Effects Of Enzyme Supplementation And Extrusion On The Nutrient Apparent Digestibilities Of Diets Containing High-level Of Defatted Rice Bran In Growing Pigs

The aim of this paper is to evaluate the effects of enzyme supplementation（cellulase+xylanase + phytase + ferulic acid esterase）and extrusion on nutrients,amino acids,non-starch polysaccharides,minerals and phenolic acids apparent digestibility of diets containing defatted rice bran in growing pigs.The defatted rice bran was used as the sole source of fiber in all diets.Four experimental diets were composed according to a 2 x 2 factorial design with defatted rice bran（DRB）or extrusion defatted rice bran（EDRB）with or without enzyme addition.Four Duroc x Landrace x Yorkshire crossbred barrows with an initial body weight of 18 ± 1.5 kg were fitted with ileal T-cannulas and were fed the 4 experimental diets according to a 4 x 4 Latin square arrangement.Four periods with 10 d of each were carried out;AfLer 5 U adaptation,faces were collected on the 6fth and 7th d,and ileal Uigesta samples were collected on the 8th,9th and 10th d from every pig in each period.The main results of the test were as follows:Experiment 1 Effect of enzyme supplementation and extrusion on proximate nutrients and non-starch polysaccharides apparent digestibility of diets containing defatted rice bran in growing pigsThe experiment was conducted to determine the effect of enzyme supplementation and extrusion on ileal and total digestive tract apparent digestibility of proximate nutrients,amino acids and non-starch polysaccharides.The results showed as follows:（1）In the ileum,enzyme supplementation significantly increased the apparent digestibility of dry matter（P=0.042）,gross energy（P=0.022）,crude protein（P=0.009）,ash（P<0.001）,methionine（P =0.005）,threonine（P=0.044）and valine（P=0.002）;TNSP（P=0.033）,Ara（P=0.036）,Xyl（P=0.013）and Glu（P=0.037）;INSP（P=0.018）,Ara（P=0.010）,Xyl（P=0.014）,Glu（P=0.046）and Cel（P=0.024）.Extrusion processing significantly decreased the apparent digestibility of dry matter（P=0·011）,organic matter（P=0.015）,gross energy（P=0.008）,crude fat（P=0.030）,isoleucine（_P=0.047）.leucine（P=0.030）,threonine（P=0.009）and valine（P=0.003）;Extrusion processing significantly increased the apparent digestibility of UA（P=0.004）,but decreased Xyl（P=0.001）in INSP and Cel（P=0.013）;Extrusion processing significantly decreased the apparent digestibility of TNSP（P=0.033）,Xyl（-P=0.008）and Glu（P=0.016）;There were no interaction among enzyme supplementation and extrusion processing.（2）In the total digestive tract,enzyme supplementation significantly increased the apparent digestibility of ash（P=0.008）,extrusion processing significantly decreased the apparent digestibility of dry matter（P=0.002）,organic matter（P=0.004）,gross energy（P<0.001）5 crude protein（P=0.040）,and crude fat（P<0.001）;Extrusion processing significantly increased the apparent digestibility of Glu（P=0.007）in TNSP,and INSP（P=0.003）and monosaccharide component Gal（P<0.001）,Glu（P=0.001）,UA（P=0.047）and Cel（P=0.003）;There were no interaction among enzyme supplementation and extrusion processing.In conclusion,enzyme supplementation could improve the apparent digestibility of nutrient,amino acids and non-starch polysaccharide at the il eum.Extrusion processing could improve the apparent digestibility of TNSP monosaccharide components Glu and INSP and monosaccharide components Gal,Glu,UA and cellulose in the total digestive tract.However,there was no advantage for other nutrients.Experiment 2 Effect of enzyme supplementation and extrusion on minerals and phenolic acids apparent digestibility of diets containing defatted rice bran in growing pigsThe experiment was conducted to determine the effect of enzyme supplementation and extrusion on ileal and total tract apparent digestibility of minerals and phenolic acids.The results showed as follows:（1）In the ileum,enzyme supplementation significantly increased the apparent digestibility of phytate（P<0.001）,caffeic acid（P<0.001）,Fe（P=0.015）,Zn（P<0.001）,coumaric acid（P=0.010）,ferulic acid（P=0.007）,salicylic acid（P=0.003）,cinnamic acid（P=0.012）and total phenolics（P=0.012）;Extrusion processing significantly increased the apparent digestibility of phytate（P=0.004）,Fe（P=0.027）,ferulic acid（P<0.001）,cinnamic acid（P=0.002）and total phenolics（P<0.001）;enzyme supplementation and extrusion processing had an interaction with phytate（P<0.001）and Zn（P=0.044）apparent digestibility.（2）In the total digestive tract,enzyme supplementation significantly increased the apparent digestibility of P（P<0.001）,Ca（P<0.001）,Cu（P=0.017）and Zn（P=0.003）;Extrusion processing significantly increased the apparent digestibility of coumaric acid（P=0·017）,ferulic acid（P<0₀01）,cinnamic acid（P=0.007）and total phenolics（P<0.001）,but significantly decreased the apparent digestibility of P（P<0.001）,hydroxybenzoic acid（P<0.001）and salicylic acid（P<0.001）;Extrusion processing and enzyme supplementation had an interaction with salicylic acid（P=0.016）apparent digestibility.In conclusion,enzyme supplementation could improve the apparent digestibility of minerals in the ileum and total digestive tract of defatted rice bran diets and improve the apparent digestibility of phenolic acids at the ileum.The extrusion processing could improve the apparent digestibility of phytate and Fe in the ileum.In addition to hydroxybenzoic acid and salicylic acid,extrusion processing could improve the apparent digestibility of other phenolic acids and total phenols at the ileum and total digestive tract.