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

Commercial dairy goat farming systems rely on the successful rearing of kids for herd replacement. Mortality in kids is variable, and the causes of death are often not well documented. Therefore, the objectives of this study were to i) determine survival from birth until mating for a large cohort of commercial dairy goat kids, ii) descriptively summarize the causes of mortality and removal from the herd during this period, and iii) compare actual (determined by post-mortem examination) and suspected (farmer reported) causes of mortality. A total of 1,263 female kids were enrolled at birth on 16 commercial dairy goat farms (Waikato region, New Zealand). Between enrolment and mating, 87.0% (1,099/1,263) of kids survived, 10.4% (131/1,263) of kids died or were euthanized, and 2.6% (33/1,263) of kids were removed from the herd for other reasons. Mortality risk was greatest in early life, with more than 90% of deaths occurring before weaning. Mortality varied between farms (min = 0%, Q1 = 6.1%, median = 10.3%, Q3 = 15.7%, max = 20.5%). Of the carcasses submitted for post-mortem, the leading cause of death was gastrointestinal disorders, including ruptured abomasum, intestinal torsion, enteritis and bloat (33.6%, 36/107), followed by disbudding-related injury (15.9%, 17/107), and septicemia (12.1%, 13/107). Farmers provided a suspected cause of death for 54 of the submitted carcasses, and they were correct for 48.1% (26/54) of these. Farmers successfully identified approximately half of the deaths attributed to gastrointestinal disorders and disbudding-related injury; however, success was lower for identifying septicemia (0%, 0/5), starvation and/or dehydration (0%, 0/4), and suffocation (18.8% 3/16). This is the first study to systematically record survival through to mating, and to confirm cause of death via post-mortem examination, in a large cohort of dairy goat kids on multiple commercial farms. We found that kid mortality is highest during the pre-weaning period and that there is a disconnect between perceived and actual cause of death, which highlights the need to use post-mortem examinations to accurately inform on-farm strategies for reducing mortality.