In vitro fermentation profiles of different soybean oligosaccharides and their effects on skatole production and cecal microbiota of broilers

Impact of dietary digestible aromatic amino acid levels and stachyose on growth, nutrient utilization, and cecal odorous compounds in broiler chickens

This study evaluated the impact of dietary digestible aromatic amino acid (DAAA) levels and stachyose on growth, nutrient utilization and cecal odorous compounds in broiler chickens. A 3×2 two-factor factorial design: Three dietary DAAA levels (1.40, 1.54, 1.68%) supplemented with either 5 g/kg of stachyose or without any stachyose were used to create 6 experimental diets. Each diet was fed to 6 replicates of 10 birds from d 22 to 42. Findings revealed that broilers receiving a diet with 1.54% DAAA levels supplemented with 5 g/kg stachyose exhibited a significant boost in average daily gain and improved utilization of crude protein, ether extract, tryptophan, and methionine compared to other diet treatments (P < 0.05). As the dietary DAAA levels increased, there was a significant rise in the concentrations of indole, skatole, p-methylphenol, and butyric acid in the cecum of broilers (P < 0.05). The addition of stachyose to diets reduced concentrations of indole, skatole, phenol, p-methylphenol, acetic acid and propionic acid in the cecum (P < 0.05). The lowest concentrations of indole, phenol, p-methylphenol, volatile fatty acids and pH in cecum of broilers were observed in the treatment which diet DAAA level was 1.40% with stachyose (P < 0.05). In conclusion, dietary DAAA levels and stachyose had significant interactions on the growth, main nutrient utilization and cecal odorous compounds in broilers. The dietary DAAA level was 1.54% with 5 g/kg of stachyose can improve the growth performance, nutrient utilization. However, the dietary DAAA level was 1.40% with stachyose was more beneficial to decrease the cecal odor compound composition in broilers.

Microbiome-metabolomics analysis reveals abatement effects of itaconic acid on odorous compound production in Arbor Acre broilers

BACKGROUND

Public complaints concerning odor emissions from intensive livestock and poultry farms continue to grow, as nauseous odorous compounds have adverse impacts on the environment and human health. Itaconic acid is a metabolite from the citric acid cycle of the host and shows volatile odor-reducing effects during animal production operations. However, the specific role of itaconic acid in decreasing intestinal odorous compound production remains unclear. A total of 360 one-day-old chicks were randomly divided into 6 treatment groups: control group (basal diet) and itaconic acid groups (basal diet + 2, 4, 6, 8 and 10 g/kg itaconic acid). The feeding experiment lasted for 42 d.

RESULTS

Dietary itaconic acid supplementation linearly and quadratically decreased (P < 0.05) the cecal concentrations of indole and skatole but did not affect (P > 0.05) those of lactic, acetic, propionic and butyric acids. The cecal microbial shift was significant in response to 6 g/kg itaconic acid supplementation, in that the abundances of Firmicutes, Ruminococcus and Clostridium were increased (P < 0.05), while those of Bacteroidetes, Escherichia-Shigella and Bacteroides were decreased (P < 0.05), indicative of increased microbial richness and diversity. Furthermore, a total of 35 significantly (P < 0.05) modified metabolites were obtained by metabolomic analysis. Itaconic acid decreased (P < 0.05) the levels of nicotinic acid, nicotinamide, glucose-6-phosphate, fumatic acid and malic acid and increased (P < 0.05) 5-methoxytroptomine, dodecanoic acid and stearic acid, which are connected with the glycolytic pathway, citrate acid cycle and tryptophan metabolism. Correlation analysis indicated significant correlations between the altered cecal microbiota and metabolites; Firmicutes, Ruminococcus and Clostridium were shown to be negatively correlated with indole and skatole production, while Bacteroidetes, Escherichia-Shigella and Bacteroides were positively correlated with indole and skatole production.

CONCLUSIONS

Itaconic acid decreased cecal indole and skatole levels and altered the microbiome and metabolome in favor of odorous compound reduction. These findings provide new insight into the role of itaconic acid and expand its application potential in broilers.