Effects of yeast cultures with different fermentation times on the growth performance, caecal microbial community and metabolite profile of broilers

Abstract

The objective of this study was to investigate the effects of yeast culture (YC) on the growth performance, caecal microbial community and metabolic profile of broilers. A total of 350 1-day-old healthy Arbor Acres broilers were randomly assigned to seven treatment groups. The first group received a basal diet without YC supplementation, whereas the remaining groups received a basal diet supplemented with either YC fermented for 12, 24, 36, 48 or 60 hr, or a commercial YC product (SZ2). MiSeq 16S rRNA high-throughput sequencing was used to investigate the bacterial community structure, and gas chromatography-mass spectrometry was used to identify the metabolites in the caeca of broilers. The broilers that received a diet supplemented with YC had a higher average daily gain and average daily feed intake than those received YC-free or SZ2-enriched diets. The feed conversion ratio (FCR) of YCs fermented for 24 hr resulted in the best feed efficiency, whereas the FCR of YC fermented for 60 hr resulted in poor feed efficiency (p < .05). In the caeca of broilers, the bacterial communities were well separated, as determined by principal component analysis, and the proportions of the eight genera were significantly different among the seven groups (p < .05). The genus Akkermansia was the most abundant when the diet supplemented with YC fermented for 24 hr (p < .05). Furthermore, the Firmicutes/ Bacteroidetes ratio was positively correlated with the FCR in the caecum (r = .47, p < .005). Five differentially expressed metabolites (i.e., L-alanine, benzeneacetic acid, D-mannose, D-arabitol and cholesterol) were identified in the caeca of broilers that received diets supplemented with YCs fermented for 24 or 60 hr. In summary, the different fermentation times of the YCs can markedly improve the growth performance and FCR of broilers by altering the caecal microbial community, and the growth performance which is related to the changes in key metabolic pathways. K E Y W O R D Sbroilers, gas chromatography-mass spectrometry, growth performance, metabolite, microbiome | 213 SUN et al.

Yeast-Derived Products: The Role of Hydrolyzed Yeast and Yeast Culture in Poultry Nutrition—A Review

“…Experiments conducted in vitro, where YC was incubated with the feed and the ceca content of broiler chickens [ 94 , 135 ] or turkeys [ 94 ], resulted in increased alpha and beta diversity, which stabilized over time. Changes in the gut microbial diversity due to YC administration in the diet were also confirmed by in vivo studies on aged breeder layers [ 83 ] and broilers [ 91 ]. Nevertheless, other studies report no effects [ 126 ].…”

“…However, the discrepancies in the observed results might be attributable to the composition of the product derived from, among other things, the production process. Sun et al [ 91 ] investigated the effect of YCs obtained by different fermentation times (12, 24, 36, 48, or 60 h), reporting improved performances in broilers fed YC fermented for 12 and 24 h, whereas poor performances were associated with YC fermented for 48 and 60 h. As highlighted by the metabolomic analysis, YCs produced with different fermentation times contain different metabolites, which thus results in different effects.…”

“…Lately, the intestinal microbiota has elicited increasing interest, and the advent of NGS technologies, among which are 16S rRNA, have paved the way to a completely new research frontier to unravel how host–microbiome interactions affect animal health. In this light, an increasing number of studies have evaluated the effect of YC on gut microbiota [ 83 , 91 , 126 ] ( Table 2 ). Microbial-diversity analysis (alpha and beta-diversity) is an essential step in understanding how the tested product impacts the microbiota.…”

Bacillus subtilis DSM29784 Alleviates Negative Effects on Growth Performance in Broilers by Improving the Intestinal Health Under Necrotic Enteritis Challenge

“…Various organic acids (such as lactic, succinic, nicotinic, acetic, propionic, and malic) are produced during intestinal fermentation and form barriers in the digestive tract, thereby preventing the colonization and reproduction of pathogenic bacteria. This enhances peristalsis and digestive enzyme secretion in the intestinal tract, thus promoting feed digestion, and improved nutrient absorption ( Sun et al, 2020 ).…”

“…Based on a previously described method ( Sun et al, 2020 ), frozen cecal digesta (0.5g) were lyophilized for 24h and transferred into a 1-ml polyethylene tube. The digesta was combined with 100μl of methoxyamine hydrochloride in pyridine (20mg/ml) and vigorously vortexed for 30s.…”