| Popis: |
SUMMARY The concentrations of progesterone in whole milk and plasma taken on days 38 and 46 after service have been used to diagnose pregnancy in 82 Friesian cows. Three levels of progesterone concentration were set for both whole milk and plasma samples in an attempt to find that most accurate for discriminating between positive and negative results. The highest success rate for whole milk samples, achieved when the discriminatory level was placed at 5.0 ng progesterone/ml milk, was 95.2% for positive diagnoses and 94.7% for negative diagnoses. The highest success rate for plasma samples achieved when the discriminatory level was placed at 0.0 ng progesterone/ml plasma, was 90.3% for positive results and 90.0% for negative results. The accuracy of the positive results suggests that some of the discrepancies encountered at an earlier sample date, caused primarily by embryonic mortality, have been overcome. |
