Most of us look forward to the drier weather, milder temperatures and longer days so that we can spend more time with our equine friends. However, many of us also experience the heartbreak of sore feet, laminitis and other issues that our horses may present in the spring (and can also occur in autumn too), that detract from our riding time. A little understanding of how we can manage our horses leading up to this time period will go a long way to ensure the health and continued use of our horses.
For many horse owners in Australia, we have the good fortune of our horses spending a great deal of time on pasture. However, this is a double edged sword - our horses are free but do require a bit more effort on our part to better manage their time on pastures. The main reason for this is due to the fact that many pastures are not suitable for horses. They are geared towards ruminants and high production such as meat, wool or milk. But our horses are out there, in sugar heaven and becoming more and more unhealthy. In summary, the surge in non-structural carbohydrates (NSC)/sugars is dependent upon the amount of sunlight, moisture, temperature and stage of growth. However, NSC can also accumulate during periods of moisture stress and low temperatures, not just during sunny, warm days following good rains.
In addition to the surge in NSC, the plants are also surging in potassium which in turn causes major mineral imbalances for the horse. Magnesium is a major mineral in over three hundred and fifty enzymatic processes in the body, including the breakdown of blood glucose. After eating a carbohydrate rich diet such as spring pasture, the blood glucose surges. If the horse is low in magnesium there is a decrease in insulin response. This decrease contributes to obesity, diabetic like symptoms, laminitis, and Cushing's-like symptoms.
In addition to being mindful of the sugars and potassium in our pastures, we also need to be aware that such pastures during spring and autumn do not provide enough fibre until it is mature and dried off. During spring, it is predominantly NSC. In the horse, the small intestine is the site of carbohydrate digestion. However, it stands to reason that during times of eating excess carbohydrates from the rich pasture, the small intestine may be overwhelmed. Therefore, much of this feed is passed onto the large intestine and hind gut area without adequate digestion. The delicate balance of micro-organisms is challenged, with good bacteria dying off and opportunistic bacteria and pathogens taking over. The pH has changed resulting in hind gut acidosis. The end result is metabolic chaos, mineral imbalances and possible inflammation of the laminae = laminitis.
While some horse owners believe it best to put their animals in a starvation or "Jenny Craig" paddock to combat excess weight gain or laminitis, it then becomes paramount to feed adequate levels of hay. That means a minimum of 1.5% of their body weight per day. Without adequate fibre, the hind gut cannot maintain the delicate balance of micro-organisms.
In practical terms, taking a pro-active approach will assist greatly in managing horses during certain times of the year.
- Monitor body weight - feed according to work load and body weight,
- As with any ration changes, if you decide to yard your horse, do so over two to three weeks to maintain good gut health,
- Consider limiting access to pasture only during early mornings when NSC are lower,
- Cross grazing with other species, grazing muzzle or grazing during certain grass heights
- Build a track and feed plenty of hay,
- Plant horse safe grasses over time,
- Soak hay for one to two hours prior to feeding - dump water after each soaking. Soaking decreases sugar levels by up to 30%,
- Do not leave soaked hay out for more than twenty four hours as moulds can grow,
- Feed plain salt at a rate of 10gms per 100Kg body weight. Salt acts as a buffer and assists in drinking, therefore flushing out any excess potassium,
- Feed adequate levels of high quality magnesium, calcium and general vitamin and mineral mix,
- Check the sugar and potassium levels in your other feeds - consider making changes to eliminate excess sugar and potassium by feeding pure feeds and not pre-mixed.
NB. Look at doing these management techniques well before the spring flush.
References.
- Australian Journal of Experimental Agriculture 2001.
Another publication of interest includes, Feeding Horses in Australia: A Guide for Owners and Managers by John Kohnke, RIRDC publication 1999, reference #99/49.
