PSIV-B-28 - Effect of feeding acidified or fermented barley grain using Limosilactobacillus reuteri with or without supplemental phytase on diet nutrient digestibility in growing pigs

Fermentation of cereal grains may degrade myo-inositol hexakisphosphate (InsP₆) thereby increasing nutrient digestibility. Effects of chemical acidification or fermentation with Limosilactobacillus (Lm.) reuteri TMW 1.656 with or without phytase on nutrient digestibility of diets composed of high β-glucan hull-less barley grain were assessed in growing pigs. Four mash diets contained 50% barley grain: 1) unfermented barley (Control); 2) chemically-acidified barley (ACD) with lactic and acidic acid [0.02 L/kg barley grain, 4:1 (v/v)]; 3) barley fermented with Lm. reuteri (Fermented without phytase); and 4) barley fermented with Lm. reuteri and phytase (Fermented with phytase; 500 FYT/kg barley grain). The 4 diets were fed to 8 ileal-cannulated barrows (initial BW, 17.4 kg) for four 11-d periods in a double 4 × 4 Latin square. The InsP₆ content of barley grain in Control, ACD, Fermented without phytase, or Fermented with phytase was 1.12, 0.59, 0.52% dry matter, or not detectable, respectively. Diet apparent total tract digestibility (ATTD) of crude protein (CP), Ca, gross energy and digestible energy and predicted net energy values were greater (P < 0.05) for ACD and Fermented without phytase than Control. Diet apparent ileal digestibility (AID) of Ca and standardized total tract digestibility (STTD) of P tended to be greater (P < 0.10) for Fermented without phytase than Control. Diet STTD of P, AID and ATTD of Ca was greater (P < 0.05) for Fermented with phytase than Fermented without phytase. Acidification or fermentation with/without phytase did not affect diet standardized ileal digestibility of CP and AA. In conclusion, fermentation with phytase completely degraded InsP₆ in barley grain and maximized P and Ca digestibility, thereby reducing the need to provide inorganic P to meet P requirements of growing pigs.