Science & Technologies Volume VI, 2016, Number 5: VETERINARY MEDICINE, ANIMAL STUDIES 61 VARIABILITY BETWEEN WHEAT DRY DISTILLERS GRAINS WITH SOLUBLES SAMPLES INFLUENCE THE EFFECTIVENESS OF EXOGENOUS ENZYMES WHEN FED TO BROILER CHICKENS V. Pirgozliev*, I. Whiting*, S. P. Rose*, S. G. Ivanova 1 , G. Staykova 1 , A. M. Amerah 2 The National Institute of Poultry Husbandry (NIPH), Harper Adams University, Shropshire, TF10 8NB, UK 1 Agricultural Institute, Shumen, 3 Simeon Veliki blvd., 9700, Bulgaria 2 Danisco Animal Nutrition, Wiltshire, SN8 4AN, UK Corresponding author: vpirgozliev@harper-adams.ac.uk Abstract A study was conducted to investigate the effects of supplementary enzyme on growth performance, N-corrected metabolisable energy (AMEn) and total tract dry matter (DMR) and nitrogen (NR) retention in broilers fed diets containing two different wheat dry distillers grains with solubles (DDGS) samples. A total of 40 male Ross 308 broilers were allocated to 4 dietary treatments in a randomized block design with 5 replicates per treatment, from 7 to 21 d post hatching. The experiment consisted of a 2 × 2 factorial arrangement of treatments with 2 DDGS samples at 2 dietary levels (0 or 150 g/kg) and 2 dietary levels of supplementary enzyme (0 or 100 g/tonne, providing 1220 units xylanase and 152 units of β-glucanase /kg diet). Titanium dioxide was included in the diets as an indigestible marker. Growth was measured throughout the experiment and excreta were collected on the last day of the study at 21d age. Feeding DDGS did not influence (P>0.05) AMEn, AMEn intake, DMR and NR. However, enzyme supplementation improved (P<0.05) AMEn, AMEn intake, DMR and NR. There was a DDGS × enzyme interaction (P<0.05) on weight gain, feed conversion and energy conversion ratios, with greater enzyme effect in the DDGS sample that had a higher polysaccharide content. Thus the composition of DDGS should be considered when evaluating the use of fibre degrading enzymes for broiler diets. Key Words: wheat DDGS; broilers; growth performance; enzyme; ME