Changes in blood properties of fasting and feeding harp seal pups, Phoca groenlandica, after weaning GRAHAM A. J. WORTHY AND D. M. LAVIGNE Department of Zoology, College of Biological Science, University of Guelph, Guelph, Ont., Canada Nl G 2W1 Received August 13, 1981 WORTHY, G. A. J., and D. M. LAVIGNE. 1982. Changes in blood properties of fasting and feeding harp seal pups, Phoca groenlandica, after weaning. Can. J. Zool . 60: 586-592. 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 phosphokin- ase (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. WORTHY, G. A. J., et D. M. LAVIGNE. 1982. Changes in blood properties of fasting and feeding harp seal pups, Phoca groenlandica, after weaning. Can. J. Zool. 60: 586-592. Les propriCtCs physiques et biochimiques du sang ont CtC CvaluCes chez des petits phoques du Groenland en captivitk durant le jeQnequi suit le sevrage et au dCbut de l'alimentation. Un groupe de phoques a CtC gardC au jeOne durant 10 semaines, un autre durant 8 jours, un autre durant 29 jours et un autre de 36 A 44 jours. Les concentrationsde calcium et de phosphore sont plus ClevCes chez les petits phoques en p6riode de jeOne que chez les petits qui s'alimentent. Les concentrations sanguines de phosphatase alcaline, de transaminase sCrique glutamiquepyruvique(SGPT), de transaminase sCrique glutamique oxalo-acCtique (SGOT) et de crCatinine phosphokinase (CPK) augmentent lorsque l'animal commence h se nourrir. Les autres paramktres du sang ne subissent pas de differences significatives entre la Hriode de jeOne et la @riode alimentaire et ont des valeurs reconnues c o m e normales pour des phoques du Groenland. Les petits phoques commencent A se nourrir moins de six semaines aprks le sevrage. Durant cette pkriode, ils semblent capables de maintenir les concentrations de plusieurs de leurs paramktres sanguins avant de parvenir A une alimentation autonome. [Traduit par le journal] Introduction to examine changes in certain blood properties during Several research facilities, public ZOOS, and aquaria the postweaning fast and at the onset of feeding in collect immature phocid seals for or public relation to n0IIllal values observed previously in imma- display. These animals are often young of the year ture (Englehardt 1979) and adult harp seals et which frequently refuse to eat when brought into a1. 1969; Geraci 1970, 1971 ; Geraci et al- 1979). captivity. For numerous animals, including sheep and cattle (Alden 1970), it has been found that prolonged Materials and methods periods of fasting, particularly at a young age, are Twenty weaned male harp seal pups, aged approximately 12 permanently detrimental to future growth and develop- days (Stewart and Lavigne 1980; Worthy et al. 1982), were ment and possibly to survival. As a precaution against collected in the Gulf of St. Lawrence on 17 March 1980 and this, seals are often force-fed milk substitutes (Cornell transported to Guelph, Ontario, where they arrived on 20 1975) or fish (Ronald et al. 1970). March. a recent study, worthy (1982) maintained Four treatment groups were maintained in tanks of artificial newly weaned harp seal pups, Phoca groenlandica, in salt water at a temperature of 10°C. One group, initially comprised of nine seals, was not offered food for the duration captivity to quantify weight lo~ses during the of the 10-week study; a "fed" group initially consisted of five postweaning fast and subsequent growth after the Onset animals which were offered food after an 8-day fast; "recovery of feeding. The general health of these animals was group 1" consisted of three animals, one of which fasted monitored by weekly determinations of physical blood voluntarily, and two of which were "force-fasted," for 29 days properties and levels of various circulating enzymes and before feeding; and "recovery group 2" consisted of three metabolites. These blood data provided an opportunity animals, one of which fasted voluntarily for 36 days, one of 0008-43011821040586-07$01 .OO/O 0 1982 National Research Council of Canada/Conseil national de recherches du Canada Can. J. Zool. Downloaded from www.nrcresearchpress.com by Shanghai International Studies University on 06/07/13 For personal use only.