Trainers blame oilseed rape for horse respiratory problems
Horses are predisposed to inhaling dust, pollen, spores, etc. from the environment
Irish racehorses are among the best in the world, and our tillage farmers are famous for their high yields, but the increase in oilseed rape crops could put them on a collision course.
Several trainers in Ireland and the UK have blamed the crop for exacerbating respiratory problems in horses.
Horses depend on their "wind" for performance, but the equine respiratory system can be affected by many environmental conditions.
Wind problems are the most frequently diagnosed conditions in sport and racing horses in veterinary checks after poor performance.
However, stabling and management practices are the most common causes of such problems, according to vets. Exposure to dust and chemically active substances like ammonia are thought by many vets to pose the greatest challenge to the respiratory tract.
Horses are predisposed to inhaling dust, pollen, spores etc from the environment. Much of this inhaled material is filtered, but some particles reach the lungs, and horses can develop allergies to pollens and grasses in their environment. But oilseed rape is only one such allergen. Others include many grasses and weeds.
However, moving horses away from pine trees or oil seed rape crops is recommended by some vets.
Trainer Harley Dunne said he has been forced to relocate his stable of horses from Clonroche, Co Wexford, to a field 20 minutes away, due to the effect a rapeseed oil crop had on them.
He told the there are 150 to 200 acres of oilseed rape near his yard. He said it caused problems last year and this year, and that other trainers also blame it for reduced racehorse performance.
"I’m not sure about the specifics, but I just know that it can cause horses who are capable of winning races to stop two or three furlongs out.
"There would be no apparent reason post-race either, as they would scope clean and the bloods would come back perfect".
He said his relocation to land about 20 minutes away, at the start of April, has helped his horses.
"It doesn’t seem to affect every horse, you could run five horses and four of them would run bad and on another day only one of them would run bad".
UK horse trainers who publicly linked oilseed rape to reduced performance include Paul Webber and Sarah Humphrey.
It is not surprising that the crop gets blamed for horse setbacks, because it is also blamed by many members of the public for increasing their problems with hay fever and other such respiratory complaints.
Medical sources say that rape seed pollen (and related irritants) can induce asthma, allergic rhinitis, and allergic conjunctivitis. But sources disagree on how common such allergies are, even in areas of intense rapeseed cultivation.
There is no justification for regulating the planting and growing of oilseed rape, based on the scientific evidence currently available of its effects on humans, according to Defra, the UK government's Department for Environment Food and Rural Affairs.
In Ireland, the oilseed rape crop increased 40% in area from 2021 to 2022, to 15,800 hectares, according to the Central Statistics Office.
It can be a highly profitable crop, especially if viewed across the entire crop rotation, because yield increases of up to 19% have been recorded in winter wheat after an oilseed rape crop. This is due to rotational benefits such as the control of problematic grass weeds, using labour resources on the farm more efficiently, and better soil health.
