Infertility in farmed species workshop

Question 1

List 3 ways that infertility presents in farm animals

Answer 1

Animals that are not (or do not appear to be) cycling at all
Animals are cycling but do not conceive
Animals that conceive but do not maintain pregnancy

Question 2

If Animals that are not (or do not appear to be) cycling at all
describe how to investigate

Answer 2

Rule out poor oestrus detection first (i.e. are these animals truly in anoestrus) –> data and clinical exam
Investigate possible reasons for true anoestrus

Question 3

If animals are cycling but do not conceive
describe how to investigate

Answer 3

Investigate reasons for non-conception including the male animal or AI procedure

Question 4

If Animals that conceive but do not maintain pregnancy
Describe how to investigate

Answer 4

Investigate reasons for foetal/embryonic death

Question 5

List 6 possible reasons for anoestrus in farm animals

Answer 5

failure to observe oestrus
metabolic/ nutritional
uterine infection
pregnancy
cystic ovarian disease
suckling calf at foot

Question 6

In sheep are infectious or non-infectious causes of infertility most important in sheep

Answer 6

infectious

Question 7

are infectious or non-infectious causes of infertility most important in cattle

Answer 7

non-infectious

Question 8

how does BVD affect fertility

Answer 8

causes Early embryonic death (EED) and Ovarian damage
causes long returns to service and reduce conception rates

Question 9

How does Border disease presentes regarding fertility in sheep

Answer 9

increased barren rate

Question 10

List 3 possible viral causes of infertility in farm species

Answer 10

BVD- cattle
Border disease- sheep and goats
IBR- cows

Question 11

List 4 bacterial and protozoal causes of infertility in farm species

Answer 11

Leptospira - cattle (sheep can act as carriers)
Brucella - all ruminants
Campylobacter - cattle and sheep
Tritrichomonas- cattle

Question 12

What are the effects of brucella

Answer 12

poor fertility
epididymitis and orchitis

Question 13

How does IBR effect reproductive performance

Answer 13

temporary ovarian necrosis
follicular degeneration

Question 14

List 2 special considerations you need to make for maiden heifer when investigating fertility

Answer 14

may not have reached puberty
may have repro tract abnormalities- e.g. freemartinism or Mucometra (rare)

Question 15

List 4 possible effects of campylobacter on the repro tract in cattle/ sheep

Answer 15

Endometritis (cattle)
Failure to conceive
Early embryonic death (cattle)
Abortion (sheep and cattle)

Question 16

Before giving PGF2a to a cow what should you do

Answer 16

check for pregnancy

Question 17

what effect does GnRH have at start of oestrus

Answer 17

ovulation in 24-48hrs

Question 18

what effect does GnRH have 10-12 days post-oestrus

Answer 18

reinforce CL action - aids progesterone secretion
Induce ovulation
Anti-luteolytic effects- makes CL less sensitive to PGF2a

Question 19

List 4 possible uses of GnRH

Answer 19

synch protocols
Treat follicular cysts
Treat anoestrus cows
Ovulation in repeat breeder cows

Question 20

List 6 possible causes of ‘ cycling cows that do not conceive’

Answer 20

improper/ incorrect insemination
infectious causes
toxins
metabolic/ nutritional cauases
iatrogenic causes- improper use of hormonal drugs
Sire choice

Question 21

How does PGF2a work

Answer 21

Cause luteolysis of CL –> fall in progesterone resulting in FSH and LH release
Only work if CL present

Question 22

at what point is a CL sensitive to PGF2a

Answer 22

CL only sensitive to PGF2α between days 5 – 15 of cycle
>17mm diameter on US scan

Question 23

List 5 potential uses of PGF2a

Answer 23

Synch protocols
Treat luteal cysts
Induce abortion or parturition
Treat pyometra
Control of breeding and oestrus timing

Question 24

Describe how progesterone works

Answer 24

Acts as an exogenous CL –> release progesterone and suppress GnRH release
Dominant follicle develops —> does not ovulate
Removal of device (drop in progesterone) –> LH surge —> ovulation

Question 25

List 5 potential uses of progesterone devices

Answer 25

Synch and embryo transfer protocols Treat cysts Improvements in oocyte quality Reduce time to service (seasonal herds) Repeat breeders

Question 26

Describe how to treat endometritis in cattle

Answer 26

PGF2a - may need 2 doses possibly wash out ???- day after PGF2a when cervix opens - variable results Recheck on next visit

Question 27

Describe how to treat follicular cysts in cows

Answer 27

GnRH or progesterone Can pop them- but this is risky - there are reports of some animals getting life threatening bleeds and formation of scar tissue that can affect ovary function

Question 28

Describe how to tell the difference between follicular and luteal cysts

Answer 28

Luteal cysts= the wall of the cyst is 4-5mm thick, made of luteal tissue so same echogenicity as a CL Follicular cyst= thin wall

Question 29

Describe how to treat multiple small follicles

Answer 29

GnRH or progesterone- could be part of a synch protocol

Question 30

what 2 things can multiple small follicles on both ovaries mean

Answer 30

the animal ovulated yesterday OR is in true anoestrus

Question 31

What is the calculation to work out fertility efficiency

Answer 31

submission rate x conception rate

Question 32

List 4 ways to improve oestrus detection in cattle

Answer 32

improve staffing improved environment oestrus detection aids synchronisation protocols

Question 33

List some examples of oestrus detection aids

Answer 33

cow worn devices tail chalk - when rubbed off = has been mounted Heat patch- change to red is mounted for >3s

Question 34

List 3 ways to make a bull infertile

Answer 34

vasectomy epididymectomy penile alterations- for venereal diseases- mostly done in US

Question 35

What are the effects of leptospira on reproduction

Answer 35

poor fertility and early embryonic death --> may be due to endometrial inflammation

Question 36

can sheep become infected with leptospira

Answer 36

yes but they rarely show disease- they are usually carriers

Question 37

What are the effects of tritrichomonas on reproduction

Answer 37

early embryonic death pyometra endometritis

Question 38

Describe how we can tell the difference between metritis and pyometra (endometritis)

Answer 38

pyometra will have a CL metritis occurs shortly after parturition- cow systemically unwell

Question 39

what size are follicular cysts

Answer 39

over 25mm

Question 40

what does ineffective oestrus detection lead to

Answer 40

a low submission rate and subsequent low fertility efficiency

Question 41

what is the submission rate calculation

Answer 41

(number of cows actually bred / number of cows eligible to be bred ) x100