Calf Milk Replacer
After the colostrum, the focus needs to be on growth and development of the calf’s immunity. Poor feeding in the initial days can have immediate consequences for the development of the calf into a productive dairy cow. Start with a high dosage of calf milk replacer directly after the colostrum therefore.
Calf milk replacers (CMRs) provide a convenient way to feed pre-ruminant calves. They can be stored long term as powder and mixed with water just prior to feeding. Calves can then be milk reared anywhere and at any time without having to source liquid whole milk. Provided the CMR is formulated correctly from good-quality ingredients and fed according to the instructions, which are usually on the CMR bag, calves can grow equally well when reared on CMR and their rumens can develop just as well as they would on a diet of whole milk.
A good-quality milk replacer should be similar in chemical composition to whole milk. It should contain the nutrients that calves can digest and in the right proportions. Most milk replacers form a clot in the abomasum and so provide a slow release of nutrients to the duodenum. There are others that do not clot in the abomasum and are primarily digested in the intestines.
Milk replacers are generally formulated from by-products of dairy processing, together with animal fats plus added vitamins and minerals. Whole milk powder consists mainly of lactose (36–40% of DM), fat (30–40% of DM) and milk protein (28–32% of DM). The protein is principally made up of casein, but also includes the whey proteins, albumin and globulin.
Commercial milk replacers usually contain 20–24% protein. Young calves can only digest proteins of milk origin, such as those from skim milk and buttermilk powders. The degree of processing of these powders affects the calves’ ability to digest this protein.