Milk composition in free-ranging polar bears (Ursus maritimus) as a model for captive rearing milk formula.
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).
Veterinary Department, San Francisco Zoological Gardens, One Zoo Road, San Francisco, California 94132, USA. hedbergs@sbcglobal.net
Gail E
GE
Hedberg
Andrew E
AE
Derocher
Magnus
M
Andersen
Quinton R
QR
Rogers
Edward J
EJ
DePeters
Bo
B
Lönnerdal
Lisa
L
Mazzaro
Russell W
RW
Chesney
Bruce
B
Hollis
D000596:Amino Acids / Q000737:chemistry; D000818:Animals; D002241:Carbohydrates / Q000737:chemistry; D005223:Fats / Q000737:chemistry; D005227:Fatty Acids / Q000737:chemistry; D005260:Female; D005526:Food, Formulated / Q000032:analysis*; D008892:Milk / Q000737:chemistry* / Q000378:metabolism; D008894:Milk Proteins / Q000737:chemistry; D001503:Ursidae / Q000502:physiology*; D014815:Vitamins / Q000737:chemistry
D000596:Amino Acids; D002241:Carbohydrates; D005223:Fats; D005227:Fatty Acids; D008894:Milk Proteins; D014815:Vitamins