Effect of microencapsulated organic acids-essential oils blend and protease on performance and gut health of broilers under nutritional challenges

Abstract

This study examined the effects of microencapsulated organic acids and essential oils (EOA) combined with a protease (PRO) supplement on the growth performance and gut health of broilers subjected to nutritional challenges through a diet high in wheat and corn distillers dried grains with solubles (DDGS). The treatments were: 1) corn and soybean meal-based diet with high levels of wheat and corn DDGS (WD); 2) WD+microencapsulated organic acids and essential oils at 300 mg/kg (EOA); 3) WD+PRO at 125 mg/kg (PRO); and 4) WD+EOA at 300 mg/kg+PRO at 125 mg/kg (EOA+PRO). Body weight gain, feed intake and mortality rate did not differ among treatments (p > 0.05). However, feed conversion ratio from day 1-35 was lower in the EOA+PRO group than in the WD group (p < 0.05). The EOA+PRO group had a lower jejunal crypt depth (CD) and a higher villus height/crypt depth (VH/CD) ratio than the other groups (p < 0.01). The putrescine level was higher in the WD group than in the other groups (p < 0.05). On day 35, the EOA and EOA+PRO groups had higher claudin-1 mRNA expression than the WD and PRO groups (p < 0.01). Occludin mRNA expression was higher in the EOA and PRO groups than in the WD group (p < 0.01). In summary, the combination of EOA and PRO improved feed efficiency and gut health in broilers fed a high wheat and corn DDGS diet. This was demonstrated by decreased jejunal CD, increased VH/CD ratio, increased mRNA expression of claudin-1 at the tight junction and decreased putrescine content in the hindgut, suggesting an indirect effect on pathogenic bacteria.