Milk Progesterone Samples in Identifying Cycling Dairy Cows

Abstract

The purpose of this study was to determine the optimal interval between 2 consecutive milk progesterone samples for the detection of cyclicity in dairy cows. Two hundred and thirty-six postpartum periods were monitored with thrice-weekly whole milk progesterone assay. Cyclicity was determined from elevation of the progesterone level. Animals which had started to cycle by 50 or 60 days post partum were included in the study. The last of the 2 samples was taken at 50 or 60 days post partum, respectively.

The lowest percentage of false diagnoses (9.0%) in cows which had started to cycle by 50 days post partum was obtained when the samples were taken at 8 days’ interval. In cows which had started to cycle by 60 days post partum the lowest percentage of false diagnoses (1.1%) was obtained when the samples were taken at 10 days’ interval.

Sammenfatning

Avsikten med denna undersökning var att bestämma det optimala intervallet mellan två på varandra följande progesteronprov för att kunna detektera mjölkkors cyklicitet. Tvåhundratrettiosex postpartuma perioder undersöktes. Progesteronproven togs tre gånger per vecka ur helmjölk. Cykliciteten bestämdes på basen av förhöjningar ac progesteronvärdet. Till undersökningen togs djur vars förökningscykel startat inom 50 eller 60 dagar postpartumt. De två sista proven togs, i respektive grupper, 50 eller 60 dagar postpartumt.

Den lägsta procenten felaktga diagnoser (9%) hos kor vars förökningscykel börjat inom 50 dygn postpartumt, uppnåddes då progesteronproven togs med 8 dygns mellanrum. Bland kor som påbörjat sin cykel inom 60 dygn postpartumt uppnåddes den lägsta procenten felaktiga diagnoser (1,1%) då proven togs med 10 dygns intervall.