What to do with cattle as a depreciated asset when part are sold? Income and cost on SCH F.

We have 33 head of cattle listed as a depreciable asset from 2015. 7 head were sold in 2017. I reported the income and cost on my SCH F. Now do I reduce the number from 33 to 26 on the asset. Trying to follow PUB 225 but getting lost.