AS-320 Sept., 1964
This publication is designed as a teaching aid for the intensive swine reproduction schools conducted by the Cooperative Extension Service. It is also included in the Pork Production Handbook for County Extension Agents. It is intended to offer a more thorough understanding of the swine reproductive system.
Introduction
The process by which new individuals come into being is known as reproduction. Reproduction is an orderly, systematic process by which each parent makes very definite contributions to the new individual’s constitution. It is through the understanding of this process and its application to the problems of swine breeding that swine breeding is gradually becoming converted from ^ art to a science. When presently known principles of breeding come into more general understanding and use, further improvements in swine production and efficiency will result.
The purpose of these papers is to help you more clearly understand the present day knowledge. You can reap the harvest °f greater usage of these principles and also 0e in a position to apply new technologies which loom over the horizon, eg. artificial lnsemination, controlled heat periods, sex termination and others.
Physiology of reproduction of swine ls a composite science. For an appreciation °fthe subject it will be necessary to draw
upon the accumulated knowledge of anatomy, embryology, physiology, endocrinology and genetics.
Terms and Definitions
Sperm, Spermatozoon; pi. sperm(s), Spermatozoa. The male sex cells, germ cells or gametes.
Ovum, egg; pi. ova, eggs. The female sex cells, germ cells or gametes.
Semen--The composite of sperm from the testicles and fluids from the testieles and the accessory glands.
Insemination--The deposition of semen in the female reproductive tract.
Semination--The penetration of the ovum by the sperm.
Fertilization--The penetration of the ovum by the sperm and the fusion of the male and female pronuclei.
Primordial germ cells--The earliest differentiated germ cells.
Spermatogenesis --The production of sperm.
Exocrine glands--Those whose secretions flow to the surface through a duct or tube; eg. tear glands.
BREEDING
Reproductive Organs of Boar and Sow
Richard Hollandbeck and C. W. Foley, Animal Sciences Department