Nutrition and Biochemistry of Survival During Newcastle Disease Virus Infection

Abstract

Cockerel chicks conditioned with diets containing protein ranging from deficient, balanced and imbalanced to surfeit were infected with Newcastle disease virus at 28 days of age. Liver DNA averaged higher in the surfeit protein groups. RNA, protein and free amino acids in terms of DNA were highest in the birds provided normal levels of dietary protein. Changes in RNA generally were reflected in similar trends for protein and the free amino acids. Based on the data observed, it was postulated that protein metabolism was most efficient in birds provided dietary protein in ranges normally assumed to be within requirement. Highest mortality, attributed to double jeopardy, was observed in the deficient and surfeit groups. Significantly lower hemagglutination-inhibition (HI) antibody titers correlated with extreme protein deficiency. Mortality was independent of HI antibody titers and showed no apparent correlation with liver nucleic and free amino acid levels.