DEPOSITION PATTERN OF MUSCLE AND ADIPOSE TISSUES OF NELLORE STEERS AND BULLS SUPPLEMENTED WITH ZILPATEROL HYDROCHLORIDE

• Grant number: 13/17496-9
• Support Opportunities: Scholarships in Brazil - Master
• Start date: November 01, 2013
• End date: January 31, 2015
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal Investigator: Mário de Beni Arrigoni
• Grantee: Carolina Floret da Costa
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

This study will evaluate the effects of providing a ²-adrenergic agonist in muscle growth and adipose tissue of Nellore bulls and steers. 120 animals will be used Nellore males, 60 castrated and non-castrated 60, with average live weight of 385 kg, and from recreates in continuous grazing. The experiment will be fully randomized divided into two tests: Test 1: Castrated animals were divided into two treatments: T1 - control treatment without the inclusion of zilpaterol hydrochloride, T2 - Treatment with the inclusion of zilpaterol hydrochloride; Test 2: Animals uncastrated divided into two treatments: T1 - Treatment Control without the inclusion of zilpaterol hydrochloride and T2 - Treatment with inclusion of zilpaterol hydrochloride (60 mg / animal / day). Each treatment will consist of 6 bays (5 animals / bays), which were considered the experimental units for this study. Adjustments will be in the form of stairs, and consist in providing diets with increasing levels of concentrated (66%, 74%) for 14 days. From the 15th day the animals receive the finishing ration (82% concentrate) until they are slaughtered. The animals will be kept in a stall of concrete floors easy to clean and they will be fed twice a day (08h and 15h) with constant water in automatic waterers. The animals will be monitored at the beginning and end of the confinement for monitoring growth of adipose tissue and muscle, using ultrassom. The experimental period consists of supply at the beginning of treatment, and that after the first day's supply hydrochloride zilpaterol be slaughtered six animals per treatment (one per pen) to establish the reference line. To monitoring the growth of muscle and adipose tissue of animals, measurements will be taken in ultrasound carcass, and after slaughter reference and final, at the 84 days of feedlot, will be collected meat samples for the determination of physical and chemical composition of the carcass by the method HH and pattern of growth of skeletal muscle fibers.