SUSPENSORY APPARATUS
The udder of a lactating dairy cow can weigh up to 60kg, and it is supported by a dense system of fibroelastic ligaments known as the suspensory apparatus. This apparatus is primarily comprised of two medial laminae, originating from the abdominal wall’s linea alba and the pelvis’s symphysis.
These laminae pass between the two halves of the udder, with one layer covering each half closely. While proximal regions are thicker, they thin out near the intermammary groove as they diverge into the udder parenchyma. The lateral laminae, composed mostly of dense white fibrous connective tissue, originate from the body wall’s aponeurotic tissues and meet the medial laminae at both ends of each udder half. They also thin out ventrally, releasing connective tissue sheets into the gland’s substance.The udder of a lactating dairy cow can weigh as much as 60kg, so the organ is supported by a dense system of fibroelastic ligaments called the suspensory apparatus. The primary supportive elements of the suspensory apparatus are its two medial laminae, which take their origin together from the linea alba of the abdominal wall and the symphysis of the pelvis. Each medial lamina passes ventrad between the two halves of the udder so that one layer intimately covers the medial side of each half. The two medial laminae can be readily separated, as they are united only by a small amount of loose areolar connective tissue; practically no vessels or nerves pass through the medial ligament from one half of the udder to the other. Proximally (close to the body wall), the laminae are thickest. As they descend, they give off sheets of connective tissue that diverge from the midline and interdigitate into the parenchyma of the udder so that the two medial laminae are thinnest near the intermammary groove.
The lateral laminae of the suspensory apparatus are composed largely of dense white fibrous connective tissue, making them less elastic than the medial laminae, which are mostly elastic connective tissue. The cranial part of the lateral lamina derives from the aponeurotic tissues of the body wall near the external inguinal ring and more cau- dally from the regions of the pelvic symphysis and prepubic tendon (the tendon of insertion of the m. rectus abdominis). From its origins, the lateral lamina passes ventrad and around the lateral side of each half of the mammary gland, meeting the medial lamina at the cranial and caudal aspects of each half. Like the medial lamina, the lateral lamina is thick close to the body wall and thin progressively ventrally as it gives off sheets of connective tissue into the substance of the gland.
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