AS100: Lec 10

• the science that deals with the application of various animal genetic application of various animal genetic principles purposely to improve or enhance the performance of livestock and poultry species

  animal breeding
• Traits improved in Animal Breeding

  • growth
  • production
  • reproductive traits
  • adaptive capabilities of domestic animals
• it involves the selective breeding of domestic animals with the intention to improve desirable (and heritable) qualities in the next generation


  animal breeding
• It is the process in which certain individuals in a population are preferred to others for the production of the next generation.

  selection
• It occurs when natural forces favor the survival of the most fitted individuals just like those indigenous animals in certain areas.

  natural selection
• It is the process of breeding animals for their desirable traits by an outside source other than the organism itself or natural selection.

  artificial selectioin
• Selection does not create new genes but rather it increases the frequency of the desirable genes and conversely decreases and eventually eliminates the undesirable ones.
• is a record of individual’s ancestors related to it through its parents

  pedigree
• Animals especially the sires are accepted or rejected depending on the performance of their progenies when subjected to a standardized test.
• Animals are accepted or rejected based on the performance records of their distant relatives such as their aunts, uncles, half-brothers and half-sisters.

  what is the basis for this selection?

  Selection on the basis of collateral relatives
• are tools that aid animal practitioners in the development of new breeds, strains and lines of animal species

  mating schemes
• It is a mating system in which progenies are produced by parents that are VERY closely related

  inbreeding
• Its genetic effect is by increasing the homozygosity of genes, thus the phenotypes or characters expressed by the inbred are more uniform.

  inbreeding
• This mating system involves half-sib mating, and cousin x cousin mating

  linebreeding
• It is the mating of animals of different breed

  crossbreeding
• It is the mating of unrelated individuals within the same breed

  outcrossing
• is the increase or improvement in the performance of hybrids (crossbreds) over those of the purebreds

  heterosis
• Period of time when a female will accept a male for copulation.

  estrus
• duration of estrus of cow

  12-18 hours
• duration of estrus of ewe

  24-36 hours
• duration of estrus of sow

  48-72 hours
• duration of estrus of mare

  90-170 hours
• duration of estrus of hen

  none
• what are the hormones that are involved in the estrous cycle?

  • estrogen
  • progesterone
• length of the estrous cycle of a cow

  19-21 days
• length of the estrous cycle of an ewe

  16-17 days
• length of the estrous cycle of a sow

  19-21 days
• length of the estrous cycle of a mare


  21-24 days
• length of the estrous cycle of a hen

  none
• number of released eggs per estrous cycle

  ovulation rate
• ovulation rate of a cow

  1 egg
• ovulation rate of an ewe

  1-3 eggs
• ovulation rate of a sow

  10-20 eggs
• ovulation rate of a mare

  1 egg
• ovulation rate of a hen

  approximately 28 eggs per month
• It is considered as the most useful and applicable strategy of increasing the number of genetically superior progenies from proven sires and dams

  artificial insemination
• pros of Artificial Insemination

  • increases in the number of females that could be mated by a single male
  • minimizes the transmission of sexually transmitted diseases
  • males that are physically unable to mate naturally may still be used for breeding
  • semen of sires that may have been long dead can still be used
  • the number of progenies that could be produced by a single male is increased
• are units of heredity which are transferred from a parent to offspring

  genes
• where are the genes located?

  in the chromosomes
• how many chromosome are there in a humans body?

  23 pairs