Effects Of Mulberry Leaf Extract On Growth Performance,immune Performance And Intestinal Microbe Of Pigs

Ningxiang pig is a local breed with good meat quality and is an important gene pool of domestic animals in China.Ningxiang hybrid pigs were high quality pigs with better carcass traits and meat quality.Mulberry trees are planted in China area up to hundreds of thousands of hectares,so there are a lot of mulberry leaf resources that can be used for animal feed production.Studies have shown that mulberry leaf extract(MLE)can promote the growth of livestock and poultry,enhance immunity,improve intestinal health,regulate lipid metabolism and other physiological functions.In this experiment,different levels of MLE were added into the diet of growing pigs,and the effects of MLE on growth performance,nutrient apparent digestibility,immune performance,lipid metabolism indexes and intestinal microbe were observed,so as to provide scientific basis for fully exploiting and utilizing mulberry leaf feed resources and improving the growth level of growing pigs.A total of 240F1 generation Ningxiang crossbred pigs(Duroc × Ningxiang)with the body weight of(23.84±3.11)kg were randomly divided into 4 groups with 6 replicates per group and 10 pigs per replicate.The pigs in the control group were fed with a basal diet,and three experimental groups were fed the basal diet supplemented with 500 mg/kg,1000 mg/kg,and 1500 mg/kg MLE,respectively.Pigs were fed ad libitum feed and drinking water.The experiment lasted for 43 days after an adaptation period of 5 days.The results show:(1)The effects of MLE on growth performance of growing pigs were studied.Compared with the control group and 500 MLE group,the final weight,average daily gain and average daily feed intake of 1000 and 1500 MLE groups were significantly increased(P<0.05).Dietary MLE had no significant effect on feed to gain ratio of growing pigs(P>0.05).The growth performance of 1000 and 1500 MLE groups was better than that of the control group,and the growth performance of 1000 MLE group was better.(2)The effects of MLE on nutrient apparent digestibility of growing pigs were studied.Compared with the control group,the gross energy and apparent digestibility of organic matter in MLE supplemental groups were significantly increased(P<0.05),there was no significant difference among the three test groups(P>0.05).Compared with the control group,there was no significant difference in apparent digestibility of crude protein in MLE group(P>0.05).The apparent digestibility of ether extract in 1000 and 1500 MLE groups was significantly higher than that in control group(P<0.05),there was no significant difference among the three test groups(P>0.05).The apparent digestibility of crude fiber in1000 MLE group was significantly higher than that in control group and 1500 MLE group(P<0.05),and there was no significant difference compared with 500 MLE group(P>0.05).(3)To study the effects of MLE on serum biochemical indexes of growing pigs,it was found that dietary supplementation of different levels of MLE had no significant effects on serum alanine aminotransferase,aspartate aminotransferase,total protein,albumin,globulin,urea nitrogen and glucose contents and albumin to globulin ratio of growing pigs(P>0.05).(4)The effects of MLE on serum immune indexes of growing pigs were studied.Compared with control group and 500 MLE group,the concentrations of immunoglobulin A,immunoglobulin M and immunoglobulin G in serum of growing pigs in 1000 and 1500 MLE groups were significantly increased(P<0.05),there was no significant difference between control group and 500 MLE group(P>0.05).Compared with the control group,the serum interleukin-6 concentration in the 500 MLE group was significantly increased(P<0.05),there was no significant difference between control group,1000 and 1500 MLE groups(P>0.05).Dietary MLE supplementation had no significant effect on serum interleukin-1β,tumor necrosis factor α and interferon γ concentrations of growing pigs(P>0.05).(5)To study the effects of MLE on serum lipid metabolism indexes of growing pigs,it was found that dietary MLE had no significant effects on serum triglyceride,high density lipoprotein,cholesterol-7α-hydroxylase,lecithin cholesterol acyltransferase and lipoprotein lipase concentrations(P>0.05).Compared with the control group,serum total cholesterol and low density lipoprotein contents in 1000 and 1500 MLE groups were significantly decreased(P<0.05),there was no significant difference between control group and 500 MLE group(P>0.05).Compared with the control group,the content of hydroxymethyl glutarate mono-acyl-co A reductase in 1000 MLE group was significantly decreased(P<0.05),there was no significant difference between control group,1000 and 1500 MLE group(P>0.05),and there was no significant difference between 1000 and 1500 MLE groups(P>0.05).(6)To study the effects of MLE on serum hormone indexes of growing pigs,it was found that dietary MLE had no significant effects on the contents of growth hormone,thyroxine and triiodothyronine in serum of growing pigs(P>0.05).(7)The effects of MLE on intestinal microflora of growing pigs were studied.Compared with the control group,the Ace index of Alpha diversity analysis in 1000 MLE group was significantly increased by studying the effects of MLE on intestinal flora of growing pigs(P<0.05).There was no significant difference in the composition of phylum level and genus level between 1000 MLE group and control group(P>0.05).In conclusion,dietary MLE supplementation can improve growth performance,increase nutrient apparent digestibility,enhance immune capacity,regulate blood lipid metabolism,and improve intestinal microflora species richness of growing pigs.Under the conditions of this experiment,the optimal supplemental level of MLE in the diet of growing pigs is 1000mg/kg.