| The energy level of the diet is not only an important factor affecting the healthy production of laying breeders,but also a key factor determining the maximum economic benefits of the poultry industry.A reasonable energy level helps the gut microbiota of chicken to perform normal functions such as nutrient absorption,immune development,and disease resistance,which is crucial for the health and productivity of the gut in egg laying chickens.As the "source" of the industry,chicken breeding is the fastest,most typical,and most market-oriented industry in the national animal husbandry industry.Its breeding management is one of the important factors affecting the quality of commercial chickens.However,there are few reports on the effects of different energy levels of diets on the production performance and intestinal microbial diversity of the laying breeders.Therefore,this study selected 216 57-week old parents of Jingfen No.2 laying breeders with similar body weight(1905±10g),consistent production performance,and health,and randomly divided them into 3groups,with 6 replicates in each group,with 12 chickens in each replicate.According to the "Yunnan Yunling Guangda Yukou Poultry Industry of Jingfen No.2 laying breeders Standard",the diet was formulated with a protein level of 16.29%,and the energy levels of the low energy group(LM),medium energy group(MM),and high energy group(HM)were 10.72 MJ/kg,11.14 MJ/kg,and 11.56 MJ/kg,respectively(with an energy gradient of 0.42 MJ/kg).After 70 days of slaughter,calculate the egg production rate,average daily weight gain,feed to egg ratio,and count indicators such as the rate of unqualified eggs and hatching rate.Then,take the midgut chyme for 16 S r RNA sequencing.The results show:(1)There was no significant difference in egg production rate,average daily gain,average egg weight,and feed to egg ratio between the LM group and the MM group(P>0.05).There was no significant difference in average egg weight among LM group,MM group,and HM group(P>0.05),The average daily gain and egg production rate of the HM group were significantly higher than those of the LM and MM groups(P<0.05).The feed to egg ratio of LM group and MM group was significantly higher than that of HM group(P<0.05).(2)There was no significant difference in damaged egg rate,sand shell egg rate,soft shell egg rate,blood spot egg rate and deformed egg rate in LM,MM and HM groups(P>0.05).(3)There was no significant difference in qualified egg breeding rate,fertilization rate,hatching rate and fitness rate in LM,MM and HM groups(P>0.05).(4)There were no significant differences in bacterial richness and diversity in the cecal microbiota of the LM,MM,and HM groups(P>0.05).(5)At the phylum level,Bacteroides,Firmicutes,and Desulfobacterota are the main bacterial groups in the cecum of LM,MM,and HM groups.The abundance of Desulfobacteria in HM group was significantly higher than that in LM group and MM group(P<0.05),while the abundance of Cyanobacteria in MM group was significantly higher than that in LM group and HM group(P<0.05).At the genus level,Rikenellaceae,Bacteroides,and Lactobacillusare are the main bacterial groups.The abundance of Rikenellaceae in MM group was significantly higher than that in LM group and HM group(P<0.05),the abundance of Prevotellaceae in LM group was significantly higher than that in MM group and HM group(P<0.05),the abundance of Alistipes in LM group and HM group was significantly higher than that in MM group(P<0.05),and the abundance of Desulfovibrio in HM group was significantly higher than that in LM group and MM group(P<0.05).The results showed that compared to the medium energy diet(11.14 MJ/kg),the low energy diet(10.72 MJ/kg)had no adverse effects on the production and reproductive performance of the parent generation of Jingfen No.2 laying breeders.High energy diet(11.56 MJ/kg)can improve the production performance of Jingfen No.2 laying breeders.The diversity of gut microbiota in the low energy group,medium energy group,and high energy group is similar,and the abundance of Prevotellaceae in the cecum of the parents of Jingfen No.2 laying breeders fed low energy diet increases,while the abundance of Rikenellaceae in the cecum of the parents of Jingfen No.2 laying breeders fed medium energy diet increases,The abundance of Desulfovibrio in the cecum of the parents of Jingfen No.2 laying breeders fed with high-energy diets increased.The results provide scientific basis for further exploring the appropriate energy levels of egg breeders,theoretical and practical support for improving the feeding standards of Jingfen No.2 laying breeders,and have guiding significance for production practice. |
