I am wondering if there is work being done on changing the brains of farm animals to increase their welfare levels without changing their environments. From what I know about the state of gene editing, it is possible to create smarter mice and flies that like cocaine, so it doesn't seem like that much of a stretch to make a happier chicken or silkworm. If you have any relevant information, please share!
Epistemic Status: hare-brained scheme
I think it might be possible to selectively interfere with any region of an animals brain using a sophisticated genetic logic gate. It'd even pass on in the germline so you'd only have to do the manipulation once or twice to get a new phenotype you can grow exponential via regular old breeding. They work a bit like this. If A and B and C but not D, make protein E. There are m0lecules called cadherins, a unique combination of which specify each region of the brain. If you made expression of A/B/C/D dependent on whether these cadherins are expressed, you could express D (i.e. any protein you want) within that brain region.
You could figure out which gene to add and where by using more traditional means of genetic engineering that don't pass on in the germ line.
One potential candidate is just destroying the amygdala. There's a case study of a woman called SM who had no amygdala. She was really happy and carefree, kinda dumb and reckless but not massively so.
I proposed this to a world expert on cadherins and he liked the idea and he agreed to let me do my my MSci project on something related, but he had no relevant expertise on animal welfare or genetic engineering and I suck at lab work so I turned him down.
If anyone's interested I'll share a little infographic I made on the idea