Herd Management problems impacting on fertility

Question 1

How big is the dominant follicle?

Answer 1

> 9mm

Question 2

What are the 3 fates of the 1st dominant follicle in post-partum cows?

Answer 2

• Ovulate
• Turnover
• Cystic

Question 3

Abnormal progesterone profiles can cause?

Answer 3

Delayed ovulation
Prolonged luteal phase

Question 4

% first insemination pregnancy rate decreased as …. increases

Answer 4

Milk yield

Question 5

Which factor also decreases as milk yield increases?

Answer 5

% of cows standing to be mounted

Question 6

Number of inseminations per pregnancy is increased the most due to which factor?

Answer 6

Previous caesarean

Question 7

List some other factors which cause an increase in the number of inseminations needed per pregnancy

Answer 7

• Drop in social status
• Bad calving
• Lameness
• Mastitis
• Milk fever

Question 8

Milk Fever goes on to increase the risk factors for…? (4 answers)

Answer 8

Difficult calving
Retained fetal membranes
Endometritis
Sub clinical low calcium – worst fertility too

Question 9

How can lameness affect fertility?

Answer 9

• Increased number of days from calving to conception
• Pregnancy rate to first AI % decreased
• Number of inseminations per conception increased
• Number of days to first luteal activity is increased
• Number of days to first oestrus is increased
• Intensity of oestrus is lower
• Specific behaviours affected e.g. less mounting, less standing to be mounted, less sniffing vulva, etc

Question 10

How can cows with mastitis have affected fertility?

Answer 10

• Mastitic cows have smaller follicles
• Mastitic cows reduced fertility
• Mastitic cows take longer to ovulate if synchronised
• Number of days to first luteal activity is increased
• Number of days to first oestrus is increased
• Increased calving interval

Question 11

Name 3 risk factors for becoming a repeat breeder

Answer 11

• Dystocia
• Retained placenta
• Metritis

Question 12

How does milk yield affect signs of oestrus?

Answer 12

High milk yield causes:
- Duration of being mounted decreases
- Incidence of standing in oestrus decreases
- Duration of standing decreases
- Number of silent heats increases

Question 13

How can BCS affect fertility after calving?

Answer 13

Number of days to 1st ovulation post calving is increased as body condition loss increases
The less of a BCS change there is the higher the 1st service pregnancy rate

Question 14

Do fat or thin cows lose more condition during lactation?

Answer 14

Fat cows

Question 15

What is the main issue with drying off early?

Answer 15

Less milk/cow/year

Question 16

What is the main issue with drying off late?

Answer 16

Delay in the next peak of milk production
Less milk/cow/year