Effect of GnRH on the day of Insemination on Ovulatory Response in Crossbred Cows
DOI:
https://doi.org/10.48165/ijar.2023.44.02.5Keywords:
Crossbred cattle, Insemination, GnRH, Ovulation, SeasonAbstract
The effect of gonadotropin releasing hormone (GnRH) analogue on the ovulatory response of oestrual follicle during cold and hotter months of the year was studied. A total of 120 crossbred cows brought for insemination with oestrus signs during colder months (December 2022 –January 2023; n=52) and hotter months (April – May 2023; n=68) to the Gynaecology Unit of Veterinary Clinical Complex, Veterinary College and Research Institute, Orathanadu were utilized for the study. Oestrus (Day 0) was confirmed by gynaeco-clinical and ultrasound examination and animals were inseminated with (n =33) or without (n = 87) GnRH (Buserelin acetate 10 mcg; im). The biometry of oestrual follicle (OF) and regressing corpus luteum (RCL) were measured ultrasonographically on Day 0 and the OF was observed every 24 hours until ovulation. The diameter of the OF on Day 0 was non-significantly (P > 0.05) larger during hotter months (12.19 ± 0.21 mm) than colder months (11.58 ± 0.32 mm). There were no significant (P > 0.05) differences in the diameter of RCL between the two periods (9.63 ± 0.21 and 9.56 ± 0.22 mm respectively). OFs were observed majorly in the right ovary during the hotter (60.76%) and colder (54.17%) months. Ovulations occurred on the mean days of 1.00 and 1.37 ± 0.18 in GnRH group during hotter (H-Gn) and colder months (C-Gn) respectively. The respective mean days in non-GnRH group were 1.14 ± 0.05 and 1.33 ± 0.08 during hotter (H-O) and colder months (C-O). In H-Gn group all the animals (100%) ovulated on Day 1, when compared to C-Gn animals (62.50%). On perusing the possible effect of RCL on ovulation, significantly increased percentages of ovulations were observed in OFs on the contralateral ovary to the ovary having the RCL in GnRH group and viceversa in non-GnRH group. It could be assumed that GnRH administration on the day of insemination may be beneficial during the hotter months of the year.
References
Bloch, A., Folman, Y., Kaim, M., Roth, Z., Braw-Tal, R. and Wolfenson, D. (2006). Endocrine alterations associated with extended time interval between estrus and ovulation in high-yield dairy cows. J. Dairy Sci.,89:4694–4702.
Burnett, T.A., Madureira, A.M.L., Bauer, J.W. and Cerri, R.L.A. (2022). Impact of gonadotropin-releasing hormone admin istration at the time of artificial insemination on concep tion risk and its association with estrous expression. J. Dairy Sci., 105:1743–1753.
Hubner, A.M., Canisso, I.F., Peixoto, P.M., Conley, A.J. and Lima F.S. (2022). Effect of gonadotropin-releasing hormone administered at the time of artificial insemination for cows detected in estrus by conventional estrus detection or an automated activity-monitoring system.J. Dairy Sci.,105: 831-841.
Kaim, M., Bloch, A., Wolfenson, D., Braw-Tal, R., Rosenberg, M., Voet, H. and Folman,Y. (2003). Effects of GnRH admin istered to cows at the onset of estrus on timing of ovula tion, endocrine responses, and conception. J. Dairy Sci., 86:2012–2021.
Mee, M. O., Stevenson, J. S., Alexander, B. M. and Sasser. R. G. (1993). Administration of GnRH at estrus influences pregnancy rates, serum concentrations of LH, FSH, estra diol-17β, pregnancy-specific protein B, and progesterone,
proportion of luteal cell types, and in vitro production of progesterone in dairy cows. J. Anim. Sci., 71:185–198. Morgan, W. F. and Lean, I. J. (1993). Gonadotrophin-releasing hormone treatment in cattle: A meta-analysis of the effects on conception at the time of insemination. Aust. Vet. J., 70:205–209.
Pineda, M.H. (1989). Female reproductive system L.E. McDonald, M.H. Pineda, (Eds.), Veterinary Endocrinology and Reproduction, Lea & Febiger, Philadelphia, PA, pp. 314.
Ryan, D. P., Snijders, S., Condon, T., Grealy, M., Sreenan, J. and O’Farrell, K. J. (1994). Endocrine and ovarian responses and pregnancy rates in dairy cows following the administration of a gonadotrophin releasing hormone analog at the time of artificial insemination or at mid-cycle post insemination. Anim. Reprod. Sci.,34:179–191.
Satheshkumar, S. (2018). Peri-follicular blood flow in the follicle from which ovulation occurs in cows. Anim. Reprod. Sci., 198:154-159.
Satheshkumar, S., Brindha, K., Roy, A., Devanathan, T.G., Kathiresan, D and Kumanan, K. (2015). Natural influence of season on follicular, luteal, and endocrinological turn over in Indian crossbred cows. Theriogenology, 84:19-23.
Satheshkumar, S., Subramanian, A., Devanathan, T.G., Kathiresan, D., Veerapandian, C. and Palanisamy, A. (2012). Follicular and endocrinological turnover associated with GnRH induced follicular wave synchronization in Indian crossbred cows. Theriogenology,77: 1144-1150.
Snedecor, G. W. and Cochran, W.G. (1994). Statistical Methods [8th ed]. Iowa State University Press, USA. pp. 950. Stevenson, J.S. (2019). Spatial relationships of ovarian follicles and luteal structures in dairy cows subjected to ovulation synchronization: Progesterone and risks for luteolysis, ovu lation, and pregnancy. J. Dairy Sci., 102: 5686–5698. Valenza, A., Giordano, J. O., Lopes Jr., G., Vincenti, L., Amundson, M. C. and Fricke. P. M. (2012). Assessment of an acceler ometer system for detection of estrus and treatment with gonadotropin-releasing hormone at the time of insemina tion in lactating dairy cows. J. Dairy Sci.,95: 7115–7127.
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