Effect of Oral Slow-Release Calcium Supplementation in Anion-Fed Second Parity Lactating Dairy Cows on Milk Production and Composition, Blood Metabolites and Animal Health

Abstract

The present study was conducted to evaluate the effect of slow oral calcium supplementation in the postpartum period on some selected blood metabolites, milk production and composition, body condition score and animal health during the 60-day experimental period.. For this purpose, forty-two Holstein cows in second parity lactating were selected and divided into two groups: control (twenty-one cows, without any calcium bolus) and experimental group (twenty-one cows,62 g oral bolus immediately after calving). The results showed that the frequency of subclinical hypocalcaemia with a cut-off point of 8.5 mg / dL at 0, 24 and 48 h. postpartum was 53 %, 13 % and 4 %, respectively. Postpartum calcium bolus consumption showed a numerically higher blood calcium concentration after 24 h. than the control group, however, it was not detectable differences. Milk yield and composition (fat and protein), body condition score and milk somatic cell count were not affected by oral calcium bolus. The incidence of metabolic diseases such as metritis and placenta was lower in the experimental group than those control group (odds ratio (OR) = 0.13). However, the incidence of milk fever was not significant between experimental treatments (odds ratio (OR) = 1). In general, with proper nutrition management during the close up, it is possible to pass the transfer cows without consuming calcium bolus, and also to avoid increasing costs.