Plasma beta-Carotene, Vitamin A and Vitamin C Levels in Cyclic and Pregnant Cows

The aim of this study was to determine the plasma beta-carotene, vitamin A and vitamin C levels and correlation between these parameters in cyclic and pregnant dairy cattle. A total of 101 Holstein cows used for this aim. Artificial inseminations (AI) were performed 12 h after determining the oestrus. The cows were allocated to two groups as pregnant (n=81) and nonpregnant (n=20) after the determination of pregnancy. Progesterone level was only higher on day 21 in pregnant cows than that in nonpregnant cows (P<0.05). There were variations in the mean levels of beta-carotene and vitamin A in pregnant and nonpregnant cows (P<0.05) whereas vitamin C levels in nonpregnant cows did not differ during the oestrus cycle. There was a negative correlation between the plasma levels of progesterone and beta-carotene (P<0.01) and progesterone and vitamin A (P<0.05) in pregnant cows, and a positive correlation between the plasma levels of beta-carotene and vitamin A in both pregnant and nonpregnant cows (P