Bovine Reproduction: Pregnancy & Assistance

Question 1

What are the reasons for pregnancy testing and what would the Vet would look for?

Answer 1

• Monitoring reproductive efficiency
• Detecting any early problems
• Identifying infertile cows
• Ability to target supplementary feeding

Question 2

How long may a cow spend preparing for calving?

Answer 2

2-4hrs (heifers up to 10hrs)

Question 3

What happens to the body of the cow during calving?

Answer 3

• Ligaments of the pelvic girdle relax
• Cervical plug becomes liquid
• Cervix relaxes to stretch

Question 4

What is the actual time for expulsion of the calf?

Answer 4

No more than one hour

Question 5

What happens shortly before birth?

Answer 5

The uterus begins contracting, mildly at first, and can continue for 24hrs during which time the cow becomes increasingly restless

Question 6

How does the foetus affect the cervix?

Answer 6

The foetus is pushed against the cervix causing it to open during which time the foetus is oriented into its proper birth position

Question 7

What is the proper birth position?

Answer 7

Lying on stomach with forelegs extended and head resting on forelegs

Question 8

What contractions occur when the foetus is pushed against the cervix?

Answer 8

Powerful contractions of the uterus aided by stomach muscle contractions, resulting the foetus to be pushed through the birth canal within a few hours

Question 9

What happens when the calf’s head and forelegs appear?

Answer 9

The fluid filled foetal membranes will burst, spilling fluid and the calf then slips out

Question 10

What is the size of the calf at birth

Answer 10

Usually larger than the diametre of the pelvic girdle as the pelvis expands

Question 11

How does the umbilical cord break?

Answer 11

When the cow is standing the calf dropping will break the umbilical cord and when the cow is lying down, she will stand and break the cord

Question 12

What will the cow do after birth?

Answer 12

Lick the mucous from the calf’s nostrils and mouth to facilitate breathing

Question 13

When should the calf be suckling after birth?

Answer 13

Within 2hrs after birth and hopefully within 15mins after birth

Question 14

What happens to the cow’s ‘afterbirth’ membranes?

Answer 14

Strong uterine contractions expel the membranes within 4 to 5hrs after birth and if the afterbirth is present after 10 to 12hrs, assistance will be needed to avoid the risk of infection

Question 15

What is dystocia?

Answer 15

Calving difficulty

Question 16

Why does dystocia occur?

Answer 16

• Calf effects: Heavy birth weight cause difficult and delayed parturition
• Dam effects: Age and pelvic size makes delivery difficult
• Foetal position at birth: Delivery may be difficult without causing damage to the calf

Question 17

How may chains be used to assist the parturition process?

Answer 17

Chains are looped around the forelegs of the calf (just above the first joint) which the farmers pull with in time with the contractions of the mother to allow for an easier birth.

Question 18

How are chain pullers used to assist the parturition process?

Answer 18

Calf pullers are mechanical devices that have ropes attached to the leg and a brace to push back against the cow. This device allows more force to be delivered with less effort.

Question 19

What is the process of Oestrous Synchronisation?

Answer 19

Oestrous Synchronisation involves all the cows in the herd to be brought into heat together. This allows for all cows to be inseminated at the same time, saving time and money. A progesterone intra-vaginal device (PIVD) is inserted in the cow’s vagina and removed 10-12 days after. Prostaglandin injection is when the cows are injected twice, 10 -12 days apart for ovulation and 48 hours later the cows are inseminated.

Question 20

What is the 1st process of Embryo Transfer?

Answer 20

Superovulation of the donor cow with hormones that allow of multiple quantities of eggs.

Question 21

What is the 2nd process of Embryo Transfer?

Answer 21

5 days later, the donor cow is inseminated when on heat.

Question 22

What is the 3rd process of Embryo Transfer?

Answer 22

Fertilised eggs are harvested 5-8 days later. A vet uses a foley catheter and a saline solution to flush the eggs from the walls of the uterus and into a receptacle.

Question 23

What is the 4th process of Embryo Transfer?

Answer 23

Embryos are isolated and graded by quality. Embryos are drawn drawn into similar straws to A.I.

Question 24

What is the 5th process of Embryo Transfer?

Answer 24

Embryo is transferred into surrogate mother. Surgically, the vet through an incision, places the egg in the uterus.

Question 25

What is the 6th process of Embryo Transfer?

Answer 25

Three months later, greg testing occurs to see if success of failure has occurred.

Question 26

What is the 7th process of Embryo Transfer?

Answer 26

9 months later, birth is finally here!