**2.1. Preparation of experimental diets**

Feed ingredients were purchased from a reliable store Melbourne, Australia. *Lactobacillus acidophilus* ATCC 4356 was obtained from a laboratory and prepared into 0, 101 , 102 , 103 , 104 and 105 cfu/mL (**Table 1**). Soya bean was further prepared by toasting in a hot plate for 15 min at 100°C. Ingredients were ground in hammer mill and mixed together to formulate 43% crude protein (**Table 1**) calculated according to Pearson Square Method [9]. The mixed ingredients were pelleted through pelleting machine. The feeds were packed in polythene bags and stored in a cool dry place at room temperature until use with labels on them. The crude proteins of the ingredients were: fish meal (72%); toasted soybean (46.2%) and white maize (9.3%) [10]. The feeds were reproduced after 21 days to avoid nutrients depletion.
