Supplementation of a β-Mannanase Enzyme Improves Feed Efficiency in Palm Kernel Expeller Rich Swine Diets

Abstract

β-Mannans are strongly anti-nutritive polysaccharide fibres found in most vegetable feed ingredients. Estimated content of soluble β-mannans in common grow-finishing diets is only 0.15-0.35%, and in vitro studies have demonstrated that as little as 0.05% soluble β-mannan in feed can elicit a strong innate immune response. This innate response is referred to as a Feed Induced Immune Response (FIIR). Hemicell™ HT (Elanco) is a β-mannanase enzyme for animal feeds breaking down β-mannans, thereby preventing economic losses from this wasteful immune response to β-mannans. The objective was to investigate whether β-mannanase improves feed efficiency in grower/finisher pigs fed diets containing high amounts (5-15%) of Palm Kernel Expeller (PKE). A 3*2 factorial design was applied consisting of 3 treatments (control, PKE, PKE+β- mannanase (PKE+)) and 2 sexes (barrows, gilts) and 2 subsequent batches. Groups were divided over 80 pens resulting in 13-14 repeats per group. Pigs were fed pelletized starter (0-28 d), grower (28-63 d), and finisher diets (63- 99 d). Body Weight (BW) was recorded on days 0, 28, 63, and 99. Feed was offered ad libitum and recorded by pen. For each phase, Average Daily Gain (ADG), Average Daily Feed Intake (ADFI), and Feed Conversion Ratio (FCR) were calculated. Data analysis was performed in R. FCR improved significantly (P=0.004) the first four weeks PKE+ (2.07) compared with Control (2.13). During grower/finisher phases, ADG and ADFI were significantly (P<0.05) higher on PKE and PKE+ compared with Control. Overall, both PKE and PKE+ performed significantly better than Control, which PKE and PKE+ performed similarly. Feeding 10-15% PKE increased ADG and ADFI (potentially due to overestimated energy content of the PKE) both with and without β-mannanase, and resulted in similar FCR. Thus, β-mannanase may improve FCR on high PKE diets from 21 to 39 kg BW.