Milk replacers are fed to baby mammals instead of whole milk either for economic or health reasons, to prevent spread of disease through mother’s milk, or as an emergency substitute for mother’s milk when she is deceased or is not providing adequate milk. The milk replacer formula must furnish the nutritional needs of baby mammals during this critical early period of its life. Generally, milk replacers approximate the specifications of the mother’s milk of the species being fed.
Crude protein levels of milk replacers vary from 18 to 28% and from species to species. Obviously, dried dairy products are the basis of all milk replacers, since in most cases, commercially available dried milk products from other species do not exist.
The fat levels in milk replacers are extremely important. Fat reduces the incidence of scours, provides extra energy under conditions of stress, improves hair coat and general appearance. Today, most quality calf milk replacers contain at least 15-20% fat levels. During extreme weather conditions, higher levels of fat (25-30%) can be helpful in maintaining weight gains. Either a higher fat level in the milk replacer or additional fat supplement can provide the extra energy.
Crude fiber level is an important gauge of determining the quality of milk replacer. Generally, the higher the percentage of milk products, the lower the fiber content of the product, but check the list of ingredients on the feed tag. An all milk and fat formula is usually rated at 0.15% crude fiber. However, there are some low fiber, non-dairy ingredients that do not affect the guarantee. Solubility and settling are other indications of non-soluble, vegetable protein.
The lactose level of milk varies by species. Some baby mammals may even be intolerant of high levels in milk replacers. Generally, lower lactose levels are present in higher protein and/or higher fat content milk.
Milk Replacer Ingredients
Milk & Whey Proteins & Carbohydrates
Since all baby mammals digestive systems are designed to function best on milk, it is essential to obtain as much protein as possible from milk and whey products. The best sources of proteins and lactose for milk replacers are spray-dried whole milk, milk protein concentrates and isolates, skimmed milk, buttermilk, whey protein concentrates and isolates, and other whey products.
The protein source is always more important than the amount of protein for all animals. Dairy and whey proteins are usuallly more expensive than vegetable or animal protein substitutes. Availability and economics dictate that most of the proteins and carbohydrates in milk replacers are derived from whey proteins since they have been shown they can be as digestible to newborn calves and other mammals as milk.
Recognized substitutes for milk and whey proteins in milk replacers are dried animal plasma and soy proteins – soy protein isolate, soy protein concentrate and soy flour. Generally, after the first few weeks of life, soy proteins become more nutritionally useful to a baby animal.
Other proteins such as dried meat solubles, eggs, dried fish and wheat proteins are less satisfactory for baby mammals. Animal plasma is usually used as a source of immunoglobulins instead of a primary protein source. Wheat protein concentrates and dried eggs are best used in finishers for older animals. Vegetable proteins are dispersible, not soluble, and will quickly precipitate from water based solution.
Specialized, homogenized animal fats are the preferred energy source for replacement and beef calf milk replacers. Edible lard is used because of its consistency, palatability, light color, low melting temperature and low odor. High quality vegetable fats such as coconut and palm oil aid digestibility and accelerate weight growth.
The ideal carbohydrate for baby mammals is lactose derived from milk and whey products. Other sugars from vegetable sources are less digestive and may contain anti-nutritional factors affecting young animals.
Milk Replacer Fortifications
Vitamins A and D3, fat soluble vitamins, are the most critical to a milk replacer formula. Our standard calf milk replacers contain 32,000 and 12,000 IU per pound of these, respectively, several times the minimum levels of the National Research Council.
It is recognized that at least 100 IU per day of Vitamin E results in increased immune response in calves. Higher levels of Vitamin C (ascorbic acid) can aid this response. B-vitamins are also supplemented in our milk replacers.
We fortify our milk replacers with chelated trace minerals, the most soluble and utilizable form of these vital elements necessary for good health but not present in whole milk, as well as selenium yeast and zinc proteinate. Calcium and phosphorus to approximate mother’s milk are also supplemented.
Neomycin sulfate/Oxytetracycline at treatment levels are being utilized. However, a current, signed Veterinarian Feed Directive (VFD) is required from the veterinarian of a feeder who wishes to purchase these medicated products.
Decoquinate (Deccox) and lasalocid (Bovatec) can be added to milk replacers for some species to prevent or control Coccidiosis (bloody sours).
ClariFly can be added to any otherwise medicated calf milk replacer formula for resale to prevent growth of fly populations in calf manure when temperatures are above 65°F.
The following ingredients are classed as nutraceuticals. That is, they are intended to enhance the health and well-being of an animal as well as being valuable for their nutritional value. Vitamins are also often included in this category.
Live strains of direct-fed microbials (DFM), such as Lactobacilli and others, can be added to milk replacer to establish colonies of beneficial bacteria in the animal’s digestive system displacing harmful bacteria and producing lactic acid to subdue pathogens.
Special carbohydrates called oligosaccharides (prebiotics) such as MOS (mannanoligosaccharide) and FOS (fructooligosaccharide) promote growth of existing colonies of beneficial bacteria in an animal’s digestive tract. Since oligosaccharides are not live organisms, they are not directly affected by heat, pelleting or medications, as are DFM.
Organic acids to lower pH, creating an environment hostile to harmful bacteria in the digestive system can help prevent scours. There is a synergy combining DFM with prebiotics and/or acids for scours protection. Higher levels of acids and food preservatives can also prevent spoilage of mixed milk replacer formula for up to 24 hours for free-choice and automatic feeding systems.
Immunoglobulins present in colostrum impart initial, essential immunity from disease for newborn mammals when fed immediately after birth. Subsequent supplementation may be less effective, but still valuable when challenged by the stresses of the animal’s environment. Supplemental sources of immunoglobulins are specially dried bovine colostrum, inoculated eggs, animal plasma, milk or whey protein concentrates and isolates.
Roughage Products and Herbals
Special insoluble fibers, described as roughage products, can help slow the elimination process when baby animals are scouring. Herbals such as garlic or oregano and other herbal blends have also been used to promote growth and lessen disease symptoms with varying degrees of success.
Active, live yeast cells (Saccharomyces cerevisiae) can be added to milk replacers, prestarters and starter feeds to enhance health and promote growth of young animals. To be used in milk replacers they should be soluble and highly concentrated, without fibrous media.
Stressed animals, especially those with diarrhea, lose vital electrolytes, become dehydrated and often die. A soluble combination of sodium, potassium and magnesium along with a source of energy such as sugar or milk replacer can reverse this loss and multiply the effectiveness of the electrolytes.
A recommended level of 5% dried animal plasma in milk replacers and starter feeds has been shown to provide additional immunoglobulins beneficial in preventing disease.
Treated Egg Proteins
Dried, treated egg yolks produce immunoglobulins for those diseases for which they have been innoculated.
Sodium Butyrate, a source of Butyric Acid found in butter but low in calf milk replacers and starters, when added can aid the immune system, metabolism, scours prevention and increase daily gain.