As spring arrives, many horse owners face concerns about the impact of lush grass on their horses’ health. The high nitrogen and potassium levels in this new growth can disrupt not only digestion but also brain, nerve, and muscle function, leading to various issues commonly referred to as ‘grass-affected’ behaviour.
The Effects of Spring Grass
During the growth phase, grass has increased leaf area, which boosts its ability to produce soluble sugars. These sugars are quickly absorbed into the bloodstream, causing an insulin response and resulting in excess energy. This can lead to anxiety, over-reactiveness, and spooky behaviour in horses that are not in heavy work.
Maturation of Grass: It takes time for grass to mature into a safer form, characterized by a stalkier appearance and reduced nitrogen content. Even once it reaches this stage, careful management is still necessary to ensure horse health.
Risks of Lush Grass
Lush grass can easily exceed the safe threshold of 10% water-soluble carbohydrates (WSC) plus starch, especially for horses prone to conditions like Equine Metabolic Syndrome (EMS), Insulin Resistance (IR), Cushing’s, PSSM, and laminitis. Horses can consume a large amount of grass in a short period, making uncontrolled grazing a risky choice.
Distinguishing Behaviour
It’s essential to differentiate between a horse that is simply energetic and one that is truly ‘grass-affected.’ An exuberant horse may display excitement but retains self-awareness and can be managed with exercise. In contrast, a grass-affected horse will show signs of distress: head up, tight muscles, and a lack of coordination, making them unsafe to ride or lunge.
Feeding Strategies
Monitoring sugar and starch levels in your horse’s diet is crucial, particularly in spring and autumn. The fluctuating sugar levels in grass can pose challenges, so it’s often safer to rely on hay, which has consistent sugar content and can be soaked to further reduce sugars.
A high-fibre diet is essential, as horses have evolved to derive energy from structural carbohydrates through fermentation in their hind gut.
Considerations for Feeding
Be cautious with extruded feeds, which may provide a quick source of energy. Choose feeds that suit your horse’s activity level, particularly if you prefer a quieter ride on weekends.
By being aware of these factors, horse carers can better manage their horses’ diets and behaviours during the grass-growing seasons, ensuring their health and safety.
Nutritional support can be especially helpful – Contact us for advice on how to help your horse through Spring and Autumn – Ask the Naturopath
