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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.
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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
Advantages Less expensive Requires no special equipment Limitations Slower genetic improvement Cost of maintaining sires Passing on traits or diseases to offspring Natural Breeding
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