Reproductive success is measured primarily by pigs produced per sow per year and is dependent upon both far rowing rate and litter size. In order to achieve optimal reproductive rates, both the anatomical and physiological workings of the reproductive system must function properly. A basic understanding of the anatomical and physiological function of the female pig reproductive system can aid producers in anticipating and troubleshooting reproductive problems, and in facilitating decisions which impact performance of the breeding herd. This article introduces the reader to the anatomy and physiology of female reproduction and how this acts to enhance or inhibit performance.
Female Reproductive Tract
General Parts and Support
The female reproductive tract is composed of paired right and left ovaries, oviducts, and uterine horns. It contains only a single cervix, vagina and vulva (external genitalia). Collectively, these structures are supported by the broad ligament and hang loosely suspended below the rectum in the both pelvic canal and lower abdomen. The broad ligament is made of tough connective tissue, attaching near the point of the spine, and running continuously with the inner most layer of the abdominal cavity. Many of the blood vessels and nerves travel through this large piece tissue in order to supply the reproductive tract with blood, hormones and neural stimuli. In prepubertal gilts, the ligament is short, paper thin, and almost transparent. However, in late pregnancy it becomes very long as it stretches and thickens in order to support the increasing weight of the pregnant reproductive tract.
The ovary of the pig is primarily important because it is the source for both reproductive hormones and eggs. The ovary is particularly responsive to important hormones that are released from other organs, especially those of the pituitary. The pituitary is located near the base of the brain and is the source