Variaciones de los niveles de grasa y proteína en la leche de la foca de Weddell (Leptonychotes weddellii Lesson, 1826) en la isla Laurie, Antártica: estudio preliminar

The Weddell seal (Leptonychotes weddelliiLesson, 1826) has in common with other antarctic phocids, a lactation characterized by high rates of nutrients and energy transfer. The study of the variations in the milk composition contributes to the knowledge about this particular model of lactation and allows the acquisition of basic information for veterinary medical studies. The present study shows the preliminary results of the analyses of the variations in milk fat and protein levels from four females sampled sequentially along lactation at Laurie Island, South Orkney Islands during the 2002 breeding season. Important inter individual variations were observed among the sampled females, but a similar pattern along time which showed: a) an increasing trend for fat levels during the first half of the lactation period (13.04 to 61.25 g 100 g^-1), and then maintaining high values (41.21 to 48.88 g 100 g^-1) from this point until the end of suckling, and b) total protein levels fluctuated within a narrow range (8.10 to 11.74 g 100 g^-1) along the period. Fat and protein values are similar to those reported for other phocids, allowing for the rapid growth and the formation of the blubber to protect the pup and assure its survival.