Study of interrelationship between blood serum concentrations of estrogen, progesterone, urea nitrogen, glucose, cholesterol and triglyceride with some postpartum reproductive parameters in dairy cows

This research was conducted to evaluate the interrelationship between concentration of estrogen and progesterone hormones and some blood serum metabolites with postpartum reproductive parameters in dairy cows. Eighteen Holstein dairy cows were used. Blood serum concentrations of estrogen and progesterone along with urea nitrogen, glucose, cholesterol and triglyceride were measured, using commercial related kits. Rectal pregnancy test was confirmed through measuring blood serum progesterone concentration 50 days after rectal test. Results showed that the concentration of blood serum urea nitrogen was low in pregnant cows than non-pregnant cows (P<0.05). Mean concentrations of glucose and cholesterol in pregnant cows were significantly higher than non-pregnant cows (P<0.05). Cows with blood urea nitrogen greater than mean, had longer interval from calving to insemination, greater insemination per pregnancy and lower pregnancy rate than another group (P<0.05). Negative correlation was found between estrogen and progesterone hormones with intervals from calving to uterus returning, calving to insemination and calving to pregnancy. Blood urea nitrogen had positive correlation with intervals from calving to insemination and calving to pregnancy. Negative correlations were found between blood serum glucose and triglyceride concentrations with intervals from calving to uterus returning, calving to insemination and calving to pregnancy. In general, current study showed that nutritional metabolites have important effect on postpartum reproductive performance.