The effect of different doses of gonadorelin on ovarian follicle dynamics in river buffalo (Bubalus bubalis).
The objective of this study was to determine the response of the ovarian dominant follicle to the different doses of GnRH in river buffalo. The estrous cycle of 12 river bufflaloes was synchronized using norgestomet implant for 12 days in association with two injections of prostaglandin F2alpha analogue on Days 0 and 7 of implant insertion. On Day 6 or 7 of the ensuing cycle (Day 0 of the experiment), females received a norgestomet implant in conjunction with two prostaglandin injections on Days 0 and 1. On Day 6 of the experiment, females were randomly allocated into three groups. At this time, Group 1 and 2 females were given an i.m. injection of 50 or 100 microg Gonadorelin, respectively. Group 3 females did not receive any further treatment and were considered as control. All females were given prostaglandin on Day 12 and implants were removed on Day 13 of the experiment. The results revealed that in the control group, ovarian dominant follicle became persistent throughout the experiment; whereas, the persistent dominant follicle in all females belonging to Group 2 (100 microg GnRH) and one female in Group 1 (50 microg GnRH) ovulated within 48 h, subsequent with an emergence of a new follicular wave and an increase in plasma progesterone concentration within 72 and 96 h after GnRH injection, respectively. In conclusion, 100 microg of Gonadorelin seems to be the most effective dose to induce ovulation followed by an emergence of a new follicular wave in river buffalo.
Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tehran, P.O. Box 14155-6453, Tehran, I.R. Iran.
A
A
Rastegarnia
A
A
Niasari-Naslaji
P
P
Hovareshti
F
F
Sarhaddi
M
M
Safaei
D000818:Animals; D002020:Buffaloes / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004343:Drug Implants; D004973:Estrus Synchronization; D005260:Female; D005300:Fertility Agents, Female / Q000494:pharmacology*; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D007273:Injections, Intramuscular / Q000662:veterinary; D006080:Ovarian Follicle / Q000187:drug effects* / Q000502:physiology; D010062:Ovulation Induction / Q000379:methods / Q000662:veterinary*; D011282:Pregnenediones / Q000494:pharmacology; D011374:Progesterone / Q000097:blood; D011897:Random Allocation
D004343:Drug Implants; D005300:Fertility Agents, Female; D011282:Pregnenediones; D007987:Gonadotropin-Releasing Hormone; C100284:norgestomet; D011374:Progesterone