Soybean oligosaccharide, stachyose, and raffinose in broilers diets: effects on odor compound concentration and microbiota in cecal digesta

Abstract

Soybean oligosaccharides have been previously shown to be associated with the production of major odor-causing compounds in broilers, although little is known about the role of stachyose and raffinose, which are key components of soybean oligosaccharide, in broiler cecal microbiota and odor compound production. To this end, soybean oligosaccharide, stachyose, and raffinose were added to the birds' diets to investigate their effects on odor compound production and the microbial community characteristics of the cecum in broilers. A total of 300 one-day-old Arbor Acre broilers with similar initial live weight were randomly allocated into 5 dietary groups with 6 replicates of 10 birds. The diets included soybean meal (positive control), soybean meal-free (negative control), 0.6% soybean oligosaccharide, 0.6% stachyose, or 0.6% raffinose. After a 49-D feeding period, both ceca were aseptically removed postmortem, and the contents were collected and analyzed for skatole, indole, volatile fatty acids, and lactic acid by using high performance liquid chromatography. Bacterial communities were detected by using a high-throughput sequencing platform based on IlluminaMiSeq 2500. Levels of skatole and indole tended to be lower in the dietary supplementation of oligosaccharides. The lowest levels of skatole and indole were observed in the stachyose group ( P < 0.05), while the highest levels were found in the negative control group ( P < 0.05). Concentrations of acetic acid and propionic acid in the stachyose group were increased ( P < 0.05) while those of butyric acid and lactic acid were decreased ( P < 0.05) compared with the soybean oligosaccharide and raffinose groups. Firmicutes and Bacteroidetes were prevalent in all groups, the proportion of Bacteroidetes was slightly decreased in the stachyose group, and Verrucomicrobia was abundant in the raffinose group ( P > 0.05). Bacterial genera Alistipes and Parabacteroides were comparably abundant in the stachyose group, while Bacteroides , Lactobacillus , and Akkermansia were more abundant in the negative control, stachyose, and raffinose groups, respectively. Collectively, these findings demonstrated that dietary oligosaccharide supplementation significantly reduced odor compound production by modulating the cecal microbial community. Compared with soybean oligosaccharide and raffinose, the addition of stachyose into diets may help improve gut fermentation and minimize odor compound generation in broilers.

Soybean Oligosaccharides Supplementation Attenuates the Fecal Odor Compounds by Modulate the Cecal Microbiota of Broilers

“…Based on the phylogenetic diversity of bacterial communities and number of OTUs, SBO and CHL did not change the chicken cecal bacterial community membership, but the treatments signi cantly altered relative abundance of certain taxa in the cecum. This observation is in accordance with the study of Zhu et al [30] who reported that SBO addition (0.6%) altered the chicken cecal microbiota. When added frucotooligosaccharide in broiler diets, the total number of anaerobes and Lactobacilli in the ceca increased while the number of E. Coli decreased [32].…”

“…4) appeared to be diminished by chlortetracycline. These results are consistent with earlier observations that in-feed antibiotic preferentially enriched butyrate-producing bacteria [19], SBO inhibited the growth of pathogenic microbes, and reduced the production of odor compounds [3,14,30]. Previous studies have found that supplementation of broiler diets with a mixture of chlortetracycline and other antibiotic increased both Ruminococcaceae and Lachnospiraceae [34].…”

“…Therefore, the results of present study provided the information of the ecology of cecal bacterial communities. In line with the previously reports on cecal microbiota of broilers [1,30], it was dominated by Bacteroidetes and Firmicutes at the phylum level, regardless of diet. The metabolism favours the fermentation of cellulose and stach etc in the cecum, results in higher microbial diversity and dominance of the saccarolytic and anaerobic order of Bacteroides and Clostridiales [1].…”

“…The most abundant genera detected in this study were unclassi ed, Bacteroides, Ruminococcus, Phascolacrctobacterium, Rikenella, Oscillospira, Faecalibacterium, and the unclassifed bacteria was the most. The results were quite similar with those obtained by Wen et al and Zhu [1,30]. Bjerrum et al [30] reported that bacterial strains closely related to Faecalibacterium prausnitzii were dominant in the ceca.…”

“…The results were quite similar with those obtained by Wen et al and Zhu [1,30]. Bjerrum et al [30] reported that bacterial strains closely related to Faecalibacterium prausnitzii were dominant in the ceca.…”