Linseed oil and heated linseed grain supplements have different effects on rumen bacterial community structures and fatty acid profiles in cashmere kids1

Abstract

This study investigated the effects of dietary supplementation with alternative sources of α-linolenic acid on growth, the composition of rumen microbiota, and the interactions between rumen microbiota and long-chain fatty acid (FA) concentrations, in goat kids. Sixty 4-monthold castrated male Albas white cashmere kids (average BW 18.6 ± 0.1 kg) were randomly allocated among three dietary treatments: (i) basal diet without supplementation (Control), (ii) basal diet supplemented with linseed oil (LSO), (iii) basal diet supplemented with heated linseed grain (HLS). The concentrate:forage ratio was 5:5 and the LSO and HLS treatments provided the kids with similar dietary FA profiles. The diets were fed for 104 d, consisting of 14 d for adaptation followed by 90 d of experimental observation. Treatment did not significantly influence BW, DMI, or bacterial richness or diversity. On the other hand, the relative abundance of bacteria participating in hydrogenation differed significantly among the three groups: the Veillonellaceae and Christensenellaceae were more abundant in LSO kids, Prevotellaceae were more abundant in HLS kids, and the Fibrobacteriaceae were more abundant in Control kids (P < 0.05). Spearman correlation analysis indicated that Ruminobacter, Selenomonas_1, Fretibacterium, Prevotellaceae_ UCG-001, Succinimonas, and Ruminococcaceae_ NK4A214_group were the genera that participated in hydrogenation of long-chain FAs. HLS-fed kids had a lower relative abundance of Ruminobacter, but a higher abundance of Prevotellaceae_UCG-001 and Fretibacterium than LSO-fed kids. These changes were associated with greater rumen concentrations of C18:3n3 and n-3 PUFA, but lower concentrations of n-6 PUFA and lower n-6/n-3 ratios, in HLS than in LSO-fed kids. In conclusion, feeding kids with HLS increased rumen concentrations of C18:3n3 and n-3 PUFA, but decreased the n-6/n-3 ratio by decreasing the abundance of bacteria that hydrogenate C18:3n3 and increasing the abundance of bacteria that hydrogenate C18:2n6.

Characterization of the Rumen Microbiota and Volatile Fatty Acid Profiles of Weaned Goat Kids under Shrub-Grassland Grazing and Indoor Feeding

“…Considering that short-chain fatty acids (i.e., VFAs) are the main end products from the carbohydrate catabolism of gut microbes, we sought to explore correlations between the microbial biomarkers identified above and VFAs in the rumen fluid. Similar to the previous findings in goats [18,66] and sheep [14], most microbes were not significantly correlated with VFAs in this study, mainly due to the complex relationships between diet composition, the gut microbiota and metabolic outputs [55,67] (e.g., substrate cross-feeding [68]). However, linear correlations were observed between several microbial taxa (e.g., Veillonellaceae and Succiniclasticum) and VFAs, which were supported by previous work.…”

Garlic Skin Induced Shifts in the Rumen Microbiome and Metabolome of Fattening Sheep

“…The taxonomic assignment of ruminal bacteria in our study revealed that the most abundant phyla were Bacteroidetes and Firmicutes, which was in accordance with the results of previous studies [37,38].The Firmicutes phylum are the main bacteria that degrade bers, including a large number of bacteria which can promote decomposition of cellulose and fermentation of polysaccharides [39]. It was reported that Bulleidia has the capability to utilize saccharides and starch as energy source [40].…”

“…It has also been reported that the genus Methanosphaera was H2 utilizing species within the rumen [47]. The genus Fretibacterium was reported to participate in hydrogenation of longchain fatty acid [38]. Thus, the decreased relative abundance of Fretibacterium in the GAS group could be partially attributed to the increased abundance of Methanosphaera.…”

Garlic skin induced shifts in the rumen microbiome and metabolome of fattening sheep

“…The taxonomic assignment of ruminal bacteria in our study revealed that the most abundant phyla were Bacteroidetes and Firmicutes, which was in accordance with the results of previous studies [26,27].The Firmicutes phylum are the main bacteria that degrade bers, including a large number of bacteria which can promote decomposition of cellulose and fermentation of polysaccharides [28]. It was reported that Bulleidia has the capability to utilize saccharides and starch as energy source [29].…”