What different dairy proteins can be found in calf milk replacers?
The dairy proteins in calf milk replacers may have been extracted from whey left over after cheese production, skimmed milk or from the caseinate left over after butter making. “All three of these sources of protein have different characteristics in the abomasum of the calves,” explained Hennes. “Whey proteins are tiny molecules, pass quickly through the small intestine and are easily and quickly digested.” The proteins from skimmed milk comprises 80% casein protein, a large molecule that requires a predigest ion stage via clotting in the abomasum under the influence of renin, before it can be absorbed in the small intestine. Digestion is therefore gradual. Caseinate is casein protein which has already undergone a predigestion stage during the processing in the factory. It does still coagulate in the abomasum and the digestion profile is somewhere between that of whey and skimmed milk.
Which protein is best?
In the various trials we carried out, no differences were discovered in calf growth and health when comparing feed with the same nutritional values. Which type of calf’s milk powder is therefore most suitable? It depends on the health status of the farm and the preferences of the dairy farmer. In the case of unlimited feeding via buckets or via an automatic drink dispenser, calves will take up smaller portions of milk spread over the day. In these cases, a milk powder based on caseinate or whey is ideally suited. In the case of bucket feeding whereby the animal receives a large volume of milk two times a day, a milk powder based on skimmed milk can deliver excellent results, because that large volume of milk is then gradually digested. However, the question also relates to the health status of a farm. On farms with healthy calves, that have received good colostrum and where the infection burden is low, bucket feeding of large quantities of caseinate or whey based milk is suitable. The best choice depends therefore on the farmer’s experience!
How do you know which protein is used in your calf milk replacer?
“Check out the label on the bag,” recommends Hennes when dairy farmers are looking to identify the milk powder that best suits them. “The highest volume ingredient in the milk powder is listed first. Or consult your feed advisor or the young stock specialist!”