Md. Arefin Rahman, Chutima Tantikitti, Naraid Suanyuk, Teerapun Talee, Bullika Hlongahlee, Sudarat Chantakam, and Manee Srichanun

DOI: 10.14456/sjst-psu.2021.128

pp. 976 - 986

Abstract

An experiment was conducted using factorial (3×4) in completely randomized design to examine incorporation of
vegetable oils in diets on seabass growth, fatty acid profile, digestive enzyme activity and immune responses. Ten isonitrogenous and iso-lipidic diets were formulated to have soybean, palm and sunflower oil replacing fish oil (FO) at 0%, 25%,
50% and 75%, respectively. Each diet was fed to quadruplicate fish groups (3.29±0.30g initial weight) for eight weeks. Results
revealed interaction effects between oil types and replacement levels on diet consumption among the feeding groups. Fish growth
and immune parameters were not affected by oil types (p˃0.05), but final weight, specific growth rate, white blood cell and
serum protein were altered by replacement levels (p<0.05). Carcass protein and lipid were influenced by oil types and
replacement levels. The highest and lowest carcass protein content was observed in fish fed diets having 75% and 25% soybean
oil, respectively while the rest of the feeding groups were similar to the control group. Fatty acid profile of fish carcass reflected
oil sources. The ratio of α-linolenic acid (18:3n-3) and linoleic acid (18:2n-6) was similar to those fed 100% FO containing diet
and 25% palm oil replaced diet. Specific trypsin and lipase activity were affected by oil types and replacement levels in intestine
and pyloric caeca, respectively. Diets replaced with soybean and palm oil showed similar results in intestinal specific trypsin
activity. The highest specific lipase activity was detected in fish fed 100% FO containing diets followed by 25%, 50% and 75%
FO replaced diets, respectively. Therefore, soybean or palm oils can replace FO at 25% in Asian seabass diet without
compromising growth and health status.