Supplementation of live yeast based feed additive in early life promotes rumen microbial colonization and fibrolytic potential in lambs

Abstract

Rumen microbiota is of paramount importance for ruminant digestion efficiency as the microbial fermentations supply the host animal with essential sources of energy and nitrogen. Early separation of newborns from the dam and distribution of artificial milk (Artificial Milking System or AMS) could impair rumen microbial colonization, which would not only affect rumen function but also have possible negative effects on hindgut homeostasis, and impact animal health and performance. In this study, we monitored microbial communities in the rumen and the feces of 16 lambs separated from their dams from 12 h of age and artificially fed with milk replacer and starter feed from d8, in absence or presence of a combination of the live yeast Saccharomyces cerevisiae CNCM I-1077 and selected yeast metabolites. Microbial groups and targeted bacterial species were quantified by qPCR and microbial diversity and composition were assessed by 16S rDNA amplicon sequencing in samples collected from birth to 2 months of age. The fibrolytic potential of the rumen microbiota was analyzed with a DNA microarray targeting genes coding for 8 glycoside hydrolase (GH) families. In Control lambs, poor establishment of fibrolytic communities was observed. Microbial composition shifted as the lambs aged. The live yeast supplement induced significant changes in relative abundances of a few bacterial OTUs across time in the rumen samples, among which some involved in crucial rumen function, and favored establishment of Trichostomatia and Neocallimastigaceae eukaryotic families. The supplemented lambs also harbored greater abundances in Fibrobacter succinogenes after weaning. Microarray data indicated that key cellulase and hemicellulase encoding-genes were present from early age in the rumen and that in the Supplemented lambs, a greater proportion of hemicellulase genes was present. Moreover, a higher proportion of GH genes from ciliate protozoa and fungi was found in the rumen of those animals. This yeast combination improved microbial colonization in the maturing rumen, with a potentially more specialized ecosystem towards efficient fiber degradation, which suggests a possible positive impact on lamb gut development and digestive efficiency.

In Vivo Competitions between Fibrobacter succinogenes, Ruminococcus flavefaciens, and Ruminoccus albus in a Gnotobiotic Sheep Model Revealed by Multi-Omic Analyses

“…The difference between in vitro studies, our animal model, and these studies on conventional sheep may be attributable to differences in the broader ecology, where a newborn immature microbiota could be more ecologically favorable to the development of R. albus and R. flavefaciens , while a conventional adult microbiota may better favor F. succinogenes through unmeasured ecological interactions. This assumption agrees with studies of newborn calves and lambs in which cellulolytic ruminococci colonized the rumen earlier than F. succinogenes ( 33 , 34 ). Diet may also influence the composition of both the cellulolytic and broader community ( 32 , 35 – 37 ).…”

Roughage to Concentrate Ratio and Saccharomyces cerevisiae Inclusion Could Modulate Feed Digestion and In Vitro Ruminal Fermentation

“…Stimulating lactic acid–utilizing bacteria could account for decreases in lactic acid concentrations induced by S. cerevisiae and the corresponding moderation of the rumen pH. The role of yeast is to stimulate lactate users, increase the number of lactate users, and serve as a competitor with lactate producers [ 8 ]. Moreover, it is interesting that the addition of LY increased ruminal pH ( p < 0.05), and it is in agreement with a previous study by Dias et al [ 35 ], who found that supplementing S. cerevisiae in the diet with high starch increased ruminal pH, whereas the concentration of lactate was reduced in lactating dairy cows.…”

“…S. cerevisiae has been used for many years, to promote ruminal fermentation, minimize the loss of energy and nutrients, and thus increase the ruminant production system. Some researchers have found that supplementation of the S. cerevisiae enhances ruminant digestion of feed in a variety of ways, such as increasing nutrient digestibility [ 6 ], maximizing the ruminal volatile fatty acid (VFA) proportion, decreasing ammonia nitrogen (NH 3 -N) [ 7 ], alleviating pH fluctuation, and stimulating the population of ruminal microorganisms [ 8 ]. High portions of concentrate in the ration significantly decreased the ruminal pH and NH 3 -N concentration.…”

Survey of rumen microbiota of domestic grazing yak during different growth stages revealed novel maturation patterns of four key microbial groups and their dynamic interactions

“…Similar to fungi, protozoa were detected in the rumen of yaks after 1 month of age. A previous study detected protozoa in the rumen of lambs at approximately 21 days of age [ 42 ], which is earlier than that of yaks. In the present study, grazing yaks drank water from rivers or lakes instead of water troughs, which may preclude the colonization of rumen protozoa, as drinking water has been identified as a main source for rumen protozoa colonization [ 43 ].…”