By government subsidies I mean money provided by the government (presumably originating from taxes) to farmers which artificially reduces the price of beef. This includes subsidies for animal feed which indirectly have this effect.
What does this have to do with being veg*n? Suppose I'm arguing with an omnivore who claims that veganism is too expensive. I counter that eating meat is much more expensive but the cost is hidden in taxes which everyone, including vegans, are forced to pay. The strength of my counter depends on the answer to this question. If it turns out that meat would only cost 5% more, I should reevaluate my position and avoid ever making such a claim. If meat would cost 2 to 3 times more and there's an answer explaining why in detail, I'd like to share that answer with my opponent.
I'm not only interested in either beef or the US, but it was decided I should narrow the scope of the question down. If you can answer this question for a different country and/or animal product, please write another question, answer it, and comment with a link to said question.