Effect of Dietary Fats on Infection by Escherichia coli in Chicks. ∗ †

Abstract

Ross and Adamson (1) reported that chicks deficient in essential fatty acids (EFA) developed aspergillosis more readily than those fed a diet containing corn oil. Hopkins et al (2) reported that chicks fed an EFA-dencient diet developed a respiratory disease while those which received the diet supplemented with soybean oil did not. The causative agent of the disease was not identified. Nagai et al (3) showed that EFA-deficient mice were susceptible to bacterial infections but added linoleate conferred protection. Dubos(4) reported peanut oil increased survival of tuberculosis-infected mice, while Hedgecock(5) found olive oil to be ineffective against that agent compared with coconut oil. The experiments reported here were conducted to determine if the EFA-deficient chick is more susceptible to E. colt infection than chicks given diets supplemented with various oils of widely varying fatty acid content and to determine the comparative activity of purified fatty acids.

Experimental. White Plymouth Rock chicks from flocks of the Poultry Disease Research Center were selected at random and placed in wire-floored electrically heated batteries. All chicks were fed the prescribed ration from the time of hatching. The basal ration was a casein-gelatin-cerelose diet described by Edwards(6). Supplementary oils: coconut, corn, menhaden and linseed, were added at the rate of 2%. The fatty acid composition of these oils as determined by gas-liquid chroma tography is shown in Table 1(7). Methyl oleate (18:1) or methyl linoleate (18:2) were added at the 1% level, approximately the amount present in the corn oil diet. The methyl oleate was prepared from olive oil by low temperature crystallization(8) and the methyl linoleate by the urea adduct method (9). The methyl oleate was 98% pure, containing traces of myristic acid, palmitic acid and palmitoleic acid.