• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: harbour seal; Phoca vitulina
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.494.1272; http://bowenlab.biology.dal.ca/data/Lang Pv Attendance Milk Compositoin CJZ 2005.pdf

Individual variation in milk composition over lactation in harbour seals (Phoca vitulina) and the potential consequences of intermittent attendance S.L.C. Lang, S.J. Iverson, and W.D. Bowen Abstract: We studied milk composition over the course of lactation in 21 harbour seal (Phoca vitulina L., 1758) females on Sable Island, Nova Scotia. Milk fat content increased significantly from 40.8 % ± 1.01 % at parturition to 50.2 % ± 1.39 % at day 7 and then remained relatively constant throughout the remainder of lactation. Changes in dry matter mirrored changes in fat content. Protein content averaged about 9 % over mid to late lactation. There was con-siderable between-individual variation in the composition of milk and how it changed over lactation, particularly in milk fat content (CV 9.1%–11.4%). In three females that were separated from their pups for 4–6 days, milk fat content declined by 20%–23 % and milk protein content increased by 6%–11%. These changes in milk composition indicate that changes in mammary gland function occur rapidly following the onset of milk stasis in harbour seals. The rapid response of the mammary glands to separation suggests that, in direct contrast to the glands of otariids, the glands of harbour seals rely on regular evacuation to maintain normal function. These results suggest that there may be a signifi-