PSII-19 - The effects of maternal programming on dairy bull calf response to an intravenous glucose tolerance test

Calves are prone to health issues with high mortality observed during the first 3 weeks of life. We hypothesized that dam milk production levels and/or mastitis infection during gestation will lead to reduced insulin production and increased circulating glucose concentration in response to an Intravenous Glucose Tolerance Test (IVGTT) in young dairy bull calves. Calves (n = 45) were selected from dams classified has high producers (HI; Top 25% for herd M305; n = 7), high producers with high somatic cell count (SCC; HIMAST; SCC test during gestation over 200,000 cells/mL; n = 15), moderate producers (MOD; lower 60% for herd M305; n =17) or moderate producers with high SCC (MODMAST; n = 6). IVGTT were performed on the calves at 7 weeks of age. Blood samples were collected prior to (-30, -15 and 0 min) infusion of glucose. After glucose (0.15 grams /kg bw) administration, samples were collected at 2, 5, 10, 15, 30, 60, and 120-minutes post infusion. Serum insulin and glucose concentrations were determined at Cornell Veterinary Medical Diagnostic Laboratory (Ithica, NY). Data were analysed in SAS using Proc Mixed. Insulin:glucose ratio was analysed using Proc Mixed with repeated measures for treatment x time. No effect of maternal milk production and/or mastitis infection during gestation was observed on calf baseline insulin, insulin AUC, baseline glucose or glucose AUC (P ≥ 0.12). Similarly, no difference in Insulin:Glucose ratio was observed in these calves (P = 0.66). In conclusion, high maternal milk production and/or mastitis infection may not have an effect on circulating insulin production in calves in response to an IVGTT. Correlation analyses will be performed on these data, as well as additional analyses, to determine if insulin sensitivity or response (ie: phase 1 response) was altered further.