WHY FEED COLOSTRUM?
Beef calves and calves born in the wild do not have to be force fed colostrum and survive perfectly well; what makes a dairy calf so different? The main difference is the number of pathogens (disease causing organisms) in the calf’s environment. Calves born and raised in clean grassy paddocks face low levels of pathogens. Dairy calves born in muddy paddocks or barns where there are high stocking densities are exposed to very high levels of pathogens. This high pathogen exposure continues when the calf is transported to a calf barn; both the transport vehicle and the housing area are often highly contaminated with disease causing organisms which can overwhelm the calf’s immature immune system.
Question: Why do we feed colostrum?
Answer: We feed colostrum for disease prevention, nutrition and “other” benefits. This is necessary because calves are born without disease protection.
Question: Why can’t calves get this by suckling their dam?
Answer: The passive transfer conveyed by the amount of colostrum a calf is able to suckle is unlikely to give sufficient protection against the disease challenges modern calves face.
Question: Why is it so important that calves receive colostrum as soon as possible after birth?
Answer: The calf’s ability to absorb antibodies is highest in the first hour after birth and has dropped to almost zero by the time she is 24 hours old.
Question: What is in colostrum to prevent disease in calves?
Answer: Colostrum contains:
 maternal immune cells.
 antibodies (scientific name is immunoglobulins).
 “other” less well understood elements.
(c) HEIFERMAX 2008
Why feed colostrum?
 +61 3 64912636 Email info@heifermax.com.au

Question: What are maternal immune cells?
Answer: They are white blood cells. Their scientific names are:
 T and B lymphocytes that produce antibodies to attack infected and cancerous cells, and are responsible for rejecting foreign tissue.
 Neutrophils, white blood cells responsible for protecting the body against infection.
 Macrophages, responsible for removing waste products, harmful microorganisms, and foreign material from the bloodstream.
Question: How do maternal immune cells prevent disease?
Answer: They protect against disease by:
 Protecting against viruses, bacteria and parasites.
 Stimulating growth of the calf’s immune system.
 Orienting the calf’s immune system.
Question: What are immunoglobulins (or antibodies)?
Answer: They are:
 Immunoglobulin G (IgG – 88%), Immunoglobulin M (IgM – 7%), and Immunoglobulin A (IgA – 5%).
 Large protein molecules that float in colostrum.
Question: How do immunoglobulins or antibodies prevent disease?
Answer: They give:
 Systemic immunity – they go everywhere in the body.
 Septicemia immunity (especially IgM).
 Intestinal immunity to pathogens that cause scours (especially
IgA).
Question: What are the “other” elements in colostrum?
Answer: They are:
 Cytokines, which are proteins secreted by lymph cells, and which affect cellular activity and control inflammation.
 Immunomodulatory compounds such as interferon, which inhibits viral replication.
 Growth factors and hormones.
 “Other” unidentified compounds.
(c) HEIFERMAX 2008
Why feed colostrum?
 +61 3 64912636 Email info@heifermax.com.au

Question: How do these “other” elements prevent disease?
Answer: They do these things:
 Initiate growth of the immune system.
 Regulate activity of absorbed maternal immune cells.
 Enhance bactericidal effects.
 Protect intestine from bacterial colonization.
 Increase secretion of hormones that influence growth, secretion, and motility of the intestinal tract.
Question: What is in colostrum to provide nutrition for calves?
Answer: Lots!
 Twice the total solids of ordinary milk.
 Proteins (some that clot in the abomasum and others that go directly into the intestine for digestion.
 Mineral and vitamins important for initiating metabolism and development of the digestive system.
 Energy from fat and lactose. Compare milk at 2.88 kj/g (0.69
Kcal/g) in ordinary milk to colostrum with 4.85 kj/g (1.16
Kcal/g).
(c) HEIFERMAX 2008
Why feed colostrum?
 +61 3 64912636 Email info@heifermax.com.au