Weed out disease issues to build on our grass-based beef product
Published 10/08/2010 | 05:00
IT'S A joy to walk the fields this time of year among a group of beef fatteners grazing the Irish landscape. That's what we do best in this country; grow luscious green grass. Beef farmers convert that to the best of Irish meat.
On one such walk I was asked what vets everywhere are asked on a regular basis: Why are my forward stores coughing? Cattle in their second grazing season would not usually suffer as much with lung disease as the young calves would, but more and more we see such cattle being held back with a widespread cough in the group.
A common misdiagnosis is that a bacterium is spreading in the batch. Antibiotics are sought and a single-shot of a long- acting product is deemed the treatment of the day. Again and again this proves to be a money-wasting exercise. Vets will take blood or faecal samples and often we find viruses or parasites are the root of the problem. The viruses are the same as in calves but we tend to see more of the IBR in older cattle. That virus is of a similar family to the virus that causes cold sores in humans. It behaves somewhat the same in that it remains dormant in the body of an animal and becomes active at periods of stress. The 400kg bullock could have been exposed as a young calf and now, at 18 months of age, he succumbs again to a bout of coughing. We don't routinely vaccinate adult cattle unless the virus is causing serious ill health. Vaccines, received as calves, will give up to 12 months cover if administered correctly, as per the manufacturers' instructions. So the coughing bullock may not have received a vaccine or may have the virus hidden in the system. A routine chore such as a run through the crush of the entire batch could trigger an outbreak.
If not a virus then what else would cause a cough? Adult cattle out grazing for a second or subsequent grazing season would normally be immune to hoose, but the more we check the dung samples the more we're finding hoose larvae in the faeces. Adult cattle do have lungworm problems from time to time. One theory is that with effective, long-acting wormers, we are almost completely killing the hoose in young calves. The calves get zero exposure in their first year and therefore fail to build up their own natural immunity. Later on in life when they should be immune, the hoose can survive and multiply in their lungs.
Now my 400kg prime beef fattener has a constant cough as I walk through the batch in the field. If I clap my hands and give a little chase among them, they all begin to cough.
This is a constant annoyance to the stockman as he sees some of the cattle not doing as well as they should. Let's sample and verify: once a diagnosis is made it's easy to treat. A worm dose in adult cattle can be a pour-on or an under-the-skin injection for ease of administration. Oral dosing, although cheaper, is too difficult in terms of manpower. Viruses, on the other hand, can be dealt with using live or dead vaccines as selected.
We'll talk again on the pros and cons of either, but always consult your vet, especially in pedigree-breeding enterprises.
Outside of hoose or respiratory viruses, we sometimes have pasteurella pneumonia in grazing cattle. This is not usually involved in low-grade, occasional coughing but will quickly come in where a beast begins to fall foul of a bad bout of IBR.