I think that the real divide is CAFO (Concentrated Animal Farming Operation) species vs non-CAFO. Runminants (sheep and beef) are at least partially fed on pastures, so they do not live in permanently overcrowded farms, with high agression and stress.
Total welfare is the product between population and welfare per animal-year. The conditions determine the welfare per animal-year, but the population is inversely proportional to the edible meat per animal-year. Chickens grow slower than cows and pigs, so more chickens are needed than cows or pigs to produce a given amount of edible meat. Consequently, holding conditions constant, assuming negative lives, it is still good to replace chicken meat by beef or pork. Assuming positive lives, the opposite would be true.
Between the two main CAFO species (chicken and pork) I have not strong opinions: given neuron counts and brain weigth, I think pigs are more morally valuable than chicken, while chicken live worse lives: hard to decide.
I have read both the RP and the post against neuron counts, and I find them unconvincing. Let’s take this: “There are studies that show increased volume of brain regions correlated with valanced experience, such as a study showing that cortical thickness in a particular region increased along with pain sensitivity”.
There is no way to know what is related to “pain sensitivity”, because all we know about consciousness comes from extrapolation. The only valanced experience you can observe is your own. Even if you find that a given part of the brain is related to pain, what matters most is not the size of that part of the brain but if there is a self to feel the pain.
There are not “royal paths” to understand consciousness. There is a “pretty hard problem of consciousness” between you and any exercise of consciousness attribution and no checklist nor neural similarity will easily bridge that gap.
Thanks for the comment, Arturo.
Total welfare is the product between population and welfare per animal-year. The conditions determine the welfare per animal-year, but the population is inversely proportional to the edible meat per animal-year. Chickens grow slower than cows and pigs, so more chickens are needed than cows or pigs to produce a given amount of edible meat. Consequently, holding conditions constant, assuming negative lives, it is still good to replace chicken meat by beef or pork. Assuming positive lives, the opposite would be true.
There are more farmed fish and shrimp than pigs.
Rethink Priorities’ median welfare range of pigs is only 1.55 (= 0.515/0.332) times that of chickens. You may be interested in the post Why Neuron Counts Shouldn’t Be Used as Proxies for Moral Weight.
You may like How to Be a Techno-Optimist for Animals.
I have read both the RP and the post against neuron counts, and I find them unconvincing. Let’s take this: “There are studies that show increased volume of brain regions correlated with valanced experience, such as a study showing that cortical thickness in a particular region increased along with pain sensitivity”.
There is no way to know what is related to “pain sensitivity”, because all we know about consciousness comes from extrapolation. The only valanced experience you can observe is your own. Even if you find that a given part of the brain is related to pain, what matters most is not the size of that part of the brain but if there is a self to feel the pain.
https://forum.effectivealtruism.org/posts/3nLDxEhJwqBEtgwJc/arthropod-non-sentience
There are not “royal paths” to understand consciousness. There is a “pretty hard problem of consciousness” between you and any exercise of consciousness attribution and no checklist nor neural similarity will easily bridge that gap.