Estimation of progesterone in buffalo milk and its application to pregnancy diagnosis.

Milk samples were collected on Days 20, 24, 28 and 40 after insemination. The percentage of fat and thr progesterone concentration in the milk were correlated (P < 0.01). Progesterone concentration in the milk of pregnant buffaloes (24.83 +/- 3.85 ng/ml) was significantly higher than that in non-pregnant animals (2.89 +/- ng/ml) on Day 20 and the difference between the two increased with time after insemination. The detection of non-pregnant animals was 100% successful at all times but the diagnosis was correct for 66, 68, 81 and 83% of animals tested on Days 20, 24, 28 and 40 respectively and predicted as pregnant.