Yeast mannan rich fraction positively influences microbiome uniformity, productivity associated taxa, and lay performance

Abstract

Background: Alternatives to antibiotic as growth promoters in agriculture, such as supplemental prebiotics, are required to maintain healthy and high performing animals without directly contributing to antimicrobial resistance bioburden. While the gut microbiota of broiler hens has been well established and successfully correlated to performance, to our knowledge, a study has yet to be completed on the effect of prebiotic supplementation on correlating the mature laying hen productivity and microbiota. This study focused on establishing the impact of a yeast derived prebiotic, mannan rich fraction (MRF), on the cecal microbiota of late laying hens. This study benefitted from large sample sizes so intra- and intergroup variation effects could be statistically accounted for.

Results: Taxonomic richness was significantly greater at all taxonomic ranks and taxonomic evenness was significantly lower for all taxonomic ranks in MRF-supplemented birds (P < 0.005). Use of principal coordinate analyses and principal component analyses found significant variation between treatment groups. When assessed for compositional uniformity (an indicator of flock health), microbiota in MRF-supplemented birds was more uniform than control birds at the species level. From a food safety and animal welfare perspective, Campylobacter jejuni was significantly lower in abundance in MRF-supplemented birds. In this study, species associated with high weight gain (an anticorrelator of performance in laying hens) were significantly lower in abundance in laying hens while health-correlated butyrate and propionate producing species were significantly greater in abundance in MRF-supplemented birds.

Conclusions: The use of prebiotics may be a key factor in controlling the microbiota balance limiting agri-food chain pathogen persistence and in promoting uniformity. In previous studies, increased α- and β-diversity indices were determinants of pathogen mitigation and performance. MRF-supplemented birds in this study established greater α- and β-diversity indices in post-peak laying hens, greater compositional uniformity across samples, a lower pathogenic bioburden and a greater abundance of correlators of performance.

Fig. 1

Comparisons of the most abundant taxa in each dietary group

Fig. 2

Impact of MRF-supplementation on a-diversity metrics. The horizontal line within each box denotes the mean and tails represent 95% confidence intervals. Observations beyond the 95% CI boundaries are represented as dots. In each plot B and P refer to the Brunner-Munzel test statistic and its associated P-value

Fig. 3

Principal coordinate analyses (b-diversity) Regularly spaced values represented on the x, y, and z axes are distance intervals as defined by their respective dissimilarity indices. The Principal Coordinates (PCo) for each axis are accompanied by their respective explained variances

Fig. 4

Principal component analyses. Regularly spaced values represented on the x, y, and z axes are standard deviations away from the mean (0) in standardized (Z-score) space. The Principal Components (PC) for each axis are accompanied by their respective explained variances

Fig. 5

Impact of MRF-supplementation on productivity factors. The horizontal line within each box denotes the mean and tails represent 95% confidence intervals. No observations exceeded the 95% CI intervals. In each plot B and P refer to the Brunner-Munzel test statistic and its associated P-value

Fig. 6

Impact of MRF-supplementation on feed conversion efficiency. The horizontal line within each box denotes the mean and tails represent 95% confidence intervals. No observations exceeded the 95% CI intervals. In each plot B and P refer to the Brunner-Munzel test statistic and its associated P-value

Fig. 7

Impact of MRF-supplementation on production consistency. The dashed line at 0 represents the mean of each productivity factor. Data from the MRF-supplemented pens were statistically closer to their respective means with significantly less variance

Fig. 8

Phylogenetic distributions of significantly enriched taxa and their correlations with productivity factors