Relationships between fertility, serum calcium and inorganic phosphorus in dairy cows

ABSTRACT

A prospective study was conducted to investigate the difference in levels of some blood constituents between fertile and infertile cows, A total of 40 dairy cows were selected at random from a dairy farm. Serum samples were collected three times on 5 +/- 3, 30 +/- 3 and 58 +/- 3 days postpartum. Serum glucose, urea nitrogen [UN], cholesterol, albumin, total protein, calcium, inorganic phosphorus and aspartate aminotransferase [AST] were measured for each sample. Cows were divided into two categories; those which conceived at either the first or second insemination [group 1] and those which conceived >/= 3 inseminations [group 2]. Seventy percent [28 of 40] of the cows conceived at first or second insemination and 30% [12 of 40] needed 3 or more inseminations. Results showed that calcium [2.34 vs. 2.17 mmol/L] and inorganic phosphorus [1.84 vs. 1.42 mmol/L] were significantly [P<0.05] higher in the group 1 cows at second stage of sampling