Last year a team of experts formed the pneumonia hit squad and visited three farms to discuss how they could address calf management to tackle the disease.
Ben and John Prior, Wiltshire
Since implementing recommendations outlined by the hit squad, as well as vaccinating stock, Ben and John Prior have had no cases of pneumonia in their calves.
When the team visited the Prior’s 150-cow, all-year-round calving herd last autumn, about 15% of calves were dying because of pneumonia. Further investigation by the hit squad highlighted colostrum management and building design as the key suppressors of calf performance.
A number of key changes were carried out after the visit:
At the time of the visit, there were three main housing steps – a high-roofed baby calf house next to the parlour; a mono-pitch brick shed for weaned calves; and a dutch barn for calves from four to five months old.
Because baby calves can’t create enough heat to drive air movement in a large space, the hit squad suggested moving the order in which calves moved through the system.
“We’ve now moved the larger weaned calves into the high-roofed building and increased the stocking rate to get the stack effect working,” says Ben Prior.
The central ridge has also been removed to provide an air outlet and wind breakers have been put up. “The air in this building is now less stale and there’s a drier atmosphere,” says Mr Prior.
Milk-fed calves are now housed in the smaller mono-pitch shed, where drainage and cleaning between batches has also been improved.
Identifying cause of infection and vaccinating
Following the hit squad’s visit, the Priors worked with their vet to identify the cause of pneumonia.
“Regardless of size or strength of calves, we were still getting pneumonia,” says Mr Prior. “We wanted to find out if there was something else going on, so we tested for a range of issues including BVD and IBR, as well as pneumonia.”
Results were clear for everything, apart from Bovine Pi3 virus – a cause of pneumonia. As a result, the farm implemented a targeted vaccination policy.
Blood immunoglobulin testing
The hit squad recommended blood immunoglobulin testing to see if calves were receiving enough, good colostrum and using a colostrum metre to monitor quality.
Subsequently blood was taken from four calves and tested for immunoglobulin levels. Results showed levels were good.
“Thanks to the help received from the hit squad, we’ve managed to simplify the calf rearing job, thus saving time, significantly reduce mortality, increase stocking rates and get some really smart looking calves and youngstock coming through the system,” says Mr Prior.
David Richards, Ridgend Farm, Worcestershire
By improving building ventilation and housing calves according to age, David Richards says he is using his buildings more efficiently.
The herd is growing in size and currently stands at 180 cows. Like many herds undergoing expansion, Mr Richards says increasing cow numbers can put pressure on the system. However, by opening up central ridges and upping stocking rates, he has been able to improve ventilation and make the most of existing buildings, before he invests in new infrastructure.
Various multi-purpose buildings are used for calf rearing throughout the farm. At the time of the hit squad’s visit small calves were often housed in large, high-roofed buildings, which were difficult to ventilate.
At the time, 5% of calves were being lost to pneumonia. This now sits at 3%.
Key changes carried out after the hit squad’s visit:
Renovating and converting a shed for baby calves
Following the hit squad’s advice, Mr Richards has renovated an existing small brick building for baby calves.
“We’ve cleared this shed out, boarded the front up, leaving a one foot gap between this and where the roof starts. Calves go into individual pens in this building at four days old.”
Although the high-roof, open- fronted building previously used for baby calves is now not in use, Mr Richards recognises it is more suited to larger animals. “Last winter we put weaned calves in this shed, with a line of square bales at the front. It was a lot warmer and ventilation worked a lot better,” he says.
Ensuring calves have separate air space to adults
Calves are no longer housed in the large lean-to next to the parlour, so as to avoid shared air space with adult cattle that can negatively affect calf health.
Ventilation has also been improved to help heat generated from the parlour to escape. “We now use this area for fresh-calved cows and not calves,” says Mr Richards. “We’ve replaced the roof panels at the join with the parlour with some clear panels and staggered it to create an outlet. It’s worked really well and the beds are a lot drier.”
David Evans, Boycott Farm, Yockleton, Shropshire
The hit squad’s visit really focused attentions on colostrum management and building design, says David Evans.
Although still a work in progress, calves from the 200-cow Holstein Friesian herd now recover much more quickly from any problem.
At the time of the visit, Mr Evans was using a number of buildings to rear calves, as well as hutches and igloos positioned on a grass field. He was seeing problems from calves getting scours at 10-14 days old and this was developing into pneumonia. The plan was to erect a new, high-roofed shed.
Key changes carried out:
Close attention to colostrum management
Following the hit squad’s advice, the team at Boycott Farm is now more focused on delivering colostrum to calves in the first few hours.
“We’re a lot more vigilant the moment a calf hits the ground,” says Mr Evans. “We ensure calves get two litres of colostrum within two hours and another two litres within the next four hours.”
Colostrum is also frozen and only taken from second parity or older cows. They have also just started on a Johne’s control programme and ensure all positive cows are calved separately and their colostrum disposed of.
Addressing building design
The initial plans at Boycott Farm were for a 16ft-high shed (to the eaves). However on advice from vet Matt Williams, Mr Evans reduced the height to 14ft.
This will mean the shed is more suited to the age of cattle, so stock is more likely to create enough heat to drive ventilation (see below).
The shed, currently open-sided, went up at Christmas with calves from the farm’s spring calving block going in from February. Although this space is designed for calves from 3-4 weeks of age, wet weather at the time meant Mr Evans moved some milk calves into one end of the shed, rather than in the hutches outside. Older, weaned calves were housed at the other end.
“We decided to move the hutches into the shed for these baby calves. This was perhaps something we wouldn’t have thought of before the hit squad’s visit. They drew our attention to the fact baby calves need to be warm and aren’t able to drive ventilation in large spaces.”
Now, with the warm weather, milk calves from the autumn calving block have been moved back into outside hutches. “We’ve put hardcore down on the outside area where calves are fed milk. It hasn’t rained yet, but we hope this will mean it will drain better,” he says.
The stack effect
A building containing animals on a still day ventilates by a phenomenon known as the “stack effect”. The animals drive this with the heat they produce.
This air rises and tries to escape through a high-level outlet. This creates a negative pressure, sucking in clean, dry, cooler air through inlets.
There is a belief that big, open spaces are good for ventilation, but you need enough animals to create heat to drive air flow, as well as adequate inlet and outlet.
It’s worse to understock baby calves than to overstock, as they will be unable to drive ventilation.