I have a calf facility with open side walls and curtains. There is significant “natural” ventilation when the curtains are down. Why do I need a mechanical ventilation system?
Some of the newer facility designs with open side walls facilitate natural ventilation. However, there are many times during the day (and night) when the wind is not blowing. During these times poor-quality air from the accumulation of ammonia and various airborne bacteria and virus can accumulate in the area immediately around the calf. Mechanical ventilation systems, such as the positive pressure tube system or fans should be included in the facility design which bring fresh air into the facility 24 hours a day, 365 days a year. Seek professional assistance to design these systems based upon your environmental conditions unique to your farm. See the following resource for more information on ventilating calf facilities. https://thedairylandinitiative.vetmed.wisc.edu/home/housing-module/replacement-housing/
Why is more than four quarts of milk or milk replacer desirable for the calf during the first weeks of life?
In desirable weather conditions when the temperature is 40oF (4oC)or less, 4 quarts provides barely enough energy to meet the calf’s maintenance requirements. As a result, there is nothing left to support growth. During colder weather, the calf must mobilize their limited amounts of body fat to stay warm. In such cases the body fat of the calf can drop to less than 5% which provides little reserves of energy. Feeding more milk or milk replacer enables the calf to grow earlier in life and support improved resistance to disease. Although cost/day may be higher, cost/unit of body weight gain is less. It is important to remember that starter intake does not contribute much to meeting the calf’s nutrient requirements until they are 6 weeks of age. Most calves will consume more than eight quarts of milk or milk replacer /day by 10 days of age. Higher milk intakes are also more readily achieved with autofeeder systems where the calf can consumer multiple smaller meals in each day.