Heritability and additive breeding value in sheep obtained through industrial crossing

This study aimed to estimate the heritabilities, the most assertive selection gain for each characteristic of sheep genetic improvement, together with the reference additive genetic value for industrial crosses in the Southern Region of Brazil. The study was carried out in the municipality of Boa Vista do Cadeado - RS, with data collection from 2020 to 2023. The animals were stratified by gender and separated into stalls, with free access to water. The measurements inherent to the parents (50 dams and 5 rams) were carried out at the time of crossing. For the 100 progenies, the height and weight of male and female lambs at birth were measured. The average daily gain of the progenies was obtained, and a standard weighing and height measurement at 80 days after birth. The final weight and carcass yield of the lambs were obtained at the time of animal slaughter. High genetic variability and narrow-sense heritability were obtained in the characteristics weight at birth of male lambs and height at birth of lambs in both genders. Average daily weight gain revealed high heritability with restricted meaning, this attribute being unrelated to the expressed meteorological variables, identifying effective potential for selection. Pressures of 10% and selection intensities of 1.76 can be employed for most traits to be improved through industrial sheep crossbreeding. Industrial crossing is effective not only due to heterotic effects but also due to additive genetic effects expressed in heritability.