In the US the most common food allergy is cow's milk. The allergic reaction is blamed on a protein allergen known at Alpha s1 Casein, which is found in high levels in cow's milk. The levels in goat's milk however are 89% less than that of cow's milk, making it far less allergenic food.
All milk contains certain levels of lactose, milk sugar. A large portion of the population suffer from a deficiency of lactase, which is an enzyme that digests lactose. Goat's milk contain less lactose than cow's milk and therefore is easier to digest for those who are lactose intolerant. Goat's milk has smaller fat globules as well as higher levels of medium chain fatty acids. This means that during digestion, each fat globule and individual fatty acid will have a larger surface-to-volume ratio resulting in a quicker and easier digestion process. It allows the body to digest the goat milk more smoothly and completely than digesting cow's milk. We know that goat's milk has a greater amount of essential fatty acids such as linoleic and arachidonic acid than cow's milk as well as significantly greater amounts of vitamin B-6, vitamin A, and niacin. Goat's milk is also far superior source of potassium.
Thermo-dynamically speaking, goat's milk is better for human consumption. Cow's milk is designed to take a 100 pound calf and transform it into a 1200 pound cow. Goat's milk and human milk were both designed and created for transforming a 7-9 pound baby/kid into an average adult/goat of anywhere between 100-200 pounds. Milk backed by science... it just makes sence!