Benefits of ad-lib milk feeding for calves

Giving pre-weaned calves access to as much calf milk replacer as their appetites demand has transformed the performance of Scottish dairy farmer Rory Christie’s heifer replacements.

Dourie Farming Co, at Port William, Wigtownshire, introduced ad-lib milk feeding after Rory saw how calves reared on foster cows thrived.

See also: How spring block calver uses nurse cows to rear replacements

“I looked at those and thought, ‘my goodness, how poor a job humans make of it compared to the cow’,” he says, recalling an old cow, in her 10th lactation, rearing three calves and “making them look fantastic”.

“I realised why – because the calf was getting what it wanted to eat, when it wanted to eat it.”

Rory Christie © Jeff Holmes

To imitate this, Rory, who runs the business with his brother Gregor, invested in teat feeders that warm milk on demand, drawn from an external container positioned outside the group calf pens; about 40 calves have access to each feeder.

“It’s a basic warmer, not a sophisticated automatic feeder, but it gives calves unrestricted access to warm milk,” he explains.

“Because the system only warms the milk as it’s being consumed, there’s no opportunity for bacteria to flourish.”

Growth rates

Feeding high-quality calf milk replacer (CMR) is central to the success of this system. A product containing 25% oil and 22.5% protein is used, mixed at a concentration of 133g/litre.

Despite the increased access to milk, overall CMR usage is generally similar to previous systems, says Rory, because of the significantly faster growth rates of the calves.

“We grow them much quicker: we regularly achieve average daily liveweight gains of 1kg, and they consume up to 1.2kg of milk solids/day. They get as much milk as they need to satisfy their appetites.”

The weaning process is started gradually from 42 days, once calves weigh about 75kg.

“We wean them slowly over 10-14 days because they’ve been feeding ad-lib and you can’t just stop – it’s important to avoid stress,” says Rory.

Calves are fully weaned at 56 days and remain indoors on ad-lib concentrates and straw for between four and six weeks; they are then turned out to graze in May.

At turnout, they are supplemented with ad-lib concentrates, the amount offered reducing daily for 10 days, down to 1-2kg/day. Concentrates are removed entirely by 16-18 weeks, normally in early July.

Each year, about 1,100 calves are reared on the system, a mix of dairy heifer replacements and dairy-beef calves destined for the store market.

Ad-lib feeding produces very even batches of calves with high daily liveweight gains.

“These are easier to sell and we have returning customers,” says Rory. “We’re adding value by producing quality stock.”

Calf health

Pre-weaning calf mortality is consistently low – typically under 1% – and antibiotics usage is also minimal. In 2024, usage across the business was 6.52mg/population corrected unit.

“We use far fewer antibiotics than we did previously,” says Rory. “I think it’s simply because the animals aren’t stressed, because their nutritional needs are met in a much better way than before.”

As the farm operates a spring block-calving, pasture-based system, calves are only vaccinated for blackleg.

“We get still get cases of calves with a high temperature, but by identifying that early, we can more often than not manage it with oral anti-inflammatory, but without antibiotics,” he notes.

Calves are reared in ventilated polytunnels, well suited to the farm’s 12-week block-calving window from February to April.

The goal is to recreate a fresh, dry spring day in the tunnel. Stocking rates are adjusted according to weather conditions and ventilation.

Investing in the first six weeks of life is critical, Rory insists. “It’s the most important stage of a calf’s life as it defines performance for future lactations.”

Genetic potential

Heifers consistently calve at 24 months. Rory says it is difficult to gauge how much more milk they produce when they enter the herd, but they hit liveweight targets.

“If you want to have any chance of optimising their genetic potential, you have to meet those targets, and ad-lib milk feeding helps us to do that.

“We’re very focused on producing good dairy heifers and on achieving optimum performance. Everything we do is about long-term investment in these animals.”

Ad-lib milk feeders – some options on the market

Milk Bar Ad-Lib feeding system

Milk Bar © Dairy Spares

Designed with two different teat heights and feeding mechanisms to adjust intake speed, the Milk Bar Ad-Lib system, distributed through Dairy Spares, offers controlled flow for four calves.

Teats sit at the lower level when calves are introduced to the feeder.

At this stage the teats are firm, which means calves have to suckle hard, adding a level of control to feeding.

After about three weeks, the teats soften, meaning drinking speed increases, and they are moved to a top row of holes and connected to milk tubes, enabling ad-lib feeding.

More effort is needed to suck at this height and through the narrow tubes, giving control to speed of intake.

This feeder is available in a range of sizes and prices.

Heatwave Milk Warmer

Heatwave © Shearwell Data

This machine is suitable for use with whole milk or milk powder, the latter being mixed cold.

Milk or milk replacer is stored in a suitable container that stands next to the Heatwave but outside the calf pen.

Because it is stored cold, manufacturer Pyon Products says good-quality milk will stay fresh for 24 hours.

Silicone pipes carry milk to four teats on two teat bars inside the pen.

When calves suck, milk is drawn from the container and warmed as it passes along pipes through a heated water tank.

Cost is about £550 ex VAT.

Britmix Milk Made 2000

Milk Made 2000 © Russ Davies

The Milk Made 2000 is an automatic feeding machine for up to 60 calves, designed and manufactured by the Nixon family since 1977.

The hopper holds about 25kg of milk replacer, which the machine mixes with water at the ratio dictated by the calf-rearing system, and does so in batches.

When the milk level falls below a certain point, a new batch is mixed.

An agitator inside the hopper allows effective mixing of non-free-flow milk powders and there is a removable mixing bowl for easy cleaning.

The Milk Made 2000 is priced at £2,170 ex VAT.