I would talk to the 'butchers' anyways. Don't be surprised if they're clueless, but they might know something about the meat. I'd write down your questions before you go in.
Where is the farm this liver comes from?
What inputs do the animals get? Water, grains, grass, minerals, hormones, vitamin injections, etc. They should only be getting air, sun, minerals, water, grass. Anything else is suspicious.
Do they spray their pastures with any chemicals organic or natural?
Are they 100% grass fed? Is it fresh grass or stored forage?
Where and how is the meat processed?
How long from death to shelf? This is important because I've had livers from cows that I know the farmer and the farmer does and excelent job, but the liver has been in the freezer so long, and without proper storage that it was light pink and mealy, even though it probably started out deep dark purple and smoothe, dense.
Don't be afraid to ask them a 100 questions and press them for good, confident answers. Pay attention to their body language and confidence.
I have dealt with so many aloof, ignorant, apathetic, condescending butchers that it's not even funny. But now I have my butchers at the local co-op who know me by name and call me up to let me know the fresh shipment has just come in and if they should reserve it for me, of course I usually buy a whole 15 lb liver, a tongue, heart and kidney all at a go, so they love me cuz they don't have to process anything, just rebag it, retag it an sell it!
everything is always stellar quality and they gave me the name of the farm so I could go visit if I wanted. I contacted the farmer and he's kickass, really doing it right!