate the effects of live yeast culture (Saccharomyces cerevisiae, strain 1026, 5 x 106 cfu/g, Beef Sacc®, Alltech, Inc.), monensin (Rumensin, 10% of sodium monensin, Elanco®, Inc.) and the combination of both additives, on the performance and carcass traits of Nellore steers fed a high concentrate diet in feedlot. Seventy-two animals, with 330 kg of live weight and 20 months of age were allotted to one of four treatments: control (no additives), diet with yeast (0,6g of Beef Sacc®/ kg of dry matter), diet with monensin (0,3g of Rumensin®/ kg of dry matter) and diet with yeast and monensin. Animals were fed ration with sugarcane bagass (21%), soybean hulls (29%), corn ground (39%), soybean meal (7%) and urea (1%), for an 84-day period. Individual feed intake measurements were possible through individual pens and Calan Gates system. Carcass pH was measured at 1 and 24 hours after slaughter. Left half-carcass was split in muscle, bone and fat for retail cuts percentage determination. Rib eye area and subcutaneous fat thickness were measured on Longissimus dorsi muscle in the region between 12th and 13th ribs. Steakes of Longissimus dorsi muscle were taken and aged 0, 7 and 14 days to shear force and cooking total losses measurements. Treatments didn\'t affect weight gain, feed intake or feed efficiency. Yeast increased carcass dressing percentage, but there weren\'t important effects of additives on other carcass traits and on retail cuts percentage. Meat quality wasn\'t influenced by additives. Additives studied showed no significant effects on the performance and carcass traits of Nellore steers fed high concentrate diets in feedlot. (AU) | |