Feeding for the season

As the seasons change so does the amount of pasture available to your horse. And as the amount of pasture changes, so does your horse’s need for supplementary feed. Failure to adjust your horse’s feeding regime correctly with changing seasons could result in an overweight, hyperactive horse or an underweight, tired mount. But is it as simple as just changing the amount of feed you are giving? We explore this in detail in the following article.

Controlling Energy

As the amount and quality of pasture changes in your paddocks, so does the amount of digestible energy (calories) available to your horse. During winter or periods of drought when very little pasture is available, performance horses often need to be provided with additional energy in the form of hay, haylage, chaff and/or pelleted, extruded or sweetfeed concentrates to ensure their daily energy requirements are met.

In the reverse, when large amounts of high quality pasture is available, the pasture alone can often go close to meeting a performance horse’s requirement for energy. When these high quality pastures are available, there is little to no need to feed additional hard feed. In the middle of those two extremes is a situation where either the quality or quantity of available pasture means additional hard feed or forages needs to be supplied to meet energy requirements.

The table below shows the energy deficit left in a working horse’s diet when excellent, fair or poor quality pasture is the only feed provided in the diet. Excellent quality pasture is able to meet 100% of this horse’s energy requirement, while the poor quality pasture leaves a 26 MJ/day energy deficit.

Pasture Conditions Energy requirement for a 500 kg horse in moderate work Amount of energy supplied by 24 hours access to pasture Energy Deficit that needs to be filled with supplementary feed
Excellent 104 MJ 104 MJ Nil
Fair 104 MJ 88 MJ 16 MJ
Poor 104 MJ 78 MJ 26 MJ

The key to knowing when to adjust the amount of feed you are feeding according to pasture conditions is regularly body condition scoring your horse to detect changes in body fatness and taking careful note of your horse’s behaviour (see FeedXL Newsletter #1). If your horse is starting to get too fat or is feeling full of itself this may indicate you are feeding too much. If your horse is losing condition or feeling flat during work pasture quality may have dropped and you may need to feed more supplementary feed.

What about minerals?

While adjusting the amount of extra feed you provide may seem simple and is something a majority of horse owners do instinctively very well, there is a catch … you need to adjust what you are feeding to control energy intake WITHOUT unbalancing your horse’s diet from a vitamin and mineral perspective.

Let’s look at an example; A horse is grazing poor quality pasture and being supplemented with 2 kg/day (4.4 lb) of alfalfa/lucerne hay and 3 kg per day (6.6 lb) of a complete feed. As spring approaches and pasture conditions start to improve the horse starts to put on some weight so its owner (wisely) reduces the complete feed being fed from 3 kg/day to 1.5 kg/day (3.3 lb) and the horse’s weight stabilises. Once the warm weather arrives, the pastures improve to excellent quality and again the horse starts to put on some weight and feels a bit fresh in its work, so the complete feed and lucerne hay is now completely removed from the horse’s diet.

This feed reduction strategy is perfect with respect to controlling energy intake and is absolutely what should happen to avoid an overweight, hyperactive horse. However, simply reducing the amount of a complete feed in a horse’s diet leaves that horse wide open to mineral deficiencies, because in reducing the amount of complete feed in the diet to control energy intake, you are also going to reduce the amount of supplementary minerals in the diet and create some mineral deficiencies. The table below demonstrates how these mineral deficiencies develop as the amount of complete feed in the diet is reduced.

Energy Copper Zinc Selenium Iodine
% of recommended daily intake provided by the diet*
Poor quality pasture + 2 kg Lucerne Hay + 3 kg Complete Feed+ 100% 129% 127% 110% 107%
Fair quality pasture + 2 kg Lucerne Hay + 1.5 kg Complete Feed+ 100% 89% 108% 82% 73%
Excellent quality pasture only 100% 44% 73% 36% 29%

*RDIs from FeedXL.com +Well formulated commercial feed for performance horses

What is the solution?

Obviously continuing to feed the same amount of complete feed all year round to meet mineral requirements is not a feasible solution as while this will prevent mineral deficiency, it will oversupply energy requirements when pasture conditions are good, causing horses to get overweight and hyperactive. So what should you do?

The best solution is to always have a complete feed and a compatible low dose mineral supplement or balancer pellet on hand so that as you reduce the amount of complete feed to control energy intake you can add some supplement or balancer pellet to meet mineral requirements without adding unwanted calories to the diet.

Let’s look at the diets above, this time with a balancer pellet added to meet mineral requirements:

Energy Copper Zinc Selenium Iodine
% of recommended daily intake provided by the diet*
Poor quality pasture + 2 kg Lucerne Hay + 3 kg Complete Feed 100% 129% 127% 110% 107%
Fair quality pasture + 2 kg Lucerne Hay + 1.5 kg Complete Feed + 200 g Balancer Pellet++ 100% 116% 130% 106% 103%
Excellent quality pasture + 550 g Balancer Pellet++ 100% 124% 153% 103% 111%

+ Well formulated commercial feed for performance horses ++Well formulated balancer pellet

Adding the balancer pellet at different rates according to pasture conditions and the amount of complete feed being fed means you can control energy intake without causing a mineral deficiency.

Of course, not all complete feeds and balancer pellets are created as equal, so use FeedXL (FeedXL.com) to work out which ones do actually meet all of your horse’s requirements. Also stick with products that fully disclose the nutrient analysis of the feed on the label so you can make informed choices on the best complete feeds and supplements to use for your horse.

Take Home Message

As seasons and pasture availability change so must your horse’s feed regime. In order to control your horse’s body condition and behaviour the amount of energy (calories) in the diet needs to be kept in check. To do this, the amount of supplementary feed you give will increase during times of poor quality pasture and in the reverse the amount you feed will need to be decreased when there is high quality pasture available.

However, in adjusting feed amounts up and down to match pasture conditions, be aware of the diet’s mineral balance because controlling energy intake by reducing the amount of complete feed you are giving may be inadvertently causing mineral deficiencies that will affect your horse’s health. Feeding a complete feed, together with specific amounts of a mineral supplement or balancer pellet will allow you to control energy intake whilst always meeting mineral requirements. FeedXL.com can help you to work out which products are best to use for your horse and will show you when you are or are not meeting mineral requirements as you adjust amounts of feed in the diet.

Dr. Nerida Richards is FeedXL’s resident equine nutrition specialist and horse nut. With a degree in Rural Science, a doctorate degree in equine nutrition and going on 13 years of full time, on the ground experience in feeding all types of horses Nerida is able to help FeedXL members solve any problem they may come up against with feeding their horses.

This newsletter by Dr. Nerida Richards was originally posted to the FeedXL user forums for FeedXL subscribers in July, 2014. If you would like be among the first to receive our newsletters then please consider subscribing to our email list.

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