How spring block calver uses nurse cows to rear replacements
© MAG/Judith Tooth Ease of management is the driver for a family farm in east Devon to leave the job of rearing heifer replacements to the cows themselves.
Tim Wall, who runs a 270-cow, spring block-calving herd with his wife Suzy and son Bertie, reckons the nurse cows do a better job of looking after calves than humans ever did.
See also: Benefits of giving dairy calves toys on farm
This method of calf rearing demands more work initially, to determine which cows will be selected as nurse cows.
However, it saves time and effort in the long run and ensures the calves get the best possible nutrition, says Tim, who learned the technique from Wiltshire dairy farmer Jonny Rider.
Farm facts: Rackleigh Farm and Hayne Farm, Devon
Suzy and Tim Wall © MAG/Judith Tooth
- 90ha grazing platform; 81ha rented for outwintering
- Spring block-calving herd of 270 Jersey-cross cows
- Year-round rotational grazing on permanent pasture
- Dairy replacements reared by nurse cows
- All other calves sold at weaning
- 0.5t concentrates/year
- Average five lactations
- Yield of 4,500 litres at 4.8% butterfat and 3.8% protein
- Herd vaccinated for leptospirosis and bovine viral diarrhoea
- Milk supplied to Arla
- Family labour, apprentice, vet students and volunteer workers
Open to new ideas
Tim grew up at Rackleigh Farm, East Worlington. He graduated in engineering physics before studying for a PhD in agricultural engineering at Iowa State University in the US.
“I was thinking of teaching but saw the entrepreneurial opportunities in farming,” he says.
“I think doing a PhD made me willing to try new things, to learn they might fail but to have a go.”
A Nuffield scholarship took him to Australia and New Zealand to learn more about milking systems and parlours.
He then combined his skills to build a rotary parlour for the farm, still in use 25 years later.
Tim’s travels also showed him the potential for extending the grazing season to produce more milk from grass, so he changed system – from set stocking, summer calving, and seven months’ housing, to rotational grazing, spring block calving and outwintering.
Expansion and outwintering
In 2015, an opportunity arose to rent 81ha (200 acres) and buildings for youngstock 18 miles away at Hayne Farm, Morebath.
Outwintering was switched here, enabling the herd to grow by 100 cows, to 270.
Each year on 28 December, Tim, Suzy and the dry herd relocate to Hayne Farm.
Starting with the farthest fields, cows graze 0.4ha (1 acre)/day in fields previously cut for hay in June and August.
Grazing is supplemented daily with 16 round bales of hay, which are stood on end with the strings removed as they are needed.
Of the 1,500 bales/year needed, 1,200 are made on farm.
One to two weeks before calving – depending on hay quality and the weather – hay is swapped for silage, fed in the same way.
Management at calving
Calving starts on 28 February. Cows are monitored frequently, and those showing signs of calving imminently are moved to a separate field.
“We select for easy-calving traits anyway, but we’ve found with outwintering the cows simply pop their calves out,” says Tim.
“In fact, it can be difficult to spot the signs – there might just be a little bit of blood on the tail.”
Bertie stays on at Rackleigh Farm during the winter months. Once calving begins, he makes a daily round trip, delivering milk in an IBC to feed dairy bull and dairy-beef calves, returning home with freshly calved cows.
With as many as 15 calves born each day, a quick, easy and accurate system is essential to identify dairy heifer calves in the field, as it can be hard to tell crossbreds from some dairy-beef calves.
Those to be kept as replacements are given a numbered green collar, and the dam noted, while the rest are fitted with red collars. Once they have been ear-tagged, all collars are removed.
Colostrum is harvested from every cow using a portable milking machine and tested using a Brix refractometer. Each calf is given 2.5 litres of colostrum with a minimum Brix reading of 22%.
Potential spread of any Johne’s disease in the herd is avoided by identifying suspect cows through milk recording and not using their colostrum on any calves wearing a green collar.
© MAG/Judith Tooth
Nurse cows
To identify suitable nurse cows, the starting point for Tim is to observe the cow once she has calved.
“The fact is, more than half of cows don’t want anything to do with their calves. Another 25% like their own calf but hate any other calves. So, we look for those that like their own calf and other calves. It’s down to stockmanship,” he explains.
Groups of three nurse cows (Johne’s-free), with an average 2.5 calves each – including their own – are then penned and monitored to check all calves are feeding.
“All we do is make sure the calf has learned how to drink from the cow. Most calves do this naturally, but not all of them.”
The pens are topped up regularly with straw, and bedding is treated with a probiotic that promotes good bugs, says Tim.
Once cows and calves know what to do, they move into bigger groups before being turned out from mid-March.
Although the cows are not being milked while nursing, they work hard. “One calf will drink 8-9 litres of milk a day, so they need fresh grass and are on two-day moves,” explains Tim.
“The calves start grazing straight away too. They learn about electric fencing – and how to duck under it to get the best grass. And they get so much exercise – they run and run and run.”
A beef bull is put in with the nurse cows in May at the same time as artificial insemination begins in the main herd.
They return to Rackleigh Farm by July at the latest, when the seasonality price of milk changes.
As they are likely to be among the later calvers the following year, they are not used as nurse cows two years in succession, so that a tight calving block can be maintained.
Weaning takes place in June when the calves are 11-15 weeks old. They continue grazing on frequent moves at Hayne Farm for their first year, with hay and silage supplemented in winter. They then move to Rackleigh as yearlings.
Cow condition
Cows are condition scored by the farm vet in September, at the same time as pregnancy diagnosis.
“We expect most to be OK, but it’s good to have another pair of eyes to check them,” says Tim.
Those used as nurse cows earlier in the year are expected to be in the same condition as the rest of the herd and are not prone to mastitis, he adds.
Scoring at this stage leaves enough time before calving to help any low-scoring cows gain condition without adding undue weight to the calves they are carrying.
From October until drying off at Christmas, the herd grazes at night and is fed silage, made from surplus grass off the platform, by day.