To be clear, it is entirely plausible to me that you are right and that there are large net moral gains to be had from CWRs. I only mean to bring up an area of uncertainty not to say I think it clearly comes out to CWRs=bad.
The Humane League has some discussion of the relationship between broiler welfare, growth, and slaughter weight. While I agree that you might be able to find some slower growing breeds that get to the same weight eventually as some faster growing breeds, I would guess that if slower breeds were widely adopted, we would be looking at a 5-10% average difference in slaughter weight. However, I certainly concede that the harms of the bird being unable to hold their own weight might far outweigh the harms from any increase in the number of birds.
As for the egg-laying case, I agree that 15% sounds like an upper bound to me and I suspect much lower.
BCC broilers already can grow to the same slaughter weight.[1] Though I do remember reading that it might be more optimal for producers to slaughter them before they reach the same weight. But that would also mean that they are live for fewer days, which might mean that they suffer less, since I imagine that the last days when they are very heavy might be more painful than average. In any case, 5-10% in average weight wouldn’t outweigh estimated 50% difference in suffering.
That said, if you think that a significant portion of suffering comes from slaughter, then the difference in slaughter weight is more concerning. And there are people who think this because they weigh excruciating suffering very highly. E.g. Brian Tomasik thinks that the pain during chicken death is equivalent to the pain experienced throughout 10 days of chicken life. That still wouldn’t come close outweighing 50% decrease in suffering during life though. But perhaps I will mention this to the Welfare footprint project. I don’t know if they take these considerations into account because the section on broiler slaughter is not yet uploaded to their website.
We analyzed the following scenarios, for which data on broiler welfare was available: (1) a baseline scenario represented by the use of conventional fast-growing breeds (e.g., Aviagen Ross 308, 708, Cobb 500) reaching a slaughter weight of 2.5 Kg at 42 days and (2) a reformed scenario, represented by the use of a slower-growing strain (ADG: 45-46 g/day), reaching the same slaughter weight in 56 days. This is a growth rate consistent with typical figures achieved by various of the breeds approved under the BCC, also referred to as medium- or intermediate-growing broilers, also falling within the acceptability of other welfare certification schemes.
To be clear, it is entirely plausible to me that you are right and that there are large net moral gains to be had from CWRs. I only mean to bring up an area of uncertainty not to say I think it clearly comes out to CWRs=bad.
The Humane League has some discussion of the relationship between broiler welfare, growth, and slaughter weight. While I agree that you might be able to find some slower growing breeds that get to the same weight eventually as some faster growing breeds, I would guess that if slower breeds were widely adopted, we would be looking at a 5-10% average difference in slaughter weight. However, I certainly concede that the harms of the bird being unable to hold their own weight might far outweigh the harms from any increase in the number of birds.
As for the egg-laying case, I agree that 15% sounds like an upper bound to me and I suspect much lower.
BCC broilers already can grow to the same slaughter weight.[1] Though I do remember reading that it might be more optimal for producers to slaughter them before they reach the same weight. But that would also mean that they are live for fewer days, which might mean that they suffer less, since I imagine that the last days when they are very heavy might be more painful than average. In any case, 5-10% in average weight wouldn’t outweigh estimated 50% difference in suffering.
That said, if you think that a significant portion of suffering comes from slaughter, then the difference in slaughter weight is more concerning. And there are people who think this because they weigh excruciating suffering very highly. E.g. Brian Tomasik thinks that the pain during chicken death is equivalent to the pain experienced throughout 10 days of chicken life. That still wouldn’t come close outweighing 50% decrease in suffering during life though. But perhaps I will mention this to the Welfare footprint project. I don’t know if they take these considerations into account because the section on broiler slaughter is not yet uploaded to their website.
Here is a quote from Welfare Footprint Project: