Reproductive Anatomy and Structure of the Bony Pelvis

The reproductive anatomy of farm animals involves distinct patterns of reproduction in both female and male farm animals, which are influenced by the structure and function of the bony pelvis.

The bony pelvis consists of the sacrum, coccygeal vertebrae, and the two os coxae, each formed by the ilium, ischium, and pubis.

The Bony Pelvis

The bony pelvis is composed of the Sacrum, the first to third Coccygeal invertebrae, and the two Os coxae, each formed by the Ilium, Ischium and Pubis.

Sacrum

Sacrum is formed by five fused vertebrae, triangular in shape between the lumbar kind coccygeal vertebrae. The ventral face is concave and smooth and the dorsal surface has the sacral spine. The wing of the sacrum articulates with Ilium laterally. In older animals the first coccygeal may fuse with sacrum in horse, cow and pigs.

Ilium

Ilium is irregular triangular in shape. The dorsal part is called the wing and the medial part, Tuber Sacrale.

The ventral medial articulates with sacrum. External portion of the wing is called the Tuber coxae or hip bone or hook bone which the wides attachment for the gluteal and back muscles. In dog and cat the wing is early parallel to the spinal column.

Ischium

Ischium forms the caudal part of the ventral floor of the pelvis. The caudal border joins the opposite ischium to form the ischiatic arch.

The caudal lateral isolation is called the Tuber ischii or pin bone. Especially the ischial and pubic bones fuse to form the pelvic symphysis. In the cow and ewe the portion of the pelvic floor formed by the two Ischia is deeply concave one side to side.

Pubis

Pubis is smallest of the three bones of the Os coxae and forms the cranial portion of the pelvic floor.

The dorsal or pelvic surface is smooth and usually concave in females while in males it may be convex.

Pelvic Ligaments

Pelvic ligaments maintain the relationship of the pelvis to the spinal column.
The pelvic ligaments are the dorsal and lateral sacroiliac ligaments, sacrosciatic ligament and the prepubic tendon.

Pelvic inlet

The shape of the pelvic inlet in all species is roughly oval in shape. In cow and sow it is elliptical in shape where as mare and dog nearly round inlet.