饲粮非植酸磷水平对14日龄仔鹅肠道组织形态、食糜酶活性及菌群结构的影响

Effects of Dietary NonPhytic Phosphorus Levels on Intestinal Morphology,Chyme Enzyme Activities and Microbial Structure of 14-Day-Old Goslings

本试验旨在通过研究饲粮非植酸磷(NPP)水平对14日龄仔鹅肠道生长、肠道重要酶活性、肠道组织形态以及空肠菌群结构的影响,探究NPP水平影响仔鹅生长性能的作用机制。选取216只1日龄的江南白鹅公鹅,随机分为3组,每组6个重复,每个重复12只。3组饲粮NPP水平依次为0.08%(低磷组,LP组)、0.38%(对照组,CP组)、0.80%(高磷组,HP组)。试验期14 d。结果表明:1)LP组十二指肠、空肠和回肠的绝对长度、绝对重量显著低于CP组和HP组(P<0.05),CP组与HP组的肠道绝对长度没有显著差异(P>0.05);而LP组肠道相对长度均显著高于CP组和HP组(P<0.05),CP组肠道相对长度显著高于HP组(P<0.05);LP组和CP组肠道相对重量没有显著差异(P>0.05),LP组和CP组空肠和回肠的相对重量显著高于HP组(P<0.05)。2)LP组十二指肠黏膜碱性磷酸酶活性显著低于HP组(P<0.05);LP组空肠Na^(+)⁃K^(+)ATP酶的活性显著低于CP组和HP组(P<0.05),CP组和HP组之间Na^(+)⁃K^(+)ATP酶活性没有显著差异(P>0.05)。3)不同组间各肠段的绒毛高度、隐窝深度、肌层厚度无显著差异(P>0.05)。4)LP组空肠代尔夫特菌属(Delftia)、苍白杆菌属(Ochrobactrum)、不动杆菌属(Acinetobacter)和黄杆菌属(Flavobacterium)的相对丰度显著高于CP组和HP组(P<0.05);TM7和厚壁菌门(Firmicutes)的相对丰度显著高于CP组和HP组(P<0.05);在属水平和门水平下,CP组和HP组之间的菌群相对丰度没有显著差异(P>0.05)。综上所述,仔鹅饲粮NPP水平过低可代偿性地增加肠道相对长度,但其造成的肠道功能性酶活性下降、空肠菌群结构失衡可能是饲粮低磷导致仔鹅生长性能下降的重要原因;同时鹅可耐受高达0.80%的NPP且对仔鹅早期肠道发育、空肠菌群结构无负面影响。

This study was conducted to investigate the effects of dietary nonphytate phosphorus(NPP)levels on the intestinal growth,activities of important intestinal enzymes,intestinal morphology and jejunal microbial structure of 14-day-old goslings,and to explore the mechanism of NPP levels on the growth performance of goslings.A total of 216 one-day-old male Jiangnan White geese were randomly divided into three groups,with six replicates in each group and 12 geese in each replicate.The dietary NPP levels of the three groups were 0.08%(low phosphorus group,LP group),0.38%(control group,CP group)and 0.80%(high phosphorus group,HP group).The experiment lasted for 14 days.The results showed as follows:1)the absolute length and weight of duodenum,jejunum and ileum in LP group were significantly lower than those in CP group and HP group(P<0.05).There was no significant difference in the absolute length of intestine between CP group and HP group(P>0.05).The relative length of intestine in LP group was significantly higher than that in CP group and HP group(P<0.05),and the relative length of intestine in CP group was significantly higher than that in HP group(P<0.05).There was no significant difference in the relative weight of the intestine between LP and CP groups(P>0.05).The relative weight of jejunum and ileum in LP and CP groups was significantly higher than that in HP group(P<0.05).2)The alkaline phosphatase activity of the duodenal mucosa was lower in LP group than in HP group(P<0.05);the Na^(+)K^(+)ATPase activity was lower in LP group than in the CP group and HP group(P<0.05),there was no significant difference in Na^(+)-K^(+)ATPase activity between the CP group and the HP group(P>0.05).3)No difference was observed in the villus length,crypt depth,and muscle layer thickness of each intestinal segment between groups(P>0.05).4)The relative abundances of Delftia,Ochrobactrum,Acinetobacter and Flavobacterium were significantly higher in LP group than in the CP group and HP group(P<0.05),the relative abundances of TM7 and Firmicutes were significantly higher in LP group than in the CP group and HP group(P<0.05),there was no significant difference in microbiota relative abundance between the CP group and the HP group at the genus and phylum levels(P>0.05).In conclusion,goslings fed low dietary NPP level can compensatory increase in the relative length of the intestine,but the consequence of lower intestinal functional enzymes’activity and imbalance of jejunal microbial structure may be important reasons for the decline of growth performance;at the same time,geese can tolerate NPP up to 0.80%and has no negative impact on the early intestinal development and jejunal microbial structure of geese.