Xylanase Significantly Improves Feed Efficiency in High Fiber Diets

Abstract Feed is the greatest expense in pig production and improving efficiency while utilizing lower priced ingredients can help ameliorate this cost. The objective of this experiment was to determine the impact of utilizing a xylanase enzyme (Danisco Xylanase, IFF) on growth performance of pigs fed high fiber diets. We hypothesized that feeding xylanase would improve G:F and ADG when added to a greater fiber diet. To test this hypothesis, 672 PIC 359 x Yorkshire pigs were randomly allotted to pens based on body weight at an average age of 20.8 ± 1.0 d. Pens were randomly assigned to one of the following treatments: Control corn/soy diet (CON), Greater fiber diet (up to 40% dried distillers grains and 10% wheat middlings FIB), and Greater fiber diet plus xylanase (XYL). The CON and the FIB diets were formulated to contain the same net energy. In the XYL treatment, xylanase was added on top of the GF diet with no reformulation or energy release assigned to the xylanase. All pigs were weighed and feed disappearance was measured weekly to calculate ADG, ADFI, and G:F. Growth performance data were analyzed using the PROC MIXED procedure in SAS with pen as the experimental unit. There were 17 pens per treatment for CON and FIB and 16 pens per treatment for the XYL treatment. To increase the number of replicates, the trial was conducted over 3 consecutive turns of pigs. Dietary treatment, repetition, week, and two-way interactions were fixed effects. Results were considered significantly different at P ≤ 0.05. In the 7-week nursery period, the pigs fed CON had increased ADG (CON: 0.52 kg/d, FIB: 0.48 kg/d, XYL: 0.48 kg/d) and ADFI (CON: 0.85 kg/d, 0.81 kg/d, 0.80 kg/d) when compared with FIB and XYL treatments (P ≤ 0.05). There were no differences in growth performance between the pigs fed FIB and the pigs fed XYL in the nursery phase. At the end of the nursery phase, pigs were randomly allotted within treatment to different cohorts in the growing finishing period. In the 12-wk growing finishing period, pigs fed FIB and XYL had decreased ADG compared with pigs fed Control diets (CON: 1.05 kg/d, FIB: 0.97 kg/d, XYL: 0.96 kg/d; P ≤ 0.05). In addition, pigs fed XYL diets had improved G:F when compared with both FIB and CON (CON: 0.402, FIB: 0.400, XYL: 0.414; P ≤ 0.05). This improvement in feed efficiency in the XYL treatment seemed to be driven by a significant reduction in ADFI (P ≤ 0.05), which suggests, adding xylanase to a diet without accounting for energy release, reduces overall feed intake and growing more efficiently, as expected with more available energy.