The association of subclinical hypocalcemia, negative energy balance and disease with bodyweight change during the first 30 days post-partum in dairy cows milked with automatic milking systems

摘要

In a prospective cohort study, the daily bodyweight (BW) and milk production of 92 cows were recorded using automatic milking systems. The objectives were to characterize calcium serum concentration variability on days 1-3 post-partum and to evaluate the association between subclinical hypocalcemia (SHPC) and change in BW over the first 30 days in milk (DIM) in Holstein dairy cows, while controlling for concurrent disease and negative energy balance (NEB). SHPC was defined as total serum calcium concentration between 6 and 8 mg/dL, NEB was defined as non-esterified fatty acids (NEFA) >0.7 mEq/L or beta-hydroxybutyrate (BHB) >= 1.2 mmol/L.