Table 4.

Digestive enzymes activity in the gastrointestinal tract of red hybrid tilapia after 12 weeks of feeding trial. Data are presented in mean ± SEM, n = 6 fish per treatment. Different superscripts in each row indicate a significant difference (p < 0.05).

(U/mg protein)	Diet
	0%	0.50%	1%	2%	4%
Protease	3.370 ± 0.549a	3.525 ± 0.564a	3.425 ± 0.366a	2.445 ± 0.316a	4.865 ± 0.135b
Amylase	0.286 ± 0.037	0.310 ± 0.018	0.307 ± 0.076	0.333 ± 0.071	0.308 ± 0.025
Lipase	47.065 ± 6.474a	44.427 ± 9.836a	68.987 ± 3.591b	35.781 ± 2.328a	46.548 ± 4.113a