The second is regarding sapience (mentioned above). There is no doubt that chickens are sentient. They can experience stress, fear, pleasure, pain, terror, anger. They even have a system of short-term and long-term thinking. So, if they deserve moral consideration, they absolutely deserve it on this scale. Hurting a chicken is immoral. It's immoral because it feels pain. If someone hurts a chicken, then we then engage in the complex moral calculation as to whether it's 'worth it'. Importantly, it's almost never 'worth it' from the chicken's perspective.
There's also really insufficient reason to think that they're sapient. This is a ginormous difference, the ability to consider their personhood in a metacognitive way. I am non-expert on this front (as mentioned), but I have a strong background in neuroscience, neuroanatomy, and (partially) psychology. Not Gladwell's 10,000 hours, but sufficient to be a professional in two of those fields and damned useful in the third. Because it's not clear that they're sapient, we actually don't know how they value their future, except insofar as it is measured on a scale involving sentience. We know that chickens will cognitively value future pleasure or future pain. They will take steps to avoid pain and seek pleasure that they can predict. They will even engage in trade-off ratios. But we cannot say that they value future existence. And especially not their future genetic lineage.
It's not a function of scale. Unlike with people, or maybe other animals (I am waiting for more data on apes and cetaceans, but I hold it as a strong possibility), you literally cannot ask "would you prefer to take these slipping pills and die, rather than continue in these conditions?" From the non-sapient's condition, it's a meaningless question. "What's South of the South pole?", type of meaningless.
They would prefer to not suffer. Every time we ask, the answer is clear. They would prefer to not suffer. And so we spend a ferocious amount of subsidy and environmental degradation (with its concomitant poverty and future poverty) maximizing the number of entities that experience this suffering, because we're a combination of 'needing food' and 'callous'. Nearly everyone here is on the wrong side of this scale.