EVALUATION OF PERFORMANCE AND WELFARE OF F1 CALVES DAIRY GYR X HOLSTEIN UNDER ENVIRONMENTAL ENRICHMENT AND TACTILE STIMULATION

Abstract

Regarding the welfare and behavior of species of economic interest, concern in our society is growing. For dairy cattle, usually calves are separated from their mothers soon after birth and this has led to questions from society about raising these animals. The present experiment will study two types of handling and two different environments, seeking to verify the effect on growth, health, welfare and behavior of 44 F1 heifers, from cross Gyr Dairy bull with Holstein cows. Female embryos were implanted and the calves will born in October 2018. The experimental design will be a 2x2 factorial, with two environments (with and without environmental enrichment) and two handling treatments (with and without tactile stimulation). Growth traits, health, behavior and physiological traits, such as heart rate, hormonal dosages of cortisol, oxytocin, will be measured. The expression of oxytocin, cortisol and serotonin receptors will be performed. Analysis of the expression of cortisol (GR), oxytocin (OTR) and serotonin receptors (HTR2A, HTR1B, HTR4) in leukocytes will be performed by the RT-PCR technique. The variables with normal distribution will be analyzed by means of mixed linear models and those that do not present normal distribution, mainly those of frequency of occurrence of certain behaviors and scores, will be analyzed by generalized linear procedures (GENMOD, SAS 9.3). (AU)