EARLY PREGNANCY ASSESSMENT IN DAIRY CATTLE USING RAPID MILK PROGESTERONE (P4) ASSAY

Sabina Neculai-Văleanu, Adina-Mirela Ariton, Alina-Narcisa Postolache, Elena Ruginosu, Şt. Creangă

Abstract
   Background: Milk progesterone-based assays may be a valuable tool for the assessment of reproductive performance in dairy cattle, because the milk progesterone levels are directly interconnected with certain fertility events such as estrus, pregnancy, acyclicity or ovarian disorders. The purpose of this study was to evaluate the usefulness of a rapid progesterone (P4) assay for determining early gestation in dairy cows in two family-type farms.
   Material and Method: Milk samples was collected from 9 cows in day 18 post artificial insemination, respectively day 21. A small volume of milk sample was collected from each cow in clean Falcon tubes, after the first jets of milk were discarded. Subsequently, 1 ml of milk sample was centrifuged 10000 rpm for 10 minutes. The milk sample was separated into 3 layers and the serum located at the bottom of the tube was recovered with a pipette. A drop of serum was placed in the cassette and the results were read in maximum 5 minutes.
   Results: From the 9 females taken into study, 3 were considered non-pregnant and 6 pregnant according to the results of the P4 rapid assay. The non-pregnancy diagnosis was confirmed by rectal palpation at 60 days, while pregnancy was confirmed for 5 out of the 6 cows examined at 60 days post-IA.
   Conclusions: The rapid P4 assay may be performed directly by farmers from either milk or urine and the results are available in less than 5 minutes, the ease and reduced costs together with the ability to determine early gestation and assess the reproductive status are making the rapid milk progesterone assay a useful tool for effective management of dairy herds including, smallholder dairy farms.