Effects Of Mulberry Leave Powder On Productive Performance And Intestinal Microorganism Of Laying Hens

With the rapid development of China’s social economy,people’s living standards continue to improvement,the demand for healthy livestock and poultry products is increasing.Therefore,the rapid development of animal husbandry is promoted,and the shortage of feed resources is caused,which seriously threatens the food security of China.Therefore,it is urgent to develop local feed resources in China.As a new type of unconventional feed resource,mulberry leaves have the characteristics of large yield,high crude protein content,low crude fiber content and rich amino acid types.In addition,mulberry leaves also contain a variety of physiological active substances such as alkaloids,flavonoids and polysaccharides,and their effects on animal physiological functions remain to be studied.There have been some domestic and foreign studies on the effects of mulberry leave powder addition on productive performance and egg quality of laying hens,but the results reported by them are quite different.There is a lack of systematic research on the effect of mulberry leave powder on the performance of laying hens,and the report on the effect of mulberry leave powder on the intestinal microorganism of laying hens is particularly rare.Therefore,this paper studied the effects of mulberry leave powder in different proportions on performance and egg quality of laying hens,measured the effects of mulberry leave powder on physiological and biochemical indexes of laying hens,and studied the effects of mulberry leave powder on cecal microflora of laying hens,in order to provide theoretical support for the feed utilization of mulberry leave powder.The main research results are as follows:1.Effects of mulberry leave powder on productive performance and egg quality of laying hensOne hundred and twenty 192-day-old Hy-line grey laying hens with an average body weight of 1.7kg were randomly divided into 5 groups and fed isonitrogenous and isoenergy diets supplemented with 0%(control),2%,4%,6% and 8% mulberry leave powder,respectively.The pre-feeding period was 1 week and the normal feeding period was 11 weeks.The results showed that the laying rate of laying hens supplemented with mulberry leave powder had a decreasing trend,and the laying rate of 2% and 4%mulberry leave powder groups was significantly decreased by 4.13% and 5.60%compared with the control group(P<0.05).The feed to egg ratio in 4% mulberry leave powder group was significantly increased by 7.08% compared with control group(P<0.05).The average egg weight was firstly decreased and then increased with the mulberry leave powder supplemental level increasing,and the average egg weight in 6%mulberry leave powder group was significantly increased by 1.51% compared with the control group(P<0.05).Mulberry leave powder had little effect on feed intake.The rate of broken soft eggs decreased after adding mulberry leave powder.Compared with the control group,eggshell strength,eggshell thickness and eggshell shape index in experimental groups supplemented with mulberry leave powder were increased,but there were no significant differences with the control group(P>0.05).With the mulberry leave powder supplemental level increasing,the protein height and Haugh unit were firstly increased and then decreased,and the protein height of 4% mulberry leave powder was significantly increased by 26.07% compared with the control(P<0.05).With the increase of mulberry leave powder adding proportion,the yolk color of mulberry leave powder groups was higher than that of control group,and the yolk color of 6% mulberry leave powder group was significantly increased by 21.96%compared with control group(P<0.05).Mulberry leave powder supplementation could decrease yolk cholesterol and increase the contents of crude protein and crude lipid in yolk,and the crude protein contents in 4% and 6% mulberry leave powder groups were significantly increased by 8.32% and 7.96% compared with the control group(P<0.05).The content of monounsaturated fatty acid(MUFA)in yolk of 4%,6% and 8%mulberry leave powder groups was decreased by 2.19%,6.93% and 12.09% compared with the control group(P<0.05).The content of polyunsaturated fatty acids(PUFA)in yolk in 4%,6% and 8% mulberry leave powder groups was higher than that in control group,and the content of PUFA in 6% and 8% mulberry leave powder groups was significantly increased by 12.29% and 22.91%(P<0.05).Therefore,adding mulberry leave powder can better improve the nutritional value of eggs.2.Effects of mulberry leave powder on physiological and biochemical indexes of laying hensAfter feeding the diet supplemented with mulberry leave powder for 11 weeks,the abdominal fat percentage and liver fat percentage of laying hens were decreased,and the liver fat percentage of 2% mulberry leave powder group was significantly decreased by 9.35% compared with the control group(P<0.05).The liver total antioxidant capacity(T-AOC)in 