Milk vs. Milk Replacer: Which Is Better for Calves?

Milk.  It’s hard to beat mother nature.  Milk is the mammal’s way of nourishing her offspring. Yes, we may have altered the product to meet our manufacturing needs, but it’s still great for calves.   Casein is the primary protein, and it forms a “clot” in the abomasum which results in slower degradation over time.   Fat is an important nutrient providing energy for the calf in a very digestible form.   On a powder basis, milk contains about 25 to 27% protein and 27 to 34% fat.  Lactose (38%) and vitamins and minerals round out the other primary nutrients.   Sounds great, right?

What are the other considerations?    How does one maintain the quality of the milk from the cow’s teat to the calf’s mouth?   Milk is not only great for the calf, but it also is great for bacteria.  At room temperature bacteria counts double every 20 minutes.   Maintaining sanitation of milk contact surfaces – milking equipment, transfer lines, storage vessels and feeding equipment is challenging at times.   Milk should be either fed immediately or cooled to < 40F for storage and then rewarmed prior to feeding the calf.   Treat milk with the same care as one does for milk for human consumption.  Would you drink the calf milk?  If not, then don’t expect success when feeding this to a young calf!   Pasteurization of milk is highly recommended as the herd may experience some diseases which can be communicated to the calf such as BVD, Johne’s, Mycoplasma ………  Will unsaleable milk be utilized?   Does this have antibiotic residues?  Ultimately, this represents an “off label” use of antibiotics and may not be best for the calf’s delicate digestive system. If one elects to use unsaleable milk remember that supply is very variable. Although pasteurization impairs bacterial growth it also destroys most of the beneficial vitamins provided by the cow.   One farm involved in a Va. Tech field study monitored waste milk volume daily for 7 months and found a variation between 300 and 800 lb. / day.  This necessitates use of “good” milk to maintain a uniform nutrient supply for the calves.

Cost.   When feeding milk or waste milk the cost for feeding calves is not readily apparent since the value of that milk is not charged against the calf enterprise.   Frequently farms indicate that unsaleable milk is “free.”  No!  There is a cost in producing milk regardless of whether it can be sold or not.  The farm should at least charge the cost of production and the milk volume used for calves should be tracked!  Field research conducted with dairy farms by Va. Tech researchers found that most farms produced only enough unsaleable milk to meet 30% of the needs of the calf enterprise.   If the farm has more of this, then the herd health programs for the lactating herds need to be re-evaluated. 

Additional concerns.   To achieve consistent success in using milk or waste milk the initial and operating cost of facilities to transport, store, pasteurize, cool, and rewarm milk need to be considered.   Does the farm have the labor resources to manage this important part of the calf feeding program?  

Milk replacers.   One of the greatest benefits of milk replacers is convenience. Open a bag, reconstitute with water, and feed it to the calf.  The powder can be stored for extended periods without impairing quality.  Bacteria counts are low.  Additives such as vitamins, minerals, and beneficial products such as ionophores, fly control products, pre- and post-biotics are also commonly added.   Simplifying the feeding program is a tremendous advantage, contributing to consistency in the feeding program and labor efficiency and effectiveness.  

Historically, the early goal for milk replacers was to reduce cost through lower levels of protein and fat and utilization of less costly sources of protein and fat which resulted in poor growth during the first month of life.   More desirable milk replacers emphasize the use of protein and fat sources with digestibility’s which are competitive with whole milk.   Research at Virginia Tech compared growth in Holstein, Jersey and cross bred calves fed equal amounts of dry matter from whole milk and a 28%protein: 20% fat milk replacer and found no difference in average daily gain or health through 8 weeks of life.  Unfortunately, it is often difficult to evaluate a milk replacer by examination of the feed tag.     Only consider milk replacers with a proven reputation for quality.

Choices for those farms utilizing calf autofeeders.   Calf autofeeders can utilize milk, milk replacer of a combination of both.   When using milk, consideration must be made for handling milk from the cow to the calf.  How will the milk be collected, pasteurized, precooled, stored, and then transferred to the calf with little deterioration in quality or bacterial growth?    The feeder will warm the milk just prior to feeding and blend with water and powder prior to mixing and consumption by the calf.  The farm has the choice of specifying the % whole milk and the desired final % solids in the mixture consumed by the calf.   Figure 1 shows a combi feeder in which the farm uses milk and a pasteurizer balancer milk replacer which adds small amounts of supplemental vitamins, minerals, and other additives just prior to consumption by the calf.