Dietary alpha-linolenic acid increases the n-3 PUFA content of sow’s milk and the tissues of the suckling piglet.
Dietary alpha-linolenic acid increases the n-3 PUFA content of sow’s milk and the tissues of the suckling piglet.
Year: 2003
Authors: R P Bazinet, E G McMillan, S C Cunnane.
Publication Name: Lipids.
Publication Details: Volume 38; 1045-1049.
Abstract:
Data from animal and human studies supports the essential role that n-3 PUFAs play in normal growth and development. Deficiency of n-3 PUFA during early development results in visual and neurological dysfunction and may have adverse long-term effects. Supplementing the maternal diet during pregnancy and postpartum with the long chain PUFAs, EPA (20:5 n3) and DHA (22:6 n3), results in an increased n-3 PUFA status in the offspring. However, whether or not the same effect occurs by supplementing the maternal diet with ALA (18:3 n3), the ultimate precursor of EPA and DHA, remains controversial. In this study, the investigators assessed whether feeding sows a diet high in ALA prior to parturition and during lactation would increase the n-3 PUFA composition of the suckling piglet. Sixteen pregnant Yorkshire-Landrace sows consumed either a control diet or an experimental diet high in ALA from approximately 8-10 d prior to parturition until day 14 of lactation. The control diet consisted of a base pig feed supplemented with 22.5g/kg of corn oil, whereas the experimental diet high ALA diet consisted of the same base pig feed supplemented with 2.5g/kg tallow and 20g/kg flaxseed oil. The diets varied only in fatty acid content. After 14 d of the piglets suckling from their mothers, the median weight piglet from each sow was anesthetized and sacrificed at 14 d of age. Blood, viscera, liver, and brain were harvested for evaluation of organ fatty acid profiles. In addition, the carcass was homogenized for subsequent proximate and fatty acid analysis. In sows consuming the experimental diet high in ALA, 141% more ALA and 86% more DHA were present in their milk compared to sows consuming the control diet. The n3:n6 PUFA ratio in the milk of sows consuming the high ALA diet was 82% higher in comparison to the controls. Furthermore, piglets from the experimental group had 423% more ALA in the carcass, as well as a 460% higher n3:n6 ratio compared to the controls. Piglets from the experimental group also had 333% more ALA and 54% more DHA in the liver, as well as a 114% higher n3:n6 ratio than piglets in the control group. The experimental group showed 24% higher DHA levels and a 33% higher n3:n6 ratio compared to the controls. A high ALA intake during lactation appears to result in an increase in DHA levels in milk, as well as in some of tissues of the suckling piglet, including the brain. However, the authors note that this study did not attempt to measure whether or not the DHA accumulation in the piglet was due to an increase in ALA or DHA content of the milk. Also, because sows began consumption of a high ALA diet prior to parturition, it is unclear how much DHA the piglet obtained from the mother versus its own synthesis. As such, further studies are necessary to fully elucidate these parameters.
