Further to Venerable Dhammānando's comment above, we should look in detail at what the commentary to the Vaṇijja Sutta says:Sattame vaṇijjā ti vāṇijakammāni.
In the seventh (sutta), “Trading,” means the livelihood of trading.Upāsakenā ti tisaraṇagatena.
“By a disciple,” means one gone to the three refuges.
Iti sabbampi imaṃ vaṇijjaṃ neva attanā kātuṃ, na pare samādapetvā kāretuṃ vaṭṭati.
- Satthavaṇijjā ti āvudhabhaṇḍaṃ kāretvā tassa vikkayo. “Trading in weapons” means, having made them he sells them.
- Sattavaṇijjā ti manussavikkayo. “Trading in living-beings,” means selling human beings.
- Maṃsavaṇijjā ti sūkaramigādayo posetvā tesaṃ vikkayo. “Trading in flesh,” means having raised pigs or deer, etc., he sells them.
- Majjavaṇijjā ti yaṃkiñci majjaṃ kāretvā tassa vikkayo. “Trading in indoxicants,” means having made whatever kind of intoxicants he sells them.
- Visavaṇijjā ti visaṃ kāretvā tassa vikkayo. “Trading in poisons,” means having made poisons he sells them.
Thus, it is not suitable to engage in these trades oneself, nor to instruct another to do them.
Trading in flesh means raising livestock and selling their meat. Whether one kills the animals oneself, or hires another to do it, it is wrong livelihood. I think it reasonable to extend this to purchasing meat from the abattoir or fish from the fish market, and then selling it as one's means of livelihood.
I think it goes too far to include cooking meat in a restaurant where one is employed or serving customers in the delicatessen counter of a supermarket.