Impact of Social Stress on Beef Cattle Welfare

Social environments can have major implications on cattle welfare and their disruption can result in stress that negatively impacts welfare. Yet, there is a dearth of information regarding the social dynamics of beef cattle and how management practices impact cattle welfare. As disruptions to social environments are a welfare concern, two scoping reviews were completed to assess the extent of research that has been conducted on their respective topics—beef cattle social dominance and social mixing. Social dominance hierarchies were observed to be complex and stable long term. Social dominance was mainly related to age in single breed groups, while breed was the predominant factor related to social dominance in multi-breed groups. Socially mixing cattle disrupted social structures and altered cattle behavior, irrespective of social mixing characteristics. To assess the impact of handling frequency on feedlot heifer welfare, heifers (n = 30 ¾ Bos taurus × ¼ Bos indicus and n = 30 Bos taurus; ~ 8 mo of age) were blocked by breed type, stratified by weight, and then randomly assigned to one of three treatments (n = 4 pens/treatment) based on frequency of handling applied across 42-d. Heifers were weighed every 7 d (7DAY), every 14 d (14DAY), or on d 0 and 42 only (42DAY). Average daily gain, average daily feed intake, gain to feed ratio, and average exit velocity did not differ among treatments (P > 0.23). The 42DAY heifers were more likely to perform animal-environmental-interactions than 7DAY or 14DAY (P = 0.02), perform more agonistic social behaviors than 14DAY (P = 0.04), and tended to stand more than 7DAY heifers (P = 0.07). Cattle form social bonds within mixed age groups similar to that which occurs in the wild and dominance relationships are influenced by group composition. Socially mixing cattle groups causes social instability and increases agonistic behavior, while handling seems to lower cattle motivation to be active, explore, or to socially interact but does not disrupt social hierarchies. Therefore, changes in cattle social behavior following cattle management practices may not always be related to social instability but may indicate changes in cattle welfare