Postbiotics from Saccharomyces cerevisiae fermentation stabilize microbiota in rumen liquid digesta during grain-based subacute ruminal acidosis(SARA) in lactating dairy cows

Background Subacute ruminal acidosis(SARA)is a common metabolic disorder of high yielding dairy cows,and it is associated with dysbiosis of the rumen and gut microbiome and host inflammation.This study evaluated the impact of two postbiotics from Saccharomyces cerevisiae fermentation products(SCFP)on rumen liquid associated microbiota of lactating dairy cows subjected to repeated grain-based SARA challenges.A total of 32 rumen cannulated cows were randomly assigned to 4 treatments from 4 weeks before until 12 weeks after parturition.Treatment groups included a Control diet or diets supplemented with postbiotics(SCFPa,14 g/d Original XPC;SCFPb-1X,19 g/d Nutri Tek;SCFPb-2X,38 g/d Nutri Tek,Diamond V,Cedar Rapids,IA,USA).Grain-based SARA challenges were conducted during week 5(SARA1)and week 8(SARA2)after parturition by replacing 20%DM of the base total mixed ration(TMR)with pellets containing 50%ground barley and 50%ground wheat.Total DNA from rumen liquid samples was subjected to V3–V416S r RNA gene amplicon sequencing.Characteristics of rumen microbiota were compared among treatments and SARA stages.Results Both SARA challenges reduced the diversity and richness of rumen liquid microbiota,altered the overall composition(β-diversity),and its predicted functionality including carbohydrates and amino acids metabolic pathways.The SARA challenges also reduced the number of significant associations among different taxa,number of hub taxa and their composition in the microbial co-occurrence networks.Supplementation with SCFP postbiotics,in particular SCFPb-2X,enhanced the robustness of the rumen microbiota.The SCFP supplemented cows had less fluctuation in relative abundances of community members when exposed to SARA challenges.The SCFP supplementation promoted the populations of lactate utilizing and fibrolytic bacteria,including members of Ruminococcaceae and Lachnospiraceae,and also increased the numbers of hub taxa during non-SARA and SARA stages.Supplementation with SCFPb-2X prevented the fluctuations in the abundances of hub taxa that were positively correlated with the acetate concentration,andα-andβ-diversity metrics in rumen liquid digesta.Conclusions Induction of SARA challenges reduced microbiota richness and diversity and caused fluctuations in major bacterial phyla in rumen liquid microbiota in lactating dairy cows.Supplementation of SCFP postbiotics could attenuate adverse effects of SARA on rumen liquid microbiota.

Combined effects of chitosan and microencapsulated Enterococcus faecalis CG1.0007 probiotic supplementation on performance and diarrhea incidences in enterotoxigenic Escherichia coli K88^+ challenged piglets

The aim of this study was to investigate the combined effects of chitosan oligosaccharide(COS) and a microencapsulated Enterococcus faecalis CG1.0007 probiotic(PRO) on growth performance and diarrhea incidences in enterotoxigenic Escherichia coli(ETEC) K88^+ challenged piglets in a 14-d study. Thirty piglets,7.19 ± 0.52 kg initial BW weaned at 21 ± 1 d.were allotted to 5 treatment groups(n = 6)consisting of a corn-soybean meal diet with no additive(negative control, NC), NC + 0.25% chlortetracycline(positive control, PC), NC + 400 mg/kg COS(COS), NC + 100 mg/kg PRO(PRO) and NC + a combination of COS and PRO(CPRO). Pigs were individually housed in cages, acclimated to treatments for a 7-d period and had ad libitum access to feed and water throughout the study, On d 8, pigs were weighed, blood samples were collected, and then orally challenged with 6 mL(1 ×10^(11) cfu/mL) of freshly grown ETEC inoculum. During post-challenge period, blood was sampled at 24 and 48 h to determine plasma urea nitrogen(PUN), and diarrhea incidences and fecal consistency scores were recorded from d 9 to 12. On d 14, all pigs were weighed and then euthanized to obtain intestinal tissue samples for histomorphometric measurements. Growth performance responses were similar among treatments during the pre-and post-challenge periods. There were no significant differences in PUN content, incidences of diarrhea, and fecal consistency scores among treatments. The intestinal histomorphology results did not differ significantly among treatments except for PC with increased(P = 0.0001) villus:crypt ratio compared with the NC. Under the conditions of the present study, it can be concluded that supplementation of piglet diets with 400 mg/kg COS, 100 mg/kg microencapsulated PRO or their combination did not significantly improve piglet growth performance both during the pre-and post-ETEC K88+ oral inoculation. Also, there were no significant reduction of incidences and severity of diarrhea after challenge compared with the control group.

