Even if this is correct, in terms of value spreading it seems to be a very problematic message to convey. Most people are deontologists and would never even consider accepting this argument for human infants, so if we implicitly or explicitly accept it for animals, then this is just going to reinforce the prejudice that some forms of suffering are less important simply because they are not experienced by humans/our species. And such a defect in our value system may potentially have much more drastic consequences than the opportunity costs of not getting some extra live-years that are slightly worth living.

Then there is also an objection from moral uncertainty: If the animals in farms and especially factory farms (where most animals raised for food-purposes are held) are above "worth living", then barely so! It's not like much is at stake (the situation would be different if we'd wirehead them to experience constant orgasm). Conversely, if you're wrong about classical utilitarianism being your terminal value, then all the suffering inflicted on them would be highly significant.