Herd management problems impacting on fertility

Question 1

What is the 3 fate of a dominant follicle?

Answer 1

• Ovulate - 46%
• Turnover - 31%
• Cystic - 23%

Question 2

What is the correlation between yield and feritlity?

Answer 2

• Negative correlation
• higher the milk yield the worse the fertility of a cow
• But now Holstein have been bred to have good milk yield and fertility genetics

Question 3

What reduces a cow’s fertility?

Answer 3

• Lameness
• Low body condition
• High yield

Question 4

What can increase the calving to conception time?

Answer 4

• Milk fever
• Mastitis
• Lameness
• Bad calving
• Caesarean
• Drop in social status
• Lack of energy (nutrition)

Question 5

How does lameness affect fertility?

Answer 5

• Lower intensity of oestrus - can’t mount + move around to sniff vulva
• Longer for first ovulation
• Longer for visible oestrus

Question 6

What problems are with a high somatic cell count?

Answer 6

• No problem on their own = 100% ovulate
• BUT if lame and SCC >100K+ = 44% ovulate
  (compared to 78% ovulation if just lame)

Question 7

When should you inseminate lame cows?

Answer 7

• inseminate later - 16-24hr after start of oestrus = takes longer for follicle to ovulate

Question 8

What do you test for with bloods for subclinical ketosis?

Answer 8

betahydroxybuturate