17 December 2012 If it’s f-f-f-freezing, your horse needs more F-F-F-FORAGE!
One of the most common ‘old wives tales’ I hear at this time of the year is horse people feeding corn or oats to keep their horses warm, in the belief that they are a “heating feed”. While this myth is actually interpreted in two ways, some mean ‘temperature’ hot, while others mean ‘mental’ hot, we’ll address the former here, and will take a look at why ad lib forage is a much better asset to your winter feeding regime.
How does the horse control his temperature?
The horse, unlike your pet lizard for example, is a ‘homeotherm’ (the opposite is a ‘poikilotherm’ for all you trivia buffs). What this means is that he does a great job of regulating his own body temperature, and even your most basic pasture-pet model comes fully-loaded with a sophisticated, on-board mechanism to take care of this.
When he’s in his ‘thermo-neutral’ zone, this means he does not have to get rid of excess heat because he’s too hot, nor does he have to produce extra heat to stay warm. When the outside air temperature falls below 30 oF (-1oC), the horse reaches the lower end of this zone known as the “lower critical temperature”. Here, he has to up his metabolic heat production to maintain his body temperature. Conversely, if the outside temperature rises above 75 oF (24oC), he reaches the upper limits of his thermo-neutral zone, known as the “upper critical temperature”, and must lose heat by evaporation, so he can lower his body temperature.
The horse’s thermo –neutral zone and lower critical temperature will vary with a number of factors such as age, body condition, breed, season, climate and most importantly energy intake, but is highly regulated in the normal healthy horse. The type of feed will also affect the horse’s internal heat production and, when it comes to that warm fuzzy glow from the inside out, forage, NOT grain, should be your fuel of choice.
Why is hay better than corn for keeping my horse warm?
When foods are digested and metabolized, they are associated with heat production; this is known as the ‘heat increment’. Your horse gets heat and calories from hay thanks to microbial fermentation in the hindgut (another one of his sophisticated, on-board, pieces of adaptive equipment). Feeds that are higher in fiber produce a higher heat increment because they take more work to breakdown, via microbial digestion, in the hindgut. This heat production is much greater than that of the enzymatic process of breaking down grains in the stomach and small intestine. So, the higher the fiber, the higher the heat increment, which means when it comes to keeping your horses warm in an economic and superbly efficient way, hay has it hands down over corn, oats, concentrates or fats.
Why is this important?
While the horse copes much better in extremes of cold, than he does heat, when air temperature gets below 30oF (-1oC), the horse has to divert food energy for maintenance, growth, performance, to produce additional metabolic heat and maintain body temperature. For each 10oF drop below the lower critical temperature of 30oF, there is a 15-20% increase in total calories required. When you add in factors such as wind, rain and mud, this can lead to an 80% increase in energy requirement i.e. a LOT more food!! Good quality forage provides an economical and effective way of keeping your horse warm during cold winters, not to mention happy and healthy all year around!