Animal Reproduction Animal Science
Functions of the Male System
What is the function of the Male? n produce large numbers of live sex cells (spermatozoa) n contribute 1/2 chromosomes
What are the Male Reproductive Organs? n Testicles - produce spermatozoa & male hormone Testosterone n Scrotom - sack which carries testicles –functions as a heat regulator n Monorchid - one fertile testicle n Cryptorchid - both testes remain in body cavity (sterile) n Castration - removal of testicles –lack sex drive –gain weight quicker
What are the Male Reproductive Organs? n Epididymis - tube connects to testes n storage of spermatozoa (200 billion at a time) n spermatozoa mature as they migrate through n Vas Deferens - tube connects to epididymus –if removed, can't reproduce = vasectomy
What are the Male Reproductive Organs? n Urethra - begins at bladder and continues through penis n Sigmoid Flexure - "S" shape in urethra allows for extension of penis outside of body for reproduction
Accessory Sex Glands n prostate n two seminal vesicles n two cowpers glands
What is the function of the Accessory Sex Glands? n provide medium for transporting sperm n adds volume n provides nutrients n cleans & flushes urinary tract
Reproduction in Males n After sexual maturity, sperm production is continuous n Testosterone is responsible for: –growth, development & activity of accessory glands –survival of spermatozoa –secondary sex characteristics:male voice, sex drive
Reproduction in Males n Semen - collective term for all fluid ejaculated n sperm and fluid from accessory glands
Reproduction in Females
What is the function of the female? n Contribute 1/2 chromosomes n Care for young in uterus and after birth until weaning
What are the Female Reproductive Organs? n Vulva - exterior portion of reproductive tract –provides visual signs of heat n Vagina - between vulva & cervix –Cows & Ewes: semen is deposited here –Mares & Sows: semen is deposited in the cervix
What are the Female Reproductive Organs? n Cervix - "Mouth of the womb“ –opening into uterus –at birth cervix stretches to allow baby to pass (most painful part) –during pregnancy cervix becomes blocked with a mucous plug to prevent infection
What are the Female Reproductive Organs? n Uterine Horns - two branches of uterus n Fallopian Tube - uterine horn becomes a small tube –lined with cilia which aid in egg migration
Ovaries n located at end of fallopian tubes n possesses large number of eggs in all stages of development n this is all the eggs she will ever have, unlike the male’s reproductive gametes n very few eggs reach maturity n if not fertilized, the egg is reabsorbed by the body
Reproduction in Females n Farm animals reach sexual maturity at 4 months (sow) to 24 months (mare), then -Female comes in heat (estrus) -Egg released by ovary -Egg travels down tube until fertilized by sperm n Estrogen - female hormone which regulates estrus
What does "in heat" mean? n Heat is the time when a female is receptive to the male and will allow breeding to take place n Heat is actually divided into 4 phases of the cycle.
Estrous Cycle: *Proestrus: ovary is about to release an egg *Estrus: female receptivity *Metestrus: uterus prepares for pregnancy –fertilized egg attaches to uterus *Diestrus: longest period of cycle –inactive n Estrous Cycles stop after conception, and begin soon after Parturition (birth)
Females also show external signs of "Heat" n Aggressive behavior n Swelling and/or color change of vulva n Mucus Discharge
Conditions for Fertilization n Anatomy of Male & Female must be compatible n Female must be in Heat n Egg must be mature
Artificial Insemination