Interaction between Dietary Protein/Amino Acid Level and Parasitic Infection: Morbidity in Amino Acid Deficient or Adequate Chicks Inoculated with Eimeria Acervulina

Abstract

In a series of experiments designed to assess the chick’s sulfur amino acid (SAA) requirement during acute coccidiosis, a striking and unexpected infection × SAA interaction was discovered. When chicks were fed diets severely deficient in SAA, Eimeria acervulina infection produced a marked growth response, while birds consuming SAA-adequate diets exhibited the expected severe growth depression when given the same dose of E. acervulina oocysts. Although the interaction was originally demonstrated in birds fed crystalline amino acid diets, it was subsequently demonstrated with intact protein diets as well. The interaction was also shown not to be unique to the SAA. Thus, lysine and E. acervulina interacted in the same manner. In fact, when birds were fed diets severely deficient in lysine, E. acervulina infection brought about a doubling of both rate and efficiency of weight gain. It was also established that the growth response to infection resulted from E. acervulina per se and not from any other component of the infective inoculum.Sulfur amino acids lysine Eimeria acervulina coccidiosis