I don't know the conversion factor for lab meat, but I expect it to be somewhere between eating mechanically harvested plants and regular meat.
There's also the aspect of how you weigh suffering of different beings, which is a complicated enough topic that I won't get into right now[1]. I'll get back to it once feeding cattle with harvested grain becomes rare.
[0] https://ourworldindata.org/grapher/protein-efficiency-of-mea...
[1] https://reducing-suffering.org/crop-cultivation-and-wild-ani...
So even if we assume that the harvest needs to affect four animals, that still seems like pretty small potatoes, no? Any hay field I've ever walked through was teaming with hundreds of visible insects alone, and who knows what else was hidden in there, in areas smaller than an acre.
> There's also the aspect of how you weigh suffering of different beings
I am not sure that is necessary. An earlier comment told that all we have to do is count animals. The larger the count, the more the cruelty. The entire discussion has hinged on that assertion.
Certainly there is going to be a whole lot of subjectivity. Some will argue that the number of animals doesn't matter with respect to cruelty – that suffering is wholly an individual experience. And many more will tell you that the animal that experiences the most cruelty of all is man himself and that ending that cruelty will solve all of the world's problems.
But I don't think we need to find a new metric. We already chose one that was good enough.
Or maybe you can, but you'll find that others don't agree with your estimations.
For example, anyone believing in panpsychism will find this hard to work with. Do you include the harvested plants in your calculation and compare them on a 1:1 basis with slaughtered animals? This kind of nonintuitive conclusions result from insisting that all beings suffer the same. Not a good enough metric IMO.
> Certainly there is going to be a whole lot of subjectivity.
I'm afraid that it's not just "a whole lot", but the final answer depends entirely on subjective definitions of suffering, unless we can find a true, objective one. Sadly, some philosophers don't think that's possible at all [0].
[0] http://www.philosopher.eu/others-writings/nagel-what-is-it-l...
An animal is an animal is an animal. While it is true that there is fluidity in language, and that one could define animal as only a creature kept by humans for the purpose of extracting meat, there was no push back on the use of the more common, broader definition that would be reflected in the dictionary.
Plants have not been considered animals. There has been a clear division between the plants harvested and the animals affected by it throughout the discussion. Whether or not their suffering should be included is and interesting side topic, but immaterial to this one. There is no value in flailing around trying to find new metrics. We picked one. It was certainly not perfect – far from it – but it was good enough. Perfect need not be the enemy of good.
While the philosophers have a point, we are only seeking something to form a belief. Beliefs need not be true. But they do need to be formed, and it seems we don't have enough information to form any kind of beliefs here?
Otherwise, the discussion falls apart because a human is an animal is an animal. But no one is slaughtering humans with such an enthusiasm as cows or chickens. Equating all animals is a fringe belief not supported by the population at large, and one I don't feel like spending time to discuss, especially as it's not required for this discussion to have been valid.
Why even? Rule of thumb is that it takes an acre of grass to feed a cattle beast. If that acre is, instead, 'clear cut' multiple times each year, over several years to match what would be fed to a live animal, to ship the product off to a factory, only one animal living in that grass will experience the cruelty? That seems surprising. An acre of grass provides a significant habitat.
And that is if grass remains the source of nutrients. Harvested grass is hard to move efficiently. If, say, a row crop is used instead then there is an attack on the habitat even before harvest begins. Row crops regularly come under fire because of how unfriendly they are to everything else.
> As I understand it though, the vast majority of cattle are currently being fed mechanically harvested plants
While that is true – the vast majority of cattle are raised on grass and finished with corn, the latter of which being almost certainly mechanically harvested – it is also not binary.
According to Oklahoma State University, most cattle in the United States will spend most of their lives on pastures and grasslands and then finished in feedlots, the latter of which accounting for 15-35% of their lives according to their figures. This does mean that mechanically harvested food does account for some of the nutrient requirements for most cattle, but there is more to the story.