Changes in milk progesterone concentrations and vagina impedance in first-calvers during oestrus after cloprostenol treatment
1991
Poeschl, M. | Rezac, P. | Havrankova, L. (Vysoka Skola Zemedelska, Brno (CSFR))
Changes in milk progesterone concentrations and vagina impedance were investigated in 104 first-calvers of the Black-Pied Lowland breed which came in oestrus within 48 hours after Oestrophan treatment (500 microgramme cloprostenol). Progesterone assays were made in whole milk. At the time of Oestrophan administration the milk progesterone concentration was 22.2 nmol/l on average. A steep fall of milk progesterone concentration to the value of 2.6 nmol/l (P0.01) was recorded a day before oestrus. Vagina impedance on the day of Oestrophan administration corresponded to 65 divisions of the apparatus scale. After Oestrophan treatment a decrease in vagina impedance was observed (P0.01), and the lowest value (24 divisions of the apparatus scale) was recorded at oestrus onset. An increase in vagina impedance was observed during oestrus (P0.01). Milk progesterone determination and vagina impedance measurements by the Estral instrument can provide useful information about the onset of oestrus and ovulation. But if the opportune moment of insemination is to be determined, these measurements cannot replace oestrus detection.
显示更多 [+] 显示较少 [-]