Do the determinants of dominance index and social rank in adult rams vary by breed?

摘要: The aim of the present study was to determine factors influencing the establishment of dominance hierarchy in Hemsin, Chios and Karakul rams. Rams aged 6–7 years old from Hemsin (n = 13), Chios (n = 12) and Karakul (n = 14) sheep breeds were used. The feed competition test was applied to determine the dominance status of rams within their own breeds. After testing all possible pairs, dominance index and social ranks for each ram was calculated. Body weight, numerous body measurements, horn length and testosterone concentration were evaluated as predictor variables in stepwise regression analysis. Improved linearity index value was 0.522, 0.6224 and 0.7033 for Hemsin, Chios and Karakul rams (Pr<0.001), respectively. In Hemsin rams, the regression model including body weight and tail width explained 75.3% of the variation in dominance index (P = 0.001). The model, which included body weight …