title: The composition of Australian fur seal (Arctocephalus pusillus doriferus) milk throughout lactation.
abstract: The proximate chemical composition of milk was determined throughout lactation in the Australian fur seal (Arctocephalus pusillus doriferus Wood Jones), a temperate species with an 11-mo lactation period typical of most temperate otariids. Average lipid and protein contents were 42% and 10%, respectively, which is similar to that recorded for the polar otariid species but higher than reported in other temperate, long-lactation species. Milk composition, however, varied substantially throughout lactation, with lipid content rising from 30% soon after parturition to 50% at 230 d postpartum before decreasing to 45% toward weaning. The trend in water content was opposite to that of lipid, while protein content increased only slightly during lactation from 10% to 12%. The peak in lipid content occurred at approximately 70% of the way through lactation, similar to that found in the Australian sea lion and several phocid seal species. Significant positive relationships were found between milk lipid content and both the duration of the preceding foraging trip and body mass. A highly significant and close correlation was found between milk water and lipid contents such that gross energy content may be accurately predicted from water content alone. Similar predictive equations have been found for several other otariid and phocid species, but these appear to differ between phylogenetic groups.
authors.affiliation: Marine Mammal Research Group, Graduate School of the Environment, Macquarie University, Sydney 2109, New South Wales, Australia. jarnould@gse.mq.edu.au
authors.forename: J P
authors.initials: JP
authors.lastname: Arnould
authors.forename: M A
authors.initials: MA
authors.lastname: Hindell
mesh_terms: D000818:Animals; D001823:Body Composition; D005260:Female; D046069:Fur Seals / Q000502:physiology*; D007774:Lactation / Q000502:physiology*; D008055:Lipids / Q000032:analysis; D008892:Milk / Q000737:chemistry*; D008894:Milk Proteins / Q000032:analysis; D013696:Temperature; D014867:Water / Q000032:analysis
chemical_list: D008055:Lipids; D008894:Milk Proteins; D014867:Water