SERUM IMMUNOGLOBULIN CONCENTRATIONS OF NEWBORN GOAT KIDS AND SUBSEQUENT KID SURVIVAL THROUGH WEANING

Serum immunoglobulin (Ig) levels were measured in 39 consecutively new born goat kids on an intensively managed dairy goat farm in New Englan d using a quantitative, spectrophotometric zinc sulfate turbidity assa y. The health and performance of these kids was monitored through wean ing at 6-7 weeks of age. By weaning time, 24 kids were healthy, four h ad required treatment, and 11 had died. The mean serum Ig concentratio n for all kids was 1170 mg/dl. Mean serum Ig level for healthy kids wa s 1439 mg/dl, for treated kids, 706 mg/dl, and for dead kids, 750 mg/d l. There was a statistically significant difference in mean serum Ig l evels between the group that died and the group that remained healthy (P<0.05). No differences were observed in either death rates or mean s erum Ig levels between male and female kids. Among kids that remained healthy through weaning, there was no identifiable correlation between initial serum Ig concentration and average daily weight gain. It was concluded that the failure of passive transfer of maternal antibodies to kids via colostrum at birth leads to increased morbidity and mortal ity from infectious disease in young goats. Results from this study su ggest that in intensively managed dairy goat herds in New England (USA ), failure of passive transfer in newborn kids can be defined by the p resence of circulating serum Ig levels less than 1200 mg/dl.