Effects of alfalfa chaff on the gastric mucosa in adult horses

Gut health of horses: effects of high fibre vs high starch diet on histological and morphometrical parameters

Background

The conventional feeding management of horses is still characterized by high starch and low fibre diets, which can negatively affect horse’s gastrointestinal health. Thus, the aim of this study was to compare the effects of a high-starch (HS) vs. a high-fibre (HF) diet on gut health in horses. A total of 19 Bardigiano horses destined for slaughter and aged 14.3 ± 0.7 months were randomly allotted to two dietary groups: HS (5 fillies and 4 colts,) and HF group (7 fillies and 3 colts). They received the same first-cut meadow hay but different complementary feeds for 72 days: HS group was fed 8 kg/animal/day of a starch-rich complementary feed while HF group was fed 3.5 kg/animal/day of a fibre‐rich complementary feed. At slaughter, stomachs were separated and washed for the evaluation of the glandular and squamous regions. Also, duodenum, jejunum, ileum, apex of the caecum, sternal flexure, pelvic flexure, right dorsal colon, rectum and liver were excised and submitted to histomorphometrical evaluation.

Results

The glandular region of HS group presented more severe gastric mucosa lesions compared to the HF group (P = 0.006). Moreover, a statistical tendency (P = 0.060) was found for the squamous region, presenting a higher score in HS than HF diet. Regarding morphometry, in jejunum villus height to crypt depth (Cd) ratio was influenced by sex, being greater in males than in females (P = 0.037) while in ileum Cd depended on interaction between sex and diet, being greater in males of HS group (P = 0.029). Moreover, in the duodenum and right dorsal colon the severity of the inflammation depended on sex (P = 0.024 and 0.050), being greater in females than in males. On the contrary, in the jejunum and in the pelvic flexure, inflammation was influenced by diet, being more severe in HS than in HF group (P = 0.024 and 0.052).

Conclusions

These results suggested that HS diet provoked more severe mucosa lesions in the glandular region of the stomach and a higher inflammation both in the jejunum and pelvic flexure. The present study can represent a starting point for further investigations on gut health in horses.

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.

Effect of Changing Diet on Gastric Ulceration in Exercising Horses and Ponies After Cessation of Omeprazole Treatment

Diet is an accepted risk factor for equine squamous gastric disease (ESGD), but there is little published evidence for the benefit of dietary change (DC). This study evaluated the effect of DC with or without initial omeprazole medication. Twelve pairs of exercising horses with ESGD Grade 2/4 (EM) and 17 pairs with ESGD Grade ≥3/4 (ES), were monitored. Paired horses had similar management, feeding times, workloads, and initially feed or forage. One of each pair was randomly assigned, postgastroscopy (Scope1), to a specified restricted starch ration; the other remained on their original diet. Omeprazole (4 mg/kg per os SID) was given to all ES pairs for 4 weeks. Gastroscopies were scored, without dietary knowledge, after 4 and 10 weeks (Scopes 2 and 3). Workloads remained similar throughout. McNemar's tests identified any changes in ESGD grade. Within the EM group, DC had no additional effect. For the ES group remaining on their original diet, there was significant improvement in ESGD grade from Scopes 1 to 2 (P < .001) but a worsening between Scopes 2 and 3 (P = .005), with Scope 3 being no different from Scope 1 (P = .08) reflecting no apparent long-term medication benefit. For the DC group, there was significant improvement in ESGD grade from Scopes 1 to 2 (P < .001) and between Scopes 1 and 3 (P = .003); In addition, there was no significant difference between Scopes 2 and 3 (P = .32). Although limited by the small number of pairs evaluated, this study provides evidence that appropriate DCs can be a beneficial management strategy for ESGD.