Short-Term Reduction in Egg Production in Laying Hens Treated with an Agonist of GNRH

Abstract

In two experiments laying hens were treated with anagonist of gonadotrophin releasing hormone (GnRH) to induce a reduction in the secretion of luteinising hormone (LH) and a pause in esrsf production. In experiment 1, 70-week-old laying hens were either given daily subcutaneous injections of saline for 7 d, offered whole oats for 7 d (nutrient restriction), given daily injections of the GnRH agonist [d-Trp6-Pro9N-ethyl amide]GnRH for 7 d at 50 //g/kg or 100 pig/kg or administered 4 biocompatible implants each containing 120 pig of the GnRH agonist. Weekly egg production was monitored for 7 weeks and blood samples were taken at weekly intervals and assayed for plasma LH and oestradiol. Egg pr..