Lipid mobilization and milk production in lactating northern elephant seals

• Published in: The FASEB Journal
• Main Authors: Fowler, Melinda, Debier, Cathy, Costa, Daniel, Crocker, Daniel
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2012
• Subjects: Elephant Seals
• Online Access: http://dx.doi.org/10.1096/fasebj.26.1_supplement.lb702

Northern elephant seals (Mirounga angustirostris) incorporate fasting into several life history stages: post weaning development, molting, breeding and lactation. The mobilization and utilization of particular fatty acids may impact both the mother and pup. This study investigated the mobilization of fatty acids from blubber to understand partitioning of fatty acids between maternal use and milk in northern elephant seals. Blubber and milk fatty acid samples were taken from lactating northern elephant seals in early and late lactation. Overall, patterns of specific fatty acid mobilization conformed closely to previously established patterns in laboratory studies. Proportions of milk and blubber were found to display a high degree of similarity both early and late in lactation. Monounsaturated fatty acids (MUFAs) were the least mobilized from the blubber and increased in the proportion it comprised of the milk across lactation. Polyunsaturated fatty acids (PUFA) and saturated fatty acids (SFA) were more mobilized from the blubber, but proportions decreased in the milk. This suggests that of the MUFA mobilized, the majority is directed to milk synthesis and PUFA and SFA may be partitioned for mother's metabolism. MUFA designation to milk may impact milk viscosity to facilitate secretion from the mammary gland, as well as contribute to the development of diving and thermoregulatory capabilities in the pup.