HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Nebel, R. L. Articles by Britt, J. H. Search for Related Content PubMed PubMed Citation Articles by Nebel, R. L. Articles by Britt, J. H.

Comparison of On-Farm and Laboratory Milk Progesterone Assays for Identifying Errors in Detection of Estrus and Diagnosis of Pregnancy

Department of Dairy Science, Virginia Agricultural Experiment Station, College of Agriculture and Life Sciences, Virginia Polytechnic Institute and State University, Blacksburg 24061

ABSTRACT

A field study was conducted in 10 commercial dairy herds to test the efficacy of a rapid enzyme-linked immunosorbent assay to identify errors in detection of estrus and diagnosis of pregnancy. Milk samples were collected at the milking following detection of estrus and on d 21 postinsemination. Progesterone was measured on-farm by an enzyme-linked immunosorbent assay and in the laboratory by radioimmunoassay. Agreement between the two methods of progesterone analysis (n = 820) was 89.8%. There were 93 cows (18.7%) by laboratory analysis and 126 cows (25.4%) by on-farm analysis for which concentration of progesterone in the sample collected at suspected estrus (n = 497) was higher than normal estrual values. Exclusion of these cases increased the overall accuracy of pregnancy diagnosis by 6.8 and 6.4% for laboratory and on-farm methods. Overall agreement between pregnancy diagnosis by milk progesterone at d 21 postinsemination and diagnosis by return to estrus or palpation of reproductive organs was 80.5 and 75.8% for laboratory and on-farm methods (75.0% and 69.7% for pregnant cows and 94.5 and 93.9% for nonpregnant cows). These results indicate that an enzyme-linked immunosorbent assay for milk progesterone performed on-farm was equal in accuracy to a laboratory radioimmunoassay for identifying errors in detection of estrus and diagnosis of pregnancy.

¹ Virginia-Maryland Regional College of Veterinary Medicine, Blacksburg 24061.

² Department of Animal Science, North Carolina State University, Raleigh 27650.

This article has been cited by other articles:

				P. Rioux and D. Rajotte Progesterone in milk: a simple experiment illustrating the estrous cycle and enzyme immunoassay Advan Physiol Educ, June 1, 2004; 28(2): 64 - 67. [Abstract] [Full Text] [PDF]