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Breeding Methods

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									Breeding Methods

   By Walt Iciek
   Topic# 3026
  Two Main Types of Breeding
• Artificial Insemination
  – Collected semen deposited directly in to
    females reproductive tract by humans


• Natural Insemination
  – Animals breeding the way they would in nature
        Function of the male
• Produce large number of live sex cells
• Contribute half the chromosomes
    Male Reproductive Organs
• Testicles
  – Produce spermatozoa & testosterone
• Scrotum- sack which carries the testicles
  – Heat regulator
• Epididymis- tube that connects testes
  – Stores sperm
  – Sperm matures there
 Male Reproductive Organs (cont.)
• Vas Deferens
  – Tube which connects to epididymis
• Accessory Glands
  –   Prostate
  –   Seminal vesicles
  –   Cowpers glands
  –   Adds volume and nutrients to semen
      Function of the Female
• Contribute half the chromosomes
• Give birth to offspring
• Care for young until weaning
   Female Reproduction Organs
• Cervix- “mouth of the womb”
  – Opening into uterus
• Uterine Horns
  – Two branches of the Uterus
• Fallopian Tubes- uterine horn
  – Lined with cilia, aids in egg migration
Female Reproductive Organs (cont.)
• Ovaries
  – End of fallopian tubes
  – Large number of eggs, all stages of
    development
  – Few eggs reach maturity
  – If not fertilized, eggs are reabsorbed by the
    body
                  “Heat”
• Time when female is receptive to male and
  is willing to breed
• Identified by:
  – Aggressive behavior
  – Swelling of vulva
• Consist of four stages of estrous
                    Estrous
• Proestrous
  – Ovary is about to release an egg
• Estrous
  – Female receptivity
• Metestrous- uterus prepares for pregnancy
  – Fertilized egg attaches to uterus
• Disestrous- longest period of cycle
  – inactive
             Natural Breeding
• Advantages              • Limitations
  – Less expensive           – Slower genetic
  – Requires no special        improvement
    equipment                – Cost of maintaining
                               sires
                             – Passing on traits or
                               diseases to offspring
       Artificial Insemination
• Definition
  – Deposition of sperm in the female by artificial
    means
  – Used commercially in U.S. since 1938
  – Most widely used in dairy and beef cattle
              Process of A.I.
• Equipment needed
  – Liquid nitrogen– used to store semen at –385
    degrees Fahrenheit
  – Semen straws contain one dose of semen
  – Stainless steel insemination straw
     • Used to place semen in reproductive tract
  – Semen thawing unit
        Insemination Process
• Restrain female gently, squeeze chutes most
  common method
• Prepare semen
• Palpate the rectum and locate the cervix
• Insemination
  – Insert insemination gun into vagina and deposit
    semen
      Eight steps in the procedure
•   Thaw frozen semen slowly
•   Place plastic glove over hand and arm
•   Lubricate plastic glove
•   Restrain animal
•   Insert arm into animal’s rectum
•   Grasp animals cervix
•   Insert insemination gun into the vagina
•   Deposit semen into animal’s cervix
        Artificial Insemination-
              Advantages
•   Use of outstanding sires
•   Alleviates danger of keeping sires
•   Lessens sire costs
•   Helps control diseases
•   Creates large families of animals
•   Increases profits
         Artificial Insemination-
              Disadvantages
•   Requires trained technicians
•   May accentuate poor sires
•   Restricts the sire market
•   Hard to identify true heats in females
•   Timing is crucial

								
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