IMMUNOLOGICAL TOLERANCE TO DIETARY ANTIGENS: APPLICATION TO THE NUTRITION OF PRE-RUMINANT CALVES

Abstract

Replacing milk proteins with vegetable proteins, particularly soybean, in the diets of pre-ruminant calves has been shown to result in poor performance. This has been related to the negative effect of these vegetable on digestion and absorption, which is said to be due to the antigenic effects of these 'foreign' proteins. Different methods have been used to induced immunological tolerance to dietary antigens. The success of these methods depends on the number of factors including those related to the host species immunocompetence level (maternal factors), and those related to the antigen (nature of the antigen, dose and method of administration). The application of some of these methods to pre-ruminant calves fed soybean proteins has not yielded the desired result. This may be partly due to the fact that the immunoregulatory mechanisms involved when calves are fed such vegetable proteins are not yet fully understood.