Which type of the ligament is primarily responsible for the udder 'breaking down'

The ligament is primarily responsible for the udder 'breaking down' in Median suspensory.
The median suspensory ligament is the most important part of the suspensory system in cows. It is composed of two adjacent heavy yellow elastic sheets of tissue that arise from the abdominal wall and that attach to the medial flat surfaces of the two udder halves.