Reproductive System Flashcards
What are the terms for each male species when entire?
Horse = stallion
Cow = bull
Pig = boar
Sheep = ram
What are the terms for each species when castrated?
Horse = gelding
Cow = steer
Pig = barrow
Sheep = wether
What are the 8 structures of the male reproductive tract?
- 2 testes
- 2 epididymis
- 2 ductus deferens
- scrotum
- accessory sex glands
- urethra
- penis
- prepuce
What is the structure of the testes?
- different position in each species
- contains mass of seminiferous tubules separated by interstitial tissue
- seminiferous tubules are lined with spermatogenic and are sertoli cells
Position of the testes in the bull?
- near the sigmoid flexure of the sigmoid
- scrotum is elongated and pendulous
Position of the testes in the boar?
- caudal to the sigmoid flexure just ventral to the anus described as being perineal
Position of the testes in the horse?
- the long axis of each testis is virtually horizontal
- testes are held close to the abdominal wall
What is the descent of testes?
- usually complete by birth or very soon after
- the testes is guided down into the scrotum via a fibrous cordlike structure called the gubernaculum
What is it called where an animals testes fail to descend?
- cryptorchid
- likely to be heritable and they can develop abdominal tumours so advised to be castrated and retained testical removed
What 4 male structures are in a similar location in each species?
- epididymis
- ductus deferens
- scrotum
- inguinal canal
What are the 4 accessory glands?
- ampullae
- vesicular glands
- prostate gland
- bulbourethral gland
What is the ampullae?
- enlargement of the last part of the ductus deferens
- well developed in the stallion, bull and ram
- not present in the boar
What is the vesicular gland?
- paired glands
- pear shaped and hollow in the stallion
- in the bull, ram and boar are lobulated and of a considerable size
What is the prostate gland?
- unpaired gland which surrounds the urethra and has multiple ducts which empty into the urethra
- produces an alkaline solution that gives semen its characteristics smell
- heart shaped in boar
- h shaped in stallion
What is the bulbourethral gland?
- paired glands on either side of the urethra just cranial to the ischial arch
- these are very large in the boar
Structure of the penis in the stallion?
- musculocavernous penis
- has a predominance of blood sinuses instead of connective tissue
- the stallions penis is flaccid when not erect
Structure of the penis in ruminants and pigs?
- fibroelastic penis
- the trabeculae of the tunica albuginea make up the bulk of the penis which makes the penis firm even when not erect
What is the structure of the glans penis in the bull and ram?
- have a helmet shaped glans
- the external opening of the bull opens into a twisted groove
What is the structure of the glans penis in the boar?
- small
- has a twisted end
What is the urethral process and which species is it present in?
- a free portion for the urethra that project beyond the glans
- the stallion and ram
What is the structure of the prepuce in the stallion?
- double fold so 2 layers surround the penis when it is retracted
What is the structure of the prepuce in the boar?
- has a pouch dorsal to the prenuptial orifice
- the pouch collects urine, secretions and dead cells, which contribute to the distinctive smell of the boar
What are the terms given to each female of the species?
Horse = mare
Cow = cow
Pig = sow
Sheep = ewe
What are the 3 functions of the female reproductive tract?
- produce ova and deliver to the site of fertilisation
- provide an environment for the development and growth of the embryo
- expel the foetus at birth
What 5 structures make up the feral reproductive tract?
- 2 ovaries
- 2 oviducts
- uterus (uterine horns, body and cervix)
- vagina
- vulva
What is the structure of the ovaries in cow and ewes?
- oval in shape
What is the structure of the ovaries in the mare?
- bean shaped
What is the structure of the ovaries in sows?
- can appear lobulated due to the fact that many ova develop at the same time
What is the function of the oviducts?
- they transport the ova from the ovaries to the uterine horns
- site of fertilisation
What is structure of the oviducts?
- they are paired convoluted tubes
- the end of the oviduct nearest to the ovary is funnel shaped and is called the infundibulum
- they are lined with mucus membrane
What makes up the uterus?
- the cervix
- a uterine body
- 2 uterine horns
What is the function of the vagina?
- the birth canal through which the foetus is delivered at parturition
- receives the penis during mating
Where is the vestibule located?
- the area between the vagina and the vulva
Where is the start of the vestibule marked?
