A large-scale dairy calf-to-beef enterprise, in the Waikato region of New Zealand, has found that through developing the rumen of young calves pre-weaning – by feeding milk replacer on a once-a-day (OAD) feeding system – is helping them achieve targets and increase margin potential.

The enterprise in question is Farrelly calf rearing – which sources calves from the dairy industry in New Zealand and rears up to 10,000 calves annually.

Dr. Christine Cummins and Dr. Amanda Dunn, of Bonanza Calf Nutrition, recently visited the farm to learn more about how calf rearing can be viable, and how it can be achieved at a low cost and to good welfare standards.

During their visit, they discovered that the key is calf selection, OAD feeding and early weaning.

Dr. Christine Cummins on the Farrelly calf rearing enterprise

The business is dedicated solely to rearing calves – with 3,000 reared in the autumn and 7,000 in the spring; all run on 1,200ac.

Purchase of calves

The calves are purchased at four days old and sold again to other rearers once they reach a target weight of 100kg. This, according to the pair, is common practice in New Zealand.

For the smooth running of the business, it also has contracts ahead of time – usually once they are bought – to ensure that a customer is in place to take the calves at 100kg.

This helps to give reassurance at purchase and a focus for rearing them – as the targets are set out ahead of time.

Selection, they said, is also important. Calves are sourced from sales in the region and chosen predominantly on colour.

Taking us through the selection of the calves, Christine said: “They are quite selective with the calves and have designated people who have authority to select calves.

Ideally, they want a black and white calf with white feet, white on the forehead and white bodies – to minimise the selection of stock with Jersey breeding.

The farms preference is to rear Friesian, Hereford and Aberdeen Angus calves – in that order.

“On our visit, the average price for 2019 was $99/calf and they were heading towards the end of the season. Calves were purchased from $25 to $200, but these extremes were minimal,” explained Christine.

Other purchasing criteria are age – calves are purchased at approximately four days old – together with an ability to stand independently and to have the capacity to perform in their new environment.

Transport is a crucial part of the process – a covered and wind-proof trailer is used to protect health and survivability – and all calves are delivered to their new environment no later than 4:00pm, to allow time for them to settle in.

Consistent feeding

Whilst on the visit, Christine observed that the feeding and monitoring of the calves is also key to the success of rearing these calves.

A large whiteboard is used to keep track of feeding in all the groups; calves are fed 500g/calf of a skim milk-based replacer once daily – in the same order every day.

This OAD feeding system is ideal for reducing labour around feeding and increasing the time allowed for: monitoring; treating; and performing routine tasks such as weighing, dosing and dehorning.

In addition, while inside all calves are offered clean water, hay and concentrates ad-lib.

Calves are initially reared indoors in small groups of 10; thereafter, provided they are performing well, they are moved outdoors into training paddocks.

Subsequently, they are moved to larger groups with a maximum of 48 to 50 per group; this allows plenty of space to avoid competition for teats in the 60-teat feeder.

Calves are rotated around paddocks; they spend no more than four days in one paddock – to ensure that they are getting good quality and clean grass. When outside they are not offered hay, but are offered meal until they leave.

“As calves are very selective grazers they will graze very inefficiently, selecting the best grass in a paddock first, then revisiting the whole paddock to get the next nicest bit, when at this stage a lot of the grass will have been walked on and is beginning to get dirty.

“This can affect calf weight gain, if calves are left in one paddock for too long, as their intakes can be variable. Furthermore, dirty grass can increase the incidence of diseases such as coccidiosis,” explained Christine.

Close monitoring

On the day after their arrival, the calves will have a full health check, are weighed and dosed with an oral multi-vitamin and mineral. They also receive a vaccine for pink eye and clostridia.

They are checked daily for signs of illness at feeding; any illness is treated immediately.

On day 35, calves are weighed to check their progress. After seven to eight weeks on the farm, calves are weighed again and grouped by: age; gender; breed; and weight.

At this stage the calves are weaned. They are approximately 75kg at this time.

By 12 to 14 weeks, they want these calves to be at least 100kg – at which point they can sell for approximately $400 each.

“It is through constant monitoring that allows the calf carers to catch illness early and to ensure they are gaining weight as they should,” Christine added.

Calves are weaned at between seven to eight weeks-of-age and are able to easily digest concentrates and grass; so there is no issue with them transitioning off milk.

“This is another great advantage to the OAD feeding system for this calf rearing unit,’’ said Christine.

Calves will consume at most 1.5 bags of powder, developing the rumen while achieving targets and increasing margin potential for the calf rearer.

Good hygiene forms part of the daily routine. After feeding, the calf feeder is cleaned at a designated cleaning area and clean water is offered daily.

Sick pen feeding equipment is not shared among other calves. Sheds are regularly sprayed with disinfectant and with each new group that enters, a new layer of woodchip is added.


Christine noted that this system of farming doesn’t come without its challenges.

“Farrelly calf rearing has measures in place to try minimise these challenges. One of the main challenges is when calves are sourced from a single farm are weak and frequently sick.

They feel this is likely to be a colostrum issue, as they usually begin to ‘melt away’ as soon as they arrive.

To minimise the need to deal with this issue, a record of calves that have constant problems is kept and no further calves are purchased from their source farms. This seems to solve the issue.

“The business feels a good-quality calf without adequate colostrum is worse than a poor-quality calf with adequate colostrum,” concluded Christine.