Is there a right time for dairy Alpine goat kid weaning: How does the weaning age of dairy Alpine goat kids affect their growth and behavior?

In dairy goat kids, weaning is often associated with poor growth leading to a decline in welfare and performance; however, little is known about optimal weaning practices. This study aimed to determine the optimal weaning age for dairy goat kids to maximize outcome measures of welfare related to growth, feed intake, and behavior. Thirty-six newborn female Alpine kids were blocked by weight and birth date, paired with a similar male companion and randomly allocated to one of the three weaning age treatments: 6 (6W), 8 (8W), and 10 wk (10W). Kids had ad libitum access to acidified milk replacer refilled twice daily, concentrates, hay, and water. Milk consumption was measured daily, and concentrate consumption, weekly. Ten behaviors were live observed on days -8, -4, 0, 6, and 12 relative to weaning (i.e., weaning day = 0). Kruskal-Wallis tests were used to assess differences from baseline between the 6W, 8W, and 10W treatments. Post hoc analysis using the Dwass, Steel, Critchlow-Fligner (DSCF) multiple comparison analysis was used to evaluate pairwise treatment differences based on two-sample Wilcoxon comparisons. Kids weaned at 10 wk had the greatest increase compared to baseline in concentrate consumption (P = 0.0160), and greatest decrease compared to baseline in vocalization (P = 0.0008) while both 8- and 10- wk kid's groups had the greatest increase compared to baseline in self-grooming time (P < 0.0001), and cross-sucking time (P = 0.0006). Kids weaned at 6 wk of age were found to have the smallest increase compared to baseline in concentrate consumption (P = 0.0160) and self-grooming time (P < 0.0001), and the greatest increase compared to baseline in allogrooming time (P = 0.0032) and in redirected behaviors aimed towards the environment (biting and licking time [P = 0.0173]; displacement at the nipple frequency [P = 0.0236]). No negative impact of weaning on growth of either group was identified. Overall, our results tend towards a higher degree of discomfort behaviors (allogrooming, biting/licking, displacement, and vocalizations) in kids weaned earlier compared to later weaning, while kids weaned later showed higher levels of positive behaviors (lying time and self-grooming).