Sayed Mortaza Alavi Shoushtari - Department of Clinical Sciences, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran
Siamak Asri Rezaie - Department of Clinical Sciences, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran
Amir Khaki - Department of Clinical Sciences, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran
Abulfazle Belbasi - Department of Clinical Sciences, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran
Hamid Tahmasebian - Department of Clinical Sciences, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran

To investigate uterine fluid and serum calcium (Ca) and Magnesium (Mg) variations during the estrus cycle in water buffaloes, ۷۱ genital tracts and blood samples were collected from the abattoir in Urmia. The phase of the estrous cycle was determined by examining ovarian structures. ۱۸ animals were pro-estrous, ۱۵ estrous, ۱۶ met-estrous and ۲۲ diestrous. The uterine fluid was collected by gentle scraping of the uterine mucosa with a curette. Blood serum and uterine fluid samples of ۷۱ pre-pubertal buffalo calves were also collected and treated in similar manners. The mean ± SEM total serum and uterine fluid Ca in cyclic buffaloes were ۸.۶۸ ± ۰.۲۸ mg dL-۱ and ۸.۱۰ ± ۰.۲ mg dL-۱ vs. ۶.۷۶ ± ۰.۶۵ mg dL-۱ and ۷.۹۰ ± ۰.۱۵ mg dL-۱ in pre-pubertal calves, respectively. Blood serum Mg was not different in cyclic and pre-pubertal animals but the uterine fluid Mg in cyclic cows was higher than those in pre-pubertal calves. Serum Ca in pro-estrus and estrus were higher than those in other stages and also higher than those in the uterine fluid. The lowest Mg content of serum was recorded in diestrus, while in the uterine fluid it was observed in estrus. In all stages of estrous cycle except for estrus the uterine fluid Mg content was significantly higher than those of the serum. These results suggested that during the estrous cycle in the buffalo cows, Ca was passively secreted in uterine lumen and mostly dependent on blood serum Ca concentrations but Mg was secreted independently. The values (except for serum total Mg) also increased after puberty.

Buffalo, Calcium, Estrous cycle, Magnesium, Uterine fluid