Study On The Optimum Level Of Dietary Energy In The Wenshang Luhua Breeding Hens

The aim of this study was to investigate the effects of different dietary energy levels on the performance,egg quality,serum biochemical indexes,reproductive performance and newborn chickens of Wenshang Luhua hens and to establish the regression equation of energy requirement to determine the energy requirements of Wenshang Luhua hens on actual production conditions,to provide the theoretical basis and practice basis for the breeding standards of Wenshang Luhua hens.Experiment 1 investigated the effects of dietary energy levels on the production performance,egg quality and serum biochemical indicators of Wenshang Luhua hens.A single factor design was used to study the effects of dietary energy levels on Wenshang Luhua hens.A total of 360 healthy Wenshang Luhua hens aged 40 weeks and with the same weight were randomly assigned to 5 treatments of 6 replicates each with 12 chickens per replicate.The diets with energy levels of 10.68,10.89,11.10,11.30 and 11.51 MJ/kg were fed respectively,and the other nutrition indexes were consistent.Pre-trial period lasted for 7 d,the test period lasted for35 d.During the test period,the feed intake and egg-laying performance of each repeat were collected.The eggs were collected to measure the egg quality,and the serum was collected to determine the serum biochemical indexes.The results showed that:1)Dietary energy levels had significant effects on the feed intake of Wenshang Luhua hens.Feed intake was significantly reduced when the dietary energy level was above 11.30 MJ/kg?P<0.05?.ADMEI also increased gradually with the increase of dietary energy level?P<0.05?,but the ADMEI began to decrease when the dietary energy level increased to 11.30 MJ/kg.2)The effects of dietary energy levels on the number of laying,laying rate and ADEM of Wenshang Luhua hens were similar,showed an increasing tendency with the increase of dietary energy level,but decreased when energy level was 11.51 MJ/kg?P<0.05?.The average egg weight of the high-energy group?the energy level were 11.30 MJ/kg,11.51 MJ/kg?is higher than the low-energy group?the energy level were 10.68 MJ/kg,10.89 MJ/kg,11.10 MJ/kg?.3)With the increase of dietary energy level,Glucose,triglyceride and total cholesterol contents of Wenshang Luhua hens showed an increasing tendency?P<0.1?.4)Dietary energy levels had significant effects on albumen height,egg yolk color,Haugh unit and egg yolk proportion?P<0.05?,albumen height and Haugh unit in low energy group were significantly higher than the high-energy group?P<0.05?.The egg yolk color and the proportion of egg yolk significantly increased with the increase of dietary energy level?P<0.05?.Experiment 2 studies the relationship between dietary energy levels and the reproductive performance and maternal effects of Wenshang Luhua hens.During the last week of the experiment 1,an artificial insemination was performed on all experimental chickens every day,and all eggs in the last 3 days were collected continuously and hatched in a constant temperature incubator.The incubation period is 21 days.Chicks were sampled when they were hatched and the effects on offspring were observed.The results showed that:1)The dietary energy level had significant effects on the number of laying eggs,the number of qualified eggs and the number of hatching eggs of Wenshang Luhua hens?P<0.05?.Within a certain range,with the increase of dietary energy level,the total number of eggs,the number of qualified eggs and number of hatches gradually increased to the maximum at 11.30 MJ/kg,and significantly decreased when the energy level exceeded 11.30 MJ/kg?P<0.05?.The fertilization rate and hatchability rate had a tendency whih increased first and then decreased?P<0.1?,and reached the maximum at 11.10MJ/kg.2)The dietary energy level had significant effects on the birth weight and organ index of the offspring of Wenshang Luhua hens.The birth weight of chicks increased gradually with the increase of dietary energy level,and there was significant difference between high energy group and low energy group?P<0.05?.The cardiac index of 10.68 MJ/kg group was significantly higher than that of 11.30 MJ/kg group?P<0.05?,and the liver index was also the largest of 10.68 MJ/kg group,which was significantly higher than 10.89 MJ/kg and 11.30 MJ/kg group?P<0.05?.The gut index of 11.30 MJ/kg group was the largest,and there was no significant difference compared with other groups?P<0.1?.3)The dietary energy level had certain effects on certain blood biochemical indexes of Wenshang Luhua hens,among which the content of glucose in chick serum was different,the glucose content in 11.10 MJ/kg group was significantly higher than that in 10.68 MJ/kg group?P<0.05?.The levels of serum triglyceride and total cholesterol in the 11.10 MJ/kg group were higher than those in other groups,but the difference was insignificant.The high density lipoprotein of 10.68 MJ/kg group and 11.51 MJ/kg group were higher,Significantly higher than 11.30 MJ/kg group?P<0.05?,while the content of very low density lipoprotein of 11.10 MJ/kg group was significantly higher than other groups?P<0.05?.In summary,the dietary energy level had significant effects on the performance and reproductive performance of Wenshang Luhua hens.Based on experimental data of the comprehensive production performance,egg quality,serum biochemical index,reproductive performance and primary chicks,establish regression equation of energy requirement of Wenshang Luhua hens:ADMEI=0.88ADG+10.63ADEM+476.40BW^0.75ADMEI=1.46ADG+9.79ADQEM+512.68BW^0.75According to the regression equation,under the actual production conditions,the appropriate dietary energy levels for the performance and reproductive performance of Wenshang Luhua hens were 11.29 and 11.10 MJ/kg respectively.