Effects of Perilla frutescens Seed Extracts on Performance,Reproductive Hormone and Immune Function of Laying Hens during the Late Laying Peak Period

In order to investigate the effects of diets added different levels of Perilla frutescens seed extracts on performance,reproductive hormone and immune function of the laying hens during the late laying peak period,a total of four hundred of eighty 48-week-old Hyline brown laying hens with the similar body weight and laying rate were randomly divided into 4 groups with 6 replicates per group and 20 hens per replicate in a single-factor completely randomized experimental design. Control group was fed a basal diet,the experimental groups Ⅰ,Ⅱand Ⅲ were fed the basal diet added with 0. 01%,0. 02% and 0. 03% Perilla frutescens seed extracts,respectively. The experiment lasted for 30 days. The results showed as follows: 1) compared with the control group,the diets added 0. 01%,0. 02% and 0. 03% Perilla frutescens seed extracts reduced the ratio of feed to egg of laying hens,but there was no significant difference( P 0. 05). Among the 4 groups,the average egg weight and rate of broken or soft egg were not significantly different( P 0. 05),and the diet added 0. 03% Perilla frutescens seed extracts significantly improved laying rate and average daily egg production of laying hens( P 0. 01). 2) The diets added 0. 01%,0. 02% and 0. 03% Perilla frutescens seed extracts significantly increased the contents of progesterone( day 15) and estradiol( days 15 and 30) in serum of laying hens( P 0. 01),and the diet added 0. 03% Perilla frutescens seed extracts significantly decreased testosterone content in serum of laying hens( P 0. 01). 3) The diets added 0. 01%,0. 02% and 0. 03% Perilla frutescens seed extracts significantly increased interleukin-2( IL-2) content in serum of laying hens( P 0. 01),the diets added 0. 02% and0. 03% Perilla frutescens seed extracts significantly increased immunoglobulin G( Ig G) content in serum of laying hens( P 0. 01),the diet added 0. 03% Perilla frutescens seed extracts significantly increased immunoglobulin A( Ig A) content in serum of laying hens( P 0. 01). These results indicate that diet added 0. 03% Perilla frutescens seed extracts can significantly increase the laying rate,average daily egg production and immune function of laying hens during the late laying peak period.