Inclusion of a high dose of phytase and xylanase to diets and its influence on growth performance and bone characteristics of growing pigs

摘要

An experiment was carried to evaluate the use of standard phytase (PHY) supplementation or a high dose of PHY and xylanase (XYL) supplementation to diets with reduced available P (avP), Ca, amino acids (AA) or net energy (NE) contents for growing pigs. One-hundred ninety-two 23.5 kg male pigs were assigned to 6 dietary treatments. Treatments corresponded to an un-supplemented control (PC) diet, or a mineral (avP, Ca) reduced (IC) diet supplemented with 500 FTU/kg PHY; Two negative control (NC) dietsformulated with a greater mineral (avP, Ca) reduction, and AA or AA plus NE reduction, respectively; and finally, these 2 NC diets supplemented with a 2,000 FTU/ kg of PHY and 9,600 BXU/kg of XYL. Pigs fed IC diets supplemented with 500 FTU/kg PHY maintained (P>0.05) growth performance, feed efficiency, and bone characteristics similar to pigs fed PC diets. On the other hand, pigs fed on both NC diets showed a reduced growth performance and feed efficiency (PO.OOl), as well as reduced bone breaking strength, stiffness,ash and ash P contents (PO.001). Dietary supplementation with both PHY and XYL enzymes restored growth, feed efficiency, bone stiffness, ash and ash P content to the same level as the PC and IC diets (P>0.05). From these results, it can be concluded that there is value in using a high dose of PHY and XYL to reduce dietary costs whilst maintaining performance of growing pigs.