Scientists analyse animal milk
At the largest collection of animal milk in the world, scientists are analysing the properties of different milks to help protect baby animals.
The huge “milk bank” is at Smithsonian’s National Zoo in Washington DC, US, and it contains more than 16,000 samples taken from more than 200 species of mammal, from hippos to tiny tree shrews.
Milk contains the ingredients that help young mammals to develop and grow. The scientists at the milk bank study the samples, which are frozen, to work out their contents. They use this information to create formula (a liquid used as an alternative to a mother’s milk) which is as close as possible to the real thing. Formula is used to feed baby animals whose mothers have died or stopped producing milk.
The scientists thaw the milk samples and separate out the different parts, such as fat and sugar. They also work out which minerals are in the milk. Sometimes things go wrong. One scientist stirred seal milk, which is slightly orange, for too long and ended up making what she called “seal butter”.
Mammal milk contains different ingredients in varying amounts depending on what a species needs. For example, hooded seals only feed their babies milk for four days and have to fatten them up quickly so they can survive the cold North Atlantic, so their milk is 61% fat. Armadillo milk has very high levels of the mineral calcium, which they need to grow the hard shell that covers and protects their body.
To make their formulas even better, the scientists are also looking at the microbes (microscopic living things, including bacteria) in animal milks. Microbes can be good or bad for us and some do important jobs, such as strengthening immune systems (the body’s tool for fighting infection). The scientists mix formula with a mammal’s mother’s poo – which contains lots of microbes
– in what they call a poo milkshake. Sally Bornbusch from Smithsonian’s National Zoo told New Scientist magazine, “We try and get all of those microbes that mom has into the baby.” The scientists are now trying to work out how to add microbes when they can’t get hold of poo.