Influence of priming dose of GnRH analogue [cystorelin] on the ovarian activity in postpartum Egyptian buffalo-cows

This work aimed to study the effect of GnRH injection at 44 days postpartum when preceded by a priming dose, on the ovarian activity and consequently, the initiation of the postpartum ovarian cyclicity in Egyptian buffalos. Routine rectal examination was carried out to diagnose the postpartum [pp] conditions of the ovaries in 18 normal parturient buffalo-cows at day 30 pp. These animals did not show any signs of etrus till day 44 pp. The animals were assigned randomly at day 44 pp into 2 groups. Group 1 [n=12], was treated with 100 mul GnRH [Cystorelin]. Each animal received 2 injections of GnRH 50 mul i.m./one hour apart. Group 2 [n=6] defined as controls and received saline [1 ml i.m.]. Visual examination was done following GnRH injection to detect the sings of estrus. Rectal examinations were conducted in the 1st week [51 days postpartum] and 2nd week [58 days pp] to detect any ovarian changes after treatment on both groups. Serum samples were collected parallel to rectal palpation to detect the progesterone and estradiol 17 beta levels before and after treatment. The animals were allowed freely for natural service by a fertile buffalo-bull and examined for pregnancy at day 45 post service. The results revealed that, the injection of GnRH analogue preceded by 1 hour apart priming dose resulted in a significant increase in the treatment and consequently induced cyclicity and shortened of the period from calving to first postpartum estrus in Egyptian buffalos

Meiotic maturation of Egyptian buffalo and cattle ovarian oocytes in vitro

This study was undertaken to determine the best culturing period needed to achieve a maximum proportion of in vitro maturation in both Egyptian buffalo and cattle oocytes. Cumulus-oocyte complexes [COC] were recovered from 2-6 mm follicles of buffalo and cattle abattoir ovaries and cultured in TCM 199 supplemented with 10% FBS, 1 mug/ml estradiol 17 beta and 5 mug/ml FSH at 39C in 5% CO2 in air for three different incubation periods [20, 24 and 30 hours]. At the end of the period, the oocytes groups were examined for cumulus expansion, then fixed, stained with orecine and examined under phase contrast optics for chromosomal analysis. Maturation rates of treatment 1 groups [20 hours] were 48% [12/25] and 60% [15/25] for buffalo and cattle oocytes, respectively. Treatment 2 groups [24 hours] maturation rates were 56% [14/25] and 80% [20/25], while maturation rates of treatment 3 groups [30 hours] were 32% [8/25] and 60% [15/25]. The cumulus cells expansion of buffalo oocytes was less than that of cattle oocytes generally, no differences were noticed among treatments. In conclusion, in spite of close results of the 20 hours period for buffalo oocytes, the 24 hours incubation period was found to be the most suitable maturation period for Egyptian cattle and buffalo oocytes. Further studies are needed to verify the maturation period effect on fertilizability and developmental capacity of buffalo oocytes in vitro

Recovery and transfer of Egyptian buffalo embryos using non-surgical technique

The present study was undertaken to apply and evaluate the new technology of embryo transfer system and its success in Egyptian buffaloes. Eleven buffalo-cows were used in this study and were assigned into two groups. The first [n=8] was for donors and the second [n=3] was for the recipients. The animals were superovulated and synchronized for estrus using a total dosage of 50 mg FSH-p [Shering Corporation, USA] and 25 mg Lutalyse for each animals respectively. The animals were naturally mated at least 2 times 36-80 hours [hrs] after Lutalyse injection. The embryos were collected and evaluated at day 5 to 5.5 after estrus. The good transferable embryos were transferred non-surgically to the uterine horn ipsilateral to the corpus luteum [CL] to 2 recipient buffaloes. The percentage of animals that responded to superovulation was 100%. Eight embryos were collected [transferable] and the average number of transferable embryos/ animals was 1.6. One animal was confirmed pregnant 45 days after estrus. The present results revealed that the technique of embryo transfer in Egyptian buffaloes needs more investigations; at the same time the present protocol was found to be satisfactory to reduce the problems facing the embryo transfer technique in Egyptian buffaloes