Influence of the calving season of Girolando calves on development in the initial phase after birth, reproductive performance, and productive performance

• Published in: Ciência animal brasileira 2024, Vol.25
• Main Authors: Oliveira, Fabiana Silva, Reis, Natani Silva, Santos, Ricarda Maria dos
• Format: Article
• Language: eng ; por
• Subjects: VETERINARY SCIENCES
• ISSN: 1518-2797; 1809-6891; 1809-6891
• DOI: 10.1590/1809-6891v25e-78655e

Abstract Raising heifers is one of the most important activities in dairy farming because heifers eventually replace the herd. This study was performed to evaluate how the calf’s birth season affects its early development and its reproductive and productive performance. The experiment was conducted at the Glória Experimental Farm of the Federal University of Uberlândia, Minas Gerais, Brazil. In total, 74 female calves born from January 2018 to March 2020 were evaluated from the first day of life to the end of their first lactation. The animals were classified according to their season of birth: spring/summer (October–March) or fall/winter (April–September). During the initial phase of life, the animals’ weights were assessed on days 0, 30, and 60 after birth and at weaning. The rectal temperature, fecal score, feed intake, and animal behavior were recorded daily. In the mature phase of life, the dates of conception and calving were evaluated, and milk production during the first lactation was monitored. The following variables were analyzed according to season of birth: weight gain and occurrence of diseases during the initial phase, percentage of heifers that calved, age at first calving, and average milk production during the first lactation. Continuous variables were analyzed by analysis of variance, and binomial variables were analyzed by logistic regression using the Minitab software program. Calves born in fall/winter had a higher weight at 30 days; however, this difference was compensated for during the initial phase and did not interfere with reproductive and productive performance. Resumo A criação de bezerras é uma das atividades mais importantes na bovinocultura leiteira, visto que estas serão os animais de reposição do rebanho. Objetivou-se avaliar o efeito da estação de nascimento da bezerra no desenvolvimento na fase de cria e desempenho reprodutivo e produtivo. O experimento foi conduzido na Fazenda Experimental Glória, da Universidade Federal de Uberlândia. Foram avaliadas 74 bezerras nascidas de janeiro/2018 a março/2020, desde o primeiro dia de vida ao final da sua primeira lactação. Os animais foram categorizados de acordo com a estação de nascimento: primavera/verão (outubro a março) e outono/inverno (abril a setembro). Durante o aleitamento foi avaliado o peso dos animais nos dias: 0, 30, 60 após o nascimento e no desaleitamento. A temperatura retal, o escore de fezes, a ingestão de alimento e o comportamento animal foram monitorados d