Continue eating them as usual but stop breeding new ones. Most of them only live a few months, they'll all be gone within two years.
The species won't go extinct either, we can still keep some around in their natural habitats and zoos, which are both much nicer conditions than most farms. Preferably we won't keep around the breeds that were created for farming, they just aren't healthy animals.
The next quandaries are what do farm owners, farm workers, slaughterhouses, tanners, textiles, feed companies, agriculture focused veterinarian services and products, etc, do now that they're no longer needed?
>Every time I see discussions like this I never see thoughts on what to do with all those animals.
[until the aliens bring tomorrow the mass production lines of cheap lab meat] Because of naturally gradual process of lab meat quality increase and price decrease there will be no point in time when suddenly "we have 70B animals we're no longer consuming "
>Once we finally have artificial meat and thus stop killing sentient beings...
But that's literally in your scenario. If you don't have an answer, that's fine, because all of this is idealism. I just never see any conversation pertaining to what we do with all the animals.
It seems like it comes down to a substantial culling, as letting them loose would be disastrous for a few obvious reasons.
The question doesn't make any sense, because it presupposes that everybody changes behavior in a timeframe that is very short compared to the typical lifespan of the animals. But I don't think that's conceivable. The total number of chickens in the world may be tens of billions but is a fraction of the number consumed in a year, I believe. Feel free to correct me if you have some knowledge about farming.
First: Your English is perfectly fine. As someone that speaks English as a first language; I greatly respect and appreciate you even trying. That's an admirable trait, friend; don't ever feel bad, or especially let someone else make you feel bad for trying to communicate. It's the most human thing there is.
Second: That's kind of my perspective. Ideas are cheap and easy. Idealism paints the perfect outcome, without the really hard parts of making it happen, or the incredibly complicated network of systems that would be effected by trying to reach the target. These are huge problems; entrenchment is incentivized and reinforced on many levels. We often don't solve problems, we treat symptoms, because it's easier than doing what needs to be done to solve the problems.
One quote from the article regarding media sharing tips for farmers:
Most people do not understand the complexity of raising pigs and getting pork from the farm to their table. That means, “[a] good rule of thumb is to speak to a level a third grader [eight to 10 years old] would understand to ensure that things are not taken out of context.
It's unlikely the world would decide all at once to not need farm animals anymore so I think it would be a case of the population falling over years as less were bred.
Also, some species have been altered through selective breeding so much they would have trouble survinging normally e.g. rapidly growing animals that would have difficulty supporting their own weight after the age they would normally be slaughtered.
There would hopefully be more land for wild cows, chickens, pigs etc. to thrive after too.
What do you do with the 70B animals we're no longer consuming?