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•Artificial Insemination
•Documents from around 1322 A.D. state that an Arab chief wanted to mate his mare to a stallion owned by his rival.
•Then in 1780, Spallanzani successfully bred two dogs with the use of A.I. Leading to him being named the inventor of artificial insemination.
•The mass breeding of cattle however didn’t come until later, in 1931. By an A.I. Cooperation in Denmark.
Most Animals May be Inseminated
• Cattle• Horses• Swine• Sheep• Goats• Poultry• Dogs
• Panda Bears• Rhinos• Elephants• Killer Whales• Chimps• Llamas• Humans
•The greatest advantage of Artificial The greatest advantage of Artificial Insemination is that it increases the Insemination is that it increases the maximum use of superior sires.maximum use of superior sires.
•Can breed more than one female per Can breed more than one female per collectioncollection•The semen being used can be tested for The semen being used can be tested for disease and genetic defects. disease and genetic defects.
•AI can be used when there are health or AI can be used when there are health or structure problems in male or female.structure problems in male or female.
•Can use deceased siresCan use deceased sires
There are several ways to collect semen. There are several ways to collect semen.
Although the use of an artificial vagina is most Although the use of an artificial vagina is most common.common.The artificial vagina is made of a firm The artificial vagina is made of a firm cylindrical tube that has a thin-walled cylindrical tube that has a thin-walled rubber lining.rubber lining.
•First the bull is allowed to mount a teaser First the bull is allowed to mount a teaser cow or mounting dummycow or mounting dummy•Then as the bull ejaculates , the penis is directed into the Then as the bull ejaculates , the penis is directed into the artificial vagina, where the semen is captured.artificial vagina, where the semen is captured.
Methods of Semen Collection
1.Mounting dummy.
(Boars, bulls, stallions, rams)
2. Digital manipulation
3. Electroejaculation
Semen Analysis
• Sperm concentration- Total sperm is determined by multiplying concentration (sperm per ml) by ejaculate volume (ml).
• Sperm motility - the percentage of sperm that are progressively motile. A progressively motile sperm swims briskly forward in a relatively straight line.
• Sperm morphology - the percentage of sperm with normal shape and size is determined.
Class ml/ejaculate Sperm Conc No. Females
Bull 5-6 800-1,200 300-500
Ram 1 800-4,000 40-100
Boar 200-300 25-1,000 15-25
Stallion 50-150 30-800 8-12
Semen Evaluation – Visual Appraisal
• Color varies from yellowish to a light cream
• Semen from most species is homogeneous in consistency, the presence of flakes or clumps usually indicates inflammation.
Hemacytometers• Can be used to count blood cells and
spermatozoa.
• A hemacytometer has two chambers and each chamber has a microscopic grid etched on the glass surface
Extending (or diluting) the semen increases the number of females that can be inseminated from one ejaculation.
There are several good semen extenders. Those made from egg yolk or pasteurized, homogenized milk are two of the most widely used. A good extender not only adds volume to the ejaculate, but favors sperm survival and longevity.
Dilution rate depends on quality of sperm..
Antibiotics such as penicillin and streptomycin are added to semen extenders to inhibit bacterial growth and reduce the spread of diseases
Semen can be frozen and stored for Semen can be frozen and stored for indefinite periods. indefinite periods.
British scientists discovered that British scientists discovered that addition of glycerol to the semen addition of glycerol to the semen extender improved resistance of sperm extender improved resistance of sperm to freezing, in 1949. to freezing, in 1949.
Glycerol removes water from the sperm Glycerol removes water from the sperm before freezing. It also prevents the before freezing. It also prevents the ice crystals from damaging the sperm.ice crystals from damaging the sperm.
•Dry ice and alcohol (-100 degrees F)Dry ice and alcohol (-100 degrees F)
•Fertility declines graduallyFertility declines gradually
•Liquid nitrogen (-320 degrees F)Liquid nitrogen (-320 degrees F)
•No deterioration with age.No deterioration with age.
Sperm Transport
• sperm can travel to the oviducts in a few minutes, which is too fast to be explained by sperm motility.
• sperm transport is largely a result of uterine contractions, and mucosal texture
• In most species, the uterus is hostile to sperm.
• sperm may remain in the uterus for several days, but fertility rapidly declines.
• Poultry are an exception, in chickens, sperm can live 1-2 weeks.
Fertilization
• One sperm only will fertilize the egg.
• When that sperm cell penetrates the zona pellucida, it hardens to prohibit additional sperm from penetrating the egg