As winter is now upon us, it’s time to make sure you can do the best for your horses to ensure they stay in good condition until the warmer weather arrives. There are several aspects to consider, and they include the condition of grazing, temperature and its fluctuations, and levels of activity the horse is expected to do.
Graze anatomy
If we consider grazing first of all, in winter in New Zealand most horses are grazed year-round. The levels of nutrients in grass decline in cold temperatures, and it stops growing when the temperature drops to 10°C or less. Grass is highly responsive to heat and sunshine, so on a warmer winter day there will be some growth and nutrient production, but mainly the levels of carbohydrates, proteins, vitamins and minerals will be lower in winter, and grass is more fibrous.
This fibre is good for horses, better than lush growth, as it encourages hind gut fermentation; however, it can compromise energy values. Rapidly-growing grass in warmer seasons will have 20% or more energy compared to winter grass, depending on the pasture species.
Other nutrients in the grass change with the seasons, with a loss in protein, vitamin and mineral levels, such as calcium which declines from around 4g/kg down to just above 3g/kg.
Some minerals appear to become more concentrated in grass in winter according to the published research for NZ pastures, with copper being highest in August and September (Grace et al., 2002) for example. However, the upshot of all this variation is that you really need to ensure your horse has access to a balanced mineral supplement, extra energy from fibre and a protein source (such as legume forage) during the winter months.
Of course, most owners put out extra feed during this time. Forages vary a great deal in their nutritional value, which depends on the pasture source (good versus indifferent pasture grass and legume species, poor fertiliser history versus well managed grassland) and the preservation method (hay versus baleage).
While hay is traditionally used for horses, recent advances in the production of ensiled forages have made them useful for winter feeding.
Baleage for horses should be cut long, well wrapped and allowed to ferment correctly for at least one month, which can be helped along by using inoculants, which provide the correct bacteria to consolidate correct fermentation.
Hay has an energy value of between 7-9 MJ/kg with around 10% protein, whereas baleage and other ensiled forages can reach 10-11 MJ/kg, and have better protein, mineral and vitamin preservation, as well as being very palatable and digestible. The sugar in ensiled forage is changed to volatile fatty acids, so can be useful in sugar-sensitive horses. Baleage contains a lot of water (around 50%) which can help maintain hydration as well, which is important in regions where water butts can become iced over.
Warm, warmer, warmest
The next issue is creating warmth. Like most animals, horses cope best when temperatures are fairly stable. As we go through autumn, we have that annoying time of ‘covers on/covers off’ as it’s warm in the day and cold at night. This cycling of temperatures can cause horses to lose weight, as they try to dissipate heat during the day and retain it at night.
For owners who are unable to keep up with the constant changes in weather, a good approach is to use a breathable rug, which helps keep heat in at night but allows sweat losses in the day.
Fat horses can be easier to maintain in winter as they can go ‘au naturel’ for the cold season, with a thick coat of hair being efficient enough to maintain their body condition.
For horses who are in winter work, feel the cold or just always seem to drop weight, plan ahead and use a combination of higher nutrient baleage as well as a concentrated feed such as broodmare mix, which will supply higher levels of digestible energy and protein as well as providing in higher levels all other nutrients that the horse needs. A concentrated form of this type of diet is useful, as you do not need to feed huge amounts to achieve the higher nutrient intakes for poor doers.
Hunt riders use such combinations with success during the winter season, when they have clipped horses who are working hard in cold weather, to maintain body condition and energy levels.
Again, baleage or wetter feeds (such as sugar beet pulp) are good for maintaining hydration in hard-working horses, especially those who may not like drinking very cold water while out and about.
Condition scoring
It’s a good policy to condition-score your horses at least once a week – and that means rugs off and a full check!
It’s surprising how many owners don’t check under the cover and then get a nasty shock in springtime.
Of course, horses should be checked every day to make sure they have access to water and feed at all times. However, it’s sometimes hard for owners, especially those who work during the day, to do everything in the dark – so keep a time every weekend to get the horse in, take the cover off and check the body weight to see if you should increase or decrease feed and forage levels.
It’s easier to make small adjustments as you go along, than trying to rectify a big weight-loss problem after winter has ended.
