Rumen bacterial, archaeal, and fungal diversity of dairy cows in response to ingestion of lauric or myristic acid1

Abstract

The objective of this experiment, part of a larger study, was to investigate changes in rumen bacterial, archaeal, and fungal diversity in cows fed medium-chain saturated fatty acids. In the main study, 6 lactating dairy cows were dosed intraruminally with 240 g/(cow · d) of stearic (SA, control), lauric (LA), or myristic (MA) acid in a replicated 3 × 3 Latin square design trial. Experimental periods were 28 d, and cows were transfaunated between periods. Lauric acid decreased protozoal counts in the rumen by 96% compared with SA and MA (compared with SA, MA had no effect on ruminal protozoa). Whole ruminal contents samples were collected 2, 4, 6, 8, 10, 14, 18, and 24 h after the morning feeding on d 23 of each experimental period, stored frozen, and later composited by cow and period for microbial profile analyses, which involved tag-encoded flexible (FLX) amplicon pyrosequencing to provide diversity analyses of gastrointestinal bacterial, archaeal, and fungal populations of the cattle. The LA treatment, either directly or through its effect on protozoa, had a profound effect on the microbial ecology of the rumen. Ruminal populations of Prevotella, Bacteroides, and Enterorhabdus were decreased (P = 0.04 to P < 0.001) by more than 2-fold in LA treatments compared with SA, and Clostridium populations were decreased (P = 0.01) in LA- compared with MA-treated cows. The proportion of Ruminococcus was not affected by treatment, although the LA treatment had the least proportion of Ruminococcus. Proportions of Eubacterium, Butyrivibrio, Olsenella, and Lactobacillus genera were increased (P = 0.03 to 0.01) by LA compared with MA or SA. The LA treatment, possibly through its effect on protozoa physically associated with archaea, resulted in an increase (P = 0.01) in the archaeal methanogenic genus Methanosphaera and a decrease (P = 0.01) in Methanobrevibacter. Few changes in fungal populations caused by treatment were detected. Collectively, results indicate that LA, either through antiprotozoal or direct antimicrobial effects, altered bacterial and archaeal populations in the rumen of dairy cows, but effects on fungal populations were not clear.

Effect of supplementing coconut or krabok oil, rich in medium-chain fatty acids on ruminal fermentation, protozoa and archaeal population of bulls

“…Hristov et al, 2012), KO, which is particularly enriched in C14:0, seemed to induce shifts in rumen fermentation patterns, protozoal numbers and archaeal abundance, diversity and community structure at lower doses than CO. Further research should elucidate whether KO could be used as a methane mitigation strategy as rumen methanogen numbers do not always seem a key factor determining CH 4 production (e.g. Popova et al, 2011).…”

“…Furthermore, the archaeal community showed a more dominated structure (greater dominance and community organization) when supplementing CO as compared with KO or KO + T. Increases in dominance and community organization were also shown when supplementing CO in vitro (Patra and Yu, 2013). Nevertheless, a recent in vivo study on dairy cattle fed lauric acid, showed a decrease in the prevalence of Methanobrevibacter, the most predominant Archaea, whereas the prevalence of the less-abundant Methanosphaera increased (Hristov et al, 2012). This reduction in dominance within the archaeal community was hypothesized to be linked to strong dereases (about 2 log-units) in protozoal numbers with which Methanobrevibacter might be associated.…”

Taxonomic Identification of Ruminal Epithelial Bacterial Diversity during Rumen Development in Goats

“…The total DNA of the rumen tissue was then diluted to 50 ng/l and was used in the preparation of amplicons for high-throughput sequencing. Conventional PCR was performed to amplify the V2 and V3 regions of the 16S rRNA gene using universal primers 104F (5=-NNNNNN GGCGVACGGGTGAGTAA-3=) and 530R (5=-CCGCNGCN GCTGGCAC-3=) (13). The forward primer, 104F, contained 6-base barcodes [represented by the italicized poly(N) section of the primer sequence] at the 5= terminus.…”

Effects of early feeding on the host rumen transcriptome and bacterial diversity in lambs

“…Currently, next-generation sequencing is widely used to study rumen microbial ecology. The application of such an approach would allow for much greater coverage of the microbial diversity and physiology of a complex environment, such as the rumen in calves26, cows2728, and goats29.…”