الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 137 |  |  |
| | | from | 137 | | |
Abstract
Objective: The present study aimed to evaluate the effect of different dose of pregnant mare serum gonadotropin (PMSG) on day 10 of the oestrous cycle (1st experiment) on supper ovulation response and using the optimal dose of PMSG when diameter of the dominant follicle of the estrous cycle was 5-7, >7-9 or >9 mm (2nd experiment) on, the ovulatory response and embryo production of Egyptian buffaloes. Ultasonography was used for monitoring the ovarian activity of buffalo cows. Methods & Results: This study took place at Animal Production Experimental Station, Mehallet Mousa, belonging to the Animal Production Research Institute (APRI), Agricultural Research Center, Ministry of Agriculture, in co-operation with Animal Production Department, Faculty of Agriculture, Mansoura University during the period of August 2013 (September and October) to November 2014 (September and October). The present study aimed to evaluate the effect of different dose of pregnant mare serum gonadotropin (PMSG) on day 10 of the oestrous cycle (1st experiment) on supper ovulation response and using the optimal dose of PMSG when diameter of the dominant follicle of the estrous cycle was 5-7, >7-9 or >9 mm (2nd experiment) on, the ovulatory response and embryo production of Egyptian buffaloes. Ultasonography was used for monitoring the ovarian activity of buffalo cows. The obtained results could be summarized as the following: 1. Experiment (1): Overall mean of follicular number (FN)was the lowest and the same in G1 And G2 (2.00, 2.14/buffalo), and little high in G3 (2.43/ buffalo), and the differences were not significant. overall mean of FN tended to be insignificantly higher on right than on left side (2.19 vs. 2.10/ buffalo). Overall mean of FN ranged between 1.86/buffalo in G1 and 2.00/buffalo in G2, while number of follicles was higher in G3 (2.21/buffalo) with insignificant group differences. Also, overall mean of FN was insignificantly higher on right than left ovarian sides (2.29 vs. 1.76 / buffalo). Overall mean of FN ranged between 2.64/buffalo in G2 and 2.21/ buffalo in G1, while number of follicles tended to be higher in G2 2.64 / buffalo than in G1 and G3 (2.21 and 2.43/ buffalo), respectively, with insignificant group differences. overall mean of FN was insignificantly higher on right than left ovarian sides (2.52 vs. 2.33/ buffalo). Overall mean of follicular number was significantly (P<0.05) the highest (2.71/buffalo) in G2, moderate in G3 (2.570/ buffalo) and the lowest in G1 (2.14/ buffalo). The differences were not significantly between groups. Overall mean of FN was insignificantly higher on right than left ovarian sides (2.57 vs. 2.38/buffalo). 2. Experiment (2): Results showed that the effect of experimental group on follicular number was not significant at all treatment times. The differences in the follicular number among the experimental groups were not significant at different treatment times, although there was a tendency of increasing follicular number Pre-PGF2α and at mating as well as decreasing number of unovulated follicles on day of flushing in G2 as compared to G1 and G3. Results revealed that the effect of the experimental group was significant (P<0.05) on diameter of the largest follicles only at mating. On day of oestrus, pre-PMSG and pre- PGF2α, the differences in diameter of the largest follicles among experimental groups were not significant, although there was a tendency of wider diameter of the largest follicles in G3, followed by G2, while G1 showed the narrowest diameter of the largest follicles. However, at mating, the largest follicles significantly (P<0.05) increased in G2 and G3 as compared to G1, respectively. According to diameter of the largest follicles of the 2nd follicular wave within the 1st 12 days of the synchronized oestrous cycle, the obtained results revealed that the duration from Day 0 (estrus) up to PMSG injection was significantly (P<0.05) earlier for buffalo cows in G1 than those in G2 and G3 (day 7.04 vs. days 9.2 and 9.8, respectively), but did not differ significantly in G2 and G3. The early time of PMSG treatment of buffalo cows in G1 as compared to those in G2 and G3 was expected, where buffalo cows were injected based on smaller follicular diameter in G1 than in G2 and G3. However, the observed insignificant early time of treatment in G3 than in G2 was associated with wider range of treatment time in G3 than in G2 (day 8-10 vs. day 8-12). The present results showed that buffalo cows in G2 showed lower number of unovulated follicles/animal or ovary than in G1 and G3, but the differences were not significant. This finding was associated with significant (P<0.05) increase of CLs number per animal or ovary in G2 than in G1 and G3 based on number of treated or CL responded animals. However, diameter of unovulated follicles was significantly (P<0.05) higher in G3 than in G1 and G2. Generally, buffalo cows in G2 showed significantly (P<0.05) higher total ovulatory response than in G1, but did not differ significantly from that in G3 Conclusion: from the obtained results indicated that the potentiality of PMSG injection to induce superovulatory response in limited level in buffalo cows is highly related to its dose and follicular diameter of the synchronized oestrous cycle. Under the experimental conditions of the present study, appropriate conditions (dose and time) for superovulation in buffalo cows were treatment with 3000 IU of PMSG when diameter of the largest follicles reached a range from 7-9 mm to reflect the highest ovulatory response.