Winter weight loss

TEXT: HANNAH BOTHA, MSC EQUINE SCIENCE, EPOL NUTRITIONAL ADVISOR

WINTER

WEIGHT LOSS

DID YOU KNOW?

Shivering helps horses to thermo-regulate by using the muscles to generate heat. However, this process requires increased energy.

KEEPING CONDITION IN THE COLD

Loss of weight in winter is a concern with many of our equines, especially those who are older or naturally leaner. The cold weather in winter increases energy demands on our horses, as they need to produce more body heat to keep themselves warm. On top of this, the amount and quality of the grazing in the paddocks during winter is dramatically reduced.

All of this means that even if you are feeding a top-ofthe-range ration to your horse, with high-quality forage and concentrate feed, you must not overlook the fact that winter conditions result in horses typically requiring more food (in the form of hay, grazing, and concentrate feed) than usual to maintain body condition and keep up with their workload.

THE EFFECT OF TEMPERATURE

All warm-blooded animals, including horses, have a critical temperature. This is the outside temperature below which a horse must produce extra heat to maintain his body temperature.

The critical temperature varies, however, depending on the horse’s condition. A mature horse in good condition, where ribs cannot be seen, has a critical temperature of around 0°C. This means that any environmental temperature drop below 0°C will require the horse to produce extra heat. After developing a winter coat, the critical temperature may drop even lower to somewhere around -5°C.

It is estimated that young horses, thinner horses and those who have been stabled and not developed a full winter coat, might only have a critical temperature of between +10°C and +5°C. This is important to note, as horses require about 15-20% more feed for each 10-15°C that the ambient temperature falls below their critical temperature. This is to produce the extra heat required to keep them warm.

Therefore, each horse must be considered as an individual when it comes to winter feeding.

IMPACT ON FEEDING

Temperatures in South Africa do not commonly reach low enough levels to require the majority of horses to need the extra 15-20% feed. However, most horses will still require some more food in winter than in summer.

Another point to note regarding feeding regime changes is that whilst horses exposed to constant chronic cold weather acclimatise to the cold, horses not used to cooler temperatures typically need 10 to 21 days to adapt to the altered temperature. It is, therefore, often helpful to adjust feeding before the cold weather sets in to avoid playing a game of catch-up to maintain condition over the winter period.

FEEDING EXTRA CONCENTRATES

As concentrates generally provide more calories per kilogram than roughage, this is often the first port of

call for many owners looking to increase energy intake. However, this is not the optimal choice for most horses, and changes in concentrate should really be reserved for horses whose workload has significantly increased, or who are pregnant, lactating or growing. Even in these cases it is often best not to simply increase the quanitity of the feed, but instead to change to a higher calorie/energy-dense feed, which allows meal sizes to remain small, facilitiating more efficient digestion, yet allowing the horse to get more from the feed.

The bottom line is that as much as feeding extra concentrates is often easier and perhaps even cheaper, forage is the key to maintaining condition through winter.

NOTE

Ideally, you should also discuss your feeding regime with a trusted equine nutritionist to ensure the diet selected is optimal. Both overfeeding and underfeeding can create a whole host of problems, and an equine nutritionist is best placed to assist you in planning a winter feeding programme.

FEED MORE FORAGE

If you want to ensure that your horse remains in good body condition, increasing his amount of forage is likely to be sufficient. Forage is fermented in the gut where

‘HOT’ HORSES

Lots of owners are concerned about feeding more to their horses, as they do not want them to become too ‘hot’ to ride. First and foremost, it is important to be realistic here as over the winter months, there are plenty of other factors that contribute to your horse displaying ‘hot’ behaviour – not just increased food intake. A change in workload and increased stable time, for instance, may well result in your horse being a little ‘fresher’ than usual – do not simply attribute all changes to food!

However, if you are concerned that food is making your horse too ‘hot’, there are steps you can take to assist in reducing the risk of over-excitable behaviour. Firstly, introduce the higher energy food slowly. Suddenly providing a horse with more energy/calories in his diet will increase the likelihood of ‘excitability’.

Secondly, the type of energy source provided is an important aspect. Feeds based on ‘slowrelease’ energy sources, such as fibre and fat, release energy gradually and are less likely to promote hot behaviour compared to sources of ‘quick-release’ energy, such as starch from cereal grains or sugars from molasses. It is thus important that the feed is high in fat and fibre and low in starch and sugars if behavioural excitability is a concern. The added bonus of this is that fibre and fat are far friendlier on the gut and can help horses prone to colic and gastric ulcers avoid these issues. bacteria are active. Bacteria produce considerable heat during fermentation that the horse can use to warm himself from the inside out, rather than having to shiver or move to maintain body temperature. This means that more forage provides a heat source in addition

to the extra calories, making it a very effective way of maintaining condition.

Unfortunately, winter forage is often of a reduced quality, which means more hay should be provided than in summer anyway to ensure the same calorie value. Then you will still need to top up the levels even further to maintain warmth. This may all lead to a considerable increase in the amount of forage required, and this can be costly. To reduce this cost, you need to find the best quality forage (highest nutrient value) so that lower amounts can be fed. This is generally cheaper than buying larger volumes of poorer quality hay.

In terms of nutrient levels in forage from highest to lowest, green pasture generally tops the list, followed by winter pasture, good quality grass hay and poor-quality grass hay. When selecting hay, look for good quality hay that is clean and dust-free. Consider feeding higher calorie hay like lucerne or teff should there be a need to boost a horse’s calorie intake further. Choose immature hay (characterised by soft stems and a larger portion of leaf matter) rather than overly mature hay (very stalky with little leaf), as this provides better nutritional value. Moreover, immature hay has a water-holding capacity that more mature hay does not have.

NOTE: Impaction colic is more common in winter as horses often drink less because the cold weather makes their water cold. Forage with higher moisture content is therefore preferred, particularly in winter.

EXTRA ADDITIONS

Keep in mind that poorer quality hay can also have reduced vitamin and mineral content. It, therefore, may be wise to consider adding in a balancer product for younger and older horses to increase their levels of vitamins and minerals without changing their diet hugely.

Adding extra oil to the diet can also be beneficial as it allows the increase of calories without adding large amounts of expensive concentrate feed. 250ml (1 cup) of oil has the equivalent calories of around 1-1.5kg of oats.

REMEMBER

You should monitor your horse’s body condition year-round, but especially before harsher winter weather arrives. You can then determine whether your horse needs extra energy by checking for decreased body weight and condition and noticing these issues as soon as they start to arise. Make sure to feel through the heavy winter coat when checking body condition – are the ribs easily felt? If so, the horse needs more energy. Is the horse shivering a lot? If so, he needs more energy.

And don’t wait for temperatures to plummet before you begin these checks and changing of diet. Ideally, you need to begin your winter nutrition programme early enough and give your horse sufficient time to build up the reserves he needs to get him through the winter. Use common sense and regular observation, and your horse should have an uneventful cold season.