Mating, embryology and exotic reproduction Flashcards
terminology
intromission - process of inserting the penis into the vagina in sexual intercourse
spontaneous ovulation - is triggered during estrus period whether the female is in the prescence of males or not
which part of the dogs penises in engorges during copulation
bulbus glandis
Os penis
what is the name of the bone found in the penises of many mammals
what tests can be done to ensure that the bitch is made it at the optimal stage
Canine mating considerations
Mating often in an artificial environment and there is increased ‘pressure’ on these animals to mate
usually, the dog has to travel a long way and then expected to mate after brief introduction
by passes pro - oestrus so minimal courtship behaviour
post mating care
bitch should be checked for bleeding
small amount of bloody fluid is normal, however if this persists or is excessive this should be assessed by a vet
The dogs penis should retract within the prepuse after mating, sometimes the breeder may try to retract this themselves
seminal fractions
canines produced 3 seminal fractions during intromission
1st fraction - small volume of clear fluid prior to intromission. prostatic fluid only - doesn’t contain sperm
2nd fraction - contains most of the sperm
3rd fraction - ‘flushes’ sperm through cervix. Clear fluid mainly prostatic
Feline mating considerations
Human interference a definite no - observe from a distance only
repeated mating - several times a day over several days may be necessary to cause surge in LH
unsuccessfully mated females will return to oestrus within 2 weeks if ovulation hasn’t occurred
queen should be examined for trauma / infection over scruff from mating
DNA
Deoxyribonucleic acid is found in the nucleus of all cells
they’re wrapped into structures called histone proteins
there are 39 pairs of chromosomes in the dog
and 19 pairs in the cat
somatic cells have the full number of chromosomes
germs (sperm, ova) cells have half the number of chromosomes
recap
Meiosis
Mitosis
gamete
zygote
embryo
foetus
conceptus
Gametes
cell division of gametes occurs by meiotic division
gametes contain haploids no of chromosomes (half) this is so genetic material can be combined from both parents
Zygotes
only one sperm can enter per ova. the zona pellucida and corona radiata prevent more sperm entering
the combination of the ova and sperm is now called the zygote
cell division now occurs by mitosis - diploid (full) no of chromsomes
Gametes
Ova, contain mothers genetic info and are covered by 2 protective layers - zona pellucida and the corona radiata
change occurs in the sperm - capacitation, involving the activation of an enzyme system which allows sperm to penetrate the through the outer layers - causing fertilisation
Blastocyst/blastocoele
at the 16 cell stage, the outer most cells of the morula flatten agasint the zona pellucida
a cavity appears within the core of the cluster, transforming it into a hollow sphere - the blastocyst or blastula
the thickest part - is the embryonic mass
the thinner part - trophoblast
germ layers
within the inner cell mass/ embryoblast is broken down into three layers, the formation of these cells is called gastrulation
ectoderm - forms intergument and nervous sytem
mesoderm - forms muscoskeletal system and organs
endoderm - forms inner lining of the digestive tract and visceral organs
implantation
once in uterine horns, the blastocysts arrange themselves equal distance along the horns - transuterine migration
occurs 14-20 days after fertilisation in the bitch
and 11-16 days after fertilisation in the queen
The placenta
during early embryonic development placenta forms
all of the vital blood components are delivered through this structure
cats and dogs have a zonary placenta
between the outer membrane of the embryo and the placenta there is the marginal haematoma
embryonic membranes
several membranes surround the developing embryo
chlorioalltois
allantoic cavity
allantois
amniotic cavity
Lagomorph / oestrus cycle
gestation 28-35 days
reach sexual maturity for 4 months
induced ovulation - penile spines irritate the cervix leading to ovulation
cycle between oestrus much like a cat
semen from buck has copulatory plug which drops out of does vagina 4 -6hrs psot mating
Rabbit breeding
alfa alfa hay is preferable during gestation due to its high calcium content
has been known to mate ‘ out of season’ but lordosis during mating good indicator oestrus phase
60-80% females develop uterine neoplasia if not spayed
Rabbit neonatal care
kits are born altrical
rabbit milk is highly calorie dense. kits will only feed once a day and are weaned by 5 weeks
prone to gastrointestinal infections
mothers milk contains colostrum
milk oil has bacteriostic properties
newborn kits should only be checked visually. handling can result in rejection
other considerations
does should be kept away from males and can get pregnant straight away
access to lots of hides as becomes more territorial and angry
minimise stress and ensure defecating
bucks
bucks testes decend 12 weeks of age. they can retract there testes into the abdomen via the inguinal canal
ferret reproduction
males - hob
females - jill
induced ovualtion
gestation 39-42 days
jills remain in oestrus until either they are mated or for the reproductive season ends
this can result in hyperoestrogenism (high levels of blood oestrogen), leading to bone marrow suppression causing aplastic anaemia and panleukopenia
