Grass Choices: Which is best for our Horses

Understanding Horse’s Digestive Needs

Horses possess a unique digestive system that thrives on a continuous supply of nutrient-dense, high-fibre forage. This forage is digested through fermentation in the hindgut, providing essential nutrients and energy.

Impact of Grass Moisture Content


The moisture content of grass significantly affects fibre intake. Green grass typically has lower fibre content compared to dry, mature grass. Horses grazing on lush grass day & night, without adequate fibre are at risk of imbalances in their gut microbiome. A horse’s hindgut is a fermentation vat that digests fibre, producing fatty acids for energy and absorption of essential nutrients.

Ideal Grass for Horses


Mature, dry grass is the best fibre source for horses. However, many horses graze on short, green, fertilized, or unsuitable grass species designed for ruminants like cows and sheep, which can promote rapid weight gain and milk production. Whereas horses benefit from slower-growing grasses that support good gut health.

Risks of Unsuitable Grass


Some grass species are too high in sugars, fructans, mycotoxins, protein, or nitrogen. They may also impair nutrient absorption or harbor toxins.

Even safe grass species can pose problems under certain conditions, such as spring or autumn growth, post-frost, after fertilization, drought-breaking rains, or overgrazing. For this reason, it is important to ensure your horse has access to safe grass hay to ensure they get sufficient fibre if they are not grazing mature, dry pasture grass.

Identify Your Pasture Grass

Safe Horse Grass


The following grass species are generally higher in fibre and lower in sugar, making them more suitable for horses:

Rhodes Grass
Rhodes Grass: Subtropical to tropical climates, drought tolerant.
Creeping Blue Grass: Temperate climates with moderate rainfall.
Crested Dogs Tail
Crested Dogtail: Temperate climate.
Kangaroo Grass: Warm, dry climate. Drought tolerant.
Wallaby Grass: Temperate climate to subtropical regions.
Red Grass: (Bothriochloa macra) Warm, dry climate. Drought tolerant.
Weeping Grass: (Microlaena) Warm, humid environments.
Spear Grass: Warm temperate climates. Drought tolerant.
Timothy Grass
Timothy Grass: Cool temperate climates.
Yorkshire Fog Grass
Yorkshire Fog Grass: Cool, moist temperate regions.
Queensland Blue Grass: Warm, humid tropical and subtropical climate.
Brown Top
Brown Top: Cool, moist temperate climates.
Pangola / Digitaria Grass: Warm, humid climates. Drought tolerant.
Signal grass: Urochloa decumbens

Problem Species


Rye grass: High in potassium and sugars; risk of metabolic disorders & ryegrass staggers.
Clover
Clover: Contains phytoestrogens that disrupt hormone balance, very high in starch & contains phytodynamic pigments which can lead to mud fever and skin issues & can aggravate head flicking.
Tall Fescue
Tall Fescue: Associated with reproductive problems and laminitis.
Kikuyu Grass: High in sugars; risk of metabolic disorders and oxalate.
Couch Grass
Couch Grass: Difficult to control; prone to overgrazing.
Sweet Vernal
Sweet Vernal Grass: Contains coumarin, which is toxic if it gets mould.
Paspalum: High sugar content and can get ergots on seedheads during humid weather. Also risk of paspalum staggers.
Phalaris: Can cause neurological problems.
Cat’s Ear: Potentially harmful toxins which can lead to stringhalt.

Oxalate Grasses


Ingested oxalates bind to calcium molecules, reducing the amount of calcium available for your horse to absorb into the bloodstream. The level of calcium that gets bound depends on the amount of oxalate in the gut. So, the higher the oxalate content in the grass and the more grass your horse consumes, the greater the presence of oxalates.

Not all calcium supplements are equal, so it is important to use a chelated mineral blend to avoid long term health issues from ‘big head’ disease.

