1) Uncertain meaning; to do with the face of an animal.
An uncommon word with an uncertain meaning. It describes the face of an animal, possibly a reference to colour, and the Yorkshire examples indicate that it is unlikely to mean ‘bridled’ as suggested in the OED. 1560 one gymber with a bronked face … one powled ewe with a bronked face, Sherburn
1580 to Elizabethe Ironside one bronked oxe, Houghton le Spring. A connection with ‘broked’ seems possible: 1533 my best broked faced whie … a brokyd faced whie, Wilberfoss
1577 a cowe called the Broke cowe, Crackpot
1748 four red brockt cows and one red harled cow, Stockton. In Scotland ‘brockit’ is used especially of animals which have a white streak down the face, possibly a reference to the ‘brock’ or badger.