Effect Of Exogenous Enzyme Preparations On Nutrients Digestibility Of Growing Pig Grains And Their Byproducts In Vitro

The objective of the study were determine the digestibility of nutrients and energy of cereals and byproducts in growing pigs using in vitro and in vivo method and the effect of inclusion of screened exogenous enzyme on the digestibility of nutrients and energy of cereals and byproducts in growing pigs.The in vitro method for simulating nutrient digestion in the gastrointestinal tract was focused in the present study to improve an establishment of a quick and accurate system for enzyme evaluation and provide support for the rational use of cereal by-products.The objective of the Experiment I was deterrmine the digestibility of nutrients and energy of grain and by-products ingredient in growing pigs.A corn-soybean meal-control diet or a diet in which corn and soybean meal partly were replaced by 19.3%of wheat,wheat bran,rice,and rice bran were prepared,respectively.In vitro ileal digestibility,in vitro total tract digestibility,and in vitro hindgut digestibility of dry matter(DM)and gross energy(GE)were determined using the in vitro method simulated the digestion process of stomach,small intestine and large intestine.Fifth pigs were prepared by T-cannula insertion into the distal ileum and allotted to 5 treatments in a 5×2 incomplete Latin square design.Apparent ileal digestibility(AID),apparent total tract digestibility(ATTD),and hindgut fermentation(HF)of nutrients and gross energy were determined in the 5 diets and the correlation between the digestibility of energy using the in vitro and in vivo method was analyzed.The results show:(1)Different in vitro ileal and total tract digestibility of DM were different in the cereals and their byproducts diets as follow:Rice diet>wheat diet>basal diet>rice bran diet>wheat bran diet(P<0.05).The ileal digestibility of GE in the diets was as fllow:Rice diet>wheat diet>basal diet>rice bran diet and wheat bran diet(P<0.05).The total tract digestibility of GE and in vitro DE was as follow:Rice diet>wheat diet and basal diet>rice bran diet>wheat bran diet(P<0.05).(2)The AID of DM and GE in the wheat diet and rice diet were higher than in the wheat bran diet and rice bran diet(P<0.01),and the AID of DM in the basal diet were higher than in the wheat bran diet(P<0.01).The ATTD of DM was as follow:Rice diet>wheat diet and basal diet>rice bran diet>wheat bran diet(P<0.01).The ATTD of GE in the rice diet and basal diet were higher than in the wheat bran diet and rice bran diet(P<0.01),and the ATTD of GE in the wheat diet were higher than in the rice bran diet(P<0.01).The DE in the rice diet were higher than in the wheat diet(P<0.01),but and the DE in the wheat bran diet were less than in the other diets(P<0.01).(3)The correlation of AID of DM(R2 = 0.92)and GE(R2 = 0.94),ATTD of DM(R2 = 0.91),and DE(R2 = 0.85)of diets using the in vitro and in vivo method was very high(P<0.01).The objective of the Experiment II was determine the effect of inclusion of screened exogenous enzyme on the digestibility of nutrients and energy of cereals and byproducts in growing pigs using in vitro and in vivo method.Exogenous enzyme(xylanase 5 g/kg,amylase 3 g/kg,and phytase 0.5 g/kg)was added to diets of the Experiment II.The results show:(1)Different in vitro ileal and total tract digestibility of DM were different in the cereals and their byproducts diets with exogenous enzyme as follow:Rice diet>wheat diet>basal diet>rice bran diet>wheat bran diet(P<0.01).The ileal digestibility of GE in the diet was with exogenous enzyme as follow:Rice diet>wheat diet and basal diet>rice bran diet and wheat bran diet(P<0.01).The total tract digestibility of GE was as follow:Rice diet>wheat diet>basal diet>rice bran diet and wheat bran diet and the in vitro DE was as follow:Rice diet and wheat diet>basal diet>rice bran diet>wheat bran diet(P<0.01).(2)The AID of DM in the rice diet were higher than in the wheat bran diet and rice bran diet(P<0.01),and the AID of DM in the wheat diet and basal diet were higher than in the wheat bran diet(P<0.01).The ATTD of DM was as follow:Rice diet>wheat diet and basal diet>rice bran diet>wheat bran diet(P<0.01).The ATTD of GE in the rice diet and basal diet were higher than in the wheat bran diet and rice bran diet(P<0.01),and the ATTD of GE in the wheat diet were higher than in the rice bran diet(P<0.01).The DE in the rice diet were higher than in the wheat diet(P<0.01),but and the DE in the wheat bran diet were less than in the other diets(P<0.01).(3)The correlation of AID of DM(R2 = 0.89)and GE(R2 = 0.86),ATTD of DM(R2 = 0.96),and DE(R2=0.98)of diets using the in vitro and in vivo method was very high(P<0.01).In conclusion,in vitro method with relatively high accuracy and acceptable repeatability,might be used to evaluate quickly nutrient and energy digestibility of cereal and byproduct diets and the effect of exogenous enzyme for growing pigs.