Abstract
The influence of under-nutrition (sub-maintenance feeding) and ad libitum feeding on the deposition of proteins in different Subcellular Sarcoplasmic fractions of red (tonic) and white (phasic) muscles of growing broilers was investigated. The relative concentration of overall Sarcoplasmic proteins was lesser in red than in white muscles from ad libitum fed broilers. The content of mitochondrial proteins was slightly more and that of lysosomal and microsomal proteins and of true soluble proteins was lesser in red than in white muscles. Besides, the relative amount of some specific molecular weight proteins in each Subcellular fractions differed by more than 50% between red and white muscle.
There was also conspicuous differences in the influence of under-nutrition on the proteins in red and white muscles. Some reduction in mitochondrial, lysosomal, microsomal, and soluble protein content occurred only in white muscle, whereas little change was found in Subcellular fractions in red muscle from underfed broilers. The relative amount of some proteins in each Subcellular fraction of both muscles remained unaffected, and that of others either decreased or increased more than 20 to 50% due to nutritional stress.
