1999 Volume 45 Issue 5 Pages 331-336
Transitional multiparous dairy cows were used to estimate the relationships between the interval from parturition to the first ovulation (1st-OV), and the interval from parturition to the first day when the plasma metabolite concentration reached the steady range (within two standard deviations from the mean value for the post-ovulational 2 weeks). Blood samples were collected from 13 Holstein dairy cows 4 times every week from 14 days prepartum to about 60 days postpartum in order to analyze plasma concentrations of progesterone and the following eight metabolites: glucose, ketone bodies, free fatty acids (FFA), urea nitrogen (UN), free cholesterol, cholesterol ester, glutamic-oxaloacetic transaminase (GOT), and glutamic-pyruvic transaminase (GPT). The interval to 1st-OV averaged 25.6 ± 8.7 days, and correlated respectively with the intervals to the days when plasma concentrations of almost all the metabolites, except GPT and UN, reached the steady range. We concluded that the interval to the 1st-OV of dairy cows is closely related to the interval to the steady range of metabolites concerned with the energy status, but not protein intake. Additionally, the interval to the 1st-OV also correlated significantly with the mean concentration of free cholesterol before the 1st-OV.
