Effect of whole linseed (Linum usitatissimum) in the diet of finishing pigs on growth performance and on the quality and fatty acid composition of various tissues

Pigs (n 144, 30 kg liveweight) were allocated to one of three diets differi ng in the level of whole linseed (Linum usitatissimum, also known as flaxse ed). The diets contained 0, 50 and 100 g/kg for diets L0, L50 and L100 resp ectively, while containing a constant oil content (60 g/kg). Pigs were slau ghtered at a liveweight of 77-87 kg. With the exception of a slight differe nce in feed intake, there was no effect of diet on production characteristi cs or carcass traits. Levels of cr-linolenic acid were increased in all tis sues studied as the amount of linseed in the diet increased. In the plasma, m. longissimus thoracis, liver and kidney eicosapentaenoic acid concentrat ion increased markedly. Docosapentaenoic acid concentration increased in th e muscle, liver and kidney, whereas in the plasma higher levels of docosahe xaenoic acid were observed. None of the longer chain fatty acids (C20 or lo nger) were detected in the subcutaneous fat. The changes in fatty acid comp osition resulted in marked changes to the n-6: n-3 and arachidonic: eicosap entaenoic acid ratios. Feeding whole linseed had no negative effect on the oxidative stability of the meat. Sensory panel results showed no significan t differences by diet except for a reduction in abnormal odour (odour perce ived by panellists to be abnormal in pigmeat) in the L50 diet and a reducti on in the skatole odour (odour of 3-methylindole) in the pigs fed on diet L 100. It is concluded that increasing the linseed content of pig diets up to 100 g/kg has no adverse effect on the carcass or meat quality whilst enhan cing the levels of n-3 fatty acids which have a potentially positive health effect in man.