High intake of sugars and starch, low number of meals and low roughage intake are associated with equine gastric ulcer syndrome in a Belgian cohort

Equine gastric ulcer syndrome (EGUS) is a pathological condition affecting the glandular and squamous regions of the stomach. It is characterized by non-specific clinical signs, behavioural changes or can also be found without any overt clinical manifestations. Nutritional factors such as intermittent feeding, high sugars and starch intake, large amounts of straw as forage and prolonged time without access to forage have all been associated with an increased risk of equine squamous gastric disease (ESGD). The aim of this study was to investigate which nutritional practices are commonly seen in clinical ESGD cases in Belgium. Medical records of 27 horses referred to the equine nutritional service at Ghent University (2013-2018) due to equine gastric ulcer lesions were reviewed. Twenty-one healthy horses referred for dietary evaluation during the same period were selected as control cases (CC). Dietary evaluation was performed on an individual basis. Forage/concentrate ratio on dry matter basis, forage content in the diet, total dietary sugars and starch intake per day and per meal were analysed. Retrospective descriptive and statistical analyses were performed. Significantly, higher amounts of forage intake (%DM per BW) in the CC vs. ESGD group were noted (p <= .05) with average values of 1.39 (SD +/- 0.27) and 1.27 (SD +/- 0.70) respectively. There were no significant differences for sugars and starch intake in g/kg BW/day (p = .18). However, the sugars and starch intake per meal (g/kg BW/meal) in the CC group (average value 1.06, SD +/- 0.56) was significantly (p < .001) lower than in the EGUS group (average value 1.85 SD +/- 0.78). Forage intake below the recommended absolute minimum value as well as high sugars and starch intake were most commonly associated with EGUS in the present case series. An adequate diet formulation taking into account these main nutritional factors is therefore essential to avoid gastric problems in horses

High-starch diets alter equine faecal microbiota and increase behavioural reactivity

Gut microbiota have been associated with health, disease and behaviour in several species and are an important link in gut-brain axis communication. Diet plays a key role in affecting the composition of gut microbiota. In horses, high-starch diets alter the hindgut microbiota. High-starch diets are also associated with increased behavioural reactivity in horses. These changes in microbiota and behaviour may be associated. This study compares the faecal microbiota and behaviour of 10 naïve ponies. A cross-over design was used with experimental groups fed high-starch (HS) or high-fibre (HF) diets. Results showed that ponies were more reactive and less settled when being fed the HS diet compared to the HF diet. Irrespective of diet, the bacterial profile was dominated by two main phyla, Firmicutes, closely followed by Bacteroidetes. However, at lower taxonomic levels multivariate analysis of 16S rRNA gene sequencing data showed diet affected faecal microbial community structure. The abundance of 85 OTUs differed significantly related to diet. Correlative relationships exist between dietary induced alterations to faecal microbiota and behaviour. Results demonstrate a clear link between diet, faecal microbial community composition and behaviour. Dietary induced alterations to gut microbiota play a role in affecting the behaviour of the host

11 Assessment of the impact of age on fecal microbial ecosystem in horses

International audienceIn humans, aging influences gut microbiota diversity and structure. In horses, modifications in gut microbiota could also occur, potentially leading to alteration in digestion and metabolism, development of diseases and even behavioral changes. Such modifications can affect microbial functions and consequently digestive capabilities. The aim of this in vivo study was to assess the age-related variations of microbial activity and physical parameters in the equine fecal ecosystem. The study population was composed of 50 horses (6–30 years old, geldings and mares from different breeds) conducted outdoors in the same sanctuary. Before the study, horses were dewormed and a dental examination was performed. They were gradually adapted during 1 week to the experimental diet (hay ad libitum + 860g muesli/horse/day). After 3 weeks of dietary management, naturally voided feces were collected individually for determination of pH, dry matter (DM), and fermentation end products concentrations (lactate and volatile fatty acids (VFA)). Age was correlated to each parameter (R software) and Pearson correlation coefficients were calculated. A GLM procedure was performed to compare the 5 age classes considered. Lactate and total VFA concentrations, propionate and iso-butyrate proportions were not correlated with age. Fecal pH and acetate (C2) proportion decreased with age, while DM, butyrate (C4), iso-valerate (iC5) and valerate (C5) proportions increased with age (Table 1). The fecal pH (P = 0.024), DM (P = 0.014), C4 (P < 0.001) and C5 (P < 0.001) proportions were different between elder horses (≥26 years) and younger (Table 1). These preliminary data suggest age-related modifications in digestion or metabolites absorption. Variation in microbiota activity and/or composition might explain some of these modifications. Bacterial structure and diversity in fecal ecosystem would provide complementary information to understand digestive evolution with age

Development of an in vitro technique to measure the cellulolytic activity of donkey caecal contents

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