Autumn and early winter is the time when many UK foals are weaned, and it coincides with a drop in availability and/or quality of grass, as well as stabling, for some. Feeding correctly during this period is crucial, because nutrition from weaning to 2 years old is essential for optimal growth and development.
Key factors for feeding during and after weaning are energy intake, protein intake and mineral intake. Maintaining a smooth, steady plane of growth with appropriate energy and protein intakes is important to reduce the risk of developmental disorders, as is appropriate intake of minerals. Both reduced growth rate and spurts in growth (especially compensatory spurts) increase the risk of developmental disorders. Weaning can be a stressful time for a young horse, and care should be taken to ensure the youngster is eating their post-weaning diet before they are parted from their dam. In this way, they are used to eating it and their gut – including the beneficial microbes – will be adapted to it. For some, this may involve creep feed, and for others – who are growing well without concentrate – it may involve a balancer pellet. It is absolutely essential to either feed the full recommended amount of either, or top up with a good multi-vitamin and mineral supplement.
Overfeeding will not result in a bigger, stronger youngster, but instead will increase the risk of developmental disorders including dyschondroplasia (abnormal cartilage development). Ideally, weanlings should be weighed regularly, but if this is not possible, then at least an estimate of bodyweight made by using heart girth and body length. In this way, the feed can be adjusted so that a steady plane of growth can be achieved.
Protein quality is as important as protein quantity, and ideally good forage should be selected, and appropriate bucket feed as necessary. Maintaining an optimal protein quality intake decreases the total amount of protein required. About 170 mg lysine/kg bodyweight/day is a guide, which equates to about 35–40 g daily for a 215 kg weanling of 6 months old. Total crude protein intake of around 13-17% is recommended for optimal growth in a weanling.
Shortages or imbalances in mineral intake also increase the risk of developmental disorders such as osteochondritis dissecans (OCD). All UK forage is short of essential minerals including copper and zinc – two minerals that are vital for correct musculoskeletal development. These must be added to a weanling’s diet in the form of concentrate feed, a balancer pellet or a multi-vitamin and mineral supplement.
Weanlings should be assessed individually and fed accordingly. Their individual requirements will vary and it is an error to try and feed them according to a set formulation. They should be fed balanced protein and energy in quantities to support a steady plane of growth, and appropriate levels of minerals.