Monoglyceride Blend Reduces Mortality, Improves Nutrient Digestibility, and Intestinal Health in Broilers Subjected to Clinical Necrotic Enteritis Challenge

SIMPLE SUMMARY: Necrotic enteritis (NE) is a common and devastating enteric bacterial disease prevalent in fast-growing broilers. It is a great concern to the global poultry industry as impaired performance and high flock mortality up to 50% in severe cases occur, leading to losses of over US$6 billion each year. Controlling NE in fast-growing broilers is crucial, particularly in the antibiotic-free era. Among many potential alternatives to in-feed antibiotics, fatty acid glycerides and formic acid supplementation in diets have shown promising effects in improving performance and intestinal health in broilers infected with subclinical NE. However, data are limited in clinical NE infected broilers. Thus, this study was conducted to evaluate the potential of monoglyceride blend (MG) and buffered formic acid (FA) as alternatives to antibiotics in the performance and intestinal health of broilers subjected to clinical NE challenge. The obtained results highlighted that the diet supplemented with MG has the potential to improve intestinal health and reduce the severity of clinical NE by reducing mortality. This study underpins the importance of additives in poultry production following the removal of antibiotics in poultry feed to alleviate the possible loss posed by enteric diseases such as NE. ABSTRACT: This study evaluated the potential of monoglyceride blend (MG) and buffered formic acid (FA) as alternatives to antibiotics in the performance and intestinal health of broilers under clinical necrotic enteritis (NE) challenge. A total of 544 as-hatched Ross 308 broiler chicks were randomly distributed to 32-floor pens housing 17 birds per pen. The four treatments were: NC—non-additive control; ZBS—antibiotic group supplemented with zinc bacitracin and salinomycin; MG—additive MG supplementation in the starter phase only; and MGFA—additive MG in starter phase and FA in grower and finisher phases. All birds were challenged with Eimeria spp. and Clostridium perfringens. Results showed that the NC group had lower BWG and higher FCR than the ZBS group in the grower and overall period (p < 0.05). The NC group had higher NE-caused mortality (days 14 to 17) than the ZBS group (p < 0.05). Birds fed MG had lower NE-caused mortality than the NC group (p < 0.05). Birds fed MG had upregulated jejunal tight junction protein1 (TJP1) and immunoglobulin (IgG) on day 16 and improved gross energy digestibility on day 24 than the NC group (p < 0.05). These findings suggest that supplementation of MG may improve intestinal health and protect birds from clinical NE occurrence.