Overnight Shedding with Daytime Mini-Paddocks
This system is effective for batch rearing. It minimises contamination of the shed, while allowing calves to sleep overnight and providing shelter during wet, windy weather. If you use this system, make sure that your calves eat the necessary concentrate ration essential for growth and early rumen development.
It is essential that mini-paddocks have shelter from prevailing winds. This can be provided by specially planted windbreaks or strategically located buildings. Treat calves with an effective drench before changing paddocks.
Train calves to use the shelter by placing the concentrate feeder in or next to the shelter areas.
Outside Rearing
If you are planning to rear calves outside, consider shedding them for the first two weeks.
Make sure quality fresh, clean water and straw or hay are always available. Place feeders and straw/hay racks high enough to prevent contamination with faeces. Clean out stale feed daily; this will encourage young calves to have a high intake of concentrate and achieve target live weight gains.
Shed Design
A calf shed need not be an expensive structure, but it should be built in a way that makes it easy to clean and keep clean.
The shed should be well ventilated; it should be open from one metre high but draught-free. Preferably it should be open on all sides, or at least open to the north or north-east so that it gets as much sunlight as possible. Lack of ventilation causes an increase in the humidity and temperature inside the shed and creates the perfect environment for bacteria and viruses to breed and survive. These are breathed into the lungs and infection can occur. The build up of gases such as ammonia also damages the lungs and makes them more susceptible to infection.
The type of flooring is important; the floor should be kept clean and dry at all times. The following flooring systems have been successfully used and are worth consideration.
Wooden Grating
A wooden grating, consisting of 50 mm x 25 mm timbers spaced 30 mm apart, is placed a minimum of 300 mm above a concrete sloping floor.
This arrangement allows the urine and dung to pass through the grating to the concrete below. Remove the calves from the shed if you are using a high pressure hose. You can also use flood washing to remove dung and straw; a cheap and effective arrangement is a 200 L drum cut sideways and counter- levered to tip when it is full of water.
Wire Mesh
Wire mesh suitable for calf shed flooring is available. It is designed specifically for pig pen floors; the openings are 12.5 mm x 150 mm. The mesh is welded to a metal frame and positioned about 300 mm above the concrete floor. It may cause problems with sore joints at the knees and hocks, and it appears that woven mesh is better.
Deep Litter
About 300 mm of litter—dry sawdust, wood chips, straw or rice hulls—is placed in the shed and ‘topped-up’ progressively throughout the rearing season. Excess dung on the surface must be removed before each topdressing of fresh material.
Note: Do not use green sawdust as it may cause problems with navel infections; straw is safer.
Remove the deep litter from the calf pens at least once a year, and thoroughly clean and disinfect the shed to prevent the carryover of disease.
Flooring in sheds can be 50 mm x 25 mm timber slats, with a 30 mm spacing to allow manure to drop away from calves.
