Evaluation of Dietary Husbandry of Marine Mammals at Two Major Zoological Parks

Marine mammal nutrition is a relatively unexplored area. In this report, nutritive values are presented for several major marine food items: five species of fish, one species of squid, and one species of clam. Nutrient concentrations determined by analysis include protein, ether extract (primarily triglycerides), calcium, phosphorus, magnesium, sodium, potassium, iron, copper, manganese, zinc, and selenium. Nutrient concentrations derived from the literature include linoleic acid; lysine; methionine plus cystine; tryptophan; arginine; threonine; isoleucine; iodine; vitamins A, B₆,$\text{B}_{12}$, D, and E; thiamin; riboflavin; niacin; pantothenic acid; folacin; biotin; and choline. Information on freezing, storage, preparation, and seasonal availability of marine products was reviewed. The dietary husbandry of cetaceans and pinnipeds at two major zoological parks in the United States was evaluated, and dietary revisions to improve nutritional status and/or provide cost or labor savings were recommended. The problem of thiamin deficiency was explored and supplementation with NaCl, vitamin E, vitamin C, thiamin, and multi-vitamin tablets was discussed. Problems that were common to both zoos were deficient levels of vitamin E, excessive supplementation with vitamins A and D, and, in animals maintained in freshwater, excessive amounts of NaCl.