🥛 Seal milk

Seal milk is the milk of female seals, with which they feed their pups. Seal milk holds the record for fat among known types of milk. According to a review by Avery and Zinn (2023), the fat content of pinniped milk ranges from 25 to 60%, while it contains only about 35–65% water and on average about 11% protein. By comparison, cow’s and human milk contain about 4% fat.

The most striking example is the hooded seal (Cystophora cristata). Its lactation lasts only about 4 days — the shortest of any mammal. During this time the pup drinks about 10 litres of milk a day at about 60% fat and gains roughly 7 kg daily, mostly as blubber. The mother does not eat during this period and draws on her own reserves.

Seal milk or cow's milk? Cow's and human milk contain about 4% fat; seal milk holds the record, with 25 to 60% fat, only about 35–65% water and on average about 11% protein. The difference follows the way of life: a hooded seal pup must build blubber in about 4 days, so the mother draws on her own reserves without eating. Seals or sea lions? True seals nurse briefly and intensively, whereas sea lions and fur seals alternate nursing with trips to sea, for months or years.

Seal milk does not belong on a shelf: it is the milk of wild marine mammals, made for their pups, and this page treats it as a nursing strategy, not as a food. Drinking milk in shops is cow's milk with the usual labels, whole or semi-skimmed, pasteurised or UHT, in supermarkets and dairies. If a product is offered under the name seal milk, read the ingredients list to see what it really contains.

True seals generally nurse their pups briefly and intensively, on ice or on shore, while sea lions and fur seals alternate nursing with trips to sea, and their lactation lasts months or even years. The rich milk lets the pup build up, in just a few days, the layer of fat it needs to live in cold water.