Enzymatic Studies Of Xylanase In Growing Pig Diets Replacing Corn With Wheat In Vivo And In Vitro

This study used a combination of the in vitro methods and the digestivetest, the effect of xylan hydrolysis in the diet of different gradients wheat instead ofcorn and its application were studied. Looking forward to finding a suitable amountof dietary xylanase, providing theoretical guidance for the production practice.Experiment1Enzymolysis effects of xylan in diet with different gradients of wheatinstead of corn in vitroBy simulating the gastrointestinal environment of piglets in vitro, the content changes ofxylan before and after enzymolysis were studied, which were in the diets of different gradients ofwheat instead of corn on corn-soybean meal diet, to find the relationship between thereplacement ratio and the adding level of xylanase. The proportion of wheat instead of cornwhich were25%,50%,75%,100%, the level of xylanase added to were0U/kg,2000U/kg,6000U/kg,10000U/kg, the cellulase level was200U/kg. The resultsshowed that:1. The experiment measured three kinds of feed ingredients of HENANlocal: corn, wheat, soybean meal, the content of soluble xylan and total xylanrespectively were1.51、51.01；5.16、71.92；2.67、47.64g/kg.2.As the alternativeproportion of wheat to increase, the content of soluble xylan and total xylan in the rawmaterial were increased, but the proportion of soluble xylan was increased first, thenunchanged.3.Content of xylan combination in raw material, a certain linear relationship existedbetween the theoretical value and the measured values; there was also a linear relation between theaddition of xylanase and the content of xylan in the filtrate after enzymolysis.4. Measured inthis experiment, the combination of several diets, each adding a suitable amount ofxylan were6000U/kg.Experiment2The application of different gradients of wheat instead of corn dietssupplemented with xylanase in growing pigsThis experiment comprised five digestion test. Selection of16healthy, weightuniform length x large crossbred pigs were randomly divided into four treatmentswith four replicates of a pig.In corn-soybean meal diets, alternative corn-based dietswith wheat, replacement ratio of25%,50%,75%,100%, consisted of four levels ofxylanase added in the proportion of each alternative0U/kg,2000U/kg,6000U/kg, 10000U/kg. The pre-test period were three days, and the official period were threedays. In the pre-test period, the0.3%Cr2O3were evenly mixed into the diet feed, inthe official period, the pig manure were collected, while collecting the pig diet for thedetermination. At the end of the test, the content of dry matter, organic matter, protein,energy, phosphorus, calcium in diets and fences were measured. The results showedthat:1.Dietary each group added xylanase could significantly improve the apparentdigestibility of dry matter, organic matter, protein, energy, phosphorus,calcium(p<0.05).In wheat-soybean meal diets, the digestibility of each index werethe highest. The digestibility of the indicators in each group were the highest with addthe amount of10000U/kg xylanase. Therefore, under this experimental conditions,the xylanase appropriate dosage was10000U/kg.3. In the same diet with differentenzyme levels, there was a certain linear relationship between in vitro and in vivo drymatter digestibility; and there was a certain linear relationship between in vitro netreducing sugar and in vivo digestibility of each substance.In the same enzyme levelswith the proportion of different alternatives,there was a certain linear relationshipbetween the replacement ratio and in vitro net reducing sugar and dey matterdigestibility;and there was a certain linear relationship between replacement ratio andin vivo digestibility of each substance;and there was a certain linear relationshipbetween in vitro net reducing sugar and in vivo digestibility of each substance.Thus, asimple method of in vitro to replace the in vivo method to evaluate the nutrition valueof diet was not perfect, it needed further research.