At this time of year, the tef has just been planted and Eragrostis can’t be harvested because the rain has made the lands too soggy, so all that’s available is oats and white buffalo grass hay. Lucerne is expensive and many horses are inclined to laminitis or colic if it’s their main source of roughage.
Even if you’ve planted pastures for the horses kept on the farm, they’re often grazed almost down to the roots by the end of winter and are still in a recovery phase come October. The co-op has baled oat hay and white buffalo grass for sale. We know horses eat oats – but what about the latter? And if horses do eat white buffalo grass, could there be unpleasant consequences?
What is white buffalo grass hay?
Two species of grass go under the name of white buffalo grass, Pannicum maximum and Urochloa mozambicensis. Seed companies recommend the latter for grazing.
It is a perennial tufted grass that can grow about 1m high, with fairly broad, slightly hairy leaves. The grass is indigenous to Southern Africa. It grows naturally in wooded grasslands and deciduous bushveld in the Eastern Cape, Free State, Gauteng, KwaZulu-Natal, Mpumalanga and North West.
It is drought tolerant, requires an average annual rainfall of about 710mm and grows on well-drained soil without flooding or waterlogging.
As a perennial pasture, it’s been acclimatised to tropical and subtropical areas in northern Australia, Fiji, Texas, Hawaii, India, Indonesia and Sri Lanka, where it’s known as ‘sabi grass’. In South Africa, it is used as silage or baled hay for feeding beef cattle. It’s also effective for erosion control.
There appears to be no information on whether this grass is suitable for horses. P. maximus has been found to cause colic, but no toxicity has been recorded for U. mozambicensis. Although young growing pastures can yield up to 20% protein, the available protein level is 10% and the total digestible energy about 50% for dry hay. This is lower than good quality Eragrostis, but will provide adequate roughage if horses are also fed concentrated rations (pellets or meal) and a lick.
As horses aren’t ruminants, but use their hind gut to digest roughage, the digestible energy may be higher than that described in the literature. In my experience, horses can graze on white buffalo pastures with cattle, but farmers have told me this isn’t desirable, as the horses graze it too low for cattle to eat. They can also damage the pasture, grazing it down to the point where it won’t regrow.
On natural grazing, horses appear to find it just as palatable as other grasses. There was, however, a question as to whether grazing horses accustomed to eating tef and Eragrostis hay would find white buffalo grass hay palatable.
But, as the photograph shows, a herd of six horses on winter grazing were more than happy to consume the hay. They also gained weight and the bale (which weighed about 400kg) lasted them about three weeks.
Email Dr Mac at [email protected]. Use ‘Horse talk’ in the subject line of your email.