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Pros and cons of feeding milk to calves

Bob James Published on 10 January 2011

Nature designed whole milk as food for baby calves. It contains 3 to 3.4 percent protein, 3.5 to 4.5 percent fat and 12.5 percent total solids. On a dry powder basis, milk contains 24 to 27 percent protein and 28 to 36 percent fat.

It seems obvious that calves would grow better when fed whole milk, as it is richer in nutrients than the traditional 20 percent protein:20 percent fat milk replacer powder. So why feed a milk replacer?



1. 20:20 milk replacers were developed to support minimal growth, encourage early consumption of calf starter, and promote early weaning of calves at low cost per day.

Recent research shows that milk replacers containing 28 percent protein encourage faster growth, which appears to be very important during the first month of life. Milk replacer companies have developed milk replacers with high protein, enabling growth comparable to whole milk.

These higher-protein milk replacers are more expensive, but the cost per unit of gain is usually less due to higher rate of gain. Performance on higher-protein milk replacers is comparable to whole milk.

2. Salable milk prices have varied from $12 to $25/cwt in the last two years, so on a dry powder basis, whole milk would cost $.90 to $1.80 per lb or $45 to $90 per 50-lb bag!

In most cases milk replacer prices will track milk price fairly closely and be less expensive on a unit of nutrient basis. Whole milk may seem cheaper because it is not a cash expense.


3. Quality of milk as compared to milk replacer – milk fed to calves primarily comes from fresh and treated cows. If the supply is insufficient, salable milk is drawn from the bulk tank.

Many dairy producers don’t take adequate precautions in handling “calf” milk and it can be a source of Johne’s bacteria, E. coli, salmonella, and mycoplasma, which are health threats for calves as well as people.

Milk is an ideal bacterial culture. Any delay in cooling results in rapid bacterial growth. Mr. Chase Scott, Wythe County dairy extension agent, conducted waste milk pasteurization studies on dairies in North Carolina and California. He found that bacterial levels varied from less than 10,000 cfu (colony forming units) to more than 5,000,000 cfu/ml.

Pasteurization was unsuccessful in reducing bacterial counts to less than 20,000 bacteria/ml of milk in about 20 percent of samples. He found that nutrient content varied considerably with fat and protein as low as 2 percent, likely due to added “flush” water at the end of milking.

If milk is fed to calves, it must be pasteurized and fed as soon as possible to prevent excessive microbial growth.

4. Variable supply of unsalable milk. A large dairy producer in this study found that daily volume of waste milk varied from 200 lbs to more than 800 lbs daily.


Most studies of the economics of pasteurized waste milk assume sufficient waste milk to feed all calves. Most farms will have serious herd health problems to produce adequate quantities of waste milk.

A typical Virginia dairy farm of 150 cows will include 25 calves consuming 1 to 2 gallons of waste milk per day and requiring 215 to 430 lbs of milk daily.

This volume would require four to eight cows in the “hospital group,” each producing 50 lbs of non-marketable milk per day. Herds with SCC of less than 200,000/ml would likely not generate enough waste milk to feed all calves.

Waste milk feeding systems can be very successful, but producers should consider all factors before choosing salable or waste milk as the sole source of nutrition for pre-weaned dairy calves.

Well-designed pasteurizer systems require a significant investment along with careful and continuous maintenance. Waste milk varies widely in nutrient content and must be cooled rapidly to prevent bacterial growth.

A spreadsheet available at evaluates the economics of different calf milk feeding systems. PD

—Excerpts from Virginia Tech Dairy Pipeline, July/August 2010

Bob James