Milk composition in free‐ranging polar bears ( Ursus maritimus) as a model for captive rearing milk formula

• Published in: Zoo Biology
• Main Authors: Hedberg, Gail E., Derocher, Andrew E., Andersen, Magnus, Rogers, Quinton R., DePeters, Edward J., Lönnerdal, Bo, Mazzaro, Lisa, Chesney, Russell W., Hollis, Bruce
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2011
• Subjects: Ursus maritimus
• Online Access: http://dx.doi.org/10.1002/zoo.20375; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fzoo.20375; https://onlinelibrary.wiley.com/doi/pdf/10.1002/zoo.20375

Abstract The goals of this study were to have an improved understanding of milk composition and to help create a suitable milk formula for cubs raised in captivity. Milk samples were evaluated for fat, fatty acids, carbohydrate, vitamin D 3 , 25(OH)D 3 , vitamin A (retinol), vitamin E (α‐tocopherol), protein, and amino acids. Total lipids in milk did not differ for cubs (mean ± SEM = 26.60 ± 1.88 g/100 ml vs. yearlings 27.80 ± 2.20 g/100 ml). Milk lipids were of 23.6% saturated fatty acid for cubs and 22.4% for yearlings. Milk consumed by cubs and yearlings contained 43.8 and 42.0% mono‐unsaturated fatty acids and 23.4 and 21.9% polyunsaturated fatty acids, respectively. Carbohydrate content was higher in milk for cubs (4.60 ± 0.64 g/100 ml) than for yearlings (2.60 ± 0.40 g/100 ml). Vitamin D 3 concentration of milk was 18.40 ± 5.00 ng/ml in early lactation compared with 7.60 ± 2.00 ng/ml for mid‐lactation. 25(OH)D 3 was lower in milk consumed by cubs (162.00 ± 6.70 pg/ml) than in milk consumed by yearlings (205.00 ± 45.70 pg/ml). Vitamin A concentrations were 0.06 ± 0.01 and 0.03 ± 0.01 µg/ml for cubs and yearlings, respectively. Vitamin E was higher in milk consumed by cubs (20.16 ± 4.46 µg/ml) than by yearlings (7.30 ± 1.50 µg/ml). Protein content did not differ in milk available to cubs (11.40 ± 0.80 g/100 ml compared with milk for yearlings 11.80 ± 0.40 g/100 ml). Taurine was the most abundant free amino acid at 3,165.90 ± 192.90 nmol/ml (0.04% as fed basis). Zoo Biol 30:550–565, 2011. © 2011 Wiley Periodicals, Inc.