"For example, the risk of leptospirosis affecting a herd is very high, so pretty much everybody vaccinates against it. On the other hand the probability of salmonella outbreak might be low, especially in a settled, closed herd, but even if there is only a small risk of it getting in, the consequences are very high because it can wipe out a crop of calves and end up taking down some of your cows too with diarrhoea and abortion.
"That's why I usually include it in what I call the six 'biggies' - the diseases you've got to be guarding yourself against. In order of importance, they are leptospirosis, BVD, IBR, salmonella, neospora and Johnes disease. These six certainly are manageable and indeed most you can vaccinate against, with a more complex programme required to tackle Johnes. Increasing herd size, especially through buying in stock will certainly increase these disease challenges. In general, you are better off to expand from within your own herd by breeding extra heifers. Don't under- estimate the cost of carrying out a comprehensive disease prevention programme including an appropriate vaccination regime.
"Salmonella alone will cost you at least €7/cow. Other costs may include extra bedding, labour or even spending money altering sheds.
"That's just the cows. In the case of calves, you're dealing with two main issues - pneumonia and scour. The latter is usually caused by rota virus, cryptosporidia, or E coli. Most of these are related to the hygiene of facilities. This is the second major area for farmers to plan in advance of the hectic period.
"The old thing of letting bedding build up in calving pens before cleaning it out is not really the done thing anymore. You should be able to kneel down anywhere in the calving pen in your good clothes, and get up afterwards and head off to the match without needing to change.
"To ensure that happens routinely takes planning. You need protocols for colostrum, feeding and bedding calves. Everyone involved should understand the standard required, and that enough time is factored in to make it happen.
"But there are other structural things that you also need to have right before calving begins. For example, does your cubicle house have enough ventilation to ensure that cubicles remain dry?
"There are the other classics that catch guys out with expanding herds such as having enough calving pens. The rule of thumb is that you need a calving box for every 15 cows.
"You also need to have adequate feeding space. So it's no good just tacking on extra cubicles without providing extra feed-rail area, which brings me on to the last area that is key to controlling disease, which is nutrition.
"You really need to maximise the drymatter intake of dry cows, not only in the last month of her pregnancy but also in the hours around calving to avoid her spiralling into a energy deficit as soon as she calves.
"So the old practice of piling up feed for the bank holiday weekend in front of the dry cow that's about to calf just doesn't cut it. In fact, ideally you should be putting fresh feed and water in front of the cow every 12 hours, but every 24 hours at a minimum. If this is too big an ask, then you should look at your system now to see what you can change in order to make that happen, routinely. That's what good system planning is all about.
"Concerns about the calf getting too big if the cow is too well fed during the last month are irrelevant. The size of the calf was determined eight months earlier by the bull used when the cow was put in calf.
"Sure, overfeeding can be an issue, especially if the silage quality is very high. The target should be to have the body condition of the cow at 3-3.25 at this stage. So sometimes the diet will need to be diluted with lower energy roughage like straw, but don't short-change the cow on essential minerals and vitamins, because this is essential in preventing diseases such as milk fever.
"Planning for prevention of disease now is a key activity on dairy farms, especially where there has been expansion. Not only will it save you money but, perhaps more importantly, it give you peace of mind," he said.
Frank O'Sullivan is a partner with Pat Farrelly and Partners, and a member of Veterinary Ireland.