Sustainable Intensification of Beef Production in the Tropics: The Role of Genetically Improving Sexual Precocity of Heifers

• Published in: Animals (Basel) Vol. 12; no. 2; p. 174
• Main Authors: Fernandes Júnior, Gerardo Alves, Silva, Delvan Alves, Mota, Lucio Flavio Macedo, de Melo, Thaise Pinto, Fonseca, Larissa Fernanda Simielli, Silva, Danielly Beraldo Dos Santos, Carvalheiro, Roberto, Albuquerque, Lucia Galvão
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 12-01-2022; MDPI
• Subjects: Age; Animal husbandry; Animal reproduction; Beef; Beef cattle; Biological activity; Bos taurus indicus; Breeding; Case studies; Cattle; early pregnancy; Efficiency; Emissions; Estimates; Evaluation; Fertility; Food security; Genetic analysis; Genomic analysis; genomic selection; Genotype-environment interactions; Genotypes; Livestock; Meat production; Meat quality; Ovaries; Parameter estimation; Pasture; Productivity; Puberty; Review; Sustainability; Tropical environments; Ultrasonic imaging; beef cattle; genomic selection; early pregnancy
• ISSN: 2076-2615; 2076-2615
• DOI: 10.3390/ani12020174

Increasing productivity through continued animal genetic improvement is a crucial part of implementing sustainable livestock intensification programs. In Zebu cattle, the lack of sexual precocity is one of the main obstacles to improving beef production efficiency. Puberty-related traits are complex, but large-scale data sets from different "omics" have provided information on specific genes and biological processes with major effects on the expression of such traits, which can greatly increase animal genetic evaluation. In addition, genetic parameter estimates and genomic predictions involving sexual precocity indicator traits and productive, reproductive, and feed-efficiency related traits highlighted the feasibility and importance of direct selection for anticipating heifer reproductive life. Indeed, the case study of selection for sexual precocity in Nellore breeding programs presented here show that, in 12 years of selection for female early precocity and improved management practices, the phenotypic means of age at first calving showed a strong decreasing trend, changing from nearly 34 to less than 28 months, with a genetic trend of almost -2 days/year. In this period, the percentage of early pregnancy in the herds changed from around 10% to more than 60%, showing that the genetic improvement of heifer's sexual precocity allows optimizing the productive cycle by reducing the number of unproductive animals in the herd. It has a direct impact on sustainability by better use of resources. Genomic selection breeding programs accounting for genotype by environment interaction represent promising tools for accelerating genetic progress for sexual precocity in tropical beef cattle.