The Effects of Feeding Diets Supplemented with b-mannanase or b-mannanase and 1,3-glucanase on Apparent Total Tract and Apparent Ileal Digestibilities in Pigs

Abstract Text:

Eight crossbred barrows (BW = 23.3 kg ± 0.22), fitted simple T-cannulas, were used to investigate the effects of Hemicell® HT1.5x (heat tolerant b‐mannanase) and Zymannase® (b-1,3 glucanase and native b-1,4 mannanase) on apparent total tract digestibilities (ATTD) of energy, dry matter (DM), and apparent ileal digestibilities (AID) of DM and amino acids. Diets were corn‐soybean meal‐based containing 22% CP, 3395 kcal/kg of ME, and 0.95% SID Lys. Pigs were fed: 1) control (CTL) 2) CTL + 0.04 MU/kg Hemicell® HT1.5x, 3) CTL + 0.06 MU/kg Hemicell® HT1.5x, or 4) CTL + Zymannase® (0.08 MU/kg glucanase + 0.112 MU/kg native mannanase).  Pigs were randomly allotted to the four dietary treatments in a 4 x 4 Latin square. Pigs were housed individually in metabolic pens (1.2 m²) with ad libitum access to water.  Feed was supplied at 9% of metabolic BW (BW^0.75) in two daily meals (0700 and 1600 h).  Each 2-wk period consisted of a 7d adjustment period, followed by a 7d collection period that included a 3d total collection, a 12h ileal collection, a 3d adjustment, and then a second 12h ileal collection. There were no effects (P=0.40) of diet on DM ATTD.  Based on analysis of the total collection DE was higher (P=0.05) for 0.06 MU/kg Hemicell HT1.5x versus the CTL diet and intermediate for 0.04 MU/kg Hemicell HT 1.5x (3244, 3271, 3283, and 3225 kcal/kg for pigs fed diets 1, 2, 3 and 4, respectively).  Addition  of Hemicell® HT1.5x at 0.04 MU/kg of diet increased DM AID (P < .05) compared to the Zymannase® treatment, but neither 0.04 or 0.06 MU/kg Hemicell® HT1.5x were different (P>0.10) than CTL fed pigs.  Although numerical means favored both concentrations of Hemicell® HT1.5x, differences were not significant (P > .05) for AID of amino acids versus CTL fed pigs.  Adding 0.04 MU/kg Hemicell® HT1.5x improved (P<0.05) the AID of Val, Ile, Leu, and Phe compared to Zymannase® fed pigs.  Based on the results of this study, Hemicell® HT1.5x may be a useful feed additive for increasing energy availability in corn‐soybean meal‐based diets fed to pigs. 

Keywords:

Pigs, Digestibility, Hemicell HT1.5x, Zymanase, Energy, Amino Acids