The use of oleic acid-rich sunflower seed in diets for growing pigs : effects on backfat quality

Oleic acid-rich sunflower seed contains much lower levels of linoleic acid than ordinary sunflower (about 30-50 vs. 300 g/kg).The use of this type of sunflower has no negative effect on carcass fat quality.One hundred and sixty pigs were used to compare four iso-energetic and iso-protein diets : TEM : without sunflower seed, TC4 : with 4% ordinary sunflower seed, TO4 : with 4% oleic acid-rich sunflower seed, TO8 : with 8% oleic acid-rich sunflower seed.The linoleic acid content was 19.7, 8.1, 9.3 and 10.5 g/kg. for the TC4, TEM, TO4 and TO8 diets, respectively.No significant differences were observed between the four treatments for growth performance and carcass characteristics.However, the TC4 diet produced carcasses with a high level of linoleic acid (15.5% of the identified fatty acids) in the backfat tissue, which was equal to the maximum recommended level of 15%. The two diets with oleic acid-rich sunflower seed (TO4 and TO8) gave linoleic acid levels of 8.41 and 8.52%, which were not significantly different from those produced by the TEM diet (7.65%). These types of levels ensure good fat quality.The fatty acid unsaturation coefficient did not differ significantly between TEM, TO4 and TO8, respectively 1.19, 1.19 and 1.18 ; but it was significantly higher with TC4 (1.33). Stearic acid levels produced by the TO4 and TO8 diets were significantly lower than those produced by the TEM and TC4 diets, however they were higher or equal to the recommended minimum level of 12%.The results confirm that oleic acid-rich sunflower seed can be used at an inclusion rate of 8% in growing pig diets, without jeopardising the fat quality of dry cured pork products.