Then I suggest you contact to your US Representative or US Senator and address your specific concerns with them. You'll probably get a form letter back, but maybe you'll get someone to actually look at your situation if you are specific. I do think you raise your chances of getting a decent response by referencing specific parts of the legislation you are concerned about and explaining why you are concerned rather than sending that form letter type thing in the link you referenced. If I were a politician (which I am not) I'd ignore those form letters. But a specific reference to a specific part of a proposed bill would get a lot more attention, especially if you explain why it might affect you specifically.
A lot of times these bills get originally written by specialists from the big businesses that are affected and they don't take into consideration how it affects the little guy. I don't think they do it deliberately to preserve market share. I think our cut is so small that they are not really concerned about us from that aspect, but I do think they are conecerned about our operations being infected which can cause panics in the buying public affecting their bottom line, or affect the export market. Russia, for example, is looking for any excuse to shut off our chicken exports to help their domestic market. That's why we have to use these review periods and come up with constructive comments so we can get them amended. S510 is a decent example of this. As originally written it could hurt those of us with gardens that sell at farmer's markets. But after some comments it was amended to exempt the small guys. The end product did not hurt us.
Anothe possible approach is to contact your county extension agent and question how this act will affect your specific operation. Not all county extension agents are the same, but this is something they should be able to help you with. Mine would not know himself, but I think Johnny would put me in contact with someone that does know.
I'm no legal expert at all. From previous discussions about this act on this forum and what I remember about those discussions (which may not be real accurate. I get confused pretty easily and there are a few of these), I don't think this act would affect either you or your cousin. From what I read, I think your cousin's specific situation is addressed and I think you'd be exempt as long as it is just a few chickens, especially if they are not going directly to slaughter in a decent sized commercial slaughter operation. You'd be silly to rely on me for this, since I'm just a voice out on the internet. You really need to check it out yourself.