Feed Restriction Modulates the Fecal Microbiota Composition, Nutrient Retention, and Feed Efficiency in Chickens Divergent in Residual Feed Intake

Abstract

There is a great interest to understand the impact of the gut microbiota on host's nutrient use and FE in chicken production. Both chicken's feed intake and gut bacterial microbiota differ between high and low-feed efficient chickens. To evaluate the impact of the feed intake level on the feed efficiency (FE)-associated variation in the chicken intestinal microbiota, differently feed efficient chickens need to eat the same amount of feed, which can be achieved by feeding chickens restrictively. Therefore, we investigated the effect of restrictive vs. ad libitum feeding on the fecal microbiome at 16 and 29 days posthatch (dph), FE and nutrient retention in chickens of low and high residual feed intake (RFI; metric for FE). Restrictively fed chickens were provided the same amount of feed which corresponded to 85% of the ad libitum fed group from 9 dph. FE was determined for the period between 9 and 30 dph and feces for nutrient retention were collected on 31 to 32 dph. From the 112 chickens (n = 56 fed ad libitum, and n = 56 fed restrictively), 14 low RFI and 15 high RFI ad libitum fed chickens, and 14 low RFI (n = 7 per sex) and 14 high RFI restrictively fed chickens were selected as the extremes in RFI and were retrospectively chosen for data analysis. Bray-Curtis dissimilarity matrices showed significant separation between time points, and feeding level groups at 29 dph for the fecal bacterial communities. Relevance networking indicated positive associations between Acinetobacter and feed intake at 16 dph, whereas at 29 dph Escherichia/Shigella and Turicibacter positively and Lactobacillus negatively correlated to chicken's feed intake. Enterobacteriaceae was indicative for low RFI at 16 dph, whereas Acinetobacter was linked to high RFI across time points. However, restrictive feeding-associated changes in the fecal microbiota were not similar in low and high RFI chickens, which may have been related to the higher nutrient retention and thus lower fecal nutrient availability in restrictively fed high RFI chickens. This may also explain the decreased RFI value in restrictively fed high RFI chickens indicating improved FE, with a stronger effect in females.

Fecal Microbiota Transplant From Highly Feed Efficient Donors Affects Cecal Physiology and Microbiota in Low- and High-Feed Efficient Chickens

“…Relevance networks showed the importance of the TFI for the cecal abundance of two Clostridiales -OTUs but identified no strong relationship of bacteria with RFI. Results from the univariate analysis for the jejunal community supported our previous findings of an association of intestinal Turicibacter with high RFI, which can most likely be related to the increased feed intake in high RFI birds (Siegerstetter et al, 2018b). Whether this was also true for the trends for the increase in Phenylobacterium in jejunal digesta and an unclassified Lachnospiraceae genus in the ceca with high RFI or whether other changes in host physiology (e.g., mucin production) or cross-feeding of microbial metabolites are behind these RFI-associated variations can only be speculated.…”

“…From the observed RFI-associated variation, energy-saving mechanisms and a potential attenuation of the mucosal immune response were indicated by the higher jejunal permeability, shorter villi in the ileum, and enhanced cecal expression of the anti-inflammatory cytokine IL10 in low RFI chickens. Since we aimed to modulate the early colonization, effects of the FMT on the jejunal bacterial composition in 5-week old birds were generally expected to be small, as other factors such as the diet and feed intake become more important for species abundances than the FMT with increasing age (Siegerstetter et al, 2018b). Nevertheless, the bacteria found in the FMT formed the dominant bacterial taxa in the jejunal and cecal communities, including Enterobacteriaceae, Turicibacter, Ruminococcaceae , and Lactobacillus .…”

“…The preparation of the FMT and inoculation procedure have been already described in detail in Siegerstetter et al (2018a). Low RFI chickens from a previous chicken experiment (Siegerstetter et al, 2018b) were monitored on 30 dph and a sufficient amount of freshly dropped excreta could be collected from four females and two males to prepare the FMT stock for each donor separately. Each fecal dropping was immediately processed under anaerobic conditions and was continuously kept on ice throughout the procedure.…”

“…The DNA concentration was quantified using the Qubit 2.0 Fluorometer (Life Technologies, Carlsbad, CA, United States) with the Qubit dsDNA HS Assay Kit (Life Technologies). An aliquot of each DNA sample was sent to a commercial provider (Microsynth AG, Balgach, Switzerland), where the V3–V5 hypervariable region of the 16S rRNA gene was amplified using the primers 357F-HMP (5′-CCTACGGGAGGCAGCAG-3′) and 926R-HMP (5′-CCGTCAATTCMTTTRAGT-3′) to generate an approximate amplicon size of 570 bp (Peterson et al, 2009) as previously described (Siegerstetter et al, 2018a,b). The KAPA HiFi HotStart PCR Kit (Roche, Baden, Switzerland) was used, which includes a high-fidelity DNA polymerase.…”

Feed Restriction Modifies Intestinal Microbiota-Host Mucosal Networking in Chickens Divergent in Residual Feed Intake

“…Further in-depth experimentation is required to determine whether the enlargement of the crop was related to increased retention time or to bacterial activity with respect to the feed in this segment. Intriguingly, only the restrictively fed high-RFI chickens had a larger pancreas and not their low RFI counterparts, which may explain the greater nutrient retention in these birds than in the birds in the other 3 groups (4). This finding may imply higher energy and nutrient needs for basal metabolism in high-RFI chickens than in low-RFI chickens (1) which would be met by the increased feed intake in high-RFI chickens under ad libitum feeding conditions (12).…”