CAL: Bovine reproduction

Question 1

what is a sensible target calving interval?

Answer 1

390 days

Question 2

what is a sensible overall 100 day in calf rate?

Answer 2

> 55%

Question 3

what is a sensible 200 day not in calf rate?

Answer 3

<20%

Question 4

what is a sensible conception rate to first service rate?

Answer 4

30%

Question 5

What is a sensible submission rate within 80 days of calving?

Answer 5

70%

Question 6

What is a sensible overall conception rate?

Answer 6

35%

Question 7

What is a sensible calving to first service interval?

Answer 7

65 dyas

Question 8

What is a sensible calving to conception interval?

Answer 8

100 days

Question 9

What is the aim age at first calving?

Answer 9

2 years (i.e. calve down on second birthday)

Question 10

T/F a farmer is required to report any bovine abortions to local AHO.

Answer 10

True - an calf born prior to day 271 of a normal gestation or prior to day 265 of embryo transfer. This is so a brucellosis investigation can be established if necessary.

Question 11

When would brucellosis testing be initiated?

Answer 11

if the suspect animal is not contributing to a bulk milk tank (as this is tested regularly)

Question 12

List 4 infectious causes of bovine abortion

Answer 12

Neospora caninum (most common)
IBR
Leptospirosis
BVDV

Question 13

When is neospora abortion usually seen?

Answer 13

Between months 3 and 8

Question 14

When does leptospirosis abortion usually occur?

Answer 14

month 5 to term (i.e. late gestation)

Question 15

When can IBR cause abortion?

Answer 15

throughout gestation

Question 16

When does BVDV affect pregnancy?

Answer 16

Causes early return to service and abortion up to 6 months of gestation. Causes PI calf if dam is infected up until day 110 of pregnancy (i.e. first trimester).

Question 17

Clinical signs - IBR

Answer 17

Upper respiratory tract infection
Pneumonia (mild to severe/fatal)
Decreased milk yield (+pyrexia, appetite loss)
Vaginitis
Conjunctivitis and ocular discharge
Nasal discharge (serous –> muco serous –> mucopurulent)
Pyrexia (up to 42 degrees)

Question 18

Clinical signs - BVDV

Answer 18

Decreased milk yield, pyrexia, appetite loss
abortion/weak calves
high levels of concurrent disease
acute upper respiratory tract infection
(haemorrhagic diarrhoea only common in type 2 in USA/Canada)

Question 19

Clinical signs - leptosprosis

Answer 19

abortion or birth of weak calves
infertility
mostly subclinical
agalactia and decreased milk yield
flaccid udder (if lactating)
(pyrexia - if severe)