Volac has led the technological revolution through the development of unique ultrafiltration systems where a combination of filtered, evaporated and gently sorted milk constituents are collected at low temperature from liquid whey.

These include proteins, fats and sugars, resulting in a highly nutritious bioactive complex called Imunopro®, which is the base of all Volac milk replacers.

“There are some who still perceive that milk replacers based on skim milk powder are better because the skim powder forms a clot in the abomasum," said calf-rearing specialist with Volac Rebecca O’Sullivan.


"The clot breaks down over a period of time and this is perceived to be beneficial to calf performance.

“However, recent research by AFBI Hillsborough demonstrated that there was no difference in growth and health when calves were fed high-quality whey-based or skim-based milk replacers,” she said.

In the trial, 80 Holstein Friesian calves were fed up to 1.05kg of milk solids/day and growth rates and disease incidence were monitored up to 10 weeks of age.

The results showed that the presence of the skim, and therefore the clotting effect of casein, was not needed for calf performance.

Rebecca O’Sullivan also stressed the variability that exists in skim-based replacers.

“In some cases, skim powder inclusion rates have dropped from 60% to around 10%. So, it is very important to check the label for the actual amount of skim included.”


She highlighted a number of additional benefits of Volac’s whey-based replacers, which are not found in skim-based products.

“Imunopro®, the base of all our milk replacers, has significantly higher levels of immunoglobulins and lactoferrin, which play an important role in the development of the calf’s immune system and in gut development, than are found in skim products.

“It also has much higher levels of amino acids, milk fats and milk sugars than are present in skim-based replacers."

Big variation in whey types

The type of whey used in milk replacers and the way it is processed has a major bearing on the quality and digestibility of the end product and the level of nutrition it can deliver to calves.

It is important to check the type of whey that is declared on the label. Is it whey powder, delactosed whey or concentrated whey protein? All three originate from whey in cheese but are processed very differently.

Table 1 below compares Volac’s concentrated whey protein with whey powder and delactosed whey.

Table 1: Comparing types of whey

Guide to selecting a milk replacer

The levels of crude protein, fats and oils, fibre, ash and key minerals in milk replacers are key determinants of calf performance and health.

Use the following guidelines when selecting a milk replacer.

Crude protein

  • For dairy replacements, use a product with 23% to 26% crude protein. For high-performing Holstein Friesian replacements, choose a product at the higher crude protein level in order to maximise frame growth. Volac Heiferlac is a perfect choice.
  • Where a mixture of dairy replacements and beef calves are being reared, a product with 23% protein can work well. Volac’s Triple A Golden Maverick is an ideal product of choice.
  • For dairy-cross beef calves, a product with 20% to 23% protein can be an economically viable option. Volac Olympian is a suitable choice.
  • Fats and oils

    Products with oil levels over 20% reduce the calf’s desire for concentrate feed and can make weaning more challenging.


    Fibre is an indicator of vegetable protein inclusion. Fibre levels should ideally be 0.1% or less. Higher levels reduce the digestibility of the milk replacer.


    Ash levels of between 7.0% and 7.5% are ideal. Levels over 8.0% reduce digestibility.


  • Sodium is an undesirable salt. Levels should not be higher than 0.5%. High levels indicate elevated ash and potassium, which reduce digestibility and increase the risk of digestive upsets.
  • Phosphorus levels should be 0.5% to 0.6% and calcium levels 0.8% to 0.9%.
  • The unique Imunopro® formula

  • Imunopro®, a highly nutritious bioactive complex, is the base of all Volac milk replacers.
  • Produced through a unique process from liquid whey, it contains high levels of immunoglobulins, amino acids and lactoferrins.
  • It has three times the level of igG, a vital immunoglobulin for early life immune development, than in milk, skim or standard whey.
  • It has significantly higher levels of key amino acids such as lysine and leucine than are present in milk, skim or standard whey.
  • It contains high levels of lactoferrins which play a critical role in the reduction of scour in calves.
  • It concentrates 16 times the amount of milk fats in comparison with standard whey or skim powders. These milk fats carry out an important anti-microbial role.
  • It has elevated levels of milk sugars which play an important role in steering the development of a healthy population of bacteria in the newborn gut.
  • Volac replacers also contain special health supplements, which enhance the immune system and improve gut health.

    Feed for Growth

    The Volac Feed for Growth programme provides expert advice on every aspect of calf rearing. In particular, it highlights the key performance milestones in rearing replacement heifer calves and puts strong focus on nutrition and management in the critical period from birth to weaning.

    Feed for Growth also contains information on Volac’s seven high-performing milk replacers - Triple A Golden Maverick, Heiferlac, Blossom Easy Mix, ImunoGard®, Golden Maverick Hi-Spec, Maverick Once a Day and Olympian.

    All seven contain high levels of Imunopro® and are formulated to deliver excellent growth rates when fed at the recommended levels following good management practices.

    For full information, visit www.feedforgrowth.com.