摘要
Abstract
This study was conducted to investigate how different dietary inclusion levels of Poria cocos polysaccharide(PCP)modulate growth performance,serum amino acid profiles,and intestinal morphological and barrier functions in broiler chickens.A total of 240 healthy,1-day-old male Arbor Acres broilers,with an average initial body weight of 42.3+1.2 g were randomly allocated into 4 experimental groups,each comprising 6 replicates with 10 birds per replicate.Birds in the control group(CON)received a basal diet,whereas the LCP,MCP,and HCP groups were offered the basal diet supplemented with 250,500,and 1000 mg/kg of PCP(purity≥85%),respectively,over a 42-day feeding period.The results revealed that:1)Broilers in the MCP and HCP groups presented significantly enhanced growth performance compared with the CON group(P＜0.05),as evidenced by a higher average daily gain(ADG)and a lower feed conversion ratio(F/G);notably,the MCP group achieved the optimal growth response,with ADG increasing by 10.2%relative to the CON group(P＜0.05).2)Serum concentrations of total protein(TP)and albumin(ALB)were significantly elevated in the MCP and HCP groups(P＜0.05),accompanied by a marked reduction in serum urea nitrogen(SUN)levels(P＜0.05).Furthermore,PCP supplementation generally increased the serum levels of essential amino acids(threonine,valine,isoleucine,and leucine),with the MCP group exhibiting the most pronounced differences from the CON group(P＜0.05).3)Histomorphological analysis indicated that the MCP and HCP groups had significantly greater villus height(VH)and villus height to crypt depth ratio(V/C),along with reduced crypt depth(CD)in the duodenum and jejunum(P＜0.05).Correspondingly,the relative mRNA expression levels of Occludin and Zonula Occludens-1(ZO-1)in the jejunal mucosa were also significantly upregulated in these two groups(P＜0.05).In conclusion,adequate dietary PCP supplementation effectively promotes growth performance,facilitates amino acid metabolism and protein deposition,and ameliorates intestinal morphology and barrier function in broilers.Under the conditions of this experiment,the recommended supplementation level of PCP is 500 mg/kg.关键词
茯苓多糖/肉鸡/生长性能/氨基酸代谢/肠道形态/紧密连接蛋白Key words
Poria cocos polysaccharide/broiler chickens/growth performance/amino acid metabolism/intestinal morphology/tight junction proteins分类
农业科技
