Research Institute for Physiology of Animal Reproduction, Bhunikey (Pattoki), Distt. Kasur, Pakistan

Abstract

     Peripheral plasma progesterone concentrations and time interval from treatment to oestrus in 12 Holstein-Friesian cows after treatment with three luteolytic agents (Dinoprost Tromethamine, Cloprostenol Sodium and dextro-rotatory D-Cloprostenol) at day-10 of the oestrus cycle were studied. The plasma progesterone concentrations at the time of treatment were 7.33 ± 0.75, 7.77 ± 0.85, 7.97 ± 0.32 and 8.07 ± 0.27 hg/ml in Dinoprost Tromethamine, Cloprostenol Sodium and dextro-rotatory D-Cloprostenol treated and untreated control cows, respectively, the difference was non-significant. In the morning of day-11 of the oestrus cycle, significantly (P<0.05) lower plasma progesterone concentrations were recorded in the Dinoprost Tromethamine and Cloprostenol Sodium treated cows as compared to control cows but the difference of dextro-rotatory D-Cloprostenol treated cows with that of control cows was non-significant. On the other hand, all the treated groups showed significantly (P<0.05) lower plasma progesterone concentrations as compared to that of control cows starting from the evening of day-11 till the morning of day-13 of the oestrus cycle. The plasma progesterone concentrations decreased to 0.80 ± 0.10, 0.85 ± 0.05 and 0.70 ± 0.10 hg/ml at the onset of oestrus in Dinoprost Tromethamine, Cloprostenol Sodium and dextro-rotatory D-Cloprostenol treated cows within 68.00 ± 4.00, 64.00 ± 8.00 and 88.00 ± 8.00 hours after the treatment, respectively.