EFFECT OF PMSG ADMINISTRATION IN RELATION TO FOLLICULAR DIAMETER ON SUPEROVULATORY RESPONSE AND EMBRYO QUALITY IN FRIESIAN COWS. | ||||
| Journal of Animal and Poultry Production | ||||
| Article 3, Volume 1, Issue 1, January 2010, Page 23-32 PDF (342.31 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/jappmu.2010.86089 | ||||
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| Authors | ||||
A. E. Abdel-Khalek 1; H. A.B. Ganah2; A. M. Shehab El-Din2
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| 1Animal Production Department, Faculty of Agriculture, Mansoura University. | ||||
| 2Animal Production Research Institute, Agricultural Research Center, Ministry of Agriculture, Egypt. | ||||
| Abstract | ||||
| A total of 20 Friesian cows (450-550 Kg LBW, 3.5-5.5 years old and 1-3 parities) were used as donor cows. Cows were divided into 4 groups (5 animals in each) according to time of PMSG injection. Before treatment, cows in all groups were injected with 2 ml PGF2α (Estrumate) to start oestrous cycles. Cows in the 1st group (Control, n=5) were i.m. injected with a single dose of 2500 IU PMSG on day 10 of the oestrous cycle. However, in the 2nd, 3rd and 4th groups, cows were injected i.m. with a single dose of 2500 IU PMSG when diameter of the dominant follicle reach 5-7.5 mm (G2, n=5), >7.5-10 mm (G3, n=5) and >10 mm (G4, n=5). After 48 h of PMSG injection in each group, cows in all groups were injected with 2 ml Estrumate and artificially inseminated (AI) when excepted estrous. Flushing was conducted 7 days after AI to determine the ovulatory response. Ultrasonography device was used during treatment period to record the number of follicles and CL and diameter of the follicles for PMSG injection.Results showed that day of PMSG treatment averaged 7.2, 9.6 and 8.2 for cows in G2, G3 and G4, respectively. All cows in G1 and G3 (100%) produced CL vs. 60 and 80% of cows in G2 and G4, respectively. Response rate of embryo production was only detected in G1 and G3, being 60 and 80%, respectively.No embryos were recovered from cows in G2 and G4.Average number of CLs/cow was higher (P<0.05) in G1 and G3 (8.0 and 7.4) than in G2 and G4 (1.0 and 3.0), respectively. Cows in G1 and G3 showed the highest (P<0.05) total response (CLs and UOF), being 9.4 and 9.8/cow, respectively. Averages number of total and transferable embryos were higher (P<0.05) in G3 by about 42 and 44% than in G1. Recovery rate of total and transferable embryos were higher in G3 than in G1 (73.0 and 70.0% vs. 47.5 and 45.0%, respectively). Yield of embryos at morula and blastocyst stageswas higher in G3 than in G1. Cows in G3 showed the highest distribution of embryos at morula stage (37.0%) versus the highest distribution of compact morula in G1 (42.1%). Cows in G3 increased yield of excellent embryos/cow (2.2 vs. 1.0) and good embryos/cow (3.0 vs. 1.8) as compared to those in G1. Excellent and good embryos represented 40.7 and 55.6% in G3, being higher than 26.3 and 47.4% in G1. The differences in production of embryos at different stages or grades were not significant. In conclusion, the obtained results, indicated that the potentiality of PMSG injection to induce high superovulatory response in cattle is highly related to follicular diameter . Under the experimental conditions of present study, appropriate time for SO in Friesian cows treated with 2500 IU of PMSG was when diameter of the dominant follicle reached a rang from ≤7.5-10 mm to reflect the highest ovulatory response and the best number of transferable embryos of excellent grade. | ||||
| Keywords | ||||
| Cows; follicular diameter; PMSG; SO; embryo | ||||
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