CONTROL THE ONSET OF PUBERTY BY APPLICATION OF GONADOTROPIN RELEASING HORMONE (GNRH) IN IRAQI LAMB RAMS

This study is design to investigate further the effect of two GnRH level treatments to onset of lamb-ram puberty and to minimize the incidence of sexual maturity age. Eighteen lamb-rams of 4-5 month of age with no previous history, body wt. around 14-17 kg, scrotal circumference around 8-10 cm, was conducted on this study which started from early November 2019 to the end of March 2020, at the animal yard of the Veterinary MedicineCollege - University of Baghdad- Al-Amerya state. Lamb-rams randomly divided into three groups; 1) Group (A) was treated with GESTAR (GnRH 0.00042g) 2ml /lamb/48 hs. 2) Group (B) was treated with GESTAR(GnRH 0.00042g)1ml/lamb/48 hs. 3) Group(C) was received nothing and stay as control group. All experimental lambs were received an equal quantities of food as 2kg of straw and 1 kg of oat and barely (grained). Testicular circumference, body wt. and hormonal analysis determined every 15 days. Results showed that; Testicular wt, of group of 2ml GnRH(A) 138.5±1.5g,group of 1ml GnRH( B) 190.0± 10.0g, and for control group(C) 96.5± 6.5g, Sc was of A) 25.5±0.5 cm, B) 29.75±0.75cm and C) 21.5±0.5, Testicular length was of A) 9.0±0.0 cm, B) 10.75±0.25cm and C) 7.25±0.25cm, testicular diameter was of A)5.05±0.05cm., B) 5.55±.05cm and C) 3.5±0.1cm. testicular size was of A)140.0±0.0ml, B) 195.0±10.0ml and C)100.0±5.0ml, animal wt. was of A)37.5±1.5kg, B)42.0±3.0kg and C)36.0±1.0, testosterone level was of A)1.3±0.52ng/ml, B)2.12±0.74ng/ml and C)0.271±0.18ng/ml, estrogen level was of A) 5.81±0.38pg/ml, B) 11.63±3.7pg/ml and C)5.15±0.22pg/ml, volume of semen was of A) 0.675±0.04ml, B)0.90±0.04ml and C)0.60±0.04ml, mass motility was of A)75.0±2.04% , B)82.5±1.44% and C)65.0±2.04% ,individual motility was of A)78.75±1.25% ,B)86.25±1.25 and C)67.5±1.44 ,viability was of A) 81.0±1.29% ,B) 89.0±0.91% and C)70.0±1.82 and normal sperm was of A)80.5±2.1% ,B) 93.0±0.57% and C)71.25±1.54% . In conclusion 1ml Gestar (0,00042gm GnRH) is better in controlling and induction of puberty and sexual maturity in lamb-ram at 120 day treatment.