Animal Reproduction Animal Science II

Estrus Cycle Time of day when a female will accept a ____________ for ________________ Length –______ day cycle Cow- _________________ hours Sow- __________ days Best indicator is when the animal stands to be _________________

Ovulation Release of the _______ from the _____________ Number of young born is an indicator of _________ released –Sows: _____ to ______ –Cow: _________ Split eggs produce _________, triplets, etc.

Methods of Reproduction ___________________ Artificial Insemination (_____) _______________ Transfer ____________ using Nuclear Transfer

Artificial Insemination Steps –Insert hand into the _____________ and grasp ___________ –Insert insemination _________ –Deposit bull ___________ from the middle of the ______________ to just into the _____________.

Artificial Insemination Bovine Reproductive Tract Diagram

Artificial Insemination Sow Reproductive Tract Diagram

Artificial Insemination

Advantages –Wider variety of superior _________ used –Increase number of _________ that can be bread to a superior ________ –Reduces _______________ –Dont have to keep a _________ on the ___________

Artificial Insemination

Disadvantages –Requires a ____________ inseminator –Requires more ____________ and herd _______________

Embryo Transfer Procedures –________________ donor –AI –Flush ______________ (catheter) –___________ and ____________ embryos –Store in liquid ______________ –Transfer to ____________ –Diagnose pregnancy ____ to ____ months later

Embryo Transfer Advantage –__________ of the female (dam) can be passed on ____________ than natural breeding

Cloning Using Nuclear Transfer Procedures –__________ (same as embryo transfer) –___________ –Remove _____________ materials from recipient oocytes –____________ is removed through microsurgery

Cloning Procedures (continued) –The nuclei are separated and each one is transferred to an unfertilized egg cell that has had its nucleus removed –Plugs are placed in sheep for 5 to 6 days (develops to the 32 to 64 cell stage) –Embryos are placed in surrogate, frozen or used to clone more animals

Cloning Advantages –Increase herd __________________ –Increase herd ________________ –Produce genetically identical animals

Parturition Process Increased ______________ causes uterus muscles to contract Water bag appears and ____________ The __________ water bag appears with the ____________

Parturition Process Normal Presentation Front ___________ first ______________ ______________ and shoulders _____________ Rear ___________ Rear ___________ last Any presentation not in order could cause ___________ of the baby and/or mother

Parturition Process Several hours later the ________________ and other membranes (_______________) are expelled –A retained placenta is _________________

Animal Genetics Genotype –kinds of ____________ pairs the animal has

Dominant Genes Genes in a pair that hides or _______________ the effect of the other gene in the pair Indicated by _____________________ letters P=___________

Recessive Genes Genes that are ______________ or covered by the dominant gene in the pair Indicated by _____________________ letters p = _____________

Homozygous Homozygous gene pair carries two genes for the ______________ trait –PP = polled and polled.

Heterozygous Heterozygous gene pairs carries two ____________ genes that affect a trait –Pp = polled, horned

Sex Determination Half the sperm carries an ___ chromosome and one half carries a __ chromosome All the _____ carry an ___ chromosome –Male offspring in mammals ____ –Females ____ In ___________ the chromosome configuration is opposite of mammals

Sex-Linked Characteristics Some traits are carried on only the __ chromosome and some on only the ___ chromosome –Traits on the ____ chromosome are transmitted only from fathers to sons Certain genes are expressed in only one ______ although they are carried by both _______ –________ production –_______ laying –rooster tail feathers Sex-linked traits are often ___________ and are covered by ______________ genes

Incomplete Dominance Takes place when _____ gene does not completely _______ the effect of other gene The offspring has a __________ of the two traits –Roan color is a mixture of red and white

Linkage The tendency for certain traits to appear in groups in the offspring because the genes for those traits are located near each other on the chromosome and stay together to pass traits in groups

Crossover Chromosomes cross over one another and _________ to form new ______________ with different combinations of genes

Crossover

Mutation A new ______ appears Did NOT ________ in the genetics of either parent

Punnett Square Used to __________ the results of crossing animals –Male __________ are shown across the ______ –__________ gametes are shown down the _______ side

Punnett Square P= Polled p= horned Example: Two polled cattle that are homozygous for the polled trait PP PPP P Polled Dam Polled Sire

Punnett Square N= Normal size n= Dwarfism Example: Normal size in cattle is dominant to dwarfism NN NNN nNn Dam Sire

Punnett Square N= Normal size n= Dwarfism Example: What if both parents are carriers for a trait or disorder? Nn NNNNn n nn Dam Sire What is the probability that a Homozygous dwarf calf is born?