One person posting a lot is not astroturfing. Astroturfing is about faking the appearance that many different people support the same cause. If it's the same account doing all the posting then they're not trying to give the appearance of being many different people.

At worst you could call it spamming. But personally I hope they keep up the spamming because seeing all troglodyte meat industry shills make asses out of themselves is giving me a new lease on life.