Probiotics help calf rearing systems
Success in calf rearing is often measured by minimising health issues and achieving target weaning weights.
Calf sheds need good air flow but if possible they should not be facing the prevailing wind, says Morgan, who is running 15 Dairy Womens Network (DWN) Successful Calf Rearing workshops around the country.
Calves should be dry and out of the wind.
“If they are cold that is not really a problem. Calves cope fine with cold weather but they don’t cope well with wet or wind chill,” she told the Ngatea workshop. “When they are exposed to that sort of weather they are using their energy to keep warm and not for growth. You could use canvas or shade cloth appropriately to reduce wind getting into the shed.”
But good air flow should be maintained so the bad gases are removed. If air flow is reduced, too much ammonia can build up which is not good for the calves or the people working with them.
“You can cut parts out of a building to provide better airflow. But calves must not be sitting in a draught. The best way of checking is to get down to calf level and light a lighter or a match and if it blows out there is a draught. If it stays lit the cows are fine.”
Slats at the base of a shed are a good bedding option because the waste drains away; but ensure the waste doesn’t just sit under the slats, it needs to be drained away.
The numbers of calves and size of the shed will always determine how many are housed. But best practice would be to have 10-12 calves per pen with 1.5m2 per calf.
Morgan recommends an all in, all out system for bringing calves into the pen. Moving calves from pen to pen as they grow means the disease challenge will build up in the first pen and day-old calves would be very susceptible. Shed spraying is important one or twice a week, and footbaths coming into the shed are recommended.
“You can do as much as you like for hygiene for the calves but birds can ruin all your good work by adding salmonella to the calf troughs,” she says. One of thr biggest reasons for birds on farms is uncovered feed. They go into the open silage face, have a good feed and come back to the nice warm shed. The silage face should be kept closed when not feeding out. The loss of the grain is reducing the nutritional value of the silage.
Morgan says woodchip, sawdust and wood shavings are all great bedding: they drain well and are good for the calves. Make sure it is not treated with a chemical or stain.
River stones are also a good, reusable bedding. They warm up in the sun and they turn over so the waste will drop below. But they need to be the right size – about cobblestone size. They need some form of chip drainage underneath. Straw is also good warm bedding.
Clean, fresh water is imperative. When a calf is being fed milk it goes to the abomasum – the final compartment of the stomach.
“What we are trying to do in rearing calves is improve the rumen and grow the giant fermentation vat that is going to be essential to break down all the fibres when we feed pasture. The milk doesn’t go anywhere near the rumen.
“In a rumen we want everything to be mixing around – all the bacteria and all the feed particles to be mixed together and broken down and absorbed by the animal. By having water in there you are moving everything around.” Many trials show the grow rates of animals on water is a lot better than those without water.
For transportation the trailer should be driven slowly and have non-slip matting. Check it is actually non-slip as some product does not live up to its name. Fake grass was also suggested. Carpet or mattresses are difficult to clean.
Calving planning is important to decide who is doing what and making sure everybody knows the plan, says Morgan.
