Nutrition and repro

Question 1

FACT CARD

Answer 1

-Number of primordial follicles is determine before birth and is influenced by nutrition

Question 2

What are the effects of nutrition on pregnancy?

Answer 2

-High planes of nutrition result in faster growth and generally earlier puberty

Question 3

At what age do you want a heifer to haver her first birth?

Answer 3

-24 months

Question 4

What effects can to high body conc of fat have on reproduction?

Answer 4

• Fat covering testes effect temperature control

- Overweight cows have more dystocia

Question 5

Which metabolic hormones have reproductive effects?

Answer 5

• Leptin= inhibits oestradiol secretion and increases folliculogenesis
• Insulin=has direct action on the antral follicle growth and steroid production. Also regulated circulatory IGF
• IGF= enhances ovarian action of donadatrophins and has a direct effect on follicle growth/ steroidogenesis

Question 6

What do leptin do?

Answer 6

-Inhibit oestradiol secretion and increases folliculogenesis

Question 7

How does insulin affect the repro system?

Answer 7

-Direct effect on the antral follicle growth and steroid production. Also regulates circulatory IGF

Question 8

What effect does IGF have on the repro system?

Answer 8

• Direct effect on follicle growth and steroidogenesis

- Enhances ovarian action of gonadotrophins

Question 9

What is the impact of feeding high levels of rumen degradable protein during pregnancy?

Answer 9

-Has toxic effects of blood urea or ammonia on the embryo

Question 10

FACT CARD

Answer 10

Nutrition has huge impacts on placental growth and development. You can manipulate foetal and placental weight with nutrition.

Question 11

How is sheep nutrition usually managed during pregnancy?

Answer 11

-They have restricted nutrition in early-mid gestation which causes them to give increased placental weight and increased foetus weight at term.

Question 12

What are the impacts of early/ late gestation nutrient restriction?

Answer 12

• Early= small at first then give increase placental/ foetal weight at full term
• Late= causes decreased placental/ foetus weight and decreases foetus viability

Question 13

How do cows deal with the negative energy balance close to calving?

Answer 13

• Due to large calf, rumen capacity is decreased= neg energy balance
• Have to mobilise body reserves (glucose/ fat in the liver)

Question 14

What impacts can a negative energy balance have?

Answer 14

• Delays return to cyclicity
• Decreased levels of circulatory glucose, IGF-1 and insulin
• Ketosis
• Impaired follicle development and luteal function

Question 15

What are the effects of selenium deficiency on the female reproductive system?

Answer 15

• Decreased conception rates
• Increased cases of ovarian cysts
• Increased cases of retained placentas
• Birth of premature/ weak/ dead calves
• Higher incidence of embryonic mortality.
• Increased chances of endometritis

Question 16

What impact does dietary iron and molybdenum have?

Answer 16

• Both decreases plasma copper concentration BUT only dietary molybdenum fed ones showed clinical signs.
• Molybdenum increases age of puberty
• Molybdenum decreases peak LH concentration
• Molybdenum decreases conception rates

Question 17

What are the clinical signs of ‘copper’ deficiency?

Answer 17

• Delayed puberty
• Don’t display oestrus behaviour
• Irregular oestrus
• Reduced conception rates
• Reduced peak ovulatory LH
• Reduced feed intake
• Hair pigmentation/ texture
• Swayback

Question 18

What is the cause of ‘copper deficiency’?

Answer 18

• Thiamolybdate toxicity

- Reduce level of available copper as it binds to it?

Question 19

What are the effects of zinc deficiency on the reproductive system?

Answer 19

MALES
-Is essential for spermatogenesis
-Needed for DNA/ protein replication
-Decreases libido and testicular size
FEMALES
-Mild deficiency= smaller litter size and increases chances of pregnancy toxaemia
-Severe deficiency in early gestation causes teratogenic effects

Question 20

What are the effects of iodine deficiency on the reproductive cycle?

Answer 20

• Decreased conception rates
• More chance of cystic ovaries
• Still births/ weak calves
• Retained placentas
• Abortions