The effect of diet and feeding level on survival and weight gain of hand-raised harbor seal pups (Phoca vitulina)
Article first published online: 2 NOV 2010
© 2010 Wiley Periodicals, Inc.
Volume 30, Issue 5, pages 532–541, September/October 2011
How to Cite
MacRae, A.M., Haulena, M. and Fraser, D. (2011), The effect of diet and feeding level on survival and weight gain of hand-raised harbor seal pups (Phoca vitulina). Zoo Biol., 30: 532–541. doi: 10.1002/zoo.20356
- Issue published online: 4 OCT 2011
- Article first published online: 2 NOV 2010
- Manuscript Accepted: 19 AUG 2010
- Manuscript Revised: 14 JAN 2010
- Manuscript Received: 30 OCT 2009
- Natural Sciences and Engineering Research Council of Canada
- The National Wildlife Rehabilitator's Association; donors listed on the Animal Welfare Program website at [http://www.landfood.ubc.ca/animalwelfare]
- harbor seal pups;
- artificial formulas;
Hundreds of stranded harbor seals pups (Phoca vitulina) are brought to wildlife rescue centers every year. Typical hand-rearing diets include artificial milk-replacers and diets based on macerated fish fed via gavage, but weight gains are often low and mortality rates can be high. This study compared survival and weight gain of orphaned seal pups fed either artificial milk-replacer or fish-formula. Pups admitted to the facility in summer 2007 (n=145) and 2008 (n=98) were randomly assigned to one of two diets and fed by gavage until weaning. In 2007, pups fed milk-replacer gained more (43±12 g/d) than those fed fish-formula (loss of 13±6 g/d; P<0.002). In 2008, when intake was increased from 8 to 11% of body weight daily, weight gain improved for both diets but remained higher in pups fed milk-replacer (123±12 g/d, vs. loss of 6±8 g/day; P<0.001). Pup survival to weaning was significantly higher in 2008 than 2007 (P<0.001) and was higher for pups on milk-replacer compared with those on fish-formula (P<0.05). Survival was also correlated with body weight at admittance (P<0.001). Although neither diet achieved the weight gains recorded in mother-raised pups (400–800 g/d), the artificial milk-replacer was clearly more successful, and pups fared better in the second year of the study when intake was higher. Zoo Biol 30:532–541, 2011. © 2010 Wiley Periodicals, Inc.