What would happen to a calf that is fed only soy milk?

Would it live or die?

A calf fed only soy milk? I would think it would almost certainly die. I’m not sure on the specific composition of cow milk versus soy milk, but they certainly are not exactly the same. Milk is the only food a young mammal eats, so it has to be precisely what their body needs. It seems possible that a calf fed some sort of specially formulated, supplemented soy milk could survive (what do they feed actual calves on modern farms? Do they actually get cow’s milk? It wouldn’t surprise me if they fed them something totally different.) Normal soy milk just doesn’t have the same stuff in it as cow’s milk. But then, an infant mammal fed solely on milk from another species would likely die as well - the composition of milk varies a lot from species to species. Human milk, for instance, is particularly high in lactose compared to most species, while many other species produce considerably more protein or fat and less sugar in their milk. This has various consequences on how often an infant needs to feed and so forth.

The basic analyses of calcium fortified soy milk and cow milk (whole) are actually remarkably similar, however, these are the analyses of how it performs as a food component in a human diet. The devil is most definitely going to be in the details; the precise nature of the proteins will be important, for a start.

I would WAG that a calf fed on soy milk would die; probably more slowly than one that was left unfed, or given water alone, but there’s bound to be something missing that is present in natural milk.

Nope - it’s the entire basis of the dairy industry. Cow’s milk is too valuable to feed to calves, so dairy calves are raised on milk replacer. Just about all of them are soy protein based.

Calf milk replacer is formulated a bit differently than soy milk that’s marketed to people so that it mirrors whole cow’s milk (not 2% or skim) more closely. But there are precious few calves fed cow’s milk (unless they are beef calves and get it direct from the source).

I sort of figured this would be the case. But just like soy-based human infant formula, I’m guessing this is still pretty significantly different from the soy milk I buy for my cereal.

Its not soy milk. Its soy juice.

I’ve never tasted soy milk marketed to humans, but I have tasted cow milk replacer. (Hey, I was a kid, I was bottle feeding calves, I was curious.) It doesn’t taste like cow’s milk, but considering it was warm (I hate warm milk) it wasn’t bad.

My grandfather got male calves from a local dairy and raised them for meat.

Right. The FDA, the AAP, and every other major medical organization has issued warnings that children under the age of one should never be fed solely on soy milk, after several deaths were attributed to doing so. Soy-based formulas are sufficiently different, with the right blend of added nutrients, to make the difference in long-term survival.

I’d guess that this wouldn’t be any different for any mammal.

Wow, I learned something fun and interesting from your reply.

In a prior thread about Childrens allergies, I had found an interesting cite that posited *a possible * link between the increase in kids that are fed soymilk and the increase in Peanut allergies.

I don’t remember, was it soymilk marketed towards adults, or soy-based infant formula? Or both, perhaps?

It’s pretty hyped in parenting magazines these days that soymilk and ricemilk are not appropriate substitutes for breast milk, formula or cow’s milk. OTOH, many pediatricians are now saying that drinking milk past the weaning stage is not important to a child’s development, and that they can get all the calcium and protein they need from other foods. I’m of mixed feelings on the topic. I think if we make that “weaning age” more like 3 or 4 or 5, like in pre-industrial societies, that might be true. But I look at my little toddler and just FEEL she still needs milk, although that’s a completely irrational sense, not based on research.

At a wild guess:

The calf would die rapidly of diarrhea. It would have failed to receive colostrum, thus placing it at great risk from local bacteria, and would probably succumb rapidly to intestinal disease (as woudl a foal, lamb, or other farmyard animal who did not receive species-appropriate colostrum).

The protein in soy “milk” is entirely wrong for calves. (The protein in cow’s milk is very wrong for humans too…there’s far too much of it, intended to grow a 1000-lb animal in a year). There would also be problems with the absence of other nutrients.


“Peanut allergy was independently associated with intake of soy milk or soy formula (odds ratio, 2.6; 95 percent confidence interval, 1.3 to 5.2), …”


Thanks for your opinion. :rolleyes: