Abstract
The aim of this research was to evaluate the nutritional value of brown marine algae (BMA) as affected by different processing methods as a feedstuff for chicken diets. Brown marine algae (Sargassum dentifebium) were cultivated from Jeddah Red Sea shore. BMA was first sun-dried (SBMA) at average day temperature of 40 degrees C until constant weight. Then, a part of the SBMA was processed by boiling (BBMA) in water (1 part algae at 45 degrees C for 4 part water) for 20 min. Another part of SBMA was processed by autoclaving (ABMA) under 115 bar/inc for 15 min. The BBMA and ABMA were then air-dried at 45 degrees C for 48 h until constant weight. Brown marine algae contained protein 7.54-7.77%, crude fat 0.41-0.47%, crude fibre 7.77-7.90%, ash 47.15-48.31%, nitrogen free extract 29.95-31.38% and soluble sugars 1.666-1.880% whereas the metabolizable energy (ME) value was 1523-1543 kcal/kg. Nature detergent fibre ranged from 27.95 to 30.21%, acid detergent fibre from 21.18 to 23.54% and hemicellulose from 6.41 to 7.73% whereas tannins ranged from 0.733 to 0.815 mg/g protein. Mineral contents of BMA were Ca 0.126-0.144%, P0.239-0.255%, Na 4.01-4.05%, Zn 215-345 ppm, Mn 216-270 ppm, I 12.72-13.51 ppm, Fe 11.2-11.5 ppm and Cu 4.6-4.81 ppm. Valine (0.94-1.03%), leucine (0.88-0.96%), arginine (0.71-0.77%) and threonine (0.63-0.74%) were the most abundant essential amino acids (EAAs) in BMA processed by different methods. The contents of EAAs were 0.17-0.25%, 0.23-0.35% and 0.30-0.40% for methionine, methionine + cystine and lysine. The saturated fatty acids (SFA) were 32-54-35.90%, monounsaturated fatty acids (MUFA) 35.79-37.02%, polyunsaturated fatty acids (PUFA) 27.77-30.43% and unsaturated fatty acids (UFA) 64.10-67.46%. The SFA:UFA ratio was 0.482-0.560. It was concluded that BMA had a valuable nutrient profiles and could be used as a feed resource for poultry feeding.