LAUSR

β-mannans (β-galactomannans) are anti-nutritive fibers found in common feed ingredients, such as soybean meal and other vegetable proteins. If not controlled, these β-mannans cause unnecessary gut inflammation which diverts nutrients from production to maintenance. Hemicell® HT has been shown to breakdown β-mannans allowing energy and nutrients to be available for growth and performance. The objective of this study was to evaluate the effects of β-mannanase (Hemicell® HT 1.5X) on sow and litter performance in a commercial farm. A total of 261 sows averaging 268 kg (± 91 kg) and 3.5 (± 2.3) average parity were randomly allotted to 1 of 2 lactation diets. Dietary treatments included: 1. Corn/soybean meal feed (control) and 2. Control + Hemicell® HT 1.5X (0.25 kg/ton inclusion). Treatments were initiated on d of farrowing and terminated at weaning. All data were analyzed as a randomized complete block design using Proc MIXED in SAS 9.4 (SAS Inst. Inc., Cary, NC). Sow and litter served as the experimental unit, farrowing room as block, and lactation length as a covariate when significant (P ˂ 0.05). Results indicated no significant (P > 0.20) differences in sow BW or body condition score (BCS) prefarrowing, postfarrowing, or at weaning. Sows consuming Hemicell® HT 1.5 had significantly (1.43 vs. 1.55; P = 0.03) greater backfat thickness (BF) at weaning and tended (P = 0.10) to lose less weight (-18 vs. -15 kg) than those fed Control. Feed intake, BCS and BF change, and subsequent wean-to-service interval were similar (P > 0.41) for sows on both treatments. Litter ADG and wean weight were not different (P > 0.18). The results indicate that Hemicell® HT 1.5 improved body reserves at weaning when consumed through the lactation period, suggesting increased energy availability during this period, which could have positive implications on overall lifetime reproductive performance.