Calf Management

Posted in: Calf Management
Colostrum is Important
By Dr. Warren Bohnhoff, Veterinarian
Feb 21, 2009 - 9:45:17 PM

Perhaps one of the most important things you can do for a newborn calf to insure that it gets off to a good start is feed it colostrum soon after birth. The importance of colostrum has been documented in many studies and publications but continues to be overlooked or not completely understood by producers.

Some producers do not realize that when they lose a calf before weaning, they are not losing a $150 calf, but rather a valuable replacement heifer and progressive genetics. She could have been the next top cow of the herd. Giving calves passive immunity at birth by feeding colostrum can help insure that she lives through the first two critical months of life and reaches the milking string.

The sooner the better
As the calf's immunity system is not yet developed at birth, it is important to give them some type of passive immunity until their active immunity takes affect. The best form of passive immunity is colostrum at birth, which provides important immunoglobulins which help the calf fight disease.

A calf's ability to absorb immunoglobulins begins to decline immediately after birth. It is recommended to give a newborn calf (large breeds) two quarts of colostrum within half an hour of birth and another two quarts within twelve hours.

Absorbtion ability declines sharply after twelve hours, by up to 40 percent. Within 24 hours of birth the calf can no longer absorb immunoglobulins from colostrum.

Quality is important
The quality of colostrum is very important in determining the level of passive immunity the calf will receive. Typically, milk from mature cows will be of higher quality than first calf heifers. Appearance is a good way to judge the quality of colostrum.

A study has shown that calves fed colostrum of dams diagnosed with mastitis had lower mean plasma protein and immunoglobulins concentration at 10 to 24 hours after birth than calves fed non-mastitic colostrum.

If possible, it is a good idea to save quality colostrum from mature cows for calves born to young cows or cows diagnosed with mastitis at calving. Freeze in two quart containers for easy thawing. It is recommended to thaw the milk in warm water rather than microwave it. Studies have shown that microwaving colostrum can destroy some of the immunoglobulins.

No colostrum = higher preweaning death rates
Studies have shown that calves classified as having inadequate immunoglobulin (IgG) concentration within 24 hours of birth were at greater risk of preweaning morbidity and mortality as well as neonatal morbidity. In fact, the risk of death prior to weaning was five times greater for calves with inadequate passive transfer.

This study also showed that calves which experienced morbidity or mortality prior to weaning had the lowest concentration of blood immunoglobulins (IgG) and mean plasma protein. Morbidity during the first 28 days of life was associated with over a seven pound lower expected weaning weight and was indirectly associated with 24 hour passive immunity status.