The effect of xylanase in grower-finisher pigs fed low or high fat diets.

Abstract Text: This trial was designed to determine if the use of a xylanase (Econase XT) would improve pig performance in low (3% added fat) or high (6% added fat) fat diets. At 21 d post-weaning 1,680 pigs were selected (840 gilts and 840 barrows), weighed and randomly (within sex) allocated to one of four treatments: 1) low fat (LF), 2) LF + 16,000 BXU/kg xylanase, 3) high fat (HF) and 4) HF + 16,000 BXU/kg. Each treatment had 20 pen replicates (10 pens of barrows and 10 pens of gilts) with 21 pigs per pen. From 21 d of age, pigs were fed an 8 phase feeding regimen with each phase allocated on a kg/pig feed budget basis. When the treatment group had consumed the delivered budget all pens within that treatment were switched to the next phase of the feeding regime. Diets were based on corn/soybean meal/corn distillers and added fat (AV blend). All pigs were weighed at 21 days post-weaning and then every 21 d until d 146. Data (d 21 to d 146) were analysed as a simple ANOVA using JMP v10 with pen as the experimental unit. Data were analysed as a 2 (xylanase level) x 2 (added fat level) x 2 (sex) factorial. There were no interactions between main effects, thus only the main effect means are reported. Barrows had a significantly greater ADG (910 v 840 g/d; P < 0.01) and ADFI (2.04 v 1.84 kg/d; P < 0.01) than gilts, with gilts having an improved FCR (2.15 v 2.24; P < 0.01). The addition of added fat from 3% to 6% significantly increased ADG (880 v 870 g/day; P < 0.05) and ADFI (1.98 v 1.88 kg/d; P < 0.01) while improving FCR (2.13 v 2.27; P < 0.01) The addition of xylanase at 16,000 BXU/kg had no significant effect on ADFI or ADG but improved FCR (2.18 v  2.21; P < 0.01). In conclusion, the use of xylanase in corn/soybean meal/corn distillers based grower-finisher diets improved FCR irrespective of added fat level (3% or 6%).

Keywords: pig, xylanase, finisher