reproduction

Question 1

What are the 6 stages of reproduction?

Answer 1

Ovulation
Copulation
Fertilisation 
Implantation 
Gestation 
Parturition

Question 2

Describe each stage of reproduction

Answer 2

ovulation - when female produces egg
copulation - male and female mate or female is inseminated
fertilisation - sperm combines with ovum
implantation - fertilised egg implants into uterus
gestation - fetus grows inside uterus
parturition - female gives birth to young

Question 3

how is reproductive efficiency measured?

Answer 3

Dairy - calving index
Pigs - piglets per sow per year
Ewes - lambing percentage

Question 4

when does sexual activity start

should you breed at this age

Answer 4

heifers - 8 months
bulls - 8 months
guilts - 6 months
boars - 6 months
ewe and ram lambs - autumn in year of birth
not advised to breed at this age as can cause difficulties

Question 5

risk of breeding females early

Answer 5

female may develop less well after pregnancy

increased risk of parturition difficulties and reduced production

Question 6

common breeding age

Answer 6

heifers - 15 months or 320-340KG
guilts - 7 months or 110KG or 3rd oestrus cycle
ewes - 18 months

Question 7

female reproductive tract from outside to inside

Answer 7

vulva
vagina
cervix
uterine horn
oviduct
ovary 
uterine body

Question 8

functions of cervix

Answer 8

narrow opening between uterus and vagina
has annular rings
thick wall allows passage way for sperm and expulsion of fetus at parturition
during pregnancy cervix is filled with thick mucous (cervical plug) this protects uterus from infections

Question 9

ovaries

Answer 9

2 ovaries produce ova
act as endocrine glands to produce hormones
eggs develop from follicles (specilised cells)
corpus luteum holds pregnancy

Question 10

oviducts

Answer 10

lead from ovaries to uterus
contain glands that secrete mucous - lubricates surface
egg expelled from ovary to oviducts
egg can be fertilised when its in the oviducts

Question 11

uterus

Answer 11

egg is implanted in uterus where fetilised egg can develop

thick muscle walls and inner lining called endometrium

Question 12

when does oestrus occur

Answer 12

cows - every 20-22 days
ewes - every 16-17 days but only during late summer/early autumn
sows - every 20-21 days

Question 13

external factors hypothalamus responds to

Answer 13

length of day
temperature
social behavior in herd (in pigs)

Question 14

internal factors hypothalamus responds to

Answer 14

nutrition
hormones
body condition
stress

Question 15

stages in oestrus cycle

Answer 15

growth of follicles
ovulation
fertilisation or non-pregnancy

Question 16

hypothalamus controls

Answer 16

ensures offspring are born at favourable times of the year
synchronises behaviour between males and females
synchronized the process within the flock

Question 17

what are the male and female sex hormones

Answer 17

female - oestrogens

male - androgens

Question 18

role of hormones for males

Answer 18

testosterone produced in testes
testosterone helps male sex organs develop function
maintains characteristics such as deeper bellow, muscular development, extra body hair

Question 19

testes

Answer 19

produce sperm

contained in external sac called scrotum

Question 20

what is the scrotum

Answer 20

allows lower temperature than body to aid sperm production

Question 21

journey of sperm

Answer 21

sperm travel from testes down vas deferens (sperm duct)
vas deferens joins urethra and is mixed with semen
sperm and semen travel down urethra to penis
is then released into females vagina during mating

Question 22

semen

Answer 22

produced in prostate gland

is the fluid that sperm travels in