by Wayne O. Hagen, DVM, PhD

Calves are born with the proverbial “2 strikes against them.” Strike 1: It is common knowledge that cows pass no disease resistance to the calf in utero prior to birth. Strike 2: This means calves are born without resistance to antigens in their environment and in turn, all antigens have the potential to cause disease and even death in the newborn calf. Even those antigens not usually considered to be pathogens.

Calves are actually born with a relatively mature immune system, able to respond to antigenic stimulation. But under the very best circumstances it takes at least three weeks for calves to produce their own antibodies against environmental pathogens. This is where colostrum becomes important!

When a calf is fed colostrum from a cow housed in the same general environment as the calf, for a minimum of three weeks prior to freshening, antibodies resistent to these pathogens are generated. It takes this long to develop the necessary antibodies based on the location she will be residing during her lactation. In the case of newly purchased cows or those raised on a different farm, it is necessary to move these cows at least three weeks prior to freshening. Therefore, our goal is the development and management of high quality colostrum.

Often times the first question that is asked is when, how much and how should colostrum be fed. The answer is early, a lot and in anyway it effectively gets into the calf. The earlier colostrum is fed the better! Calves acquire a load of oral pathogens shortly after birth and if immunoglobulins from colostrum are present when exposure occurs, the antibodies will more effectively neutralize them.

Calves have the ability to absorb antibodies for 24 hours after birth but the efficacy declines rapidly, dropping to 50% absorption 6 hours post birth, 33% absorption 8 hours after and essentially 0% 24 hours after birth. Antibodies fed the first 24 hours of life persist for at least 5 days in the gut, while the same antibodies do not persist when fed on day two. Absorbed antibodies are slowly released from the systemic circulation into the intestine, providing protection against enteric pathogens. The more antibodies absorbed the more available for intestinal release.

The quantity of colostrum to feed is also important and really depends on quality, to some degree. The calf requires 150 to 300 grams of immunoglobulin for protection against enteric disease. If a high quality colostrum is available it can, in theory, be fed at a lower rate but quality is difficult to measure.

The most practical determination of amount to feed is to choose colostrum from healthy cows and feed an appropriate amount

The average Holstein calf should receive 1 gallon of colostrum as soon after birth as possible. It is essential for this to be the first colostrum from a cow that has not leaked milk before calving.

The calf should be fed approximately 15% of its body weight in colostrum by 24 hours of age. A 90 pound Holstein calf, for example, should be fed 1 gallon or 8 pounds within one hour of birth, at 12 to 24 hours of age should be fed another 3 quarts of colostrum. Colored breed calves should receive proportionately less. These levels will not cause diarrhea and apparently cause the calf no discomfort.

It is best to feed the calf from a nipple bottle or pail to appetite and feed the remaining portion with an esophageal feeder. Calves fed the entire gallon with an esophageal feeder had a higher death loss than when fed to appetite with a nipple bottle first. Calves sucking the cow only consume on average about 2.5 quarts of colostrum in the first 24 hours, an inadequate quantity for good passive protection.

A colostrometer can be used to measure the quality of colostrum by analyzing the specific gravity of the colostrum, at or above 68 degrees F. If the specific gravity is 1.050 or greater the colostrum contains at least 50 grams/quart of immunoglobulins and should be of adequate quality.

Colostrum substitutes and supplements are available and beneficial but do not take the place of good quality colostrum. ANC's Calf Power Plus contains the supplement Protimax, which has proven quite successful. Protimax is a hyperimmunized spray dried egg product containing antibodies against several of the most pathogenic of the enteric microorganisms. This product contains immunoglobulins against most of the major pathogens.

If, despite all of your best management, the calf still develops diarrhea treatment is required. In the past we have used oral and systemic antibiotics, but their use may be contradicted.

Antibiotics are necessary if systemic infections are present. However, antibiotic use needs to be evaluated on a case by case basis. Electrolytes are a necessary component of treatment. Formulas with a strong ion difference are best, there are several of these on the market. In the past we have removed milk from the calf and fed only electrolytes. This recommendation has changed and milk is generally fed at the standard level. This leads to less weight loss and more rapid recovery.

Your ANC representative can furnish additional details concerning management and other supplemental products.