That works out to less than a pound a day (~0.68 lbs). Large numbers have a way of being misinterpreted, it helps to put them in perspective.
That's a lot of meat for one person in one day. It's almost three quarter-pounder hamburgers every day . An entire package of deli meat is 6oz (I checked). So 0.68lbs a day is two whole packages of deli meat every day. Even with bones, included, that's more than two chicken drumsticks a day (four drumsticks are about a pound). Nutritionally speaking, 0.68 lbs is over 300 grams, which is far more protein than anyone needs (the RDA is 50-60 grams). It's not even healthy on the consumer end, let alone the production end.
Regarding what people would eat instead of meat, I don't know the answer to that. Maybe we could take the corn being used for high fructose corn syrup and make something nutritional out of it. Yes, that would involve sacrifice. The main problem seems to be overconsumption (which I mentioned earlier) and possibly overpopulation. We do have an obesity epidemic, after all.
you say this as if it's a new idea... It is cheaper to keep a pig healthy than it is to restore health to an already sick pig. This is one place where Human medicine could learn a thing or two in the US. The current health insurance system has no mechanism to foster disease prevention as opposed to disease treatment because it is too focused on the cost of each procedure and not on the total cost of providing health care of each patient under each scenario.
I admit that I am venturing into territory that I am not an expert in, but my understanding is that many of the practices of factory farming, including nutrition (not feeding animals their natural diet) and "housing" (cramming many animals in a confined space than is natural), is causing a higher rate of disease. That was what I was referring to. You mentioned stress as a potential factor. As presented by opponents of factory farming, animals are put into situations where they're more likely to get sick (due to cost-cutting measures), and then fed antibiotics to compensate. Perhaps that narrative is false, but that is what most opponents of factory farming believe.
I completely agree with you regarding human medicine. I believe prevention is starting to become more of a focus. Things like stress should also be more of a focus (if it's true for animals, it's definitely true for humans!).
Meat and Bone meal and Offal are ground up and fed back to recycle the high quality protein other high quality nutrients
I honestly thought this practice was banned after the Mad Cow outbreak. And cows are herbivores, so why would they need to eat animal-based protein? Unless they're being deprived of something else. Since you focus on nutrition, I'm sure you have insight into this. But it seems to me that this practice would increase the risk of disease.
All human activity has an effect on the environment, the problem is that we pick a couple of industries and target them to the exclusion of all others.
Maybe you just feel picked on because you're in the industry, so you're more aware of criticisms of it. I have plenty of concerns about practices in other industries. I generally don't actually hear many people talking about the meat industry at all. Most people don't care, or don't want to think about it. It's only since Michael Pollan's book came out that more people are even starting to question where their food is coming from.
I'm in New York, and the people who do care try to support local farmers who they actually get to meet and know. For example, Manhattan has seasonal Farmer's Markets several times a week in several locations, and they are very successful. That's in reference to your earlier comment about how 99% of people are disconnected. Some people do make an effort to get reconnected.