Ovarian Development and Ovulation in Hens Treated with Synthetic (Porcine) Luteinizing Hormone Releasing Hormone/Follicle Stimulating Hormone Releasing Hormone (LH-RH/FSH-RH)

Thirty five hens were equally divided into seven groups and injected intramuscularly with various doses of synthetic LH-RH/FSH-RH following the terminal egg of an ovulatory sequence (tC egg), as determined by previous oviposition pattern. The birds were maintained on a daily photoperiod of 14 hr. light starting at 0800 hr. and all injections were performed at 1800 hr. on the tC day. Ovulation induced prematurely by 6–9 hr. on the first day of a clutch (tC day) was detected by presence of a soft-shelled egg in either the magnum or uterus. Levels of LH-RH/FSH-RH injected into each of five birds in each group as follows: 0, 1, 5, 10, 20, 40 and 60 μg. The number of premature ovulations induced by the treatments of LH-RH/FSH-RH were 0/5, 0/5, 3/5, 4/5, 3/5, 5/5 and 5/5, respectively. Nonovulatory hens maintained on a daily photoperiod of 6 hr. light were injected subcutaneously for 14 consecutive days with either 3.4 μg. LH-RH/FSH-RH or an equal volume (0.5 ml.) of saline. The birds were sacrificed on day 15 for observation of ovarian changes. No significant differences were noted between LH-RH/FSH-RH and saline injected hens in either largest ovarian follicular diameter, follicle diameter of ten largest follicles or ovarian weight.