Adaptation of Nellore cattle to high-concentrate diets: performance, feeding behavior, carcass characteristics and rumen health

Abstract

The objective of this study will be to evaluate the length of protocols to adapt Nellore cattle to high concentrate diets on feedlot performance, feeding behavior, carcass characteristics, rumenites and liver abscesses incidences, and rumen morphology of papillae. One-hundred twenty Nellore bullocks (380 kg) backgrounded on pasture will be randomly disposed in 24 pens (5 animals/pen) according to the 2 x 2 factorial arrangement of treatments: T1) step up program during 14 days; T2) step up program during 21 days; T3) Restriction program during 14 days; T4) Restriction program during 21 days. Cattle will be fed twice daily (8h and 15h). After the period of adaptation, animals will be fed an unique diet containing 85% concentrate until reaching 490 kg of body weight and a minimum of 4 mm of back-fat thickness. The variables evaluated will be as follows: feedlot performance, feeding behavior, carcass characteristics, rumenites and liver abscesses incidences, and rumen morphology. (AU)