Working with healthy calves is much more enjoyable than working with sick calves. Ensuring the health of our calves needs to be a top priority.
Healthy calves grow faster and have the potential to outperform their peers that need treatments for sickness. Healthy calves make sense.
First, let’s consider dry and comfortable. A picture of best management is a bright-eyed calf nestled in a deep bed of straw, contently resting, chewing her cud; her ears are up and her hair shiny.
Cold and wet is a big problem for calves; cold and dry is not. “Colder is better” is a good thought to consider when looking at calf barns. A temperature of -10ºC can be more comfortable than +10ºC if the calves are dry.
Automatic feeders and free-choice feeding systems are becoming more popular as effective ways to raise milk-fed calves.
As the temperature in a calf barn gets colder, the calf’s requirements for energy and protein to sustain growth increase. An ample supply of milk, water, good-quality hay and a high-protein starter are necessary requirements of a good feeding program.
Fresh air with no draft is a simple requirement that can be quite difficult to accomplish. To do a good job of designing a ventilation system for calves, we need to know the number of calves, weights and ages.
What type of penning? Small groups or individual pens? Is it a new building or existing barn being renovated, and do we want the barn to be cold or warm? For the purpose of this discussion, we’ll consider a new, cold barn.
Simple can be good in ventilation design. Let’s start with curtains – making use of natural air movement is a good thing several months of the year.
As well, curtains let lots of natural light into the barn. Come cold weather, curtains have to be managed to eliminate drafts. This can be done effectively by installing mesh shade cloth in the top 18 inches of the curtain opening. This cloth allows fresh air to enter but minimizes the draft.
The second step is to ensure a fresh air supply. This can be done effectively and economically with a positive pressure duct system.
Fresh outdoor air is blown into the barn by a hooded fan attached to a rigid duct or plastic bag. The duct has holes sized and positioned to provide air to the calf level.
A properly designed system disperses fresh air without a draft before it reaches the calves. Typically this fan will run year-round, providing the minimum air required. Air exhausts through chimneys or open sidewalls.
Natural chimneys work on the basis of heat rising and creating a draw to pull air out of the barn. With small calves, there is typically not enough heat produced to create a sufficient draw.
In some circumstances, cold air can come down chimneys and fall over the calves. To address this, a power-ventilated chimney controlled by temperature or humidity sensors can work very well. These chimneys can effectively move air out, while limiting the cold air coming in.
Asking ourselves a few simple questions gives us a good measure of how successful we are at raising calves.
Are the calves quiet and content? Is their hair shiny and smooth? Are their eyes clear and bright? Do they romp around and play? Are the calves clean and dry? Is the air fresh and draft-free at the calf’s level? If the answer is no to any of these questions, we need to make improvements.
If we ensure these three basic needs are met, we can be confident we’ll have healthy, happy calves that grow into great cows. PD