Animal Reproduction

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Animal Reproduction

• Extension beyond the Textbook

Original Power Point Created by Casey
Osksa Modified by Georgia Agricultural Education
Curriculum Office June 2002
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Conditions for Fertilization

• Anatomy of Male Female must be compatible
• Female must be in Heat
• Egg must be mature

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What is the function of the Male?

• produce large numbers of live sex cells
  (spermatozoa)
• contribute 1/2 chromosomes

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What are the Male Reproductive Organs?

• Testicles - produce spermatozoa male hormone
  Testosterone
• Scrotom - sack which carries testicles
• functions as a heat regulator
• Monorchid - one fertile testicle
• Cryptorchid - both testes remain in body cavity
  (sterile)
• Castration - removal of testicles
• lack sex drive
• gain weight quicker

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What are the Male Reproductive Organs?

• Epididymis - tube connects to testes
• storage of spermatozoa (200 billion at a time)
• spermatozoa mature as they migrate through
• Vas Deferens - tube connects to epididymus
• if removed, can't reproduce vasectomy

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What are the Male Reproductive Organs?

• Urethra - begins at bladder and continues through
  penis
• Sigmoid Flexure - "S" shape in urethra allows for
  extension of penis outside of body for
  reproduction

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Accessory Sex Glands

• prostate
• two seminal vesicles
• two cowpers glands

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What is the function of the Accessory Sex Glands?

• provide medium for transporting sperm
• adds volume
• provides nutrients
• cleans flushes urinary tract

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Reproduction in Males

• After sexual maturity, sperm production is
  continuous
• Testosterone is responsible for
• growth, development activity of accessory
  glands
• survival of spermatozoa
• secondary sex characteristicsmale voice, sex
  drive

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Reproduction in Males

• Semen - collective term for all fluid ejaculated
• sperm and fluid from accessory glands

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Artificial Insemination
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What is the function of the female?

• contribute 1/2 chromosomes
• care for young in uterus and after birth until
  weaning

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What are the Female Reproductive Organs?

• Vulva - exterior portion of reproductive tract
• provides visual signs of heat
• Vagina - between vulva cervix
• Cows Ewes semen is deposited here
• Mares Sows semen is deposited in the cervix

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What are the Female Reproductive Organs?

• Cervix - "Mouth of the womb"
• opening into uterus
• at birth cervix stretches to allowbaby to pass
  (most painful part)
• during pregnancy cervix becomes blocked with a
  mucous plug to prevent infection

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What are the Female Reproductive Organs?

• Uterine Horns - two branches of uterus
• Fallopian Tube - uterine horn becomes a small
  tube
• lined with cilia which aid in egg migration

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Ovaries

• located at end of fallopian tubes
• possesses large number of eggs in all stages of
  development
• this is all the eggs she will ever have, unlike
  the male
• very few eggs reach maturity
• if not fertilized, the egg is reabsorbed by the
  body

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Reproduction in Females

• 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
• Estrogen - female hormone which regulates estrus

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What does "in heat" mean?

• Heat is the time when a female is receptive to
  the male and will allow breeding to take place
• Heat is actually divided into 4 phases of the
  cycle.

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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
• Estrous Cycles stop after conception, and begin
  soon after Parturition (birth)

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Females also show external signs of "Heat"

• aggressive behavior
• swelling and/or color change of vulva

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Gestation Period for Animals
Animal Length of gestation
Human 266 to 274 days
Rabbit 31 days
Cattle 284 days
Mouse/Rat 21 days
Pig 114 days
Dog 61 to 74 days
Horse 366 days
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• Beef Terms
• A Mature Male is called a
• Bull
• A Mature Female is called a
• Cow
• The act of Giving Birth is called
• Calving
• Gestation
• 283 days
• A Castrated Male is called a
• Steer
• An Immature Female is called a
• Heifer

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• What do you call a mature male hog?
• Boar
• What do you call a mature female hog?
• Sow
• What do you call the act of giving birth?
• Farrowing
• What do you call a castrated male hog?
• Barrow
• What do you call an young female hog?
• Gilt
• What is the gestation for hogs?
• 114 days or 3 months, 3 weeks, 3 days

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• Poultry Terms
• What do you call a mature male?
• Rooster
• What do you call a mature female?
• Hen
• What do you call a young female?
• Pullet
• What do you call a castrated male?
• Capon
• Chickens Hatch
• What is the incubation period?
• 21 days

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• What do you call a mature male horse?
• Stallion
• What do you call a mature female horse?
• Mare
• What do you call a castrated male horse?
• Gelding
• What do you call a young horse?
• foal or colt

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• What do you call an immature female horse?
• Filly
• What do you call the act of giving birth for
  horses?
• Foaling
• What is the gestation for a horse?
• 330 days