- it is marked by the external urethral orifice, which is where the urethra opens in to the reproductive tract
What is the suburethral diverticulum and which species is it present?
- the short blind ending sac which is just ventral to the opening of the urethra
- pigs and cows
What is the vulva?
- the external genitalia of the female
What is the perineum?
- the area surrounding the anus and vulva
Where should the vulva be located and why is this important?
- it should sit ventrally and vertically in line with the anus
- this allows faeces to drop clear away from the vulva which will stop any infection harbouring there
What are the mammary glands?
- modified sudoriferous glands
- they produce milk for offspring nourishment
What is colostrum?
- the first milk produced on delivery of newborns
- important for survival and provide temporary immune protection
What is polyoestrous?
- animal that continuously cycle throughout the year
What is seasonally polyoestrous?
- animal with oestrous cycles that occur during certain seasons of the year, this depends on daylight
When are cows breeding seasons?
- non seasonally polyoestrous
- they come into oestrus all year round
What are mares breeding seasons?
- seasonally polyoestrous
- they come into oestrous at specific times of the year
- mares are long day breeders which means they start to come into season during spring/summer
What are sows breeding seasons?
- polyoestrous with a period of lactation all anoestrus, which will last until the piglets are weaned
- hormonal changes do not respond to the changing seasons in the sow so she will continue to cycle throughout the year
- sows are spontaneous ovulators
What are ewes breeding seasons?
- seasonally polyoestrous
- sheep are short day breeders, she will cycle in response to shorter hours for daylight
- some breeds are less seasonal and breed all year round
What are the 4 stages of the oestrous cycle?
Pro-oestrus
Oestrus
Met oestrus
Di-oestrus or Anoestrus
What happens during pro oestrus?
- the building up phase
- ovarian follicle develops under the influence of follicle stimulating hormone and leutenising hormone
- as the follicle develops it secretes oestrogen
What happens during oestrus?
- period of sexual receptivity
- females should stand for mating
- oestrogen levels remain high and some progesterone is released
- a surge of leutenising hormone is reposnsible for the rupture of the ovarian follicle and release of the ovum
What happens during met-oestrus?
- begins once sexual receptivity ends
- corpus luteum forms at the site of the ruptured follicle
- oestrogen levels fall, swelling will reduce at this stage
- corpus luteum releases progesterone
What happens during di oestrus?
- in polyoestrous animals a short period of inactivity follows met, oestrus before they return to pro oestrus
What happens during anoestrus?
- no sexual or hormonal activity
- normally animals with long oestrus cycles
What are mares oestrus table of events?
Onset of puberty = 18 months
Age at first service = 2 to 3 years
Oestrus cycle = 21 days
Oestrus = 6 days
Gestation = 336 days
What are cows oestrus table of events?
Onset of puberty = 1 to 2 years
Age at first service = 1 to 2 years
Oestrus cycle = 21 days
Oestrus = 18 hours
Gestation = 282 days
What are ewes oestrus table of events?
Onset of puberty = 8 months
Age at first service = 1 to 1.5 years
Oestrus cycle = 17 days
Oestrus = 1 to 2 days
Gestation = 150 days
What are sows oestrus table of events?
Onset of puberty = 7 months
Age at first service = 8 to 10 months
Oestrus cycle = 21 days
Oestrus = 2 days
Gestation = 114 days
What are the 3 cow breeding facts?
- ovulation occurs 10 to 14 hours following oestrus
- artificial insemination takes place 12 hours after oestrus
- bovine sperm needs to be in the uterus for 6 hours
What are the 4 sheep breeding facts?
- oestrus normally lasts 30 hours
- ovulation occurs near the end of oestrus
- 2 to 3 ovulations may occur hence twins or triplets
- best time to breed is mid to late oestrus
What are the 5 pig breeding facts?
- 10 to 25 ova are shed
- ovulation occurs in the later part of oestrus
- sows can exhibit oestrus post parturition most are infertile
- oestrus post weaning occurs 7 to 9 days after
- oestrus post weaning 65 hours
What are the 4 horse breeding facts
- prostaglandins can cause mild colic
- pg can be used to induce season, should come into season within 2 to 4 days
- foaling heat, first season post foaling lasts 2 to 3 days
- hormonal changes are important
