Short communication: Survival of replacement kids from birth to mating on commercial dairy goat farms in New Zealand

Commercial dairy goat systems rely on the successful rearing of kids for herd replacement. The objectives of this study were to (1) determine survival from birth until mating for a large cohort of commercial dairy goat kids; (2) descriptively summarize the causes of mortality and removal from the herd during this period; and (3) compare actual (determined by postmortem examination) and suspected (farmer-reported) causes of mortality. A total of 1,262 female kids were enrolled at birth on 16 commercial dairy goat farms in New Zealand. Median ages at weaning and mating were 86 d [minimum = 54, quartile (Q)1 = 78, Q3 = 97, maximum = 144] and 223 d (minimum = 183, Q1 = 208, Q3 = 237, maximum = 310), respectively. Overall, 87.1% (1,099/1,262) of kids remained on farm at mating, 10.4% (131/1,262) died or were euthanized, and 2.5% (32/1,262) were lost to follow-up or sold. Mortality risk was greatest in early life, with more than 90% of deaths occurring before weaning. Mortality from enrollment to mating varied between farms (minimum = 0%, Q1 = 5.9%, median = 8.9%, Q3 = 15.8%, maximum = 20.5%). The leading cause of death was gastrointestinal disorders (33.6%, 36/107), followed by disbudding-related injury (15.9%, 17/107), and septicemia (12.1%, 13/107). Farmers correctly identified approximately half of the deaths attributed to gastrointestinal disorders (56.0%, 14/25) and disbudding-related injury (44.4%, 4/9), but were less successful at diagnosing septicemia (0%, 0/5), starvation or dehydration (0%, 0/4), and suffocation (18.8% 3/16). This is the largest cohort of dairy goat kids to be systematically followed over time to confirm survival until mating and to determine causes of death by postmortem examination. We found that kid mortality was highest during the preweaning period and there was often a discrepancy between farmer-perceived and actual cause of death. Postmortem examinations should be more widely used to establish causes of death and inform on-farm strategies to reduce kid mortality.