Impact of Both Growth Hormone and Gonadotropin Releasing Hormone on Puberty Based on Serum Progesterone and Insulin-Like Growth Factor-1 Level in Iraqi local Breed Ewe Lambs

Objective: To investigate how Growth Hormone(GH) and Gonadotropic Releasing Hormone (GnRH) injection influence on the growth and onset of puberty in Iraqi crossbred ewe lambs. Methods: Two equal groups of fourteen Iraqi local breed ewes-lambs, with an average body weight of 24.16 ± 1.05 kg and an age of 5±0.5 months, were randomly assigned. One group was used as a control, whereas the other received treatment with GH and GnRH. Weighing was done on the ewe-lambs both before and after the experiment. Furthermore, the number of ewes exhibiting their first estrus at the end of therapy, as well as the body condition scores. Blood samples were taken until the onset of pubertal symptoms also progesterone and insulin-like growth factor-1 (IGF-1) levels in sera samples were measured. Findings: It was shown that the group administered with Growth and GnRH reached puberty 3.5 weeks (24 days) sooner than the control group. The body weight (38.22±1.21b) kg , body condition scores (4.14±0.14 b) and pregnancy rate (71.43%) of the Iraqi local ewe lambs was higher than those of the control group. Progesterone and IGF-1 levels in Iraqi local ewe lambs were higher in treated group compared to control group. Conclusion: GH. and GnRH injection accelerate puberty.