Effects of Different Dietary Energy Levels on NPY mRNA Expression Level at the Time before and after Laying and the Traits at the First Laying of Wenchang Chicken

Objective to investigate the effect of different energy level diets on NPY mRNA expression level in hypothalamus and ovary at the time before and after laying(the age of 15 weeks,20 weeks and 25 weeks) and the traits in the first laying.In this research,600 Wenchang chickens were randomly divided into 3 groups: low energy group(GroupⅠ),control energy group(GroupⅡ) and high energy group(Group Ⅲ).There are 5 replications in each group,and 40 chickens in each replication.Subsequently,the age,the body weight and the egg weight in the first laying were recorded accurately.The NPY mRNA expression in hypothalamus and ovary in each energy groups before and after laying were analyzed by RT-PCR.The result showed that the high energy can advance the age of first laying.At the age of 15 weeks,20 weeks and 25 weeks,the NPY mRNA expression level of hypothalamus in low energy group was higher than that in the control and high energy groups,whereas,the NPY mRNA expression level of ovary among the three energy groups had no significant difference.The results indicated that the change of energy level was able to affect the NPY mRNA expression level in hypothalamus and ovary and the sex mature time of Wenchang chicken.