Protein quality is a long-accepted paradigm for human protein needs however the quality is affected with
processing methods. The protein and amino acids content of poached or charcoal or wood smoked horse
mackerel fish (HMF) were determined using standard methods. Chemical analyses were carried out on the
processed fillet and skin, head and bone (SHB) diets under standard conditions. A total of 40 weaned male rats
were fed with processed fillet or SHB diets for 12 days to assess protein quality and amino acids digestibility.
Fish samples were also analyzed for protein efficiency ratio (PER), net protein ratio (NPR), Protein Digestibility-
Corrected Amino Acid Scores (PDCAAS), true and apparent protein digestibility (TPD and APD). Results
showed that the wood smoked fillet had the highest PDCAAS regarding to the controls whereas PER, NPR and
TPD was highest in SHB. The best results were obtained from animals fed on coal or wood smoked fillet/SHB
on protein quality and amino digestibility parameters selective. The SHB could be used as a valuable source of
ingredients for animal feeds and human consumption instead of being discarded as agricultural waste.