Intestinal morphology, digestive organ size and digesta pH of broiler chickens fed diets supplemented with or without Moringa oleifera leaf meal
The intestinal morphology and pH of digesta of broiler chickens at 35 days old were studied. Birds were reared on these dietary treatments (T). T1, positive control, contained 668 g salinomycin and 500 g zinc bacitracin per kg of feed. Treatments, T2, T3 and T4, contained graded levels of Moringa oleifera leaf meal (MOLM) per kg of feed, namely starter (1, 3, 5 g), grower (3, 9, 15 g) and finisher (5, 15, 25 g). T5 was a negative control (without supplementation). Birds were provided feed and water ad libitum. Birds in T3 had the highest proventriculus digesta pH, and T5 birds the lowest. Birds that were supplemented with MOLM – and surprisingly those from the negative control – had significantly higher caecal digesta pH, while T1 had the highest ileal digesta pH. Duodenal villous length was longest in T2, and shortest in T4. Jejunal villous length was longest in T3 and shortest in T2 birds. T3 and T4 jejunal villi were widest, with T1 birds having the shortest. Ileal villous was longest in T2 and T5 birds, while T3 birds had the shortest. Duodenal surface area for absorption was larger in T2 and T5, and smaller in T4, while T3 had the largest ileal surface area, and T1 the smallest. The jejunal surface area was largest in T3 (53.2) and T4 (50.7), and smallest in T1 (25.0). The current results reveal a regulatory effect of MOLM on the gastrointestinal tract, which could be attributed to the coarseness of the diets, thus raising the pH and resulting in thicker digesta viscosity, which is a clear sign of a healthy gut.
Keywords: Digestive physiology, intestinal morphology, plant additives, poultry