Genetic, environmental and phenotypic trends in a register brahman herd

This research was carried out in order to estimate the Genetic, Environmental and Phenotypic trends for the 18 months weight (P540) in Brahman cattle. A total of 3558 electronic records from the “La Cumaca” experimental station, belonging to the Faculty of Veterinary Sciences. from the Central University of Venezuela. Genetic trends were estimated in three ways: a) by twice the difference of the regression slopes estimated with the annual means in the population and the within-sire slope in years for the trait, b) by using weighted regression analysis with the annual means derived from the adjustment of models with groups of half or full siblings and c) simple animal model. The models included the effects of sex, year and month in which the weight was recorded, and the effect of the sire and dam with variants due to the elimination of ancestors with the purpose of obtaining estimates of the trends due to differences in the regression slopes. The genetic trends according to the first alternative was 1.2614 Kg/year; using half-sibs the estimator was 3.0308 Kg/year, while with groups of full sibs the genetic change was 2.5332 Kg/year. In the third case, the annual genetic change of 0.829 kg/year obtained via animal model, the other estimates overestimated the true trend; In reference to the population average for the character, the changes are less than 1%. Consequently, it is suggested to review the selection procedure.

• Hovedforfatter: Roman Bravo, Rafael Maria (author)
• Andre forfattere: Verde Sandoval, Omar Gerardo (author), Gómez Ramos, Benjamín (author), Diaz Maldonado, Isaías de Jesús (author), Oviedo Boyso, Javier (author), Trujillo Pahua, Verónica (author)
• Format: article
• Sprog: spa
• Udgivet: 2024
• Online adgang: https://revistasespam.espam.edu.ec/index.php/Revista_ESPAMCIENCIA/article/view/483