The practicalities and pitfalls of calf rearing were discussed at the first of Beef + Lamb New Zealand’s Central Otago Farming for Profit winter webinar series.
As both a scientist and calf rearer, Professor Rebecca Hickson was the ideal subject matter expert but pointed out from the start that there was no single right way to rear calves, rather it was important to understand the trade-offs within an individual farm system.
While rearing systems vary, for Rebecca, the non-negotiables were genetics and colostrum- the quality of both were vital in a successful calf rearing operation.
Genetics
Genetics drive rearing and finishing performance and set the ceiling for what the animal is capable of. Numerous trials, including B+LNZ’s long-running Dairy Beef Progeny Test, have reinforced the value of superior beef genetics in driving efficiencies in a beef- on- dairy rearing and finishing system.
Rebecca said it is impossible to tell a calf’s genetic make-up by looking at it and added that there was as much variation within breeds as between breeds.
This highlighted the value of buying calves directly from dairy farmers as they will know the genetic background of each calf – and how the calf was looked after in its first four days of life.
“Ask you potential suppliers about colostrum – good colostrum practices are critical to get the calf off to a good start – in addition, ask about navel care, cow nutrition, calf nutrition and the frequency of pick-ups, particularly in bad weather.”
Calves should be a minimum of 96 hours old when they are moved to a rearer, although the older the better, said Rebecca.
“They are just that much more robust.”
Buying direct versus sales
The advantage of buying calves at sales is that the calves can be bought in batches and can be of a more uniform size. When buying calves directly from a dairy farmer, the calves can be ready in small numbers, which means more transport costs, and the calves can vary in size.
The risks of buying calves at the sale yards include unknown genetics, unknown colostrum history and unknown disease status- as sale calves could have been exposed to diseases through transport and yarding.
Housing
Calf sheds must be warm, dry and well ventilated- without being draughty.
They can vary from converted farm sheds to purpose-built tunnel houses or calf sheds.
Most importantly, they need to be well set up before any calves arrive.
Factors to consider when setting up a calf shed include having the ability to feed meal and milk from outside the pen (makes life easier and reduces the risk of spreading disease between pens), compartment or open feeders, having the ability to refresh the bedding easily and how and where sick calves will be cared for. Rebecca uses a wheelbarrow to transport sick calves to her hospital wing.
Other factors to consider include how to keep track of calves with issues- collars, paint or tags can be useful for calf identification, especially in systems where more than one person is caring for the calves.
Feeding
Rebecca said there is no right or wrong way to rear calves to weaning and she outlined both a high and low milk system. While the high milk system was more expensive, the calves grew faster than those on the low milk system. See more information here Feeding milk to calves.
To aid rumen development, calves should have unlimited access to meal from day one up to a maximum 2-3kg/head/day. Initially the meal is a substrate for rumen development rather than a source of nutrition.
Straw or hay should make up about 10 percent of the calf’s diet.
To help calves adjust to calf milk replacer (CMR) Rebecca suggests offering a 50/50 mix of cow’s milk and CMR.
If the calves have had a long day being transported, it is a good idea to give the calves electrolytes upon arrival at the rearing unit and milk at least two hours later.
CMR should be mixed in either cold or warm water. Hot water can denature some of the proteins in the CMR.
Compartment feeders are valuable for low volume feeders, especially for slow feeders, but the slow feeders really need to be supervised to ensure they get their full allocation.
The quality of the CMR is important- as is consistency- cheaper products can be more costly in the long run.
Temperature matters
Cold and sick calves will partition their energy intake into keeping warm or immune function rather than growing. Cold for a young calf is anything below 15 degrees and this reinforces the importance of having warm, dry housing and using calf coats in colder areas.
Sick calves
Sick calves are a reality of rearing, hence the need to set up a care plan right from the outset.
Scouring calves are the biggest – and most common – challenge. These calves should be isolated and fed with milk as usual but also given electrolytes, to keep total fluid intake up at six to 10 litres a day in three to five feeds, depending on the severity of the scour. They may require tube feeding electrolytes.
Antibiotics are usually unnecessary (talk to a vet) and the calves will benefit from extra milk once they’ve recovered to regain condition.
Benchmarks
If death rates are over 4 percent and hospitalisation above 10 percent, Rebecca recommends rearers seek advice from their vet or advisor.
A 40 kg bull calf on a low milk system should be reaching 100 kg by 12 weeks of age.
Weaning
The weaning decision should be based on the cumulative total intake of Non-Fibre Carbohydrates (NFC) the calf has consumed, as this determines how functional the rumen is. They should have consumed a minimum of 5kg of NFC before weaning is considered, but at least 15kg is required to achieve a fully developed rumen. Depending on meal composition, this is around 12.5 kg of meal eaten to reach 5 kg NFC, and 37.5 kg total meal eaten to reach 15 kg NFC.
Weaning based on weight is commonly practiced, but it’s important that the weaning weight reflects the feeding system, so that calves have consumed sufficient solid feed to develop their rumen prior to weaning.