GnRH ANALOGUE (BUSERELIN ACETATE) MODULATES REPRODUCTIVE PERFORMANCE IN „OLD HENS‟

Abstract

To test the influence of a GnRH analogue (buserelin acetate, BA) on the reproductive activity of aging hens, a total of sixty, 50-wk-old Alexandrian hens were randomly and equally distributed among three treatment groups. Two groups received weekly intramuscular injections of 0.1 or 0.2 mL of the GnRH analogue solution, providing 0.42 and 0.84 µg of buserelin acetate, respectively, for 1 month. The control group received 0.15 mL of physiological saline. Reproductive parameters (egg production, egg weight and egg mass) and plasma FSH, LH and Estradiol (E 2 ) were measured. Overall, respectively, resulted in 58% and 30% increases in LH concentrations; 77% and 50% increases in FSH concentrations; and 41% and 8% increases in E 2 concentrations; compared to control. Weekly egg production increased by 37% and 29% with low-and high-BA, respectively. Egg weight on the other hand responded differently to treatments, as it declined to 97% of control. It can be concluded that in Alexandrian laying hens the decrease in egg production associated with advancing age can be attributed to reduction in plasma LH; hence treating aging hens with the GnRH analogue was capable of increasing egg production.