Blood plasma minerals and their effects towards the fertility in 136 cows randomly selected from 26 dairy farms in central Thailand were studied. An average of 8.60 mg% Ca, 5.97 mg% P, 2.45 mg% Mg, 85.9 關g% Cu, and 160.9 關g% Zn in plasma was observed. Compared to the critical deficient values, 24.3, 10.3, 11.8, 28.7 and 0.0% of the surveyed cows obtained the respective elements in plasma below the standard levels. No significant difference(p>.05) in plasma concentrations of Ca, P, Mg and Zn for the low fertile (conception rate>3) and fertile (conception rate<3) cows was found. However, plasma Cu of the low fertile cows (averaged 77.2 關g%) was lower(p<.01) than that of the fertile ones(averaged 91.12 關g%). Additionally, it is observed that 47.1% of the cows with the low fertility problem obtained plasma Cu below the 65.0 關g% critical deficient value. |