Putting words in other peoples mouths isn't good practice. Simply calling the supply store to ask about animal protein in the feed you were interested in would work much better than your current tantrum.
Not "The" source of protein, but "A" source of protein in the feed. Meat proteins are more costly, but can still be had in custom mixes at a local feed mill, and maybe a couple commercial formulas.
Changing formulas in all types of animal feed happens, you just gotta roll with it.
Ignorant people spreading misinformation should be a concern. Some of the folks on these threads, I have learned, intentionally mislead people. So I won't roll with that, thank you. I can not begin to imagine why people would try to mislead others knowingly.. but some are at BYC. Maybe they are connected to certain feed companies -- I don't know. They forget, the internet remembers everything, and they more they post, the more likely they are found out and called out.
What he stated was fact not ignorance... Feed companies change up formulas of their feed based on location, seasonal availability and cost that is why most use a sewn in feed tag vs printing on the bag itself... The feed ingredients can literally change from day to day or even in the middle of the day... And if the feed company has multiple manufacturing plants it's highly probable (likely) that each plant is using different ingredients for the feeds...
For this reason the feed companies have multiple formulas that they rotate through the seasons or based on availability/price.... For example if they can't get animal protein "A" at a reasonable cost due to a local shortage or price spike they simply switch to a formula that uses protein 'B" or "C" that is available at that moment... This is not unique to feed companies either, take for example hay, the hay composition that I can easily get in the Midwest isn't available at the same price all over the US, composition varies by region...