Universidade Estadual Do Sudoeste da Bahia, Pós-Graduação Em Zootecnia, Campus de Itapetinga, Praça Primavera, 40, Primavera, CEP 45.000-700, Itapetinga, BA, Brasil.
Department of Animal Science, College of Agriculture, Purdue University, S Russel St, West Lafayette, IN, 270, 47907, USA.
Trop Anim Health Prod. 2022 Feb 24;54(2):111. doi: 10.1007/s11250-022-03104-y.
This study investigated phenotypic differences of zebu females from four breeds using variables of growth, feed efficiency, and age at first calving. Weights throughout the life were recorded, and a growth curve was fitted using the Gompertz model. The growth was also evaluated at standardized ages (205, 365, and 550 days) using the body weight and the total and daily weight gains. The Kleiber index and age at first calving were used as measures of feed efficiency and sexual precocity, respectively, totaling 25 variables. New variables were created using the factor analysis and used in new multivariate analyzes. Only six factors explained 95.41% of the total variance and were used for the subsequent analyses. The factors were defined as maturity, precocity, feed efficiency postweaning, feed efficiency post 1 year of age, puberty, and birth weight. There were differences between breeds according to the multivariate analysis of variance. Each breed appeared in a quadrant on the Biplot graph, showing relationship with different factors, demonstrating the diversity of zebu females. There is a difference in growth, feed efficiency, and sexual precocity in Brazilian zebu females, allowing the identification of potentials of the animals and help breeders and decision-makers.
本研究利用生长、饲料效率和初配年龄等变量，研究了四个品种瘤牛雌性的表型差异。记录了整个生命周期的体重，并使用 Gompertz 模型拟合生长曲线。还使用体重和总增重和日增重在标准化年龄（205、365 和 550 天）进行生长评估。克莱伯指数和初配年龄分别用作饲料效率和性早熟的衡量标准，总计 25 个变量。使用因子分析创建新变量，并用于新的多元分析。只有六个因素解释了总方差的 95.41%，并用于随后的分析。这些因素被定义为成熟度、早熟度、断奶后饲料效率、1 岁后饲料效率、青春期和初生重。根据方差的多元分析，品种之间存在差异。每个品种都出现在散点图的一个象限上，与不同的因素有关，表明巴西瘤牛雌性的多样性。巴西瘤牛雌性在生长、饲料效率和性早熟方面存在差异，这使得能够识别动物的潜力，并为饲养者和决策者提供帮助。
