regarding the point of the enviroment, i cannot but agree there, although i do not think meat consumption would be completely abolished, just made enviromentally friendly, knowingly of the fact that meat would be far more scarce.
but your second point, what a disgusting point, the true cancer that always plagued the left. Politics is not applied ethics, there is no place for morality in politics if one aims at being victorious, both in motivation and in goals, in means and ends. Both workers and animals are exploited, but there is no reason we should care about it from a moral standpoint, as any value, dignity or rights you project onto them are merely a fabrication and an excuse for being a communist. The only thing that matters is loving communism because of its pure beauty, all sacrifices are worth being made for this cause. once we let down applied ethics and embrace fanaticism, ceaseless pursue of interests unrestrained by morality, which cannot be but bourgeoise liberal morality, and beauty, aesthetic value, that day our movement will pursue victory and possibly archieve it. until then, we shall behave as an ethics committe for the world, without any true aspiration or plan, much like the beautiful soul.