Whole-body retention of α-linolenic acid and its apparent conversion to othern-3 PUFA in growing pigs are reduced with the duration of feeding α-linolenic acid

Abstract

In the present study, fifteen growing pigs were used to determine the whole-body oxidation, retention efficiency (RE) and apparent conversion (AC) of a-linolenic acid (18 : 3n-3) to n-3 highly unsaturated fatty acids (HUFA), including EPA (20 : 5n-3) and DHA (22 : 6n-3). The pigs were fed a diet containing 10 % flaxseed for 30 d. Whole-body fatty acid composition was determined at initial (27·7 (SE 1·9) kg), intermediate (day 15; 39·2 (SE 1·4) kg) and final (45·7 (SE 2·2) kg) body weight. On day 12, four pigs were fed 10 mg/kg of uniformly labelled 13 C-18 : 3n-3 (single-bolus dose) to determine the oxidation of 18 : 3n-3. Expired CO 2 samples were collected for 24 h thereafter. The wholebody content of n-3 PUFA increased linearly (P, 0·0001) with time; however, the content of 22 : 6n-3 exhibited a quadratic response (P,0·01) with a peak occurring at 15 h. As a proportion of intake, the RE of 18 : 3n-3 tended to reduce with time (P¼ 0·098). The AC of ingested 18 : 3n-3 to the sum of n-3 HUFA was reduced with time (P,0·05; 12·2 v. 7·53 % for days 0-15 and days 15-30, respectively). The AC of 18 : 3n-3 to 20 : 5n-3 or 22 : 6n-3 was lower than that to 20 : 3n-3, both for days 0 -15 (P,0·05; 1·14 or 1·07 v. 7·06 %) and for days 15-30 (P,0·05; 1·51 or 0·33 v. 4·29 %). The direct oxidation of 18 : 3n-3 was 7·91 (SE 0·98) % and was similar to the calculated disappearance of 18 : 3n-3 between days 0 and 30 (8·81 (SE 5·24) %). The oxidation of 18 : 3n-3 was much lower than that reported in other species. The AC of 18 : 3n-3 to n-3 HUFA was reduced over time and that to 20 : 3n-3 in the present study was much higher than that reported in other species and should be explored further.

Maternal Fish Oil Supplementation Affects the Social Behavior, Brain Fatty Acid Profile, and Sickness Response of Piglets

“…Furthermore, the brain FA composition of a piglet is similar to that of a human infant (28). Finally, as in humans (34), the whole-body conversion rate of ALA into DHA is very low in pigs (35), whereas recent evidence suggests that, in rodents, this conversion may be more efficient than in humans (36,37). Given the aforementioned similarities between pigs and humans, the pig seems to be a pertinent model to investigate the effect of maternal FA supplementation on the behavioral, immune, and brain functions of the offspring during early life.…”

Dietary Linoleic and α-Linolenic Acids Affect Anxiety-Related Responses and Exploratory Activity in Growing Pigs

“…The pig, an omnivorous animal with high cognitive abilities, which is easy to maintain under controlled conditions, makes a good new alternative model to rodents to evaluate the effect of dietary manipulations on behavioral variables (25). In addition, as in humans (26), the conversion of ALA into DHA is very low in pig (27). In contrast, there is recent evidence that, in rodents, wholebody conversion of ALA into DHA is higher than originally predicted and more efficient than in humans (see reference 28), suggesting that the pig might be a better model than rodents for the investigation of dietary FA modulation.…”