Bull health: Time to get clean-up stock bulls and vasectomised bulls in shape for the summer. Get them out to grass if you can. Ideally, hold off introducing vasectomised bulls into the herd until the first four or five weeks of the breeding season has passed. That way you will have them in good shape for when you want them.

I attended a session with vet and AI technician Jimmy Quinn last week, when he spoke at a farmer discussion group meeting. I’ve captured some of his thoughts in the Dairy Know How column on page 47, but below I discuss more of the detail.

Five-minute rule: Jimmy talked about the five-minute rule to get the AI straw into the cow once it has been thawed. He said that if it takes any longer than this, the sperm begins to die in the straw because it’s feeding on its own waste instead of being inside the cow. For the farmer doing DIY AI, this means you shouldn’t thaw too many straws at the same time. It all depends on how fast you are at inseminating, the facilities and proximity of your tank to the AI crush, etc. I know many farmers that don’t thaw straws at all and they still suggest they are getting good conception rates. Jimmy said you can do that, but research has shown better conception rates with frozen straws that are thawed in water at 30 degrees for 30 seconds. He suggested using plug-in water heaters designed especially for thawing straws (€250), or simply using an insulated travel mug with a thermometer (€20). He said both will do the same job, but farmers must decide what suits them best.

Wash outs: In terms of washing out cows, Jimmy raised a number of points. First of all, he said cows will clean themselves naturally, so time is the best healer. However, if a cow is more than four weeks calved, and it’s getting near the start of breeding, and you think she has some uterine infection (endometritis), then it might be worth investigating and potentially washing her out. Metricure is the product of choice. However, Jimmy maintained that sometimes this won’t be enough. If she has retained a lot of fluid and is very dirty, then the Metricure tube will be just like a drop in the ocean against the volume of dirt or puss inside the cow. He suggested the best option then, if the cow is sick, is to use injectable antibiotics that will get to the site of infection much better – obviously then you will have to withhold milk.

Grass growth: Growth rates are taking off on most farms (over 80kg/day in the south) and given the weather forecast you can expect good growth on paddocks that have been well fertilized. Try to get silage nitrogen out, so that you at least have options at the end of May if the weather is right for silage harvesting. Leaving silage nitrogen too late, even if the harvesting weather is right, will force you to wait for the nitrogen to get taken up by the crop.