Vet's Corner: are your cows getting what they need in their diet?

Breeding season is here, and with margins tighter than the Strait of Hormuz, every conception counts.

This spring, we are seeing a higher than usual frequency of trace element deficiencies in herds around Kilkenny.

Selenium is the standout concern, but deficits in iodine, copper and phosphorus are also showing up across the region, consistently enough to be worth paying attention to.

Most farmers are already supplementing.

Minerals go in the trough, boluses go down the throat, boxes get ticked and yet, deficiencies are still appearing. Why? Because supplementation and absorption are two very different things and timing matters more than most people realise.

There are three critical windows where mineral status can make or break performance: pre-calving, pre-turnout and pre-breeding which is exactly where we are now.

Miss one and you are playing catch-up at the worst possible moment. The calf has already made a significant withdrawal from the cow’s reserves before it hits the ground.

Feed intake drops by 30-40% around calving, and mineral antagonisms, high molybdenum blocking copper for instance can quietly undermine even a well-intentioned programme.

The real question isn’t just are you supplementing - it’s is it targeted to the right animals at the right time?

That is where blood testing earns its keep. Sample at least two weeks after turnout and consider testing cows and heifers separately.

It gives you concrete, herd-specific data, not a guess based on what’s going into the trough, but honest feedback from the animals themselves.

In a world where everything feels increasingly unpredictable, that is a rare bit of peace of mind. So if in doubt, bleed a few cows but have a chat with your vet first. They’ll tell you more than any bag of minerals will.

Joaquim Canotiho DVM, XLVets. Ormonde Veterinary Hospital, Kilkenny