But nothing is as strange as sticking things up heifers’ teats.
When the concept of using teat sealants in heifers was first suggested I put this in the Hyundai basket and figured it would never catch on.
The problem of heifer mastitis has been around for a while. Typically, heifers are more likely than any other age group of cows to develop mastitis within the first few weeks of calving. ‘Normal’ heifer mastitis is challenging enough. It’s hard on the heifers, reducing their lifetime production, increasing their risk of further mastitis and higher somatic cell counts (SCC) and increasing their risk of being culled.
For those of you who have suffered an outbreak of heifer mastitis, it’s even more heartbreaking watching the calves you reared two years ago struggle. And in outbreak situations as many as 30-40% of heifers might become infected.
Over the years we have tried many things to manage this. Most research has suggested that heifers pick up the bacteria – typically Strep. uberis – within a short period either side of calving, particularly in an outbreak situation.
However, some data suggests they may be infected at any stage from birth to calving, and the bacteria simply lie in wait until there’s plenty of milk to multiply on.
With these theories some researchers had good success with treating heifers near, either before or just after, calving with antibiotics.
This had the effect of reducing mastitis significantly. However, antibiotics as group therapy is not ideal, and while this was a potentially useful tool for mobs of heifers with severe incidences of mastitis, it’s virtually impossible to predict how severely affected any mob might be.
Then someone came up with the idea of protecting their udders with a teat sealant. These sealants had been around for a while and worked well, but the idea of sticking them into heifers’ tiny teats was novel, as well as marginally mad. Whatever, an enterprising couple of veterinary researchers demonstrated that not only was it possible, but it was effective. Heifers treated with an internal teat sealant experience about half the incidence of clinical mastitis compared with untreated heifers.
These trials have been repeated, with different variations, and the results are always consistent with this original effect with roughly half the incidence of mastitis following teat sealant use. Cautiously, we offered this bizarre service to our clients, confident the hassle, time and expense would ensure that this remained an esoteric activity confined to a few Highlanders supporters.
The use of teat sealants in cows has certainly taken off, with our clients treating 136% more cows over the past three years. In heifers the increase has been even more significant, from zero in 2010 to 11,192 heifers in 2013. The increase from 2011 alone has been 327%.
Being cynical, and doubting that teat sealants were that effective (mastitis risk roughly half), we ran our own analysis on the effect of teat sealants on preventing mastitis in heifers locally.
Our results were indeed different, but showed an even greater effect. For the past two years, on farms where we have data, our incidence of heifer mastitis has been 15.9% and 15.6% for 2012 and 2013 respectively. Over the same period, on farms where heifers were given teat sealant, the incidence was 3.6% and 4%.
This is not strictly scientific, because of course the farms in each group are different. But the results over two years are remarkably similar and compelling.
Similarly, if we look at a group of farms where they didn’t use teat sealants on their heifers in 2012 but did in 2013, the average incidence of heifer mastitis was 17.2% in 2012 without sealants and 5% the following year with them.
More importantly, despite the difficulties in inserting teat sealants into large mobs of heifers in winter at runoffs in the mud, farmers see through the challenges and recognise the value in it.
Hyundai is now New Zealand’s third most popular passenger car so maybe it’s about time I went out and bought one.
Dr Mark Bryan is a director and practising veterinarian at VetSouth in Southland. He is an executive member of the Society of Dairy Cattle Vets of New Zealand and owns shares in a dairy farm.
