Effects Of Dietary Cottonseed Meal Level On The Intestinal Barrier Function System Of Chickens

Three experiments were conducted to study the effects of cottonseed meal on intestinal barrier system in laying hens and male young chick by diets supplemented withdifferent levels of cottonseed meal; futher more, on the basis of this experiment, westudied the effect of adding glutamine in high cottonseed meal diets on the basis on the mitigation role of the intestinal barrier dysfunction in male young chick, so as, wecan provide a theoretical basis for passing feed phenomenon due to using many mixed meal which lead to chicken intestinal damage.Trial1, two hundred seventy23week old sea blue brown laying hens were randomly dividedinto three treatments each consisted of three replications of thirty chickens. According to the national standards for feed hygiene, free gossypol in compound feed for laying hens is limited20mg/kg. Three treatment groups were no cottonseedmeal control group、equivalent to20mg/kg gossypol complete feed cottonseed meal group、equivalent to40mg/kg gossypol complete feed cottonseed meal group. The experiment period was35weeks, during period, free feeding and drinking water.The resultsof experiment1showed that: compared with control group, cottonseed meal group significantly increased the TNF-α level in the plasma of hens(P<0.05), high cottonseed meal group significantly increased the LPS level in the plasma(P<0.05); The cottonseed meal group significantly decreased the mRNAexpression of ZO-2in the jejunum(P<0.05); The cottonseed meal group had no effect on immune indicators in laying hens(P>0.05); also, cottonseed meal group significantly increased the number of E.coli in the cecum and decreased the number of lactic acid bacteria in the cecum(P<0.05); cottonseed meal group significantly reduced the villus height in jejunum(P<0.05),high cottonseed meal group significantly reduced villus height and crypt depth ratio in jejunum(P<0.05). Trial2, two hundred forty1day old sea blue brown male young chick were randomly divided into three treatments each consisted of four replications of twenty chickens. According to the national standards for feed hygiene, free gossypol in compoundfeed for the growing chicken is limited100mg/kg. Three treatment groups were no cottonseed meal control group、equivalent to100mg/kg gossypol complete feed cottonseed meal group、equivalent to200mg/kg gossypol complete feed cottonseed meal group. The experiment period was4weeks, during period, free feeding and drinking water. The results of experiment2showed that: high cottonseed meal group significantlyreduced the average daily gain of male young chick for four weeks period(P<0.05),but the cottonseed mealgroup had no effect on feed intake and feed conversion(P>0.05); high cottonseed meal group significantly increased the TNF-α level in the plasma(P<0.05), but low cottonseed meal group and control group were no significant difference(P>0.05), also, cottonseed meal group had a increased trend of LPS in plasma;Highcottonseed meal group significantly decreased the mRNA and protein expressionof Occludin(P<0.05), but low cottonseed meal group and control group were no significant difference(P>0.05); cottonseed meal group had a decreased trend of the mRNA expression of IL-2in duodenum and jejunum, high cottonseedmeal group significantly increased the mRNA expression of TLR-5in the jejunum(P<0.05), but low cottonseed meal group and control group were no significant difference(P>0.05); cottonseed meal group significantly increased crypt depth and reduced villus height andcryptdepth ratio in duodenum(P<0.05), cottonseed meal group significantly reduced thevillus height in jejunum(P<0.05), high cottonseed meal group significantly reduced villus height and crypt depth ratio in jejunum(P<0.05), but low cottonseed meal group and control group were no significant difference(P>0.05); cottonseed meal grouphad a certain impact on microbial community in cecal.Trial3, on the base of trial2, glutamine supplementation treatment. Ninety six1day old sea blue brown male young chick were randomly divided into four treatmentseach consisted of three replications of eight chickens. Four treatment groups were nocottonseed meal control group、1%L-glutamine group、equivalent to200mg/kg gossy pol complete feed cottonseed meal group、equivalent to200mg/kg gossypol completefeed cottonseed meal+1%L-glutamine group. The experimentperiod was3weeks, during period, free feeding and drinking water. The results of experiment3showed that:glutamine group significantly increased the average daily gain of male young chick forthree weeks period(P<0.05), glutamine and cottonseed meal combination group hadsome improvement on average daily gain, also, glutamine group significantly increasedintake feedand had a decreasedtrend of feed conversion of male young chick(P<0.05); glutamine group significantly increased the D-xylose content in the plasma(P<0.05), but glutamine and cottonseed meal combination group had no elevated phenomenon; glutamine group had a increased trend of duodenum index, but glutamine and cottonseed meal combination group had no elevated phenomenon; glutamine group significantly decreased the TNF-α level inthe plasma(P<0.05), also, glutamine and cottonseed meal combination group had a decreased trend of the TNF-α level in the plasma; glutamine group and cottonseed meal combination group had a decreased trend of IL-6level in the plasma; glutamine group and glutamine group and cottonseed meal combination group significantly decreased the LPS level in the plasma(P<0.05).In conclusion, long term feeding high gossypol content of cottonseed meal will affect intestinal barrier function system in sea blue browm laying hens and male youngchicks; adding appropriate amount of glutamine based on high gossypol content of cottonseed meal has a role in mitigation.