It’s a little daunting starting a new dairy season when you’re coming off the back of the best season the farm has ever had; record production has the effect of setting high expectations of yourself and your staff, and the desire to beat the previous year’s results is foremost in your mind.
Mid Canterbury has had the perfect start to the 2020 season; pasture covers lifted in June thanks to mild temperatures and good rainfall while all the cows were off farm, and the continuing mild and dry weather since the cows came home has made this one of the easiest calvings I can remember.
While I’ve been making the most of the fine and settled weather I’ve also been waiting for something to go wrong, after all nothing this good can last forever. I’ve been maximising the benefits of the great conditions while simultaneously bracing myself for an adverse event along the lines of the snowfall of 2006, the one that left this farm without power for twelve days and others in the dark for much longer.
Sure enough things did go wrong. Awfully, spectacularly and terribly wrong in a way I never imagined they could.
Around the 20th of June each year I walk the heifers back from grazing at my neighbour’s place so they can calve conveniently next to the cow shed. This year my neighbour called to say there were three heifers lame on their front feet and, being the conscientious man he is, he’d scoured their paddock for anything that might have caused them physical harm but found nothing.
Those three animals weren’t going to make the trip home unassisted, so we left them behind and made the short journey back to the farm with the rest. By the time we’d finished the two kilometre walk I had two more heifers limping on their front feet.
I’m no stranger to lame cows but I’d never seen anything like this so, after my own inspection revealed nothing obvious, I administered pain relief to all five animals and called the vet.
Shannon from VetLife Ashburton arrived in short order and it was clear from the look on her face as she got out of her truck that she knew what was up, and it wasn’t good. A quick examination of the closest animal confirmed her fears, spontaneous humeral fractures; all five heifers had broken shoulders.
I was horrified and asked if there was any chance they could recover. Shannon had heard this before and was quick to point out I’d been fooled by the benign nature of the term fracture, in reality the bones had exploded in spectacular fashion and the only course of action was to put the heifers down.
There doesn’t need to be any great physical exertion on the animal’s part for the bone to break, they can be walking normally down the track and suddenly pull up lame. The fracturing truly is spontaneous.
The exact cause of the fractures isn’t fully understood; though copper deficiency as a calf is known to be a factor preventing animals from reaching peak bone mass. Fracture doesn’t convey the full horror of what happens in these instances, and Shannon took a bone to display in the clinic to help raise awareness of the severity of the injury.
It’s an issue unique to New Zealand, first reported here in 2008 and affecting some 4% of dairy farms, approximately 5000 heifers are thought to be lost to the condition each year. Affected farms all over the country have reported losses ranging from 1% to 25% of their replacement heifers, though I have heard anecdotes about a farmer who suffered losses of 50%.
I was bitterly disappointed when a liver biopsy confirmed copper deficiency as the likely cause, our copper supplementation regime hasn’t changed in years and we’ve never had any issues before.
We’ve lost 10% of our heifers to spontaneous humeral fractures this year, a fact that I find very upsetting and quite embarrassing, not to mention the distress of the afflicted animals and the need to act quickly to end their suffering.
Until now I’ve kept this situation to myself, sharing it only with people who absolutely have to know, but seeing Shannon’s frustration at getting farmers to understand the severity of the problem and the simplicity of the prevention convinced me to put my feelings aside and talk about it here.
Very few people check the trace element status of their young stock, but this is one of those situations where you definitely don’t want to find out about it the hard way.
No comments:
Post a Comment