Breeding Methods

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Breeding Methods

• By Walt Iciek
• Topic 3026

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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

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Function of the male

• Produce large number of live sex cells
• Contribute half the chromosomes

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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

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Male Reproductive Organs (cont.)

• Vas Deferens
• Tube which connects to epididymis
• Accessory Glands
• Prostate
• Seminal vesicles
• Cowpers glands
• Adds volume and nutrients to semen

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Function of the Female

• Contribute half the chromosomes
• Give birth to offspring
• Care for young until weaning

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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

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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

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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

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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

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Natural Breeding

• Advantages
• Less expensive
• Requires no special equipment

• Limitations
• Slower genetic improvement
• Cost of maintaining sires
• Passing on traits or diseases to offspring

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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

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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

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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

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Eight steps in the procedure

• Thaw frozen semen slowly
• Place plastic glove over hand and arm
• Lubricate plastic glove
• Restrain animal
• Insert arm into animals rectum
• Grasp animals cervix
• Insert insemination gun into the vagina
• Deposit semen into animals cervix

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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

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Artificial Insemination- Disadvantages

• Requires trained technicians
• May accentuate poor sires
• Restricts the sire market
• Hard to identify true heats in females
• Timing is crucial