EARLY PREGNANCY DIAGNOSIS IN DAIRY CATTLE BY PROGESTERONE RADIOIMMUNOASSAY

Abstract

Sensitivity, specificity and efficiency of a plasma progesterone radioimmunoassay were determined for early pregnancy diagnosis in dairy cows. Production costs of the radioimmunoassay validated in laboratory tests were determined. Ninety eight blood samples of Holstein and Brown Swiss cows to measure plasmatic progesterone were collected, and pregnancy confirmation was done by rectal palpation 45 days after mating. Diagnostic results were 37 true positives, 47 true negatives, 13 false positives and one false negative. Sensitivity of the immunological technique was 97.4 %, specificity 78.3 % and efficiency 85.7 %. Cost per tube of the radioimmunoassay was $7.05 mexican pesos in 1996 ($0.94 USD) and cost per sample measured was $14.10 ($1.88 USD). The effect of other variables (such as embryionic mortality) on the efficiency of the early pregnancy diagnosis is also discussed. The immunoanalytical technique is cheaper than the commercial kit (1996 prices).