Setaria: Very high oxalate.
Buffel Grass
Buffel: Cenchrus ciliaris
Kikuyu: Cenchrus clandestinus
Green Panic: Megathyrsus maximus subsp. pubiglumis: May contain steroidal saponins and moderate levels of oxalate.
Pangola / Digitaria Grass: Warm, humid climates. Drought tolerant.
Guinea Grass: Megathyrsus maximus subsp. maximus
Para grass: Urochloa mutica
Signal grass: Urochloa decumbens

Toxic Trees and Plants to Avoid


Remove the following toxic plants from pastures:

Lupins: Cause severe gastrointestinal issues.
Capeweed: Neurological toxicity.
Ragwort: Highly toxic; liver damage risk.
Poison Hemlock: Extremely toxic and potentially fatal.
Tomato Plants: Contains solanine, harmful to horses.
Avocado Trees: Leaves branches are toxic.
Oleander: All parts are toxic; cardiac issues risk.
Red Maple: Wilted leaves are highly toxic.
Potatoes: Plants are toxic.
Prunus Trees (apricot, cherry, peach, plum, nectarine, almond): Trees are toxic even in small amounts.
Paterson’s Curse: Highly toxic.
Buttercups: Toxic and can cause digestive distress.

It’s crucial to make sure your horse’s pasture is free of harmful plants, especially when grazing options are limited, as they may resort to eating undesirable plants when they’re hungry. Offering a varied diet supports a healthy gut microbiome, and horses often seek out specific plants for their nutrients or medicinal properties.

The following plants are safe for horses to consume in moderation, so you can include small amounts in their diet or grow them in fenced areas where they can nibble on the leaves over the fence.

Forage Snacking: Safe Options


Bamboo: High fibre, can be high in protein so restrict access.
Berries (leaves, vine and fruit): Blueberries, Strawberry, Raspberries & Gooseberries.
Calendula: Supports skin health.
Carob Tree & Pods: Nutritious tasty treat in moderation.
Chamomile: Calming and soothing.
Dandelion: High in vitamins.
Fennel: Good for digestion.
Hawthorn: Supports heart health.
Hazel: Safe and nutritious.
Lemon Balm: Calming effects.
Marshmallow: Soothes digestive issues.
Meadowsweet: Anti-inflammatory benefits.
Mulberry: Nutrient-rich.
Nettle: Highly nutritious
Parsley: Vitamin-rich.
Peppermint: Aids digestion.
Plantain: Supports respiratory health.
Rosemary: Supports digestion.
Tree Lucerne (Tagasaste): Rich in protein so restrict access.
Willow: Natural anti-inflammatory.
Yarrow: Anti-inflammatory properties.

Managing your Pasture

Creating a healthy pasture for your horse is essential for their overall well-being and digestive health. By understanding their unique digestive needs and the impact of grass choices, you can ensure that your horse has access to safe, nutritious forage.

Prioritizing mature, dry grasses while avoiding high-sugar or toxic species will promote a balanced gut microbiome and prevent potential health issues. Additionally, offering a variety of safe plants for foraging can enhance their diet and provide beneficial nutrients.

Always remain vigilant about the plants in your pasture. With careful management and informed choices, you can cultivate a thriving environment that supports your horse’s health and happiness.

The following supplements are beneficial in supporting horses while grazing grass


GrazeEzy – Formulated to counteract excess of potassium and nitrogen in grass and balance gut pH.

Metabolize – Is designed to assist your horse in dealing with sugar in their diet.

Digestive EQ – Helps to combat hindgut acidosis and stabilise hindgut microbiome.

Please note * We do not sell grass or pasture seeds. For suitable native grass seed mixes or for advice regarding growing grasses in your area, please consult local suppliers or consider adding native species from Native Seedshttps://nativeseeds.com.au/product-category/native-grasses/

For horse health advice, complete our Complimentary Horse Questionnaire. Our animal naturopath can provide recommendations to help improve the health of your equine friends.