The way you manage the hedgerows on your land could shelter livestock and allow wild animals and birds to feed up and hibernate through the coldest months. A thriving, living landscape is beneficial to you in many respects, and to all who rely upon it.
A healthy hedge line also has a healthy root system that takes up surface water; to do this, it needs to regenerate naturally in spring from growth that has lain dormant from the autumn. When all this growth is sheared off, long shoots spring upwards in a desperate effort to regain height and valuable energy is needlessly lost, preventing green cover foliage from restoring in time for nesting birds to find sites in early spring. Hedge plants subjected to annual cutting to the same height (thugging) cannot provide any of the resources Nature designed them to perform.
Please - leave the body of the hedge to flower and fruit next year if you decide to cut, and raise cutting height above 'knuckles' that have formed, lightly trimming twigs of new growth. No need to take out the underbrush - it doesn't get in anyone's way and helps pollenators and hibernators survive through the winter. Ancient pleachers providing critical shelter and nest sites should stay covered at all times, all year round.
Ease back the blades, well away from the core of the hedge - a really easy implementation even if you still want to cut annually... but you don't have to cut annually! Rotational or incremental cutting is widely advised. You can save diesel, aid carbon capture and prevent the ecosystem from irreversibly breaking down by doing things differently this year.
Take a new approach and see what happens! You can have a living border that looks like a real hedge and functions as real hedges should! Stop thugging and become a genuine guardian of the countryside.