Comparison Of Performance And Intestinal Health Of Laying Hens Under Two Welfare Rearing Modes

With the development of the breeding industry,people are paying more and more attention to the welfare of the animal of farm.Green,healthy,and high-quality welfare products of livestock and poultry are deeply accepted by the public.The welfare breeding of laying hens has many advantages compared with the traditional breeding model: The environmental pressure of laying hens decreased and the incidence of diseases decreased;The free nature of laying hens is satisfied and the quality of products is improved;The intestinal microbial colony structure of laying hens was stable and the body resistance was enhanced.Therefore,this study took the plastic net housing system(NRS)and the floor litter housing system(LRS)as the research objects to explore the effects of two on non-cage housing systems on the production performance and health status of laying hens,and to provide reference for further research on welfare rearing modes of laying hens.There are 1200 30-week-old Shendan No.6 laying hens in this study were fed in NRS and LRS houses,and each house was divided into 5 groups with 120 laying hens in each group,respectively.The pre-trial period was 2 weeks,and the official test was 32 to 40 weeks.The laying rate and mortality rate of each group were recorded every day;The indoor air quality parameters was tested every 2 weeks;The level of ground pollution in the shed was tested every 4 weeks;Egg quality traits and serum parameters were measured every 2 weeks;At the age of 40 weeks,4 laying hens were randomly selected from each group and analyzed for intestinal mucosal morphology and microbial colony structure;The results are as follows:1)The average laying rate of laying hens in NRS was 13.87% higher than that in LRS,and was significantly higher at 34 to 40 weeks of age than that in LRS(P<0.05);From 36 to 40 weeks of age,the laying rate in NRS decreased slowly(4.14%),while laying rate in LRS decreased sharply(11.39%).There was no significant difference in eggshell strength and Haugh unit between the laying hens of the two houses(P<0.05).2)The serum malondialdehyde(MDA)content of laying hens in LRS was higher than that in NRS(P<0.05);The serum glutathione peroxidase(GSH-PX)and superoxide dismutase(SOD)activities of laying hens in NRS laying hens were higher than those in LRS(P<0.05);The contents of total cholesterol(T-CH),triglyceride(TG)and corticosterone(CORT)and creatine kinase(CK)activity in serum of laying hens from two houses were not significantly different(P<0.05).3)The number of aerosol bacteria in LRS at 32,36 and 40 weeks of age was significantly higher than that in NRS(P<0.05);The number of bacteria on the floor and floor egg surface of LRS was significantly higher than that of NRS(P<0.05);There were no significant differences in temperature,relative humidity and CO2 concentration between the two laying hen houses(P<0.05).4)The villus height(VH)of duodenum and jejunum and ileum of laying hens in NRS was significantly higher than that in LRS(P<0.05);The jejunum and ileum VCR of laying hens in NRS were 2.44,2.31 and 1.38 units higher than those in LRS(P<0.05);There was no significant difference in the crypt depth of intestinal mucosa between the two laying hen houses(P<0.05).5)OTU cluster analysis showed that the average number of OTU in cecum and duodenum of laying hens in NRS was significantly lower than that in LRS(P<0.05);The results of Alpha diversity analysis indicated that the Shannon index of cecal and duodenal microflora of laying hens in LRS was significantly higher than that in NRS(P<0.05);In the cecum,the relative abundance of Proteobacteria and Kiritimatiellaeota of LRS laying hens was significantly higher than that of NRS laying hens(P<0.05),the relative abundance of Bacteroidetes was significantly lower than that of NRS(P<0.05),Phascolarctobacterium and Ruminococcaceae＿UCG-005 of laying hens in LRS were significantly lower than those in NRS(P<0.05);The content of Lactobacillus in the duodenum of laying hens in NRS was significantly lower than that in LRS(P<0.05),the relative abundance of Pseudomonas in LRS was significantly higher than that in NRS(P<0.05).In conclusion,the plastic net housing system keep inner environment quality is better than that of the floor litter housing system,the NRS can improve the chicken group of antioxidant capacity and enhance ecological environment of the intestinal mucosa structure and colony;The intestinal digestion and absorption of nutrients and egg production performance was improved.