Intestinal structure and function of broiler chickens on diets supplemented with a mannan oligosaccharide

Abstract

A study was conducted to evaluate the response of broiler chickens to a commercial synthetic mannan oligosaccharide, Bio-Mos 2 (BM), included in sorghum/lupin-based diets at 0.0, 1.0, 3.0 or 5.0 g kg À1 diet. The diets were fed between 7 and 28 days of age, and both the gross response and mechanisms involved were evaluated. The highest level of BM in the diet resulted in longer (P < 0.01) jejunal villi than those observed at other levels of supplementation. The RNA content of the ileal mucosal homogenate was signi®cantly greater (P < 0.05) in chicks raised on diets supplemented with 3.0 and 5.0 g BM kg À1 diet than in other groups. The protein/DNA ratio of the jejunal mucosal homogenate was also higher (P < 0.05) in chicks fed the 1.0 g BM kg À1 diet than in chicks fed the other diets. The protein/RNA and RNA/DNA ratios in ileal homogenates were signi®cantly (P < 0.01) in¯uenced by the presence of BM in the diet. There were signi®cantly greater speci®c activities of maltase (P < 0.01), leucine aminopeptidase (P < 0.05) and alkaline phosphatase (P < 0.001) in the jejunum as a result of supplementation with BM. Digestive enzyme activities in the ileum were unaffected. L-Tryptophan uptake by jejunal brush-border membrane vesicles was signi®cantly higher (P < 0.01) in chicks raised on the 5.0 g BM kg À1 diet than in the other chicks. The supplement led to minor improvement in body weight but no improvement in feed conversion ratio. These effects were related to changes in digestive enzyme activities and, perhaps, amino acid transport. INTRODUCTIONOligosaccharides occur naturally in many feed ingredients, the most common natural forms being the raf®nose series oligosaccharides. Raf®nose series oligosaccharides do not succumb to animal enzymes and tend to accumulate towards the posterior end of the gastrointestinal tract (GIT) where they are digested by microbial enzymes, to release gases that cause¯atulence in non-ruminant animals. 1,2 Previous research has therefore tended to attribute the poor growth of animals on legume seeds to the presence of oligosaccharides. This has been disputed by more recent research.

Desempenho de frangos de corte de 1 a 21 dias de idade alimentados com rações contendo extrato de leveduras e prebiótico e criados em diferentes temperaturas

“…Este efeito ocorreu provavelmente pelo efeito sinérgico entre o extrato de levedura e o prebiótico, pois, quando não se incluiu o extrato, este fato não foi observado. Por outro lado, Iji &Tivey (1998) e Iji et al (2001) observaram que o uso de oligossacarídeos pode ocasionar aumento no consumo de ração.…”

Natural plant extracts and prebiotic compounds as alternatives to antibiotics in broiler chicken diets in a necrotic enteritis challenge model

“…However, the results showed that villus length was not affected by the plant extracts or prebiotic compounds. Dietary supplements such as prebiotic and bioactive compounds have been shown to have a trophic effect on the gut mucosal morphology in chickens (Iji et al 2001;Yamauchi et al 2006). It should be noted that these prior studies assessed compounds under hygienic husbandry practices and not in a disease-challenged condition as was the case of the present study.…”

Mannanoligosaccharides or flavomycin in turkeys diets: effect on mucosa-associated microflora and growth performance

“…Commercially available mannanoligosaccharides are complex carbohydrates extracted from cell wall of yeast Saccharomyces cerevisiae. Added to feed, as entirely safe compounds, MOS appeared to be promising in suppressing enteric pathogens, modulating immune response, and improving integrity of the intestinal mucosa (Iji et al, 2001;Swanson et al, 2002;Elmusharaf et al, 2006). According to current knowledge, MOS prevent bacterial infection via mechanisms that are different from antibiotics, and therefore, circumvent the pathogens ability to develop resistance.…”