This seems like an interesting and important point, thanks for writing.
I might nitpick the way you’re characterizing the terrestrial animal case though. Layers and broilers may technically be the same species, but I think they’re different enough that a lot of the same considerations apply from the fish case. For example, you mention cage-free as the paradigm scalable intervention, but actually they only apply to layers, which I’m guessing constitute less than 5% of global terrestrial animals (most are broilers). Applying a similar intervention to broilers (BCC) has been less successful than for layers.
Speaking just about the US, I would say there are actually four groups of poultry worth considering. The following are their population sizes and days spent on form from this population per year (US):
Broilers − 9.3b individuals, 437b days on farm / year
Layers − 311m individuals, 113b days on farm / year
Breeders − 77m individuals, 28b days on farm / year
Turkeys − 200m individuals, 27b days on farm / year
This is much more homogenous than aquatic animals, but it’s not quite as homogenous as you made it seem!
Hi Hazo, yes I completely agree with you about overstating the homogeneity of chickens! The broiler/layer distinction is a problem, but most advocates intuitively understand this only for terrestrial systems. My analysis only segments aquaculture by species and country. I don’t break down by production system, life stage, or procedure, all of which I think create additional target populations within a single species. Atlantic salmon farmed in RAS vs marine cages alone should be considered completely different target populations.
This seems like an interesting and important point, thanks for writing.
I might nitpick the way you’re characterizing the terrestrial animal case though. Layers and broilers may technically be the same species, but I think they’re different enough that a lot of the same considerations apply from the fish case. For example, you mention cage-free as the paradigm scalable intervention, but actually they only apply to layers, which I’m guessing constitute less than 5% of global terrestrial animals (most are broilers). Applying a similar intervention to broilers (BCC) has been less successful than for layers.
Speaking just about the US, I would say there are actually four groups of poultry worth considering. The following are their population sizes and days spent on form from this population per year (US):
Broilers − 9.3b individuals, 437b days on farm / year
Layers − 311m individuals, 113b days on farm / year
Breeders − 77m individuals, 28b days on farm / year
Turkeys − 200m individuals, 27b days on farm / year
This is much more homogenous than aquatic animals, but it’s not quite as homogenous as you made it seem!
Hi Hazo, yes I completely agree with you about overstating the homogeneity of chickens! The broiler/layer distinction is a problem, but most advocates intuitively understand this only for terrestrial systems. My analysis only segments aquaculture by species and country. I don’t break down by production system, life stage, or procedure, all of which I think create additional target populations within a single species. Atlantic salmon farmed in RAS vs marine cages alone should be considered completely different target populations.