Plasma and tissue fatty acid profiles of growing pigs fed structured or non-structured triacylglycerides containing medium-chain and marine oil fatty acids

Dietary structured lipids for post-weaning piglets: fat digestibility, nitrogen retention and fatty acid profiles of tissues

In four groups of post-weaning piglets the effects of triacylglycerol structure and fatty acid profiles of four dietary fats on apparent faecal nutrient digestibility, nitrogen retention and fatty acid profiles of platelet and erythrocyte membranes, liver, adipose tissue and skeletal muscle were examined. Dietary fats included as 10% (w/w) of the diets were two structured fats of rapeseed oil interesterified with tridecanoin (R1) or coconut oil (R2), respectively, one mixture of rapeseed oil and coconut oil (R3) and rapeseed oil as control (R4). Faeces and urine from piglets weaned at 28 days of age were collected quantitatively during three periods each of 5 days, in which the piglets were kept in metabolism cages for measurement of apparent faecal nutrient and energy digestibility and nitrogen retention. Apparent faecal fat digestibilities were significantly improved in groups fed interesterified fats or the physical mixtures (R1, R2 and R3) compared with rapeseed oil (R4). Apparent faecal nitrogen digestibility and retention were similar in all four groups in the three periods, but increased with time. Apparent faecal fat digestibilities were significantly improved from the first to the third week in the groups R1 and R2. Fatty acid profiles in platelet and erythrocyte membranes and in tissues reflected the fatty acid profile of the dietary fat, except for medium-chain fatty acids, which were only found in low proportions, indicating that 10:0 was mainly used as an energy source.

Effect of medium-chain fatty acid positional distribution in dietary triacylglycerol on lymphatic lipid transport and chylomicron composition in rats

The present study was carried out to examine if the positional distribution of medium-chain fatty acid (MCF) in dietary synthetic fat influences lymphatic transport of dietary fat and the chemical composition of chylomicrons in rats with permanent cannulation of thoracic duct. Four types of synthetic triacylglycerol were prepared: (i) sn-1 (3) MCF-sn 2 linoleic acid, (ii) interesterified sn-1(3) MCF-sn 2 linoleic acid, (iii) sn-2 MCF-sn-1(3) linoleic acid, and (iv) interesterified sn-2 MCF-sn-1(3) linoleic acid. A purified diet composed of equal amounts of the synthetic fat and cocoa butter was given to rats with permanent lymph duct cannulation. The positional distribution of MCF in the dietary fat had no significant effect on the lymph flow, triacylglycerol output, phospholipid output, lipid composition of chylomicrons, or the particle size. The positional distribution of MCF in the synthetic triacylglycerol was maintained in the chylomicron triacylglycerol. These results showed that MCF in the dietary triacylglycerol is transported into lymphatics and the positional distribution is well preserved in chylomicron triacylglycerol.

Structured triacylglycerol containing medium-chain fatty acids in sn-1(3) facilitates the absorption of dietary long-chain fatty acids in rats

A study was carried out to examine if the positional distribution of medium chain fatty acids (MCF) in triacylglycerol influences dietary fat absorption in rats. Two types of structure-specific fats, one predominantly composed of MCF in sn-1(3) and iinoleic acid in sn-2 [sn1(3)MCF-structured] and the others of MCF in sn-2 and linoleic acid in sn-1(3) [sn-2MCF-structured], were initially prepared, and the two structure-specific fats were interesterified and designated as sn-1(3)MCF-interesterified and sn-2MCF-interesterified. Synthetic fat was mixed with an equal amount of cocoa butter (103 g/kg of diet) and was supplemented to the AIN93G-based diet. Rats were fed on the diets for 4 wk. Long-chain saturated fatty acids were the predominant fatty acids excreted into the feces, and the positional distribution of MCF resulted in an altered fat absorption rate (%) of 81.8, 82.5, 84.2 and 86.3 for the rats fed on the diets containing sn-2MCF-structured, sn-1(3)MCF-interesterified, sn-2MCF-interesterified and sn-1(3)MCF-structured fats, respectively. The proportion of MCF in the serum, liver and adipose tissue triacylglycerols was not affected by the MCF distribution of the dietary fats. These results indicate that the distribution of MCF in dietary triacylglycerol is a determinant of intestinal fat absorption.

A preliminary study on the effect of dietary supplementation with cod liver oil on the polyunsaturated fatty acid composition of boar semen

Eight mature Norwegian Landrace boars, of proven fertility and in routine semen production for AI, were fed individually with the same basic diet for 9 weeks. One group of 4 animals served as the control, the remaining 4 boars received a daily supplement of 75 ml cod liver oil (CLO-group). Fifteen consecutive semen samples were collected from each boar. The fatty acid composition of the semen was determined, and the content of the 15 most numerous fatty acids with a chain length longer than 12 carbon atoms was followed over time. In both groups, the proportion of 16:1n-7 decreased significantly, while 16:0 and 22:6n-3 (DHA) increased. By the end of the experiment, DHA had tended to increase and 22:5n-6 to decrease to a greater extent in the CLO-group. A significant difference between the groups was seen for one n-6 PUFA (22:4n-6), which remained unchanged in the control group but decreased in the CLO-group. No change was seen in docosapentaenoic acid (22:5n-3) and eicosapentaenoic acid (20:5n-3) was not found in any sample. These results indicate that CLO supplementation affects the fatty acid composition of boar semen. There were no significant differences in the non-return rates (4-25 days) between the two groups before, during or after the experiment.