Two factors to consider id say. Blood isn’t the only organic source of nitrogen so it’s not as if its necessary, thus I’d wager many vegans would consider it unnecessary animal suffering, at least in theory. However the caveat would be blood is byproduct, no ones killing the animals in order to obtain blood meal, many people including vegans may think it more ethical to not let it go to waste.
That second point would require intimate knowledge about which animal parts would be disposed of if they didn’t find a buyer.
In reality, everything is used. If there wasn’t a market for part of an animal, a use was found and a market created (which is part of the reason why industrially produced white sugar, beer, wine, apple juice, potato chips and bread usually aren’t vegan).
Anyway, vegans usually don’t care about whether an animal product could be leftover. Their philosophy boils down to “Just fucking leave animals in peace.”
Two factors to consider id say. Blood isn’t the only organic source of nitrogen so it’s not as if its necessary, thus I’d wager many vegans would consider it unnecessary animal suffering, at least in theory. However the caveat would be blood is byproduct, no ones killing the animals in order to obtain blood meal, many people including vegans may think it more ethical to not let it go to waste.
That second point would require intimate knowledge about which animal parts would be disposed of if they didn’t find a buyer.
In reality, everything is used. If there wasn’t a market for part of an animal, a use was found and a market created (which is part of the reason why industrially produced white sugar, beer, wine, apple juice, potato chips and bread usually aren’t vegan).
Anyway, vegans usually don’t care about whether an animal product could be leftover. Their philosophy boils down to “Just fucking leave animals in peace.”