Effects of exogenous enzymes and dietary energy on performance and digestive physiology of broilers

Jialing Zou,Xuemei Ding,Ping Zheng,Shiping Bai,Keying Zhang

doi:10.1186/2049-1891-4-14

Abstract

The study was conducted to compare the effects of XG with AG and BM at different metabolizable energy diets on growth performance, digestive physiology and energy utilization of broilers fed with corn-SBM diet. A 2 × 4 factorial design was used with two basal diets (the positive control group, PC; negative control with ME reduction 100 kcal/kg, NC) and with or without the addition of three exogenous enzymes (0.02% BM; 0.01% AG; 0.05% XG) respectively. 1,200 one-day-old broilers were randomly allocated to 8 treatments with 10 pens of 15 broilers. There was no significant difference on BW, BWG, and FI at 0-21d, 21-42d or 0-42d for diet, enzymes or their interactions, but FI at 22-42d and 0-42d were tend to be decreased with the addition of enzymes. The F/G was significantly improved by the addition of enzymes especially in NC diet. The dietary AME and TME in PC or NC diet were significantly increased by XG or AG in NC diet. The villus length and V/C of ileum were significantly increased by the addition of BM or XG. XG improved the activities of trypsin, chymotrypsin and amylase, BM improved the activity of trypsin at 21d, and AG improved the activity of chymotrypsin at 21d. Comparing to PC diet, the addition of enzymes in PC or NC diet decreased feed cost per kg body weight gain especially in NC diet (except AG in PC diet) with the highest profits for XG in NC diet. In conclusion, supplementation of 0.02% BM or 0.01% AG or 0.05% XG could improve feed conversion of broilers in corn-soybean meal diet by improving energy utilization and digestive physiology, and also supplementation of 0.05% XG had a preferable efficacy in low energy diet.

Highlights

The identification and alleviation of factors that inhibit nutrient utilization are necessary for poultry production
BM at two metabolizable energy diets on growth performance, digestive physiology and energy utilization of broilers fed with corn-SBM diet
There was no significant difference on body weight (BW), body weight gain (BWG), and feed intake (FI) at 0-21d, 22-42d or 0-42d for diet, enzymes or their interaction, but the FI at 22-42d and 0 d 21 d 42 d 0-21 d 22-42 d 0-42 d no 42.4 816.5 2,590.2 774.1 1,773.0 2,547.0

Summary

Introduction

The identification and alleviation of factors that inhibit nutrient utilization are necessary for poultry production. Researchers have proved that corn-SBM diet contains numerous antinutritional factors, such as β-glucans, β-mannose, protease inhibitors and lectins, and it has been proved that the addition. BM is a commercial β-mannanase product, AG is a commercial galactosidase product and XG is a new commercial enzyme product containing endoxylanases and β-Glucanase. Studies have demonstrated that β-mannanase in corn-SBM diet improved growth performance and energy utilization in broilers [4]. AG is used in poultry diet containing soybean meal with improved growth performance of broilers and nutrient availability of soybean meal [5,6]. Owusu-Asiedu reported that the addition of mixed xylanase and β-Glucanase improved performance in weaned pigs [7]. Cowieson reported that Xylanase and β-Glucanase improved feed conversion ratio and ileal nutrient digestibility in broilers [8]

Methods

Results

Conclusion