Guardian Crossword 20.6.24

[fraseralex]

String runs through pipes (6)

The solution must be HORSES. The wordplay is straightforward but please can someone explain why string means horses? 

[Hazlinny]

In this case, a group of horses kept on a farm are sometimes known as a 'string'. This term is usually applied to horses which are all owned by the same person. So, if there are ever multiple horses mixed in the same field, each owner will have their own 'string' of horses which belong to them.

[fraseralex]

Thanks for your knowledge. New to me.