Calf- and herd-level factors associated with dairy calf reactivity

摘要

A positive relationship between handlers and animalsin farm systems is essential because the human–animalrelationship has implications for welfare and productivity.For this reason, on-farm animal welfare assessmentprotocols often include the behavioral responseof animals to humans to measure the quality of thehuman–animal relationship. The existing literaturehas described this relationship as being multifactorialin nature. In the current study, we aimed to investigatethe potential influence of farm management andinfrastructure characteristics, calf manager traits, andintrinsic features of dairy calves on the human–animalrelationship. To this end, an escape test was conductedwith 698 calves on 30 dairy farms in Chile. This testmeasured the calf’s response to the active approach ofan unfamiliar human (and was scored from 0 [fearful] to4 [friendly]). The explanatory variables used to predictcalves’ response in the escape test were grouped accordingto the following categories: (1) farm managementand infrastructure (e.g., calf-dam separation age, spaceallowance); (2) calf manager (e.g., attitudes, behavior,and background); and (3) calf (e.g., breed, sex, age).We concluded that calf managers with additional jobson the farm, no training, low job satisfaction, a greaterproportion of negative contacts, and more negative attitudeswere predictive of fearfulness in the escape test.Holstein breed (compared with Holstein and Jerseycrossbreeds) was associated with greater odds of fearfulcalves. Our study confirms the association between animals’fear and handlers’ features, which can potentiallybe used to select employees on a farm. Understandingthe factors that influence fear responses in calves mayhighlight ways to improve the relationship betweenanimals and humans.