Vegans don't realize how many animals are killed to protect fruit and vegetables, says a pig farmer and author.
Matthew Evans has written a book - On Eating Meat - which calls on omnivores and vegans to look at the impact of their dietary choices.
He has studied Australia's food industry for years, and says that around 40,000 ducks are killed annually to protect Australian rice production and a billion mice are poisoned to protect wheat in Western Australia, among others.
'Don't understand scale'
"I think a lot of vegans probably understand some animals die, but they may not understand the scale," he told ABC News. "So a duck dying to protect a rice paddy for me is not much different for a cow dying to produce a steak.
"They are both animal deaths that happen in the name of us being able to eat. So there is nothing that we can do that doesn't have an impact on animals."
He added that he wasn't telling people whether they should or shouldn't eat animals - but that they should be aware of the impact of their choices - blasting factory farming as 'absolutely abhorrent'.
'Reduce your impact'
"Most vegans are fully aware that it is not possible to live without causing harm to other animals. However, many animals that are used for meat and milk need to have additional food grown for them. This is particularly the case in zero grazed systems but even where animals are allowed to graze this may not be sufficient for all of their needs. For every 100 calories fed to animals we receive only 12 calories by eating their flesh and milk," Samantha Calvert, Head of Communications at The Vegan Society, told Plant Based News.
"If you want to reduce your overall impact on animal suffering and death – as well as reducing your food related carbon footprint – then veganism is the best 'off the shelf' diet to choose. If you eat animal products then even more animals will be killed to feed you.
"Veganism does not eliminate the suffering and death of other animals but it is the best option to dramatically reduce it. You can use our Veganalizer to find out how many lives you can save as a vegan."