Changes in Docosahexaenoic Acid (DHA) Content in Longissimis dorsi and Backfat Tissue of Finishing Pigs Given Diets Containing 1% Heterotrophically-Grown Algae during the Last 28 Days

Consumer focus on nutritional value of pork and other animal products has driven industry interest in improving fatty acid (FA) profiles by providing dietary fat sources high in omega-3 long chain FA, particularly DHA. The objective of this study was an evaluation of tissue DHA content and performance of pigs fed either 0 or 1% algae (1.6 g DHA/kg feed) for 28 days before slaughter. A total of 144 pigs (PIC x Goland, 72 females and 72 castrates; average weight 117.1 ± 13.1 kg were assigned by sex and weight to pens of 6 to provide 12 pens per treatment. Diets were pelleted and fed ad libitum. The test diet contained 1% unextracted <i>Aurantiochytrium limacinum</i> CCAP 4087/2 algae (FORPLUS^TM, Alltech Inc). Average daily gain (ADG) and feed efficiency (feed:gain) were calculated for days 0-28 on all animals using pen as the experimental unit. At study end carcass characteristics and tissue DHA content if 72 animals (36 per treatment, half females and half males) were evaluated. Fatty acid profiles of Longissimus dorsi muscle (LD) and backfat were sampled from each right carcass at the 13^th rib. Daily gain, intake, and F:G were unaffected (P>0.05). No differences due to treatment in backfat and LD thickness, lean meat content and dressing % were noted (P>0.05). DHA increased from 0.009 to 0.0312 g/100 g tissue in treated animals (P&lt;0.001), while backfat DHA increased 0.0616 to 0.1924 (P&lt;0.001). There were no trt x gender interactions in DHA values, however values in females were numerically lower. It was concluded that 1% dietary FORPLUS^TM algae fed during the last 28 days can increase DHA content by >3 times control values in LD and backfat of finishing pigs. This increase makes possible production of added value pork products.