Effect of GnRH on Enhancement of Pregnancy Rates of Artificial Insemination in Cross-Bred Cattle
Though large number of cross-bred cattle are available, their productivity still remained marginal due to low conception rate and more repeat breeding problems with artificial insemination (AI). Therefore, the aim of the study was to evaluate the effect of supplementation of different doses of Gonadotropine Releasing Hormone (GnRH) along with AI and twelve days post AI in cross-bred dairy cattle on enhancement of pregnancy rates. Fifty five cross-bred dairy cattle that exhibited estrus and apparently healthy were randomly selected. The cattle were randomly divided into five equal groups, G1 (n=11) cattle were treated intramuscularly with each 20 µg GnRH, Buserelin acetate, at the time of AI. G2 (n=11) cattle have the same procedure as G1 but with the dose of 10µg Buserelin acetate. G3 (n=11) cattle were given the 10 µg GnRH (Buserelin acetate) twelve days post AI. The G4 (n=11) cows were given double insemination with 6-12 hours interval. The last group was given a single service which was considered as the control group. Pregnancy diagnosis was conducted after three months rectally. The pregnancy rates were 72.72%, 63.63%, 54.54%, 45.45% and 36.36 % in the cattle grouped with G1, G2, G3, G4 and G5, respectively. The pregnancy rates of the treated groups were higher than the control by 36%, 27%, 18% and 9 % from the first to the fourth group, respectively. The first two groups showed a significant statistical variation (P<0.05). The other finding that was observed was that treated heifers became more responsive to the therapy than the treated cows with a significant variation (P<0.05). The study concluded that the supplementation of GnRH at the time of AI can enhance pregnancy rate; and is helpful and cost effective to minimize financial losses incurred from milk production lost, managemental, and feed cost; by reducing the calving interval and treating repeat breeding cases.
2. Blowey, W. (1999). The repeat breeder cow, 3rd edition, A Veterinary Book for Dairy Farmers.
3. Davis, T.L., Mussard, M.L., Enright, W.J. and Kinder, J.E. (2003). Chronic treatment with an agonist of gonadotropin-releasing hormone enhances luteal function in cattle, Biol Reprod 69: 398–403.
4. Dougall, S., Williamson, N. and Macmillan, K. (1995). GnRH induces ovulation of dominant follicle in primiparous dairy cows undergoing anovulatory follicle turn over. Anim.Reprod.Sci. 39:205-214.
5. Herbert, C.A. and Trigg, T.E. (2005). Applications of GnRH in the control and management of fertility in female animals, Anim Reprod Sci. 88: 141–153.
6. Jaswal, R. S. and Singh, M. (2013). The effect of administration of gonadotropin releasing hormone analogue at estrus or during luteal phase on reproductive performance of dairy cows maintained under sub-temperate climate. Iranian Journal of Veterinary Research, Shiraz University, Vol. 14, No. 1, Pages 57-60
7. Kharche, S. and Srivastava, S. (2007). Dose dependent effect of GnRH analogue on pregnancy rate of repeat breeder cross breed cows. Indian Veterinary Research institute Anim. Repro. Sci. 25:352-359.
8. López-Gatius, F., Santolaria, P., Martino, A., Delétang F. and. De Rensis, F. (2006). The effects of GnRH treatment at the time of AI and 12 days later on reproductive performance of high producing dairy cows during the warm season in northeastern Spain, Theriogenology, 64: 820-830.
9. Markandeya, N. (2006). Approaches to enhance conception rate and embryo survivability, Department of Gynecology and Obstetrics Veterinary College, Reproductive Techniques to augment Fertility in dairy animals. Karnataka Veterinary Animal and Fisheries Sciences University.
10. Millar R.P, (2005). GnRHs and GnRH receptors, Anim Reprod Sci. 88: 5–28
11. Morgan, W .Lean, I. (1993). Gonadotropin Releasing Hormone treatment in cattle a Meta analysis of effects on conception at the time of insemination. Aust. Vet. J. 70:205-209.
12. Mukasa-Mugaerwa, E., Agaze, T., Tafese, M and Teklu, Y. (1993). Reproductive Efficiency of Bos indicus (Zebu) cows under Artificial Insemination. Anim.Reprod Sci 24:63-67.
13. Nagaraja, R. and Devaraj, M. (2006). Multi facet Roles of GnRH in Reproduction. Veterinary college, Karnataka Veterinary, animal and Fisheries Sciences University.
14. Pawson A. and McNeilly, A. (2005). The pituitary effects of GnRH, Anim Reprod Sci 88: 75–94
15. Peters, A., Martinez, T. and Cook, A. (2000). A studies of the effect of GnRH 12 days after insemination on pregnancy rates in cattle, Theriogenology 54:1317–1327.
16. Peters, A.R. (2005): Veterinary clinical application of GnRH—questions of efficacy, Anim Reprod Sci. 88: 155–167.
17. Petrie,A. and Watson, P.(2000). Statistics for Veterinary, Revised edition. Blackwel Science Ltd., Osney Mead Oxford OX2 OEL, 25 John Street, London WCIN2 BS.
18. Shahneh, A.Z., Mohammadi, Z., Fazeli, H., Babak, M.M.S. and Dirandeh, E. (2008). The effect of gonadotrophin releasing hormone injection on plasma progesterone concentration, conception rate and ovulation rate in Iranian Holstein cows. J. Anim. Vet. Adv., 7: 1137- 1140.
19. Sherwood, N.M., Lovejoy, D.A. and Coe, I.R. (1993). Origin of mammalian gonadotropin-releasing hormones, Endocr Rev 14: 241–254.
20. Srivastava, S. and Kharche, S. (2002). Effect of GnRH on fertility in crossbred cows. Indian. J.Anim.Sci. 72:428-430.
21. Stevenson,J., Caller, S. and Phatak, N. (1990). Double insemination and gonadotropin releasing hormone treatment of repeat breeding dairy cattle .J.Dairy Sci 73:1766.
22. Szenci, O., Takacs, E., Sulon, J., Melode, S.N. and Beckers, J.F. (2006). Evaluation of GnRH treatment 12 days after AI in the reproductive performance of dairy cows. Theriogenology. 66: 1811-1815.
23. Thatcher, W.W., Drost, M., Savio, J.D., Macmillan, K.L. and Entwistle K.W. (1993). New clinical uses of GnRH and its analogues in cattle, Anim Reprod Sci 33:27–49.
Copyright (c) 2014 The Indian Journal of Veterinary Science
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.