Effect of Fish Oil on Growth Performance, Carcass Characteristics, Sensory Parameters, and Fatty Acid Composition in Pigs

Abstract

Abstract Thirty pigs averaging 10.3 kg were used to study the effect of fish oil supplementation as a means to enrich fat and muscle tissue with n-3 fatty acids and the effect of fish oil elimination five weeks prior to slaughter on the concentration of n-3 fatty acids in these tissues. The diets were barley-soybean meal based and contained either 3% soy oil (group A; control), 1% fish oil + 2% soy oil (groups B and C) or 3% fish oil (groups D and E). Pigs in groups B and D were fed the experimental diets until day 112 of the experiment, when they were switched to the control diet until slaughter at day 148. The other groups received the same diets throughout. Fish oil supplementation had no significant effect on growth performance or carcass characteristics. Fish oil increased (P < 0.001) the concentration of the fatty acids 20:5n-3, 22:5n-3 and 22:6n-3 in subcutaneous fat and muscle. This effect was dose dependent (P < 0.001) for subcutaneous fat. The level of the fatty acids 20:5n-3, 22:5n-3, and 22:6n-3 in subcutaneous fat and muscle was lower (P < 0.01) in groups B and D compared with groups C and E. The off-flavour and off-odour intensity of subcutaneous fat increased (P < 0.001) with increasing levels of fish oil in the diets. Thus, fish oil supplementation increased the level of n-3 fatty acids in muscle and fat tissue, and decreased the n-6/n-3 ratio. Feeding of 1–3% fish oil had an adverse effect on the sensory profile of the product, especially when used until the day of slaughter.