animal reproduction animal science ii estrus cycle time of day when a female will accept a...
TRANSCRIPT
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
Artificial Insemination
Artificial Insemination
Artificial Insemination
• Advantages– Wider variety of superior _________
used– Increase number of _________ that can
be bread to a superior ________– Reduces _______________– Don’t have to keep a _________ on the
___________
Artificial Insemination
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= Polledp= hornedExample:• Two polled cattle
that are homozygous for the polled trait
P P
P PP PP
P PP PPPol
led
Dam
Polled Sire
Punnett Square
N= Normal sizen= DwarfismExample:• Normal size in
cattle is dominant to dwarfism
N N
N NN NN
n Nn NnD
am
Sire
Punnett Square
N= Normal sizen= DwarfismExample:• What if both
parents are carriers for a trait or disorder?
N n
N NN Nn
n Nn nn
Dam
Sire
What is the probability that a Homozygous dwarf calf is born?