Research into diet and behaviour and the effects on the digestive system has increased significantly in the past decade, with many researchers looking at the effects of different diets on bacteria in faeces. Whilst ideally we want to know what bacteria are present and in what amounts in the hindgut itself, sampling here is quite invasive. Looking at bacteria in faeces has become more popular as a way to understand the effects on the hindgut microbiome.
Many horse owners believe certain foods can cause their horses to become “spooky” or “excited” but probably most of our knowledge relates to the effects of starch. High-starch feeds include cereals such as oats, barley, wheat or maize, but others such as rice bran and whole carob can also be very high. High-starch intake can cause or worsen gastric ulcers in the stomach but can also cause upset in the hindgut with an increased risk of colic or laminitis.
A recent study from the University of Glasgow looked at the effects of feeding a group of 10 ponies for two weeks on either a high-starch (hay 3.6% starch + compound feed 23% starch) or a high-fibre diet (hay 3.6% starch + alfalfa 5% Starch). They found the ponies were more “reactive” and “less-settled” when fed the high-starch diet. The different diets changed the gut (faecal) bacteria and they were also able to relate the changes in behaviour to changes in the microbiome: “Results demonstrate a clear link between diet, faecal microbial community composition and behaviour."
So if you have a horse or pony that reacts to high-starch diets what are the options?
• Always feed hay or allow horses to graze before hard feed to ensure you don’t feed on an empty stomach. Hay slows the passage of feed and reduces the risk of undigested starch (which can cause upset to the hindgut bacteria and colic) reaching the hindgut
• Feed 3-4 small meals rather than 1-2 large meals
• Does your horse or pony really need a high-starch diet? This is usually only required in animals in moderate to hard work
• If your horse or pony needs more energy and is out of work or in light work then this can often be met by giving more forage
• For horses prone to gastric ulcers, the starch content of the feed should be below 12%
• Replace some of the starch energy with energy from oil e.g. Linseed Oil. This is beneficial for both behaviour and for reducing the risk of gastric ulcers
• Feed a high-dose protected live-yeast probiotic such as Science Supplements Gut Balancer which has been proven in studies to reduce disturbance to the hindgut
Link to Study: HERE