Synchronization with controlled internal drug release (CIDR) and prostaglandin F2α (PGF2α) influences oxidant/antioxidant biomarkers and mineral profile in summer-stressed anoestrous buffalo (Bubalus bubalis)

During the summer season, high ambient temperature in tropical and subtropical countries exposes buffaloes to oxidative stress that have antigonadotropic and antisteroidogenic effects. Uses of hormonal therapy can improve the state of ovarian inactivity caused by heat stress and cause anoestrous buffaloes to come into oestrus and successfully achieve pregnancy. Therefore, this study was designed to detect the role of oxidative stress in production of the anoestrous state in summer heat stressed buffaloes and the effects of treatment by Controlled internal drug release (CIDR) in solving of this problem. Also it monitored the changes in Oxidant/antioxidant biomarkers and mineral profile before and after the treatment. Forty buffaloes with no signs of oestrus for more than 120 days after calving were selected. The animals were divided into two groups: the first group (group I, n = 25) was subjected to treatment with CIDR, while the second group (group II) received no treatment and was considered the control group (n = 25). Blood samples were collected before treatment, after treatment and after 45 days of oestrus. The serum level of TAC, MDA, NO, ascorbic acid (vitamin C), P, Cu and Zn were measured. The results showed that 80% of treated buffaloes came into oestrus. The conception rate was 75%. TAC concentrations were significantly higher in group I than in group II. There were significant decreases in the mean values of MDA, NO and ascorbic acid in the buffaloes in oestrus, but these values increased when the buffaloes became pregnant. In contrast there were no significant differences in the mean values of MDA, NO or ascorbic acid in the buffaloes that came into oestrus but failed to conceive. The mean serum P, Cu and Zn values were significantly increased (P < 0.05) in the buffaloes that came into oestrus compared to the control animals. The levels of P and Zn significantly increased when the buffaloes became pregnant and remained unchanged when they failed to conceive. In conclusion, known physiological and pathological variations in the oxidant/antioxidant parameters and mineral profile of summer anoestrous buffaloes may help to understand this problem of infertility.

Ovulatory and fertility response using modified Heatsynch and Ovsynch protocols in the anovular Murrah buffalo (Bubalus bubalis)

We studied the effect of modified Heatsynch and Ovsynch protocols on the ovulatory response (OR), estrus induction rate (EIR) and conception rate (CR) in the anovular postpartum Murrah buffalo (n = 35). In the modified Heatsynch protocol (Group I; n = 12), buffaloes were given two GnRH at 2 h interval on treatment day 0, PGF (PGF2α) on day 7 and estradiol (E₂) 1 mg on day 8. Two FTAI were done at 20 h intervals after E₂ administration. In the modified Ovsynch protocol (Group II; n = 15), GnRH was given on day 0, 7 and 16 with a PGF on day 14. Two FTAI were done; one at last GnRH and the other 20 h later. Group III served as untreated negative control (n = 8). During the treatment, ovarian changes were monitored by transrectal ultrasonography and plasma progesterone (P₄) and E₂. Administration of two GnRH at 2 h interval neither increased the OR nor strengthened the subsequent P₄ priming. Interestingly, in group I, none of the buffalo ovulated to E₂ though the EIR was 100% indicating the occurrence of behavioral, but not ovulatory estrus. Administration of GnRH 7 day prior to the commencement of Ovsynch protocol (Group II) did not improve the CR (21.4%), though the OR was 71.4%. No significant difference was found in the diameter of largest follicle between the ovulated and non-ovulated buffalo in response to GnRH suggesting that follicle of ≥9.5 mm is necessary but not sufficient to induce ovulation in the anovular buffalo. In both the protocols, the plasma P₄ was higher on day 7 in those buffaloes that ovulated to GnRH. Buffaloes treated with modified Ovsynch regimens were 5.27 times more likely to become pregnant than modified Heatsynch protocol. It is concluded that modified Ovsynch protocol is superior to modified Heatsynch protocol in terms of OR and CR.