Bovine Therio 2 - Reproductive management

Question 1

The gestational length of the bovine is

Parameter:Target

Answer 1

280days (9mths)

Parameter:Target; Calving interval:12-13mths

Question 2

The lactation curve of a cow extends to how many days

Answer 2

305days

Birth of calf and start of curve is day 0

Question 3

Peak lactation of a cow is at day

Answer 3

70

Question 4

Do not serve cows before how long

Answer 4

45days

Question 5

How long after the first calving, should the cow first be served
(Parameter:Target)

Answer 5

65days

Parameter:Target;First service conception rate: 45%

Question 6

After first serve, non pregnant cows should be served at which day
(Parameter:Target)

Answer 6

90days (85)
(Parameter:Target; Services per conception:2.0-2.5)
Day 0 - 90

Question 7

When should post partum checks be

Answer 7

25-30days

0-25

Question 8

How are cows dried off

Answer 8

Abruptly stop milking

Decreased milking is coming back

Question 9

What is the am to pm rule for bovine servicing

Answer 9

Oestrous in the morning, serve at night

Question 10

Reproductive exam guidelines for cows

Answer 10

Calving complications
Post Partum evaluation (25-30days)
Pregnancy exam (5-6 wks. post-breeding)
Problem cows

Question 11

Problem cows are

Answer 11

Repeat breeders > 3 services
Oestrus not Observed: open, calved > 60dys + anoestrus
Abnormal cycles, discharges

Question 12

What are clean up bulls and the risk of its use

Answer 12

Combination of AI and natural service to improve reproductive performance

• Risk of venereal disease
• Indiscriminate breeding
• Danger and expense
• Still importation to record services

Question 13

Bovine oestrus synchronisation indications (2)

Answer 13

To synchronise oestrus for A.I.

To synchronise oestrus for E.T. - donors/recipients

Question 14

Prerequisites for oestrus synchronisation

Answer 14

Open, cycling
BCS plane of nutrition
Normal GT w/o disease
Adequate A.I. Facilities
Personnel - heat detection

Synchromisation should not be a substitute for good management

Question 15

Timed AI vs Heat detection

Answer 15

Timed: Sync and how much ever time later service

Heat detection: Check for heat then service

Question 16

What are the methods of oestrus synchronisation in the bovine

Answer 16

Manipulation of the CL
Ov Sync Protocol
Suppression of ovarian activity by inhibition of hypothalamo - pituitary axis

Question 17

Explain bovine oestrus sync via manipulation of the CL

Answer 17

Give PGF at day 6 to 18 of cycle. Single injection (if CL identified) & double injection schemes 10-11 days apart

i.e. 0-4 > no change
8-14 > ovulation
16 > no change (following own timeline)

PFG @ Cow’s day 8, sync day 0
She will ovulate at Cow’s day 11, sync day 3
Syncing at day 11, Cow’s day 8

Question 18

Explain bovine oestrus sync via Ov sync protocol

Answer 18

GnRH at day 0 > PGF at day 7 > GnRH at day 9 (tighten the ovulation window)

Question 19

Explain bovine oestrus sync using suppression of ovarian activity

Answer 19

Progesterone vaginal implants - PRID, CIDr

Give GnRH at day 0 to ensure CL
Day 6 give PGF to remove endogenous progesterone
Day 7 remove device (exogenous progesterone)