Effects of lactic acid fermentation on wheat and barley carbohydrate composition and production performance in the chicken

Abstract

Effects of dietary inclusion of dried lactic acid fermented wheat or barley whole meal flours (WMF) on chicken performance were studied. WMFs were fermented for 16 h at 30 °C by a Lactobacillus strain isolated from a Norwegian rye sourdough. Four diets containing 600 g wheat WMF kg −1 (0, 200, 400 and 600 g fermented kg −1) and three diets containing 600 g barley WMF kg −1 (0, 400 and 600 g fermented kg −1) were used. Each treatment comprised 125 one-day-old sexed chickens (Ross) were fed on experimental diets until slaughtering at 35 days. Average weight, feed intake and feed:gain ratio in the 0–14, 14–35 and 0–35-day periods were recorded. At day 35, six chickens of each sex from each diet were slaughtered for determination of dressing percentage and abdominal fat. Fermentation significantly reduced levels of total and soluble dietary fibre in cereal WMF. In barley WMF, total β-glucans decreased from 36.9 to 29.3 g kg −1 dry matter (DM) and soluble β-glucans from 17.8 to 12.6 g kg −1 DM after fermentation. The effects of fermentation on dietary fibre and β-glucans were reflected in the analysis of the experimental diets. Total starch was not significantly affected by fermentation. Cereal source and level of fermented WMF in the diets significantly affected chicken body weights. At 14 days, average weights were increased from 277 to 333 g for wheat diets, and from 252 to 322 g for barley diets, when untreated WMF was entirely substituted by fermented WMF. Linear regressions showed significant increase in average weight at 14 days with increasing levels of fermented wheat ( R 2=0.448 ∗∗∗) and fermented barley ( R 2=0.604 ∗∗∗). The effects of fermentation on weights at 14 days were similar for wheat and barley, as there was no significant difference between the regression slopes. Feed intake during the 0–14-day period was not significantly affected by the content of fermented cereal in the diet. Increasing level of fermented cereal significantly improved feed:gain ratio during the 0–14-day period for both wheat ( R 2=0.329 ∗∗∗) and barley ( R 2=0.389 ∗∗∗). Level of fermented wheat had no significant effect on weight gain or feed intake in the 14–35-day period, while fermented barley significantly increased weight gain and feed intake in this period. At 35 days, average weights of chickens fed diets with solely untreated or fermented barley were 1344 and 1576 g, respectively. Feed:gain ratio in the 0–35-day period decreased significantly with increasing levels of fermented barley, but not with fermented wheat. Dressing percentage was not significantly affected by treatment. Abdominal fat increased significantly with increasing level of fermented cereal. It was concluded that fermentation of barley and wheat with a β-glucan-degrading lactic acid bacteria can improve growth and early feed:gain ratio in broiler chickens.