Effect of age and the individual on the gastrointestinal bacteriome of ponies fed a high-starch diet

Changes of faecal bacterial communities and microbial fibrolytic activity in horses aged from 6 to 30 years old

Horse owners and veterinarians report that from the age of 15, their horses can lose body condition and be more susceptible to diseases. Large intestinal microbiome changes may be involved. Indeed, microbiota is crucial for maintaining the condition and health of herbivores by converting fibres into nutrients. This study aimed to compare the faecal microbiome in horses aged from 6 to 30 years old (yo), living in the same environment and consuming the same diet, in order to assess whether the parameters changed linearly with age and whether there was a pivotal age category. Fifty horses were selected from the same environment and distributed across four age categories: 6-10 (n = 12), 11-15 (n = 11), 16-20 (n = 13), and 21-30 (n = 14) yo. All horses had no digestive problems, had teeth suitable for consuming their feed, and were up to date with their vaccination and deworming programmes. After three weeks of constant diet (ad libitum hay and 860 g of concentrate per day), one faecal sample per horse was collected on the same day. The bacterial communities' richness and intra-sample diversity were negatively correlated with age. There was a new distribution of non-beneficial and beneficial taxa, particularly in the 21-30 yo category. Although the faecal concentration of short-chain fatty acids remained stable, the acetate proportion was negatively correlated with age while it was the opposite for the proportions of butyrate, valerate, and iso-valerate. Additionally, the faecal pH was negatively correlated with age. Differences were more pronounced when comparing the 6-10 yo and 21-30 yo categories. The values of the parameters studied became more dispersed from the 16-20 yo category onwards, which appeared as a transitional moment, as it did not differ significantly from the younger and older categories for most of these parameters. Our data suggest that the microbiome changes with age. By highlighting the pivotal age of 16-20, this gives the opportunity to intervene before individuals reach extremes that could lead to pathological conditions.

Effects of Concentrate Feeding Sequence on Growth Performance, Nutrient Digestibility, VFA Production, and Fecal Microbiota of Weaned Donkeys

In this study, effects on the growth performance, nutrient digestibility, volatile fatty acids (VFA) production, and fecal microbiota of weaned donkeys were observed using different concentrate feeding sequences. Fifteen healthy 6-month-old weaned male donkeys with a body weight of 117.13 ± 10.60 kg were randomly divided into three treatment groups, including group C1 (roughage-then-concentrate), group C2 (concentrate-then-roughage), and group C3 (total mixed ration, TMR). The experiment lasted 35 d. We measured nutrient digestion by the acid-insoluble ash method and analyzed the fecal microbiota of the weaned donkeys by high-throughput sequencing of 16s rRNA genes in the V3-V4 region. The results show that group C3 obtained the best growth performance, and the digestibility of crude protein (CP) and crude extract (EE) was significantly higher than that of group C1 (p < 0.05). Acetic acid, isobutyric acid, valeric acid, isovaleric acid, and caproic acid were notably different among all groups (p < 0.05). In addition, we observed that Firmicutes and Bacteroidetes were dominant in the fecal microbes of each group, and Firmicutes was significantly higher in group C3 (p < 0.05). At the genus level, the different genera were Treponema, Rikenellaceae-RC9-gut-group, Unidentified-F082, and Bacteroidales-RF16-group (p < 0.05). The prediction of fecal microbiota function by PICRUSt indicated that different feeding sequences had minimal impact on the function of the fecal microbiota, particularly on the high-abundance pathway. In summary, the concentrate feeding sequence changed the composition of the fecal microbe of weaned donkeys.

Regulatory effects of Lactobacillus fermented black barley on intestinal microbiota of NAFLD rats

Gut microbiota dysbiosis and oxidative stress may play important roles in the progression of nonalcoholic fatty liver disease (NAFLD). Fermented foods contain probiotics and other bioactive components that may improve gastrointestinal health and provide other health benefits. Here, we investigated the effect of Lactobacillus-fermented black barley on NAFLD rats. Adult Sprague Dawley rats were randomized into four groups: normal chow diet (NC), high-fat diet (HF), HF + fermented black barley treatment (HB) and HF + Lactobacillus treatment (HL). The rats in the HB and HL groups were continuously administered fermented black barley or Lactobacillus, respectively, for 12 weeks (1 mL/100 g·BW, containing 1 × 10⁸ CFU/mL Lactobacillus). Compared with the HF treatment, HB treatment effectively inhibited the increase in body weight, liver and abdominal fat indexes and hepatic lipids (p < 0.01), increased hepatic SOD activity (p < 0.05), decreased thiobarbituric acid reactive substances (TBARSs) (p < 0.01) and improved liver function. Moreover, Lactobacillus-fermented black barley exhibited regulatory effect on high-fat diet-induced intestinal microbiota dysbiosis by increasing the relative microbiota abundance and diversity, increasing the relative abundance of Bacteroidetes, decreasing the Firmicutes/Bacteroidetes ratio, increasing the abundances of some intestinal probiotics (such as Akkermansia and Lactococcus), and influencing some of the fecal metabolites related to hormones and lipid metabolism. The supplementation of fermented cereal food might be a new effective and safe preventive dietary strategy against NAFLD.

What Would Be Good for All Veterinarians to Know About Equine Nutrition

Nutrition and management have enabling and supporting roles to play in the health, welfare, and performance of equines. Poor or inappropriate nutrition may therefore impose limits on an animal's ability to perform and adversely affect health and welfare. Understanding the gastrointestinal tract from a nutrition perspective can help to reduce the risk of certain clinical problems. This article outlines key factors with respect to the equine digestive tract and discusses relevant aspects of ration formation. Forage is highlighted, because inappropriate forage provision is one of the key limitations in many horse diets.

How Can Nutrition Help with Gastrointestinal Tract-Based Issues?

Many horses are fed differently than their wild ancestors. They often have limited access to pasture and are fed conserved forage and concentrates rich in starch and sugars, in only 2 meals per day. Feeding practices in contrast to natural feeding behavior can lead to gastrointestinal issues. Standard nutritional evaluation is warranted because of its important role in prevention and in treatment and management of diseases. When medical and nutritional treatments are combined, success rates are higher. New techniques to characterize equine microbiota have been used, allowing for microbiota manipulation to prevent and treat intestinal diseases.