Aderemi Theophilus DARE DVM (A.B.U.) 1990, M.Sc. (A.B.U.) 20072023-09-212023-09-212021-09-08https://teras.ng/api/asset/document/5875e9b6-600e-402f-8bbc-41e9df8268dehttps://teras.ng/catalog-item/56e3d87e-2b0a-47c5-a124-d751caa076aahttp://dspace.teras-network.net:4000/handle/123456789/15676Gonadotrophin–releasinghormone (GnRH) and its synthetic analogues (Buserelin, Goserelin, Leuprorelin, etc.) are widely used in veterinary practice to treat cystic ovarian disease and to synchronise oestrus and ovulation in cattle. The aim of this study was to compare the follicular dynamics, follicle stimulating hormone, luteinising hormone and progesterone profiles in response to the administration of two doses of GnRH in combination with Prostaglandin F2 alpha (PGF2α; Ovsynch protocol) in apparently healthy Bunaji and Friesian x Bunaji cows. Two treatments were performed. Treatment 1: Bunaji cows (n = 15) and Treatment 2: Friesian x Bunaji cows (n = 15). In both treatments, it was hypothesised that follicular dynamics, FSH, LH and P4 profiles did not differ between two ovsynch protocols administered to Bunaji and Friesian x Bunaji cows. Moreover, each treatment group was randomly divided into three groups. Group I: (control, n = 5) animals received 2 ml normal saline at time of hormonal treatments. Group II (n = 5) animals received 50 μg GnRH (Lecirelin® ) on day 0 , day 7 a dose of 500 μg of PGF2α, and the second administration of 50 μg GnRH on day 9. Group III: (n = 5) animals received 100 μg GnRH (Lecirelin® ) on day 0, day 7 a dose of 500 μg PGF2α, and administration of 100 μg GnRH on day 9. Ultrasound examination was done on all animals from day -1 to day 12. The animals were examined 12 hourly from day 9 until detection of ovulation. Blood samples were collected at 15 to 30 minutes intervals for 6 hours after the GnRH administration to determine serum concentrations of FSH and LH, and once daily for 12 days after the injection of the first GnRH to determine concentration of plasma progesterone. All animals had follicles > 8 mm at time of first GnRH administration. The ovarian responses of the various groups to first GnRH administration showed 0 % ovulation rate for both control groups and 40 % and 60 % ovulation rates for group ii and iii, respectively in Bunaji cows and 60 % each of cows in group ii and iii of Friesian x Bunaji cows. The organized event of follicular growth leading to ovulation following the second GnRH administration occurred in 20 % of controlled groups,60 % each of treated groups in Bunaji and 60 % Group II; 80 % group III in Friesian x Bunaji cows. There was no difference in the day of new follicular wave emergence after the first GnRH injection in both treated groups and breeds. The changes in the small, medium, large and subordinate follicles did not differ significantly between the treated groups and breeds. The GnRH at the doses administered induced release of FSH and LH from the pituitary within 30 min of injection in treated groups than in control cows. Both hormones reached peak concentrations at about 120 min and then returned to pre-treatment concentrations by 300 to 360 mins after the first GnRH injection. There was a statistically significant difference (P < 0.05) in the peak values of serum FSH and LH obtained on day 0 (FSH Bunaji cows: 50 μg and 100μg dosages = 2.64 ± 0.21 mIU/ml and 2.70 ± 0.09 mIU/ml respectively; FSH Friesian x Bunaji cows: 50 μg and 100μg dosages = 3.38 ± 0.01 mIU/ml and 4.20 ± 0.25 mIU/ml respectively; LH Bunaji cows: 50 μg and 100μg dosages = 8.50 ± 0.50 mIU/ml and 10.20 ± 0.80 mIU/ml respectively; LH Friesian x Bunaji cows: 50 μg and 100μg dosages = 14.10 ± 0.46 mIU/ml and 16 ± 0.63 mIU/ml respectively) and those obtained on day 9 of GnRH administration (FSH Bunaji cows: 50 μg and 100μg dosages = 15.80 ± 0.66 mIU/ml and 26.00 ± 2.92 mIU/ml respectively; FSH Friesian x Bunaji cows: 50 μg and 100μg dosages = 31.00 ± 1.87 mIU/ml and 39.40 ± 1.96 mIU/ml respectively; LH Bunaji cows: 50 μg and 100μg dosages = 17.90 ± 0.90 mIU/ml and 20.20 ± 1.56 mIU/ml respectively; LH Friesian x Bunaji cows: 50 μg and 100μg dosages = 16.20 ± 0.66 mIU/ml and 26 ± 2.92 mIU/ml respectively). Plasma progesterone increased among treated groups following injection of GnRH reaching a higher peak on day 7 than in control, but did not differ among treated groups and breeds. Estimated cost benefit of using 50 μg as compared to 100μg dosages of GnRH in Bunaji and Friesian x Bunaji cows was N 6, 000:00 for each cow, N 30 000:00 for all cows and for each ovulation synchronised, N 10:000:00 and N 4, 458:00 in Bunaji and Friesian x Bunaji cows respectively. It was concluded that the GnRH analogue at50 μg and 100 μg doses was effective in synchronisation of ovulation in Bunaji and Friesian x Bunaji cows but recommended the 50 μg for Bunaji and 100 μg for Friesian x Bunaji cows based on their synchronisation outcomes and cost-benefit analysis.Post Graduate Theses