Impact of Maternal High Stocking Density during the Dry Period on Dairy Calf Health, Behaviour, and Welfare

Simple Summary Negative impacts of stressful maternal experience during pregnancy on offspring health and behaviour have been reported in various mammalian species including humans, laboratory animals, and farm animals. This study investigated the effect of limited space allowance for dairy cows during late gestation on the growth and behaviour of their offspring during the pre-weaning period. Our results indicated associations between maternal high stocking density and a higher frequency of social behaviours and increased behavioural reactivity to weaning in offspring. Maternal high stocking density also reduced behavioural reactions of healthy offspring to a painful procedure. However, there was no association between maternal high stocking density and offspring growth or behaviour in the first week of life. To our knowledge, this study is the first to attempt to demonstrate associations between maternal stocking density during late pregnancy and offspring behaviour in dairy cattle. This study aimed to investigate the effect of maternal stocking density during late pregnancy (approximately 60 +/- 4 days before calving) on offspring performance during the pre-weaning period. Forty-five dairy calves were born to cows that went through either industry minimum standards (H:n= 24, high stocking density) or more extensive space allowances (L:n= 21, low stocking density) during the dry period. Body weight and average daily gain during the pre-weaning period (day 1-49) were measured. Observations were made of: (i) activity levels (day 2-6); ii) the level of training required to use an automatic feeder, and behavioural reactions to the group environment (d7); (iii) feeding and social behaviour in the group pen (day 7-21); and (iv) responses to weaning (day 40-49) and disbudding (day 28+). Compared to L calves, H calves made more frequent social contacts with pen mates in the group pen (p= 0.003) and decreased their lying time around weaning (p= 0.045). Among the healthy calves, L calves displayed more severe behavioural reactions to the disbudding procedure (p< 0.001), a significant increase in salivary cortisol concentrations (p= 0.013), and more frequent pain-related behaviour (p= 0.036). This study indicated associations between maternal stocking density during late pregnancy and some welfare-relevant offspring outcomes during the pre-weaning period; these effects were found to be modulated by offspring health status.