No abstract

Heat tolerance is an important trait for deciding on which genetic resource to use on farms in tropical regions. Three genetic groups of lambs were evaluated by physical and physiological parameters related to adaptation and multivariate analyses used to test if these traits were efficient in separating the genetic groups and which traits were more important in this separation. Crossbred lambs were more similar to each other than to Santa Inês, in general; but individually there was an overlap between Ile de France and Santa Inês lambs. Size traits had higher canonical correlation with physiological variables, while rectal temperature, heart rate, and hemoglobin were more highly correlated with physical traits. Error rates using only physiological traits were high, suggesting that these are inefficient in separating groups of lambs for heat tolerance, while separation with physical traits was more efficient.

This experiment evaluated the effect of genetic group and slaughter weight on rib eye area, tissue and centesimal composition of the 12th rib. Were used lambs Santa Ines, ½ Ile de France x ½ Santa Ines and ½ Texel x ½ Santa Ines lambs, slaughtered at different weights (35 and 45kg). After cooling at 4°C for 24 h, the 12th rib was removed for tissue and centesimal. The experiment was in a 3 (genetic group) x 2 (sex) x 2 (slaughter weight) factorial design and analyzed using Correlation and Duncan 0.05 means test in SAS®. Texel x Santa Ines animals had the best potential for quality traits of the 12th rib, with earlier finishing for slaughter. The lambs slaughtered at 35kg had lowest fat and highest edible proportion, this being the recommended slaughter weight.

ao longo dos anos em relação à população total, talvez pela baixa rotatividade de reprodutores. As estimativas de co-ancestralidade molecular também evidenciaram aumento da similaridade genética entre os indivíduos do rebanho ao longo dos anos. Há elevado número elevado de alelos privados na população principal, embora esses alelos tenham freqüência menor que 10%. A região do Ovar-MHC do cromossomo 20 ovino foi altamente polimórfica e pode ser usada para auxiliar na manutenção de rebanhos. A continuação deste monitoramento ao longo dos anos é desejável e deve ser implantada como ferramenta adicional visando, por exemplo, indicação de acasalamentos e descarte de animais.