Suspensory Apparatus of the Bovine Udder in the Estonian Black and White Holstein Breed: Increased Milk Production (Udder Mass) Induced Changes in the Pelvic Structure

Abstract

Bovine udders, together with the attached section of the ventral abdominal wall, as well as the bony pelvic floor were studied. The parts of the suspensory apparatus and attachment to the body were investigated. The location of the medial and lateral laminae served as the basis for classifying them into abdominal and pelvic parts. The udder base is attached to the ventral abdominal wall by means of the dorsal connective tissue plate. The abdominal part of the medial lamina and the pelvic part of the lateral lamina are the functionally more important bands. Sixty per cent of the udder base is attached to the ventral abdominal wall and 40% to the pelvic floor by the symphysial tendon. The symphysial tendon is attached to the ventral pubic tubercle and the symphysial eminence as well as to the symphysial crest, which develops by the fourth year. In order to study the osseous changes, bovine pelvises from the Middle Ages, the beginning of the 20th century, and the present time were compared. Increased udder mass has brought about changes in the structures of the suspensory apparatus of the udder and in the structure of the pelvis.