Source
http://www.saanendoah.com/compare.html#digestibilityThese requirements generally increase after the first 6 months of life.
Infants consume about 750-800 g/day for the first 4-5 months (450-1200g/day range).
Note that most of the minerals in goat and cow milk are significantly higher than in human milk. This, coupled with the higher protein of cow and goat milks (more than 3% compared to about 1.3%), make dilution necessary so as to avoid hypertonic dehydration (a result of high solutes in urine). But, after dilution, carbohydrate should be added to cow or goat milk because human milk contains 7.0 g/100g lactose compared to about 4.5 g/100g lactose found in cow and goat milks.
Distinguishing between allergies and lactose intolerance:
Allergies and lactose intolerance are different things.
An allergic reaction is the body's response to a foreign body (antigen), typically proteins. Goat milk proteins have slightly different amino acid structures than cow milk proteins. Thus, a person who produces antibodies to cow milk proteins, may not produce antibodies to goat milk proteins. However, there is no guarantee that a person who is allergic to cow milk will not be allergic to goat milk, because the milks are similar.
Lactose intolerance or lactose maldigestion result from a person's inability to completely digest lactose. Because microorganisms in the gut will produce gas, symptoms of lactose intolerance include cramps, flatulence and bloating. Lactose is present in all milks. Thus, goat milk can not successfully be substituted for cow milk in cases of lactose intolerance.
A note about goat milk digestibility:
Goat milk's tendency to be more easily digested than cow milk is due to its protein make-up. Goat milk has low levels of the protein alpha s1-casein, a protein that is involved in curd formation. Cow milk has higher quantities of alpha s1-casein than goat milk. In fact, some goats naturally produce very little alpha s1-casein. The higher proportion of small milk fat globules present in goat milk compared to cow milk may also contribute to goat milk's tendency to be more easily digested.
Perhaps you've heard that goat milk is 'naturally homogenized':
Because fat is lighter than water, the cream portion of milk floats on top of the skim portion of milk. Most cows milks in the store are homogenized so that we do not see the two phases of milk. The milk is forced through tiny pores under high pressure to break the fat into smaller sized globules. Small globules distribute in milk and do not float as readily. One reason goat milk does not have to be homogenized is because it has a high proportion of small fat globules. The other reason is that goat milk lacks the protein agglutinin. Agglutinin makes fat globules stick together and float.
...my own personal bias is goats milk btw, but cows milk is more plentiful and therefore could be cheaper if you're doing GOMAD.