Temperament of growing beef cattle and buffaloes on grazing system: performance, blood parameters and intake behavior

Abstract

The purpose of this study is to evaluate the temperament of growing beef cattle and buffaloes on grazing system regarding animal performance, blood parameters and intake behavior. Forty growing animals (n = 20 Nellore, n = 20 water buffalos) on rotational stocking system (Brachiaria brizantha cv. Xaraés), receiving or not receiving supplementation [n = 10 animals of each genetic group for each treatment, pasture or pasture plus supplementation (0.6% of the animal body weight; corn, urea and mineral salt)] will be used. Pastures will be grazed for 4 days of occupation and 28 days of interval of defoliation in rotational stocking system. Forage samples will be collected before entry and after output of animals from pasture to calculate the forage allowance. Animals will be evaluated for animal temperament (chute score and exit velocity), body weight, body condition score (BCS) and hip height (HH) on days -28 (arrival of animals in the field), zero (after adaptation period) and, subsequently, every 28 days until the end of trial period (84 days). Average daily gain (ADG) and total gain (TG) will be calculated. For classification purpose, animals will be evaluated for temperament (excited or calm) at entry in the field (d -28). Ultrasound evaluation (ribeye area; backfat thickness - 12th rib) will be carried out on days 0 and 84. Blood samples will be collected for evaluation of metabolic parameters such as cortisol, insulin, glucose and haptoglobin on days -28, 0, 56 and 84. Intake behavior evaluation will be performed by 8 and 24 hours with 15 minute intervals between observations. Data will be analyzed with MIXED procedures of SAS (SAS Institute Inc., Cary, NC, USA), submitted to analysis of variance and comparison of means. Significance will be set at P < 0.05. (AU)