Advice on cost-efficient calf feeding with milk replacer

Calf rearers looking to make strategic cost savings in light of lower milk price could make efficiency gains by reviewing calf milk replacer feeding volumes and fat levels.

Dr Jessica Cooke, R&D Manager at Feed For Growth (Volac Milk Replacers Limited), says tighter margins underline the importance of cost-effective calf growth, but should not be a reason to cut corners in the rearing stage or be tempted to feed whole milk to calves.

“It’s always worth investing in calf growth, whatever the milk price,” she explains. “Ultimately, you’re investing in your herd’s future.

“If you cut back now, you’re not making the most of high feed conversion efficiency during the milk feeding stage.”

Save money and boost performance

However, she believes there is potential to be more cost-efficient  and boost performance by thinking about fat inclusion levels in calf milk replacers (CMR) and feeding volumes.

Milk replacers of over 22 to 23% fat will likely cost more and can  suppress starter intakes, which could have  a detrimental impact on long-term performance.

Dr Cooke explains: “Feeding a CMR with a fat content of less than 22% typically stimulates the earlier consumption of solid feed.

f”This is what you want because solid feed intakes pre-weaning stimulates rumen development, which is key to ensuring a smooth transition around weaning.

“Heifers with good rumen development will continue to grow well immediately post weaning which is an economical stage to grow heifers due to the lower cost of dry feed.”  

Encouraging starter intakes

A recent Canadian¹ study found that average daily liveweight gain was greater over a 91-day period for calves fed a 17% fat CMR, versus a 23% and 29% fat CMR.

The CMR was a blend of 20% coconut and 80% palm fat at 26% crude protein. There were 128 male Holstein calves enrolled in the study.

Calves fed the 17% fat CMR had higher starter intakes pre and post weaning and consumed 33kg more starter by the end of the study compared to the 23% fat group.

Average daily gain was also higher meaning their final body weight was 13.6kg more (see table).

This improved performance is likely driven by increased nutrient intake from greater solid feed consumption, particularly post weaning.

Dr Cooke adds: “In this study, calves fed a milk replacer with 17% fat had greater solid feed intake and improved body weight gain compared with those fed a milk replacer with 23% and 29% fat.”

Another study in The Netherlands saw a similar positive impact. In it, 136 pre-weaned bull calves were fed either a 17% fat or 25% fat, 23% protein skim-based milk replacer.

While both groups received 50.4kg of milk powder, the calves fed the 17% fat milk replacer consumed 10.4kg extra starter feed over a 12-week rearing period.

“It’s important to get the balance of milk and starter feed right,” Dr Cooke stresses.

“Too much fat in your milk replacer in combination with high CMR feeding levels of around 90kg per calf add cost to your system.

“It may mean your calves grow well and look amazing to begin with, but immediately post weaning growth rates will likely crash because calves haven’t eaten enough starter.

“Research suggests feeding 50-60kg of milk solids across the rearing period is the optimum.”

Effect of calf milk replacer fat levels on calf performance after 91-day study
	17% fat CMR	23% fat CMR	29% fat CMR
Final body weight (kg)	160.8	147.2	149.6
Average daily gain (ADG) kg/day	1.24	1.09	1.12
Total DMI (kg)	234.5	201.3	208.7
Total calf starter intake (kg)	182.9	149.9	157.2
Note: 128 male Holstein calves weighing around 47kg on day one (JVR Lovatti et al, 2026)

Dr Cooke says thinking about fat and feeding rates is an easy win for improving efficiencies without increasing costs.

It also acts as a much safer route than looking to lower costs by feeding whole milk to calves in-light of lower milk prices.

“By feeding whole milk, you could inadvertently introduce diseases like Johne’s, bovine TB and Mycoplasma bovis, which could have a detrimental impact on growth and stop heifers from calving in at 24 months, which is the optimum for health, fertility, survival and higher lifetime daily yield,” she explains.

A quality CMR is not only more hygienic but also has a more consistent macro and micro-nutrient supply for calves and can provide additional health package benefits.

Whether feeding whole or CMR, she says milk should always be prepared in hygienic conditions and stored in clean containers.

When feeding whole milk cannot be avoided, pasteurisation should be considered and pooling should be avoided.

Milk from Johne’s-positive cows must never be fed.

References:¹Lovatti, JVR, TE da Silva, AJ Keunen, M. A. Steele, DL Renaud, and JHC Costa. 2026. Effects of fat level and coconut-to-palm fat ratio in milk replacer on solid feed intake and performance of pre- and postweaning dairy calves

Milk replacer gold standards

Whilst each farm is individual, and requires an individual plan, as a guide to hit key performance targets of doubling birthweight at weaning (having grown at 0.75-0.81kg per day), the gold standard is to feed pre-weaned calves around 60kg of a good quality calf milk replacer at:

• 16-21% fat (anything over 22% fat can suppress starter intakes).

• Over 23% protein (from quality skim or concentrate whey protein). This is ideal for building lean muscle mass for dairy heifers.

• 900g of milk solids per day.

In addition:

• Provide palatable, fresh starter feed, water and chopped forage (3-4cm).