Every year we write about the best way to prepare for winter and what to feed alongside our preserved forage to maintain condition, engage in environmental enrichment and any number of other topics. What we tend to ignore is grass.
Where it is likely that our horses are stabled and fed mainly on hay or haylage, we assume that winter grass has no part to play as it isn’t growing and therefore has no value. It is true that the nutrients in winter grass may be depressed and that any growth is minimal but, if there is a sufficient sward, it does have value and can be used.
During winter the nutrient level of grass drops about 10-50% depending on whether its fibre, sugar or protein. In the main, the fibre content keeps high but the proportion of different factions changes. More primary cell wall material (cellulose) remains whilst the hemicellulose and soluble fibres tend to drop off. This means that the fermentation of grass in the hind gut can give a different profile of slow release energy.
The energy content of winter grass, although variable will be about 80% of its summer value and, arguably, insufficient to maintain a reasonably active animal. Another factor, of course, is availability. As the grass is not growing there will be a limit to grazing. Supplementation with hay or haylage will be necessary to maintain sufficient daily intake of fibre and maintain gut fill.
However, in winter there are the restrictive factors in that horses have less daylight in which to feed (artificial light helps to a certain extent but intake is reduced) and require more energy to maintain their body temperature. So we need to complement the winter grass/hay base with feed that both modifies the fibre fermentation profile in the hindgut (to bring it in line with summer values) and improve the energy intake of the diet.
We can achieve this with the use of super fibres. This was a term coined for those fibre sources that had a greater fermentative capacity – and therefore more slow release energy – than grass or hay. Broadly speaking these sources contain beet pulp, alfalfa, oat fibre or soya hulls, and tend to have lower levels of cellulose (the main structural fibre) and higher levels of hemicellulose and soluble fibre.
Supplementing winter grazing and hay with, for example, Speedi-Beet or Fibre-Beet will ensure that energy intakes are improved and will help maintain condition through winter.