grammatical number - When do I use "livestock is" and "livestock are"?

Honestly, I know the answer is most likely going to be some form of "it depends", so here's the context I'm using the phrase noun in:

the livestock are acting up and now I need to...

the livestock is acting up and now I need to...

I know there are instances when "livestock" feels more singular than plural, but in my use case I'm leaning plural. I'm just not sure.

Any help and other examples are appreciated

Answer

ODO defines livestock as a mass noun, and none of its many examples has either is or are following the word:

livestock noun (mass noun)
Farm animals regarded as an asset.
‘markets for the trading of livestock’
- ODO

Interestingly, though, M-W provides this pair of examples:

a market where livestock are bought and sold
a market where livestock is bought and sold

M-W's learner's dictionary provides a little more information, noting both plural and noncount usage of the word livestock, with the above examples repeated.

So if you're treating the livestock as a (plural) set of animals, use livestock are, and if you're treating the animals as a collective (massed) group, use livestock is.