Effects of ground flaxseed in swine diets on pig performance and on physical and sensory characteristics and omega-3 fatty acid content of pork: I. Dietary level of flaxseed.

Forty-eight barrows and gilts were fed diets containing 0 (CO), 5, 10, or 15% ground flaxseed (FS) for the final 25 d before slaughter. Flaxseed treatments did not affect any production or carcass traits (P > .10). No pork processing problems due to lack of firmness were encountered. Amounts (milligrams/gram of tissue) of alpha-linolenic acid (ALA [18:3n-3]) and eicosapentaenoic acid (EPA [20:5n-3]) increased (P < .01) in both backfat layers and ALA increased (P < .01) in kidney (leaf) fat after FS. Alpha-linolenic acid and EPA increased (P < .001) in the raw belly in response to FS; the effect was maintained throughout processing (P < .01) to microwaved bacon. Alpha-linolenic acid and EPA increased (P < .01, P < .05, respectively) with amount of FS in longissimus thoracis and liver. In the brain, DHA decreased (P < .05) with amount of FS. Trained panelists in triangle tests were able to identify bacon from pigs fed 10 and 15% flaxseed. Panelists could not identify various treatments in the loin tests.