Current Progressive Dairy digital edition

Added IgG’s optimize a calf’s immune system

William Kautz Published on 21 September 2009
When the newborn dairy calf is immediately taken from its mother, there is a break of passive immunity that can compromise optimum immune system development.

Passive immunity is defined as protection from disease by the transfer of antibodies from one animal to another – in this case, from the cow to the calf.

This passive immunity is critical until the calf is older and can develop active immunity. There are two ways to address passive immunity – the use of high-quality colostrums and the use of specific immunoglobulins (IgG’s).



Good colostrum is typically defined as that with high specific gravity. High specific gravity is an indicator of the amount of IgG protein present in the colostrum. IgG’s are proteins produced by certain cells in the body.

Many, but not all, IgG’s act as antibodies in the animal. Antibodies are specific proteins that bind with potential disease-causing bacteria and viruses, making them incapable of causing disease. These antibodies reduce the calf’s chances of becoming ill or worse.

To boost passive immunity, dairymen have relied on high volumes of “good” quality colostrum administered to the calf within the first few hours after birth.

This practice has worked fairly well, but recent research and development by a Wisconsin company has demonstrated a program that can address passive immunity significantly by making the “best” colostrums even better with the addition of specific IgG’s.

Absorption of IgG’s in the first few hours of life is very important. However, IgG’s that are not absorbed are effective at binding potential pathogens in the gastrointestinal tract and upper respiratory tract. IgG’s can be delivered orally and intranasally at times when the animal is subjected to stress or exposed to potential pathogens with good effect.


Dr. Peter Nash of the Mach One Corporation has said: “All antibodies are IgGs, but all IgG’s are not antibodies.”

This means that high specific gravity colostrum may not always provide optimum protection to the young calf. He has also shown that a targeted “package” of IgG confers greater immunity than any targeted IgG given individually.

IgG’s are synergistic with each other. As is commonly thought, more is not better. The better the dairyman does in addressing passive immunity means a potentially better response to vaccinations that will be given later.

The program is designed to “bridge” the gap between passive and active immunity in the young animal by supplying targeted broad-spectrum IgG’s to keep the infective capability of potential pathogens at a low level in the gastrointestinal and respiratory tract while the animal is developing active immunity.

This can potentially reduce morbidity and mortality in young animals. The IgG’s used in this program are low-dose and designed only to prevent potential problems and not treat any “pre-existing” conditions.

The IgG supplement used at birth is given orally and contains broad-spectrum IgG’s that bind with a group of commonly encountered gastrointestinal bacteria and viruses. It also contains IgG’s against common viruses and bacteria that can infect and damage the respiratory system.


The second IgG supplement is an intranasal package of IgG’s given at birth, seven to 10 days later and at weaning or grouping. It is important to note that this IgG supplement is not a vaccine, which differentiates it from other intranasal products currently on the market.

It contains a targeted set of IgG’s designed to bind potential pathogens that are contracted by the animal through the upper respiratory tract, including viruses and bacteria. The supplement is sprayed into each nostril. The IgG’s mix with mucus in the upper respiratory tract.

When a potential pathogen is encountered, the mucus slows its passage into the body. The IgG’s then bind with the virus or bacteria, potentially rendering it harmless to the animal.

A powdered version of the IgG supplement technology can also be fed through milk or milk replacer during the first two to four weeks. These IgG supplements are designed to be part of a good calf management program.

Sanitation in the maternity and in the calf-rearing areas is still critical. The products are designed to address passive immunity and help bridge the gap to active immunity. They do not replace the use of high-quality colostrum at birth but are designed to improve high-quality colostrums and address immunity in healthy calves.

Overall effects seen when using these types of supplements in a calf-rearing system will likely be a significant reduction in morbidity and mortality. Calves that are not immune-compromised when they are very young will likely grow faster, becoming more productive members of the herd.

If they are born healthy and remain healthy through growth and development, they are much less likely to have problems when they do become part of the milking herd. They can become productive members of the herd earlier and remain productive longer. PD

Bill Kautz () is an independent consultant and veterinarian.