Impact of xylanases on gut microbiota of growing pigs fed corn-or wheat-based diets

This study investigated the effects of xylanase supplementations with cereal-based diets on nutrient digestibility and gut microbiota of growing pigs. A total of 96 individually penned pigs(initial BW = 22.7 ± 0.65 kg) were allotted to 12 treatments and subjected to a completely randomized block design experiment. Pigs in each treatment were fed an isocaloric wheat-based or corn-based diet with or without 1 of 5 types of xylanase supplements(XA, XB, XC, XD, XE). On d 42, all piglets were euthanized to obtain ileal and cecal digesta for microbial analysis, which involved high-throughput sequencing of the V1 - V3 regions of 16 S rRNA gene. Corn-and wheat-based diets differed(P < 0.05) in digestion characteristics. Dietary treatments affected the alpha-and beta-diversities of microbiota in the cecum but not in the ileum. The wheat-based diet increased(P < 0.05) alphadiversity and clustered separately(P < 0.05) compared with the corn-based diet. Wheat-based diet also promoted the relative abundance of genus(g.) Succinivibrio while corn-based diet promoted the proportion of family(f.) Veillonellaceae in the community. Among xylanases, only XC within the wheat-based diet altered(P < 0.05) the beta-diversity of the cecal microbiota compared with control. For each cereal-based diet and compared with the controls, xylanase treatments affected(P < 0.05) the proportions of 5 bacterial taxa in the ileum(f. Peptostreptococcaceae, order [o.]Streptophyta, f. Clostridiaceae, g. Clostridium and g. Streptococcus) and 8 in the cecum(g. Lactobacillus,g. Streptococcus, class [c.] Clostridia, f. Clostridiaceae, g. Megasphaera, g. Prevotella, g. Roseburia and f.Ruminococcaceae). Network analysis showed that across diets under control treatments, Bacteroidetes was the most influential phylum promoting cooperative relationships among members of the ileum and cecum microbiota. Xylanase treatment, however, reduced the influence of Bacteroidetes and promoted a large number of hub taxa majority of which belonged to the Firmicutes phylum. To maximize the efficiency of xylanase supplementation, our data suggest that xylanase C originated from Bacillus subtilis was more effective when applied to wheat-based diets, while xylanase A originated from Fusarium verticillioides was more beneficial when applied to corn-based diets.

Effect of chicken egg anti-F4 antibodies on performance and diarrhea incidences in enterotoxigenic Escherichia coli K88^+-challenged piglets

The aim was to evaluate the effects of dietary supplementation of spay-dried whole egg containing antiF4 antibodies(SDWE) against recombinantly produced F4 antigens in enterotoxigenic Escherichia coli K88^+(ETEC)-challenged piglets. Twenty-seven 21-d-old and individually housed piglets were randomly allotted to 3 treatments consisting of a wheat-soybean meal basal diet containing either 0(control egg powder; CEP), 0.1%(SDWE1) or 0.4%(SDWE2) SDWE. After a 7-d adaptation period, blood samples were collected from all pigs,and pigs were weighed and orally challenged with an ETEC inoculum. Blood was sampled at 24 and 48 h post-challenge, and diarrhea incidences and scores were recorded. On d 14, all pigs were weighed and then euthanized to obtain intestinal tissue samples for histomorphology measurement. During the pre-challenge period, pigs fed the SDWE showed a linear improvement(P < 0.05)in average daily gain(ADG) and gain to feed ratio(G:F), but there were no differences among treatments in growth performance during the post-challenge period. Diarrhea incidences and scores, fecal shedding of ETEC, plasma urea nitrogen content and intestinal histo morphology were similar among treatments.The results show that 0.4% SDWE supported greater piglet performance before challenge although such benefits were not evident during the post-challenge period at either 0.1% or 0.4% supplementation.