Resumen de Criterios de selección para tolerancia al estrés por calor en rumiantes de aptitud lechera. Correlación entre tolerancia y nivel productivo
M. Ramón, C. Diaz, A. Molina, María Dolores Pérez-Guzmán Palomares, M. Serrano, Manuel Sánchez Rodríguez, M.J. Carabaño
Selection towards increasing tolerance to the effects of heat is presented as a tool of great interest to obtain more adapted animals to the environment in which they are reared. In this work, we examined the correlation between the production level of animal ,measured as the EBV in absence of heat stress (EBV-CONF: Tª=18ºC; THI=15), and 3 selection criteria based on the EBV under heat stress (EBV-EC), the slope of decrease of EBV in the heat stress region (EBV-Pendiente: T>24ºC; THI > 22) and the principal components 2 to 4 obtained from the vector of random-regression coefficients. A moderateto-high correlation between different criteria and the production level of animals were observed. Among all criteria considered, only the EBV-Pendiente for milk yield in cows and protein yield in ewes, the CP2 component in cows and ewes, and the CP4 component in the three breeds resulted useful as selection criteria towards more tolerant animals to heat.
