Determining the effect of dam milk production and mastitis infection during pregnancy on blood biochemistry in dairy bull calves

Abstract Maternal programming can affect offspring health postnatally. We hypothesized that high milk production and/or mastitis infection during pregnancy will adversely affect calf blood biochemical analytes. Holstein bull calves (n = 45) were transported to the University of Rhode Island within 24 hrs of birth. Calves were classified by dam production and somatic cell counts (SCC) during pregnancy; HI (top 25% for herd M305, n = 7), MOD (lower 60% for herd M305, n = 16), HIMAST (HI with SCC ≥ 200,000 cells/mL; n = 15), and MODMAST (MOD with high SCC; n=6). Calves were sampled once a week for 8 wks. Serum was sent to the Missouri State Veterinary Medical Diagnostic Laboratory (Columbia, MO) for analyses. Results were analyzed in SAS using proc mixed. At wk 1, Calcium (Ca) concentrations were greater in HI calves (11±0.61mg/dL; P =.05) than MOD calves (10± 0.25mg/dL). At wk 3, Ca concentrations were greater in HIMAST (10± 0.13mg/dL) compared to HI (8±.048mg/dL; P<0.01) and MOD (9±0.36mg/dL; P =.02) calves respectively. MODMAST calves (10 ± 0.460 mg/dL) exhibited greater Ca concentrations than HI calves (P = 0.05). Aspartate aminotransferase concentrations were greater in HIMAST calves compared to MODMAST calves at wk 1 (36±2.49 Units (U)/L vs. 27±2.63U/L; P = .04) and wk 8 (79±7.08U/L vs. 47±5.71U/L; P<0.01). At wk 8, total protein concentrations were greater in HIMAST (6 ± .13g/dL) calves compared to MODMAST(5±0.13g/dL; P =.01) and MOD calves(5±.13g/dL; P = .03). In conclusion, maternal mastitis infection and production level during pregnancy does affect key circulating factors in the offspring. Correlation and gene expression analyses will be performed to better understand these changes.