Effects Of Enzyme Preparation On Duck Performance, Digestive Organs And Characteristics Of Intestinal Tract

Two experiments were done to study the effects of enzyme preparations in low ME diets on growth performance,digestive organs and characteristics of Intestinal Tract for ducks. The experiment 1 was carried out to compare the effects of 4 enzyme preparations on the ducks performance and nutrients ileal apparent digestibility of diets.There were 7 treatments as follows:positive control(PC,ME:0～21 d 12.13 MJ/kg,22～42 d 10.92 MJ/kg);negative control(NC,ME:0～21 d 11.76 MJ/kg,22～42 d 10.59 MJ/kg).Other five treatments were NC with the addition of enzyme preparation A(500 g/t),or B(200 g/t),or C(150 g/t),or C(300 g/t),or D(200 g/t).Enzymes B,C,D were liquid.The enzymes composition and activity(u/g) were as follows:A were cellulose(15000), xylanase(220000),glucanase(330000),pectinase(40000),mananase(2500), acid-protease(3000),nutrual-protease(3000),amylase(50),gluco-amylase(2400);B was xylanase(1800),glucanase(4600);C was cellulose(500),xylanase(15000),glucanase(5000), pectinase(100);D was xylanase 9300.784 1-d-old male Cherry Valley ducks were randomly allotted to 7 treatments with 7 replicats of 16 ducks.The basal diet was com-soybean meal- rapeseed meal-wheat bran diet.All diets were in mash.Ducks were fed in cage and free access to feed and water.Results were as follows:The growth performance and ileal apparent digestibility of nutrient in the NC group were tended to lower than that in PC(P＞0.05).The 42-d body weight,22～42 d and 1～42 d average body gain in enzyme D group were significantly higher than enzyme A group(P＜0.05).There was no significant difference in average feed intake among the groups.During 1～22 d,the feed to gain ratio(F/G) was the highest for enzyme B with the great significant difference to enzyme D(P＜0.01),PC and enzyme C(150 g/t)(P＜0.05),while there were no significant difference among the groups during 22～42 d.During 1～42 d,the F/G was the lowest for enzyme D with the significant difference to enzyme A,B,C(300 g/t) and NC(P＜0.05). Compared to NC,the crude protein ileal apparent digestibility were improved by the addition of enzyme C(150 g/t) or enzyme D(P＜0.05).It was concluded that the addition of enzyme D or enzyme C(150 g/t) in NC diets could improve the growth performance and nutrients ileal apparent digestibility of diets for ducks,while there were no improvement effects with the addition of enzyme A,or B,or C(300 g/t).The experiment 2 studied further the effects of xylanase added in the different-energy-density diets on the growth performance,digestive organs and characteristics of the intestinal tract for ducks.A trial of 2×4 factorial design was conducted with xylanase addition of 0 or 1860 u/kg in the duck diets with different ME levels(0～14 d & 15～42 d respectively:diet A 12.13 & 10.92 MJ/kg;diet B 11.76 & 10.59 MJ/kg;diet C 11.38 & 10.25 MJ/kg;diet D 11.00 & 9.92 MJ/kg).576 1-day-old male Cherry Valley ducks were randomly assigned to the 8 treatments with 6 replicates of 12 birds.The basal diet was corn-soybean meal-rapeseed meal-wheat bran diet and in mash.Ducks were fed in cage and free access to feed and water.Results showed that xylanase improved average body weight(ABW)(P＜0.01) and average body gain(APG)(P＜0.01) and the feed to gain ratio(F/G)(P＜0.05) during 1～42 d,while the lower ME level decreased the ABW(P＜0.01) and APG(P＜0.01) with the increase of average feed intake(P＜0.05) and F/G(P＜0.01).The lower ME diet decreased the cecum digesta pH on day 7(P＜0.01),while xylanase had no such effects(P＞0.05).The relative length of 37 d jejunum was decreased by xylanase(P＜0.05) and increased with lower ME level(P＜0.05).Both xylanase and ME content did not affect the digesta viscosity of jejunum and ileum,the relative weight of pancreas and gizzard,the relative length of each segments of small intestinal except the 37 d jejunum,the digesta pH in cecum on day 13 and 37 and the relative proportion of Lactobacillus and Escherichia coli in ileum(P＞0.05).There were no significant interaction effects between the ME level and xylanase(P＞0.05).In conclusion,the duck growth performance could be improved with the addition of xylanase in different ME diets.With the addition of xylanase in lower ME diet,the growth performance could reach to the degree of the higher ME but without xylanase diet.