Effects of endo-1,4-β-d-mannanase enzyme (Hemicell HT 1.5 ×) on the growth performance of nursery pigs

The objective of the current study was to compare nursery pigs fed endo- 1,4-ß-d-mannanase enzyme (Hemicell HT 1.5x) and 1% added fat with those fed a control diet (no enzyme) and increasing added fat. Soybean meal contains ß-mannans, which are polysaccharides in cell walls of legumes. These ß-mannans induce an immune response that prevents nursery pigs from reaching maximum growth potential. Endo-1,4- ß-d-mannanase hydrolyzes ß-mannans, which allows pigs to realize full growth potential. Nine hundred twenty total cross-bred pigs were used in a randomized complete block design at 5.78 kg of initial BW for 42 d. Treatments were (1) 250 mg/kg of endo-1,4-ß-d-mannanase with 1% added fat, (2) control (no enzyme) with 1% added fat, (3) control with 2% added fat, (4) control with 3% added fat, and (5) control with 4% added fat. Data were analyzed using a Dunnett's test of difference from control to determine the effects of the enzyme. Endo-1,4-ß-d-mannanase did not affect ADG (P ≥ 0.29) or ADFI (P ≥ 0.96). No differences in G:F were noted between the enzyme-fed pigs and pigs fed 1 or 2% added fat (P = 0.68). Pigs fed 3% added fat (0.716; P = 0.02) were 2.58% more efficient, whereas pigs fed 4% added fat (0.728; P < 0.001) were 4.30% more efficient than pigs fed endo- 1,4-ß-d-mannanase and 1% added fat (0.698). Endo-1,4-ß-d-mannanase was not effective in improving feed efficiency in pigs fed an isocaloric diet and was not able to improve feed efficiency to levels demonstrated by nursery pigs fed 3 and 4% added choice white grease.