Mating, embryology and exotic reproduction

Question 1

terminology

Answer 1

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

Question 2

which part of the dogs penises in engorges during copulation

Answer 2

bulbus glandis

Question 3

Os penis

Answer 3

what is the name of the bone found in the penises of many mammals

Question 4

what tests can be done to ensure that the bitch is made it at the optimal stage

Question 5

Canine mating considerations

Answer 5

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

Question 6

post mating care

Answer 6

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

Question 7

seminal fractions

Answer 7

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

Question 8

Feline mating considerations

Answer 8

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

Question 9

DNA

Answer 9

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

Question 10

recap

Answer 10

Meiosis
Mitosis
gamete
zygote
embryo
foetus
conceptus

Question 11

Gametes

Answer 11

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

Question 12

Zygotes

Answer 12

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

Question 13

Gametes

Answer 13

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

Question 14

Blastocyst/blastocoele

Answer 14

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

Question 15

germ layers

Answer 15

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

Question 16

implantation

Answer 16

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

Question 17

The placenta

Answer 17

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

Question 18

embryonic membranes

Answer 18

several membranes surround the developing embryo

chlorioalltois
allantoic cavity
allantois
amniotic cavity

Question 19

Lagomorph / oestrus cycle

Answer 19

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

Question 20

Rabbit breeding

Answer 20

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

Question 21

Rabbit neonatal care

Answer 21

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

Question 22

other considerations

Answer 22

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

Question 23

bucks

Answer 23

bucks testes decend 12 weeks of age. they can retract there testes into the abdomen via the inguinal canal

Question 24

ferret reproduction

Answer 24

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