Acid-base parameters and steroid concentrations in pre-ovulatory follicles and plasma of lactating dairy cows with spontaneous and synchronized oestrus or follicular cyst.

摘要

The study aimed to compare the acid-base balance and steroid concentrations between follicular fluids (FF) of pre-ovulatory follicles derived from a spontaneous oestrus (SO), synchronized or induced oestrus (IO) and follicular cysts (CYS) and between FF and blood in dairy cows. Forty-two dairy cows were included in this study. The animals were allocated to three groups: SO (n=23); IO (n=11) using GnRH at day 0 and day 9 and PGF 2alpha at day 7; and animals with CYS (n=10). The follicular fluids (FF) were aspirated from the cyst/pre-ovulatory follicles (O 鈮?5 mm) after SO and after second GnRH dose in IO by transvaginal ultrasound-guided ovum pick-up technique. Blood samples (BL) were collected in heparinized vacutainer tubes. The oxygen tension (pO2) in FF of IO was higher (p<0.05) than in SO and CYS groups. There were negative correlations (p<0.001, r=-0.89) between FF and blood pO2. The carbon dioxide tension (pCO2) and lactate level in FF of CYS group were higher (p<0.05) than in SO and IO groups. There were negative correlations (p<0.01, r=-0.73) between blood and FF pO2. Oestradiol-17beta concentration in pre-ovulatory follicles and plasma of the SO group was higher (p<0.001) than in IO and CYS groups. Progesterone concentration in pre-ovulatory follicles and plasma of the SO and IO groups was lower (p<0.01) than in CYS group. Plasma androstenedione concentration in SO and IO groups was higher (p <0.05) than in CYS group. In conclusion, acid-base parameters, E2 and P4 levels in the follicular fluid of both IO and CYS groups were deviated greatly from the physiological level (disturbances of intrafollicular/intracystic environment), which may affect the quality of both the oocyte and the granulosa cells.