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Calf barn ventilation 101

Dan Veeneman for Progressive Dairyman Published on 02 June 2017
calves in individual pens

When we talk about calf barn ventilation, there are as many ventilation options out there as there are calf facilities. Many people promote positive-pressure tube ventilation, while others suggest tunnel or cross ventilation, and some claim that outdoor calf hutches are still the best way to go.

With so many options and opinions, how can dairy producers be expected to sort through the noise and find the solution that works best on an individual farm?

A proper calf barn ventilation system must achieve the following three objectives to make it effective and have a positive impact on calf health:

  1. The system must always distribute a minimum amount of 100 percent fresh air from outside the barn into the microenvironment of the calf.
  2. The air must be evenly distributed to each calf.
  3. In cooler periods, aim to keep air speed below 60 feet per minute (fpm) to avoid a draft, but in higher temperature periods, we must be able to increase this air speed to 200 to 300 fpm to combat heat stress.

In calf housing we look for a minimum ventilation rate of 15 minutes or four complete air exchanges per hour. In addition, airflow should be a minimum of 30 to 40 cubic feet per minute (cfm) per animal. A constant supply of fresh air is important for the respiratory health of your animals.

The best way to guarantee this fresh air is always coming in is through powered ventilation. By using properly sized positive-pressure fans to pull in the correct amount of fresh air, or using exhaust fans and a coordinating inlet, you can guarantee this air exchange is constantly occurring. Simply relying on natural ventilation and hoping the breeze will blow long and hard enough is setting your future herd up for failure.

When we look at the air coming into the facility, it is imperative that we get this air directly into the microenvironment of the calf. If we are not able to turn over the air in the calf space, then our ventilation efforts are for nothing.

winter tube ventilation system

Positive-pressure tube ventilation allows us to target the air, more so than any other form of calf barn ventilation. Positive-pressure tubes, when designed properly, will fill the calf environment with the fresh clean air that we are bringing in. While tunnel and cross ventilation can guarantee the air exchange rate of the facility as a whole, any obstructions to the airflow, such as walls, calf pen panels, calf feeders, etc., may stop the fresh air from reaching the calf.

The bare minimum air speed at the calf level should be “still air” at 60 fpm or below. This ensures that in cooler temperatures the calves will not get a draft. Calves in general are more comfortable in higher temperatures than full-grown animals, but their tolerance to temperature fluctuations is limited (see Figure 1).

Figure 1 temp tolerances of cattle

As the temperature in the barn increases, we must increase the air speed to keep the calves within their thermoneutral zone. The target air speed in warming temperatures is 200 to 300 fpm. We can increase the air speed over the animals in a few different ways. Adding panel fans is a great way to increase the air speed when ambient temperatures require additional cooling, and they work well in open buildings, where there are limited obstructions.

The downside to panel fans is that you cannot guarantee the higher speeds will reach the calf in its microenvironment. This gets especially difficult if you are using individual pens with solid walls. The solid walls, which have other benefits, are a major obstruction when trying to get airflow to the calf. The same principles apply to tunnel or cross ventilation of calf facilities – it is important that the airflow is able to reach the calf space.

Running a summer ventilation positive-pressure tube system is another option if the building does not suit panel or exhaust fans. This system is designed to produce air speeds of 200 to 300 fpm, as well as increase the air exchange rate in the facility. This tube would be larger in diameter and have larger holes than a tube designed for a minimum ventilation rate. It would direct the faster moving air in a similar manner to the winter tube.

It is important to note that if you are using a tube ventilation system, the minimum ventilation tube should be kept running all year to ensure the minimum ventilation rates are being met. Any additional ventilation can be run using an automated controller based on temperature. This ensures the system always provides the ventilation your calves need.

With all ventilation systems, the barn design, layout, climate and management style will also play a role in what system is best suited for an individual facility. What works best for a neighbour may not be what is best for your farm. Talk to your local dealer or ventilation expert to review all of your options. Choosing a system that meets the three calf barn ventilation objectives and is also tailored to your facility needs will go a long way in ensuring the health and future productivity of your next generation of animals.  end mark

References omitted but are available upon request. Click here to email an editor.

Dan Veeneman
  • Dan Veeneman

  • Artex Barn Solutions
  • Email Dan Veeneman

PHOTO 1: It is important that airflow is able to reach a calf’s microenvironment, especially when there are physical obstructions such as walls. Photo courtesy of Artex Barn Solutions.

PHOTO 2: An example of a winter tube ventilation system. Photo by Lora Bender.

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