Introduction
In the United States, as well as other parts of the world, calves are fed using various nutrition plans and feeding systems to meet the growth, performance, and economic goals of the calf producer. Nutrition plans and feeding systems range from the traditional 1 pound per day of a 20% protein/20% fat milk replacer to 4 to 6 pounds per day of 22 to 28% protein and 18 to 14% fat milk replacer to other feeding levels of milk replacer, waste milk, returned milk, and/or other products. Growth, efficiency, and production cost of calves fed with these different programs vary widely. Regardless of the feeding program, several underlying nutritional principles need to be met to optimize calf performance and producer profit. This paper will attempt to identify and examine the key principles and available technologies to meet the nutritional needs of calves on milk. For the purpose of this paper, the term “milk replacer” will be used but can include other products such as pasteurized waste milk.
Basic Principles – Be Consistent
- Feed calves at the same time every day.
- Milk replacer mixing should be consistent in temperature, time, and concentration.
- Milk replacer feeding should be consistent in temperature and quantity.
- Mixing and feeding equipment should be cleaned on a consistent basis.
Why Feed at the Same Time?
Like many other animals, calves develop circadian rhythms that should be met by the calf feeder. If calves become used to being fed at 7 a.m. and 4 p.m., for example, hormones, enzymes, and even rumen protozoa become accustomed to feeding at these times. By feeding consistently at the same times, calf feeders can minimize stress and maximize performance of calves, regardless of what is being fed.
Milk Replacer Mixing
The three most important components of milk replacer mixing are a specific mixing temperature, a specific amount of time, and a specific final concentration. To ensure an accurate concentration on the final product, the components of the milk replacer must be weighed prior to mixing.
Different milk replacer manufacturers use diverse methods to make milk replacers. As a result, milk replacers from various companies have different mixing characteristics that need to be met. Some milk replacers are made by blending ingredients that were previously dried. Others are made by using heat to dry proteins on the outside of fats. Still others are made by using extreme cold to crystallize fat on the outside of protein. Ideal mixing temperature for a milk replacer depends on the method used for manufacturing. Dry-blended milk replacers can generally be mixed from 110° to 150°F; milk replacers with protein dried on the outside of the fat can generally be mixed from 120° to 140°F; milk replacers made by crystallizing fat on the outside of protein generally require mixing temperatures from 150° to 170°F.
The cow uses protein-encapsulated micelles to emulsify butterfat in milk, but milk replacer manufacturers must use emulsifiers to facilitate powdered fat mixing into water. Individual manufacturers use various emulsification systems to accomplish this. Also, the composition of the fat will affect the final mixing temperature for the milk replacer because the fats’ melting points will depend on their composition. For example, lard, tallow, and coconut oil have melting points of 97° to 113°F, 86° to 104°F, and 76°F, respectively. Calf feeders should pay close attention to manufacturer’s recommendation with regard to mixing temperature and mixing time to assure milk replacer has solubility, homogeneity, and high digestibility.
Ideally, calf feeders should add approximately 50 to 70% of the total water needed for a batch of milk replacer at the hot mixing temperature. Then the milk replacer powder should be slowly added while the mixer is running to avoid lumps. Milk powder should be weighed to assure desired nutritional levels. Next, the milk replacer should be mixed for 5 minutes; then cooler water should be added to meet the final volume and temperature of the mix.
Milk Replacer Feeding
Calves should be fed at the same time every day. Milk replacer should be mixed and fed according to manufacturer’s directions and always fed at the same temperature. This means that in winter, the final mix temperature should be warmer than in summer to accommodate the heat loss due to cold feeding equipment and colder ambient temperatures. What temperature should milk replacer be when fed? That seems to depend on where you live. Most U.S. manufacturers and textbooks recommend feeding temperatures from 101° to 107°F. European manufacturers recommend higher milk replacer feeding temperatures of 113° to 118°F because of improved sanitation and feed conversion. Regardless of the feeding temperature chosen, the temperature should be consistent. Use a thermometer. The amount of milk replacer fed should be accurate. Use a flow meter, a scale, or other weighing device to assure that calves are accurately fed milk replacer at every feeding.
Cleanliness is Next To…
The old adage says that “cleanliness is next to godliness,” but the reality in most calf operations is that cleanliness is next to impossible. To minimize disease transfer in calves from milk replacer mixing and feeding equipment, calf producers should follow a clearly defined set of cleaning procedures with regard to temperature, time and sanitizing agents. Generally, milk residue should be rinsed from equipment with warm water (110° to 120°F) to remove manure, dirt, and all milk residues. Rinsing with lukewarm water allows milk residues to rinse off the mixing and feeding equipment without becoming sticky and hard to remove. Use a thermometer to adjust rinse temperature to between 110° and 120°F every time you rinse. Next, clean equipment using a mixture of chlorinated alkaline soap and hot water (165°F). Chlorine dissolves proteins, and alkaline soap dissolves fat. Wear gloves and scrub all surfaces to remove protein, fat, and foreign materials that adhere to surfaces. Special brushes may be needed to clean nipples, bottles, esophageal feeders, floating nipples and feed buckets. At the end of the washing cycle, final temperature should be above 130°F to prevent scum from attaching to clean surfaces. Use a thermometer to adjust wash temperature to 165°F every time you wash. Rinse with cool water after cleaning. Once per week, clean with acid cleaner per manufacturer’s directions. Finally, rinse with an acid-sanitizing solution in warm water (70°F) per manufacturer’s directions. Acid final rinses reduce surface pH to less than 4 for up to 12 hours, which reduces the growth of bacteria. After sanitizing, allow equipment to dry completely, if possible, between uses. Dry surfaces also inhibit the rate of bacterial growth.
Source: Drew A. Vermeire, Ph.D., PAS, Dipl. ACAN, Nouriche Nutrition Ltd.,
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http://www.extension.org/pages/Technology_&_Nutritional_Needs_of_Milk-Fed_Calves