Effect of xylanase on the performance of laying hens fed a low energy corn and soybean diet.

This study was conducted to determine the effect of high- and low-activity xylanase in a corn and soybean diet on the performance of laying hens. There were 2 phases each with 4 treatment diets: positive control (PC), negative control (NC) with lower metabolizable energy (ME) and nutrient density, and 2 different xylanases supplemented to the NC diet. Phase 1 was 23-43 wk of age and phase 2 was 43-58 wk, for a total duration of 35 wk. The NC diet had a lower ME in phase 2 than phase 1. There were 72 cages with 3 Bovan White Leghorns each. Egg production (EP) was recorded daily, feed intake (FI) weekly, and average egg weights (EW) biweekly. Egg production and FI were calculated using biweekly periods, also used to determine egg mass (EM) and feed conversion (FC) with biweekly EW. BW was recorded and analyzed for weeks 0, 10, 20, and 35 of the study. Egg production did not differ among treatment groups (phase 1: P = 0.47; phase 2: P = 0.54). In phase 1, EW and EM were significantly lower in the NC diet with enzyme B, compared to both the PC and NC diets (P = 0.019; P = 0.01). The PC diet yielded higher EW than all other treatments in phase 2 (P = 0.036), but no differences in EM were present (P = 0.12). Baseline BW was not different (P = 0.63), but hens fed the PC diet had higher BW in subsequent measurements (P ≤ 0.05). Hens fed the PC diet had lower FI than all other treatment groups in both phases (P = 0.0001), and had an improved FC than the 2 enzyme groups in phase 1 (P = 0.0001) and all other treatment groups in phase 2 (P = 0.0001). The enzymes did not improve the performance of the birds.