Would be interesting to see if these animals were located only in the US or if this is a worldwide phenomena

It's very likely climate change-related: https://www.theguardian.com/environment/2014/may/07/climate-...

Industrial farming also produces less nutritious food generally. Plants can uptake 20+ minerals from the soil, but industrial farms only add the 3 that directly fuel growth - Nitrogen, Potassium, and Phosphorus. You get taller, faster, less nutrient-rich crops.

> industrial farms only add the 3 that directly fuel growth - Nitrogen, Potassium, and Phosphorus

Source? I don't industrial farm, but I highly doubt that as plants suffer significantly when they lack micro-nutrients.

Gabe Brown mentioned it in this lecture on regenerative agriculture. Sorry, but I don't have a timestamp, it's been a few weeks since I watched it. https://www.youtube.com/watch?v=uUmIdq0D6-A

I'm not an expert in farming, but I do know a little bit of plant biology. My understanding of what he said was that the combination of atmospheric CO2 and fertilizer increases the growth rate of the plant, but the plant doesn't uptake a proportionately larger amount of other micro nutrients, either because it is biologically rate limited or doesn't have access.

Other Googling suggests that it could be a result of selective breeding picking crops that grow faster but are less nutritious, but that would seem to be a correlated problem. Those crops tend to be selected for their ability to grow with synthetic fertilizer and *-cides, with the lack of nutritional value being an unintended consequence.