Effects of prepartum serum calcium, magnesium and potassium levels on postpartum performance and milk composition of dairy cows

The study was conducted to determine effects of serum Ca, Mg, and K levels and parity on postpartum body weight, body condition score, milk yield, total milk yield at 120 days postpartum, milk composition and yields (fat yield, protein yield, 4% fat corrected milk, and fat and protein corrected milk yield). Eighty nine Holstein cows were used. Prepartum (-4, -3, -2, -1 weeks) serum mean concentration of Ca, Mg, and K were determined as 2.10±0.15 mmol/l (mean±standart deviation), 1.24±0.19 mmol/l ve 5.04±0.57 mmol/l, respectively. Cows were divided into three parity blocks (1. 2. and ≥3) and mean serum mineral concentration (low group and high group) within the parity blocks. Invidiual body weight and body condition score were measured between prepartum -4 weeks through postpartum 8 weeks. Also, milk yields were recorded daily for all cows after calving and milk samples were collected from individual cows weekly and analyzed for total solids, fat, crude protein, casein, lactose, MUN. In conclusion, total milk yield at 120 days postpartum was increased and postpartum performance was improved when serum Ca ve K levels were <2.10 mmol/l and <5.04 mmol/l, respectively. Also, same effects on those two variables were observed when serum Mg level was ≥1.24 mmol/l. It could be say that nutrition management that decrease serum Ca and K levels and increase Mg levels in prepartum period would positively affect postpartum performance of dairy cows.