This is a common question that many people ask. In New Zealand the first few milkings, which is the most concentrated colostrum are reserved for the calves so they can take in important immune and growth factors needed for healthy growth and development. When a calf is born, their digestive tract is not fully mature and has “holes” in its intestinal wall. Colostrum contains large molecules that are only able to pass into the circulation of the calf due to these holes. However over a period of about 24 hours, the growth factors in the colostrum cause these gaps to close tightly and after this time no more colostrum can enter. At this point the value of colostrum for the calf has decreased significantly and colostrum collection begins.
For ethical and practical reasons (preservation of the herd) the calf’s needs must be met first. Companies that sell “first milking” colostrum are not being truthful in their claims. A cow produces significantly more colostrum than humans, so there’s plenty to go around after the calves’ needs are met!
Failure to take in a sufficient amount of good quality colostrum is major risk factor which can lead to death and disease in young calves. This first feed contains important antibodies or immunoglobulins necessary to provide the calf with protection from disease.
The most common conditions encountered from lack of colostrum are septicaemia and diarrhoea. It is essential that the newborn calf receives six pints of good quality colostrum within six hours of birth.