EFFECTS OF AUTOCLAVING, SODIUM HYDROXIDE ADDITION AND THEIR COMBINATION ON PROTEIN AND AMINO ACID CONTENTS AND PEPSIN DIGESTIBILITY OF CHICKEN FEATHERS  

Ahmed Al-Sooti1*, Wenresti Gallardo, Michel Claereboudt and Osman Gaafar
*Corresponding author: A. AL-Sooti, Department of Marine Science and Fisheries, College of Agricultural and Marine Sciences, Sultan Qaboos University, PO Box 34, Al-Khod 123, Muscat, Sultanate of Oman. E-mail: souti@squ.edu.om  Tel.: +968 24141211  Fax: +968 24413418

Feather waste at poultry processing plants has been of interest in nutritional studies because of its high protein content. For it to be useful on feed ingredient, it must be treated to be digested by the animals. The aim of this study was to determine the effects of two types of treatments (NaOH addition and autoclaving) on the protein, amino acid contents and pepsin digestibility of chicken feathers. The first experiment consisted of the following treatments: 1) 2-h treatment with 50ml of 1.0N NaOH, 2) 12-h treatment with 50ml of 1.0N NaOH, 3) 24-h treatment with 50ml of 1.0N NaOH and 4) control which was raw feathers incubated with only 100 ml of distilled water for 24 h at 37°C . The second experiment consisted of the following: 1) raw chicken feathers autoclaved at 2.5 kgf.cm-2, temperature of 121°C for 30 minutes; 2) raw chicken feathers soaked in 0.5% NaOH solution for 24 hours, followed by autoclaving at 2.5 kgf.cm-2, temperature 121°C for 30 minutes. The results indicated that prolonged treatment (24 h and 12 h) with NaOH improved feather solubility but low protein retention, whereas NaOH addition followed by autoclaving resulted in high protein and amino acid contents, pepsin digestibility, and in vitro amino acid digestibility.