I’ve had conversations with two good farmers over the weekend about continuing to use beef or dairy AI semen on their cows after four weeks of AI.

Both were planning what to purchase this week.

One farmer who had a large herd is going to stay with dairy genetics and using AI, because he said the extra value he would get for beef calves would be lost in the extra days held in-calf and the odd calving difficulty.

His point was that all the dairy AI sires are delivering calves at least on time, if not a week in advance. He also argued extra dairy heifer calves always have a market and could be sold.

Later calves

The other farmer has a smaller herd, and his objective is to raise the value of later-born calves. He said: “I’m going to be here calving the herd, and I want to get more valuable calves to increase stock output.” He plans to use an easy-calving beef sire with short gestation.

Under no circumstances is he going to use a long-gestation sire because he said late-calving cows don’t need to be further delayed in their calving. Both are right, as long as cows are picked up in-calf. Vasectomised bulls should be sorted this week if planning to use them. They are key for week four and five, when a good proportion of the herd are in calf.

If bringing vasectomised bulls in from another farm, isolate them and vaccinate for whatever is necessary for your herd – usually IBR, BVD and lepto. These bulls should be kept separate until the full course of the vaccinations are complete. Have them on good grass not locked into a field with no grass.

Don’t let them with cows until at least week four or you risk not having them fit and ready.

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Dairy breeding: decision time on farms