2% and 4% mulberry leave powder groups was significantly increased by 21.84% and 13.39% compared with the control group,and the liver T-AOC in 8% mulberry leave powder group was significantly decreased by 12.10%compared with the control group(P<0.05).Compared with the control group,liver superoxide dismutase(SOD)content in 2%,4% and 6% mulberry leave powder groups was significantly increased by 22.22%,12.44% and 7.90%,while liver SOD content in8% mulberry leave powder group was significantly lower than that in the control group(P<0.05).Compared with the control,the content of glutathione peroxidase(GSH-Px)in 2% mulberry leave powder group was significantly increased by 14.37%,and the content of GSH-Px in 8% mulberry leave powder group was significantly decreased by20.56%(P<0.05).Compared with the control group,the content of malondialdehyde(MDA)in 2%,4% and 6% mulberry leave powder groups was significantly decreased by 33.67%,44.90% and 25.51%(P<0.05).The contents of plasma total cholesterol,triglyceride and low density lipoprotein of laying hens supplemented with 2%,4%,6%and 8% mulberry leave powder were decreased,and the contents of high density lipoprotein were significantly increased by 65.71%,97.14%,97.14% and 51.43%compared with the control group(P<0.05),respectively.3.Effects of mulberry leave powder on cecal microflora of laying hens16S rDNA sequencing was performed on the cecal contents of laying hens in each group,and the bacterial community function was predicted by PICRUSt.The results showed that the number of OTU and the diversity and richness of cecal microorganisms in the groups supplemented with mulberry leave powder decreased by OTU analysis and α diversity analysis.A total of 18 phyla and 209 genera were detected in cecal contents.At the phylum level,Bacteroidetes and Firmicutes were the dominant phyla,accounting for more than 90% of the total abundance of bacteria.The relative abundance of Proteobacteria in mulberry leave powder groups was significantly lower than that in control group,decreased by 33.84%,66.68%,45.96% and 44.95%(P<0.05),respectively.Compared with the control group,the relative abundance of Tenericutes was significantly decreased by 63.51%,70.27%,81.08% and 62.16%(P<0.05),respectively.The relative abundance of Actinobacteria was significantly higher than that of the control group,which was increased by 208.05%,251.72%,289.66% and417.24%(P<0.05),respectively.At the genus level,there were 23 genera with abundance greater than 1%,including Bacteroides,Lactobacillus and Rikenellaceae＿RC9＿gut＿group,etc.Compared with the control group,the relative abundance of Bacteroides in 2%,4%,6% and 8% mulberry leave powder groups was significantly decreased by 31.35%,26.09%,42.01% and 45.48%,respectively(P<0.05).The relative abundance of Desulfovibrio was significantly lower than that of the control group,decreased by 56.49%,83.77%,61.04% and 57.14%(P<0.05),respectively.Except for 2% mulberry leave powder group,the relative abundance of Lactobacillus in4%,6% and 8% mulberry leave powder groups was significantly higher than that in control group,increasing by 255.15%,208.08% and 214.95%,respectively(P<0.05).The relative abundance of Bifidobacterium in 4%,6% and 8% mulberry leave powder groups was significantly higher than that in the control group,increased by 45.4,46.2and 69.8 times(P<0.05),respectively.PICRUSt functional prediction analysis showed that the nucleotide metabolism,translation,replication,repair and lipid metabolism of cecal microorganisms were significantly increased(P<0.05).Compared with the control group,lipid metabolism of the group supplemented with mulberry leave powder increased by 0.33%,5.28%,3.96% and 5.28%,respectively.These results indicated that the supplementation of mulberry leave powder increased the number of beneficial microorganisms and reduced the number of harmful microorganisms in the cecum of laying hens,and the lipid metabolism ability of the body was enhanced,which was beneficial to the health of laying hens.When mulberry leave powder was added into the feed of laying hens,the laying rate of laying hens decreased,but the egg quality was improved.After adding mulberry leave powder,the abdominal fat percentage and liver fat percentage of laying hens were decreased,the liver antioxidant capacity was increased,the plasma total cholesterol,triglyceride and low density lipoprotein contents were decreased,and the high density lipoprotein content was significantly increased.Mulberry leave powder supplementation can significantly increase the proportion of beneficial microorganisms in cecum and enhance the ability of lipid metabolism,which is beneficial to the health of laying hens.Considering the effects of mulberry leave powder supplementation on productive performance,egg quality,physiological and biochemical characteristics and cecal microorganisms of laying hens,it is concluded that the appropriate supplemental amount of mulberry leave powder in the diet of laying hens is about 4%.