Yeah, I think most of the infant deaths had more to do with unpasteurized milk adulterated with raw eggs and not the cow's diet.

Edit: Pasteurization didn't even arrive in the US until the 1890s so even if these cows had unadulterated milk, it would still be killing massive amounts of infants by feeding it to them.

In a place like New York City, without adequate pasture and no refrigeration in the first place so nessicating literal factory farming, there was no way to market milk that wouldn't be lethal at the time.

It's frankly baffling that anybody was drinking raw milk at all at the time. Usually you'd process it into yogurt or cheese unless you directly lived on a farm or had a breastfeeding problem (which would likely result in the death of an infant).

I guess they saw a market of poor rural immigrants who had lived on a farm and decided to swindle them to death.