Get Grass Smart around rye grass...
Rye-grass is very easy to identify because the under-sides of the leaves SHINE in the sun! All you need is a sunny day!
Spring is a good time of the year to assess how much rye-grass is in your horse pasture.
There are numerous strains of rye-grass; steer clear of all of them including:
• Perennial ryegrass - has leaves that are long and narrow with a well-defined mid-rib. The leaves are soft, thin, and dark green, with a smooth, shiny underside.
• Italian ryegrass - has a ribbed upper surface that resembles corrugated iron. The leaves are wider and not as dark green but also shine on a sunny day.
If there is a relatively small amount scattered through your pasture amongst your other grasses, it won't be a problem. Same with hay.
However do not sow it!
Lifestyle blocks that were dairy farms previously are likely to be predominantly rye-grass and clover. We would advise against buying such land for horses because the ‘older’ more ‘horse-friendly’ grasses are difficult to establish on soil where rye/clover has been encouraged.
Here are the reasons:
Rye-grass is a Cool Season grass which, when dominant in the pasture, is unsuitable for horses whether endophyte free or not.
Rye-grass produces a high yield. It provides a LOT of nutrition per mouthful where horses do best on low nutrient density forage.
Rye-grass has a propensity for rapid growth and the very traits that make it desirable for fattening livestock and maximising milk production cause health troubles for equines.
Here in NZ, we refer to it as ‘disaster pasture’ because of its propensity to cause laminitis, obesity, head-shaking, hyper-sensitivity, hives, reproductive, respiratory, staggers, fire-breathing dragons and behavioural issues in record time!
Rye-grass is inherently high in potassium (3-4%) which is known to cause metabolic problems in dairy cows. High potassium also causes variations of these same metabolic issues in horses.
Rye-grass when short or lush, is dark green which means it is high in non-protein nitrogen (NPN). The plant readily uptakes nitrogen as nitrates and under certain climatic conditions (cold night-time temps, frosts, consecutive cloudy days, when growing in the shade) they accumulate in the grass. The horse’s digestive system is NOT adapted to high nitrogen diets AT ALL. They have a mono-gastric style digestive system not a ruminant one.
Sugars
Rye-grass, when actively growing, is very efficient at manufacturing sugars used to fuel the rapid growth at night.
However, especially when there is a drop in temperature, rye-grass stores excess sugars as ‘fructans’. Horses do not have the particular enzyme necessary to break down fructans.
Warm season grasses store excess sugars as starch, not that we want their diet to be high in starch, but at least they do have the enzyme to process it.
Fructans are included in the WSC reading on forage analyses, (not the ESC reading). Fructans are stored in the leaves and roots of the plant. They are ‘on the plant’s side’ helping with recovery after cold, even freezing temperatures – they give rye-grass improved cold tolerance.
Mycotoxins
Perrenial rye-grass contains the endophyte which produces the Lolitrem-B mycotoxin when the plant is stressed, usually in the heat of late summer. Lolitrem-B will cause ‘staggers’ in all livestock including horses.
Even ‘endophyte-free’ strains like Italian rye-grass cause ‘staggers’ in horses in spring - a time when it is minerally very unbalanced.
Many strains of rye-grass have been purposely bred with specific endophytes to produce mycotoxins to protect the plant. For instance AR1 ryegrass contains peramine for protection against Argentine stem weevil and pasture mealybug.
Can you get rid of rye grass?
It takes heavy duty chemicals to eradicate rye-grass which, of course, we want to avoid because they are far too hard on the environment
If you have more rye-grass in your horse’s pasture than you would like then take measures to prevent it dropping its seeds every year. Graze it with other stock prior to seeding or have it made into bailage and sell to a local dairy farmer so you can buy more suitable hay.
Avoid fertilising or harrowing more than a couple of times per year.
Rye-grass troubles are common in most regions of NZ, particularly Victoria and Tasmania in Australia and in the UK
GrazeEzy is formulated to help counterbalance these aspects of spring grass, including rye-grass.
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