Influence of dietary linseed, fish and coconut oil on growth performance of growing pigs kept on small holdings in central Vietnam

The aim of the study was to investigate the effect on growth performance of the addition of 5% of either linseed, fish or coconut oil to the diet of growing pigs kept on small holdings in central Vietnam. The diets were fed on six different farms; there were three animals per treatment per farm. The farmers fed a base diet according to personal choice, but were instructed to use linseed, fish and coconut oil. The diets were fed to the pigs from 70 to 130 days of age. The diets with 5% linseed oil on average contained 2.4 g alpha-linolenic acid/MJ of metabolizable energy (ME) and the diets with 5% fish oil on average contained 0.06 and 0.75 g eicosapentaenoic and docosahexaenoic acid/MJ ME, respectively. The relative percentages of docosahexaenoic, eicosapentaenoic, alpha-linolenic and linoleic acid in adipose tissue were determined by the intake of the corresponding fatty acids. Dietary linseed oil vs. coconut oil significantly enhanced daily weight gain and vs. fish oil it also stimulated growth, but this effect just failed to reach statistical significance. It is concluded that extra intake of alpha-linolenic acid may stimulate growth in growing-finishing pigs, this effect being independent of the conversion of alpha-linolenic acid into eicosapentaenoic and docosahexaenoic acid.