It is probable that the degree of saturation of fat may modify the response to increasing Free Fatty Acid (FFA) content and of apparent metabolisable energy (AME). The objective of the current study was to investigate the effect of FFA content on the AME value of soya bean oil.

Soya bean oil (A) and soya bean acid oil (E) with FFA content of 14.4 and 683.4 g/kg fat respectively and of similar fatty acid composition, were obtained for evaluation (Table 1). Fats A and E were then mixed in proportions 75A:25E, 50A:50E and 25A:75E to give three blends of calculated FFA content of 181.7 (B), 348.9 (C) and 516.2 (D) g/kg fat respectively. All fats were included into a basal diet (Table 2) at 40, 80 and 120 g/kg and were evaluated with broiler chicks aged 1.5 weeks and 7.5 weeks of age. Apparent metabolisable energy (AME) values of fats was achieved by regression of apparent fat availability (AFA) on rate of inclusion of fat with extrapolation (linear functions). AME was determined as a product of AFA and fat gross energy.