Addition of nonstarch polysaccharides degrading enzymes to two hulless barley varieties fed in diets for weaned pigs

A study was conducted to evaluate the effect of 2 hulless barley varieties, with or without the addition of a nonstarch polysaccharide (NSP) enzyme complex (β-glucanase and xylanase), on growth performance of weaned piglets in a 42-d feeding study. The study was conducted with 140 piglets (PIC × Duroc). Pigs were allocated to pens (4 castrated males or 4 females per pen) based on BW and sex, and pens were assigned to 5 experimental diets with 4 pens of castrated males and 3 pens of females per treatment. Five isonitrogenous and isoenergetic diets were compared: 1) control corn-based diet (CTR), 2) diet with corn and wheat bran replaced by the Astartis hulless barley variety (AS), 3) diet with corn and wheat bran replaced by the AS supplemented with the NSP enzyme complex (ASE), 4) diet with corn and wheat bran replaced by the Alamo hulless barley variety (AL), and 5) diet with corn and wheat bran replaced by the AL supplemented with the NSP enzyme complex (ALE). The diets were formulated to meet or exceed nutrient requirements and offered in 2 phases: d 0 to 14 and d 14 to 42. At the end of the study, pigs fed AS and AL had equal weights as pigs fed CTR. Pigs fed the hulless barley diets had greater (P < 0.05) ADG during the second phase (P2) and overall phase, BW at d 42, and G:F during the P2 than those fed the CTR. Pigs fed the ASE and ALE had greater (P < 0.05) ADFI during the P2 and overall ADG than those fed the AS and AL. The increases in ADG during the P2 and final BW obtained with NSP enzyme supplementation were greater in pigs fed the AS than those fed the AL (barley × enzyme, P < 0.05). On the other hand, the NSP enzyme complex increased G:F in pigs fed the AS during the P2 and overall phase, but it had no effect on those fed the AL (barley × enzyme, P < 0.05). In conclusion, hulless barley with or without the NSP enzyme complex can be a replacement ingredient for corn and wheat bran in weaned pig diets. Addition of the NSP enzyme complex to AS variety, but not AL variety, improved growth performance of weanling pigs.