A retired Taranaki vet has turned his focus to lameness among cows. By Delwyn Dickey.
Be kind to your cows – it’s the cheapest and easiest way to prevent lameness in your dairy herd, says lameness expert Neil Chesterton.
The Taranaki vet, now retired from general practice, and fully focused on his training business Vet Education Transfer Services, has made a name for himself here and overseas. Over the years he has not only treated the various types of lameness but also figured out what’s causing them. He can recommend changes to tracks and milking sheds, along with onfarm animal management, in efforts to reduce or prevent it recurring.
Tracking down the cause of lameness in a dairy herd is often like being a detective, he says. His best tools for the job are understanding both dairy cow behaviour and farmer behaviour.
Whiteline
There are four types of lameness and the cause of the most common – whiteline lameness – is usually the result of putting pressure on cows to move faster along tracks than they would naturally, and their moving and turning quickly in the milking shed which is usually a sign they’re anxious or afraid, he says.
Hooves slipping on surfaces like the track or on concrete can see the separation of the nail – the wall on the side of the hoof – to the sole, at the back.
Cows’ heads will be down when they are calm, watching where they’re going and where to put their front feet – the back feet moving into the same spot. An anxious or frightened cow will have her head high and not be watching her feet, Neil says.
Cattle have a healthy respect for electric fences. Aside from milkers being impatient or lashing out in frustration at the cows, one of the issues in the yards and shed on the big farms in the south can be top gates. When lowered, chains hanging down carry low voltage electricity giving the cows a mild shock to hurry them along.
Most farmers only put electricity through the top gate at the beginning of the season so the cows learn to move away from it, keeping animal flow steady. But some farmers turn on the power once a month which keeps the cows in a heightened state of anxiety all season, and sees them moving away from them quickly for months, putting pressure on their feet.
Neil recalls one Northland farm with a lot of whiteline disease which he initially couldn’t find the cause of. The tracks were excellent, everything else looked really good.
But when he stayed for milking – he was shocked. All of the cows’ heads were up.
“While the farmer couldn’t see while he was milking, the whole herd surged forward whenever he moved his backing gate.”
The gate was motorised but wasn’t set up for a low voltage. Looking closer Neil spotted a stray electrical wire to the motor was touching the gate, making it live. When the motor was turned on the cows were getting a real belt of electricity from the gate.
“He had good flow because the cows at the back were getting electric shocks.”
But getting to the bottom of shed problems isn’t always easy. If Neil’s not sure the shed behaviour of the milkers is ‘usual’ as he’s watching them, he’s been known to come back, unannounced, to see what a ‘normal’ milking actually looks like.
Neil recommends all farmers keep records of their lameness. Some action on the farm may also be leading to the lameness, but you may not connect the two without records, he says.
Footrot
The second most common injury is footrot and often seen in wet weather.
This is caused by stones getting jammed up between the claws of the hoof, the wet soil keeping it there with rubbing breaking the skin, which then gets infected. Visible swelling above the hoof is commonly seen from this.
The wet weather sees the surface of the paddock (or track) getting soft and the cows’ hooves go through it into any underlying stones. Neil looks for where new stones have just been laid, usually at gate entrances or around water troughs especially in the north where there is a lot of clay.
Warm northern weather sees minerals washing off rocks more readily and over eons has led to a lot of fine clay in the Northland region.
This sees northern paddocks and tracks often a mix of clay and stone. And, while a dry clay track is very easy on a cow’s feet, once it rains the clay turns to mud and the cows feet sink into the stones.
Rain also washes the clay away at the edges of the track exposing the stones that cows will walk through if under pressure.
To counter this, farmers often also use smaller-sized good quality lime rock on the race. Rolling it in sees the finer lime locking the bigger stones in place.
Neil recommends using GAP 6 lime for this where the biggest chunks are 6mm wide.
Lameness tends to show up three days after the stone injury.
“You can track back to which paddock the animals were in and if there was anything new going on in that paddock.”
One lot of footrot recently came from the farmer putting new stone down around his troughs in five paddocks with the stones being just 1.5cm across.
The stones were jamming up between the cow’s claws.
“He was doing the right thing but with the wrong material,” Neil says.
With spring calving herds and the end of mating, cows can have a tough time of it, with most lameness showing up before Christmas.
The cows are riding on each other, or the bulls may be in the paddock with the cows putting pressure on them, or holding them up from getting to milking on time so then pressure comes on the cows from the farmer to walk faster to make up time. Neil recommends separating the bulls before milking and putting them in the paddock the cows will be going into after milking to stop pressure on the track and in the cowshed.
Whatever the terrain, if cows are allowed to walk at their own pace they will naturally look after their own feet, Neil advises.
But good camber on the track is important, he says. Too high in the middle and the cow is always walking on an angle. Put pressure on them to walk faster and their hooves start slipping or they’re forced down into stones.
A typical Northland track will be 4m wide. The fall on the track shouldn’t be more than 16cm from the middle of the track to the edge or 8cm per metre, with less being better.
Sole injuries
Neil recommends lime on all the tracks although if that’s not financially possible for a young farmer starting out he suggests liming before the points where the track meets concrete like the yard or concrete bridges on the track, and lime more of the tracks each year.
Stones on the cow’s hooves from the track, fall on to the concrete with cows coming behind standing on them and causing sole injuries – the most painful injury. Walking in the lime should see the stones staying there and not coming off on the concrete.
Axial crack
The axial is between the claws of the hoof. Around half of axial lameness happens a few months after a bout of footrot when an animal goes lame again on the same foot, advises Neil.
The hole in the skin that caused the footrot infection may also damage the claw at the top which then moves down as the claw grows. When it gets down to the sole of the foot the extra pressure on that claw can crack them making it uncomfortable to stand on.
The other axial problems are on cows with poorly shaped claws – long or curly toes.
If a cow has issues with an axial crack, and she’s an otherwise good producer Neil will recommend to the farmer that he amputate the claw rather than thinking about having her culled. The cow can manage with one claw gone.
Neil recalls one canny Taranaki farmer who would turn up early to clearing sales and look for these cows, and make very low offers – “to take them off the seller’s hands” – ending up with 12 of them in his herd.
His reasoning was this took some of the guesswork out of buying new cows. They were all good producers, always got in calf and had low somatic cell counts. They had to have been good animals for their owners to go to the trouble of amputating claws in the first place – and he got them for a song.
While covid has put a temporary end to overseas travel, a refund for a cancelled booking to the United States to run some training events is unlikely, Neil has been kept busy running training days here, showing groups of farmers how being kinder to their cows can help their bottom line.
