Changes in blood properties of fasting and feeding harp seal pups, Phoca groenlandica, after weaning

Abstract

Physical blood properties and blood biochemistry were monitored in captive harp seal pups throughout the postweaning fast and during the onset of feeding. One group was fasted for a period of 10 weeks and three other groups commenced feeding after fasts of 8, 29, and 36 to 44 days, respectively.Calcium and phosphorus levels in fasting pups were lower than in feeding pups. Circulating levels of alkaline phosphatase, serum glutamic-pyruvic transaminase (SGPT), serum glutamic oxalo-acetic transaminase (SGOT), and creatinine phosphokinase (CPK) increased with the onset of feeding. Other monitored blood parameters exhibited no significant differences between feeding and fasting animals and were within the range of normal values previously reported for harp seals.Harp seal pups commence feeding within about 6 weeks after weaning. During this period they appear capable of maintaining homeostasis with respect to many blood parameters, prior to achieving nutritional self-sufficiency.