EFEITOS DE UM ANÁLOGO À SUBSTÂNCIA APAZIGUADORA BOVINA SOBRE O CRESCIMENTO, COMPORTAMENTO, ESTRESSE E CARACTERÍSTICAS DE CARCAÇA DE BEZERROS DESMAMADOS

Abstract

VIEIRA, D.G. Effects of an analogue of the bovine appeasing substance on growth, behavior, stress, and carcass characteristics of weaned calves. 2024. 97f. Tese (Doutorado) - Faculdade de Medicina Veterinária e Zootecnia, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, 2024. Objectives: The objectives were: Chapter 1) to carry out a literature review on the use of an analogue of bovine appeasing substance (SAB) in beef cattle; assess the impacts of SAB administration. Chapter 2) evaluates the effect of applying SAB at the time of weaning on the growth, stress, behavior, and response to vaccination of Nelore calves. Chapter 3) Application at weaning on weight gain, response to vaccination, stress, daytime behavior, carcass characteristics, and meat quality of Brangus heifers. Material and methods: Animals from all experiments were divided into 2 treatments: Saline, saline injection, and SAB. Cap.2) a total of 90 Bós taurus indicus calves, [n = 90; body weight (BW) = 198 ± 30.8 kg and 8 ± 1 month of age]. The calves were raised from birth to weaning on Marandu grass pasture Urochloa brizantha (Hochst. ex A. Rich) R. D. Webster, cv. Marandu; where they had free access to water and a complete mineral/vitamin mix. Chap.3) a total of 30 Brangus PC calves (199.8 ± 16 kg; 8 ± 1 month of age) were used. The calves were raised from birth until weaning on Capim-Marandú pasture (Urochloa brizantha cv Marandú) and on the day of weaning, they were transported 3 km in a single truck, to the experimental confinement. Upon arrival (d 0), calves were stratified by body weight and assigned to treatments: SAB (n = 15; SecureCattle; Nutricorp, Araras, SP, Brazil) or Saline (n = 15; saline solution, 0.9% NaCl ). Results: The application of SAB: Chapter 2) SAB can improve the immune system via greater production of antibodies to vaccines and greater adaptation of animals to the new environment and reduction of weight loss caused by stress: Chapter 3) Administration of SAB the calves upon arrival at the feedlot, ADG improved in the initial 45 days, appearing to accelerate adaptation to the new scheme and environment. Furthermore, it alleviated (or not; cortisol and haptoglobin remain to be evaluated) the physiological reactions induced by stress.