PSVI-14 Effect of Morphometric Traits Upon Social Hierarchy of Dorper Rams from Northern Mexico

Abstract Usually, social order is defined by the animal size, live weight, or age. This study aimed to evaluate association among horn presence (HP), and size (HS) on rank hierarchy. Adult Dorper rams (n=24) with similar weight (LW), body condition score (BCS), age (AG) were subjected a behavioral test define success index (SI, ranked form 0 1) based male-to-male interactions, determining three ranks: low hierarchy (LHR; SI = 0-0.33; n=9), medium (MHR; SI=0.34-0.66; n=10) high (HHR; SI= 0.67-1; n=5). Afterward, skull, (HP HS), morphometrics measured. The GLM procedure of SAS (SAS Institute, Cary, NC) was used analyze LW, AG, BCS, HS HP ranks five ten replicates per group. Rams within experimental units. Differences considered as significant at P < 0.05. Regarding HP, 80% HHR had horns, while 77.7% LHR hornless, intermediate values for MHR (50%), but no differences found regarding between low, (85.1±2.6, 84.3±3.3, 90.7±4.7, respectively). In conclusion, horns have an important role establishing hierarchy, it complex trait influenced factors other than so, we recommend more research in relation that could influence position levels herds.