A renewed focus on vaccination, colostrum management and building ventilation has had a huge impact on pneumonia incidence and overall heifer performance on one Wiltshire unit.
Having a fresh pair of eyes on-farm to review youngstock rearing has enabled the team at The Manor Farm to focus in on ‘easy wins’, which have quickly resulted in less disease and better heifer performance.
About 18 months ago, farmer Charles Reis was aware that calf rearing was a significant pinch point within the organic business, which runs 170 pedigree Holstein Friesians and Dairy Shorthorns at Compton Bassett.
Cows calve all-year-round and yield 7,000 litres a cow a year.
Mr Reis says: “We had far too many calves scouring and too many cases of pneumonia. We recognised our youngstock needed improving. Everyone was aware that heifers are your future.
The calves are where it starts. If you rear calves badly, you end up with a heifer at 15 months which is not ready to be served. It runs all the way through.”
As a result, when farm vet Gethin Roberts, of The George Vet Group, suggested undertaking an MSD Animal Health Calf Health Checklist with colleague Kat Hart, Mr Reis was quick to take him up on the offer.
As part of the review, Ms Hart went round the farm with the farm team and assessed every aspect of calf rearing, including colostrum management, nutrition, disease pressure and environment, with each area given a score and recommendations then made.
Ms Hart identified pneumonia and scours due to rotavirus as the main issues on-farm and subsequently put together some key action points to resolve the problems.
Mr Reis adds: “A lot of the things you kind of know, but it needs pointing out to you. That’s where it is useful getting someone to reinforce it.” The main recommendations included:
Previously, calves received their dam’s colostrum once it had been milked. This meant a calf born at 10am, for example, would not receive its first feed until about 4pm.
As the calf’s ability to absorb immunoglobulins reduces with time, this was restricting uptake and hence compromising calf immunity.
Now, all colostrum will be tested using a refractrometer and only quality supplies will be stored in four-litre bags and frozen. They are then defrosted in a warm bucket of water as needed and tube-fed to the calf within four hours of birth.
Mr Reis says: “We always owned a refractometer, but didn’t do it [test] as religiously as we should have. Kat’s visit took us back to basics and allowed us to regroup.”
Calves are also routinely blood tested by the vet every two weeks to get an indication of immunoglobulin uptake, which is a measure of colostrum feeding success.
Although these tests had been carried out in the past, they were infrequent and the information was not acted on. “Now it’s all part of the calf rearing protocol and it’s acted on,” adds Mr Reis.
Draughts at calf level can lead to stress and partitioning of energy away from growth and immunity to keeping warm.
Consequently, when Ms Hart identified draughts in the pre-weaning shed, she suggested sheeting up the gates and putting straw bales along one side to act as a wall.
Mr Reis says: “The cost was minimal. It was just riveting a bit of sheet to a gate. We religiously keep the gate shut now in summer and winter.”
Calf jackets are also used in winter to keep calves warm. These, as well as the straw bales, are removed in summer.
Many of the outbreaks of pneumonia were occurring in the lean-to used as the post-weaning shed. Subsequently, Mr Reis has installed a positive pressure air tube ventilation system in the building.
This system uses a fan in the building wall to draw in fresh air from outside and blow it down a duct with numerous small outlets along its length.
This means fresh air is distributed evenly throughout the shed. Mr Reis says the ‘air feels fresher’. The system cost about £1,000.
In the past, calves may have been vaccinated on an ad-hoc basis, largely if there was a pneumonia problem. Today, all heifer calves born from October to March are vaccinated using an intranasal vaccine as soon as possible.
Individual calf data is now recorded in a dedicated book. This includes calf number, time of birth, how many hours after birth colostrum was given, the volume of colostrum fed, the quality of the colostrum fed and weight of the calf, which is measured using a weigh tape.
Weighing calves in such a way was an action point from the Calf Health Checklist and will enable growth rates to be tracked moving forward.
Calves were originally being fed a restricted amount of an 18% calf pellet up until weaning, however this is now being provided ad-lib. Calves are also being fed more concentrate post-weaning.
Mr Reis says the benefits to calf health and growth as a result of all of the changes have been marked. He estimates a 50% reduction in pneumonia incidence, with ‘very little’ calf mortality.
Calves are also achieving average growth rates of 1kg a day pre-weaning, when he estimates they were about 750g/day before the changes.
Less disease also equates to reduced antibiotic use – something Mr Reis is particularly keen on.
“On our organic system we want to limit antibiotic use.
“We use very little antibiotic on-farm. However, previously, the calves were our pinch point for antibiotic use.”
All-in-all he is struck with the general improvements to heifer performance.
“It has been the overall health of the heifer,” he says. “We rear much better youngstock than we did before as it is a better calf at six months, a year and so on.”
A cow works so hard in lactation, it can be the equivalent in energy terms as running one-and-a-half to two marathons a day. If its lungs are damaged as a calf, it will never perform at its best
Sub-clinical pneumonia can still cause long-term lung damage, despite not showing any signs and never receiving treatment
Viruses that cause pneumonia are on every farm, particularly PI3 and RSV. Often stress events such as weaning can cause pneumonia. When calves are reared away from the herd and brought back just before they calve, they can often succumb to pneumonia – vaccinate them as early as possible in life to protect them.
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