Joel and Emma Redfern have built up a 200 head flying dairy herd near Yarlet in Staffordshire after taking on the farm in 2017. We caught up with them after doing some investigatory work into some calf respiratory problems. It’s prime time of year for respiratory issues, so we hope this will help those of you facing similar problems.

Calf health and welfare is key to building up healthy calves to achieve a maximum price at market, and it is a top priority to the pair who have spent much time and dedication to improving their rearing system.

Robust rearing protocols are in place at the farm, with importance placed on cleanliness in the calf pens and housing. The calf shed itself is self-contained, located away from the cubicle and dry cow housing with age group pens, making it the near perfect set up. However, faced with a TB breakdown, they encountered health problems associated with an increased stocking density.

“As an all year-round calving system, we would usually have 20- 25 calves in the shed, as we usually sell them before they are 42 days old, but TB breakdowns meant that our calf stocking density increased significantly, more than doubling. The shed in itself was big enough to accommodate extra capacity, but despite the cleanliness, the additional calves increased the pressure on the environment and we started to notice some health problems.”

The calves were experiencing respiratory problems in the form of Pneumonia. The key to limiting new Pneumonia cases is to quickly put an action plan in place. With some investigatory work, the reason behind the increase in respiratory problems came down to the additional calves and the change this had on the air quality within the shed. Working in conjunction with Sarah, the team wanted to explore options to prevent this happening in the future.

“We are in a high-risk TB area and so the likelihood of us having breakdowns in the future is high. Additionally, we have always wanted to reduce our use of antibiotics, therefore finding a solution to the problem whilst at this higher calf capacity was the goal for us.”

Many of you will know that Rob Hall is keen on housing and ventilation following some work in Wisconsin, U.S.A. On visiting the farm, it was clear that the health problems were linked to insufficient air flow, with a solution being a bespoke positive pressure tube ventilation system. The first step was assessing and improving the natural ventilation. This calf building’s orientation wasn’t perfect for catching the prevailing winds, so was always going to struggle. Ideally, a prevailing wind should hit the long side of the shed and blow up and over the roof. Young calves generate very little heat so wind is the main driver of ventilation, not the ‘stack effect’.

Wind direction at shed location

Positive pressure tube ventilation (PPTV) works by providing a constant supply of fresh air from outside the building and discharging it uniformly throughout the building, ensuring every animal is provided with clean air. When looking at calf buildings, we are aiming for a minimum of four air changes per hour, all year round. This doesn’t sound like much, but roughly half of UK calf buildings fail to achieve this without the help of a well-designed fan system. The beauty of the tube ventilation is that every corner of the shed benefits from the increase in air changes, reducing the risk of respiratory disease
in calves by removing the stagnant air. PPTV systems are essential where wind-driven ventilation is failing, such as when higher stocking densities are leading to poor air quality.

PPTV suggested location with air flow measurements

Although ventilation plays a large part in managing respiratory disease, it isn’t a fix-all solution. In this situation, it was the logical next step as calf hygiene and protocols were already at a very high standard. Improving the ventilation meant they have been able to increase capacity and improve calf health – a real win-win situation.

Since installation of the PPTV, Pneumonia in the calves has dropped by 75% and antibiotic usage has dropped even further:
“We’re very pleased with the results of this system, especially the reduction in antibiotic usage as that is something we consistently look at across the herd. “I was keen to improve our calf health even further after this. I decided to start pairing our new-born calves in small pens and include some calf enrichment features, including hanging balls, molasses licks and scratch posts which have really helped keep them occupied.

I’ve also implemented a stricter colostrum protocol; anything below 22% on the Brix refractometer is discarded. As an independent nutritionist, I have been careful adjusting the dry cow diet to boost the cows’ health – increasing the output of high-quality colostrum.

“Overall, we couldn’t be happier with the result and ease of improving the calf shed. Finding the solution meant we could take the next steps with calf welfare, whilst being able to cope should we have another TB breakdown”

Thanks to Joel and Emma for letting us share their improvements on farm! If you would like any more information on  reducing respiratory problems, please speak to your vet – there might be some simple steps that have massive gains.