Reproduction

Question 1

What organs are involved in reproductive activity?

Answer 1

Hypothalamus
Pineal Gland
Pituitary Gland (anterior lobe)

Question 2

What are some important reproductive hormones in Ewes?

Answer 2

GnRH - stimulated by melatonin, produced by hypothalamus, goes to pituitary gland
LH - stimulated by GnRH, travels to ovaries
E2 - stimulated by LH and FSH, produced by ovaries, travels to brain to start Estrus
Progesterone - secreted by CL, has negative feedback loop on GnRH and LH
Prostaglandin - produced by uterus, travels to ovaries, leads to regression of CL

Question 3

What are the seasonal Polyestrous cycles?

Answer 3

1. Long Day Breeders (Spring breeders, horses, etc.)
2. Short Day Breeders (Autumn breeders, sheep, goats, etc.)

Question 4

Does daylight affect testosterone in Rams?

Answer 4

Yes

Question 5

How long does estrous last?

Answer 5

17 days

Question 6

How long does estrus last?

Answer 6

15-45 hours

Question 7

What sort of toxicity is at highest risk for pregnant ewes (especially those with multiples)?

Answer 7

Pregnancy Toxemia / Ketosis

Question 8

What trimester does majority fetal growth take place?

Answer 8

third trimester - 70% of fetal growth happens here

Question 9

Why do we pregnancy test?

Answer 9

lowers cost/increases economic efficiency by reducing the amount of open ewes being fed pregnancy rations, as well as allowing for early culling of open ewes

Question 10

What are breeding marks?

Answer 10

the use of a pigment placed on a rams chest, where when he mounts an ewe he leaves behind marker and shows the rancher the ewe has been mounted and by which ram.

Question 10

What are the pros and cons of using breeding marks for pregnancy testing?

Answer 10

Pros: early detection, inexpensive
Cons: not 100% accurate / guaranteed

Question 11

What is udder palpation?

Answer 11

a form of pregnancy testing where the ewe is ‘bagged’ to test mammary development 2 weeks prior to lambing to see if she is pregnant.

Question 12

What are the pros and cons of udder palpation?

Answer 12

Pros: the only input is time and labor and is fairly accurate
Cons: variation in udder size/development, as well as being a late term pregnancy detection so not much money is saved

Question 13

What is ultrasonography used for?

Answer 13

a form of pregnancy checking that can be done 45-70 days after ram removal to see if the ewe is pregnant

Question 14

what are the pros and cons of using ultrasonography for pregnancy testing?

Answer 14

Pros: very accurate (98%) and can save money on feed
Cons: expensive and doesnt count fetus with decent accuracy

Question 15

What are blood tests used for?

Answer 15

a form of pregnancy checking where blood is drawn from an ewe 30 days after ram removal. The test measures the amount of pregnancy protein present.

Question 16

What are the pros and cons of using blood tests as pregnancy checks?

Answer 16

Pros: 99% accuracy, saves money on feed, and not much training required
Cons: costly and determining amount of fetuses isnt possible

Question 17

how long are ewe pregnancies and how soon after lambing can they be bred again?

Answer 17

144-150 days and can be bred again 30 days after lambing

Question 18

How long does the ram spermatogenesis cycle take?

Answer 18

6-8 weeks

Question 19

what are the effects of temperature on sperm production?

Answer 19

optimal sperm temperature is 96 degrees F, where the typical ram body temp is 101-104. The higher the temperature of the testes the lower the sperm production (even a 0.5 temp variation lowers the production)

Question 20

What are some reproductive behaviors of ewes during estrus?

Answer 20

1. tail-fanning
2. standing still
3. head turning/looking at ram

Question 21

What are some reproductive behaviors of rams during estrus?

Answer 21

1. sniffing
2. flehman
3. nudging ewes with head/pawing at ewes

Question 22

What are some things to consider towards ram care during estrus?

Answer 22

additional feed to accommodate the increase travel distance and movement as well as assuring the ram doesnt get overwhelmed by the amount of ewes (only having the max amount of ewes per ram)

Question 23

What are maiden ewes?

Answer 23

ewes that are younger and have less experience with estrus; are ‘shy’

Question 24

how to ensure mating of maiden ewes?

Answer 24

1. utilize active/experienced rams 2. mate maiden ewes and mature ewes separately 3. increase rams present

Question 25

Which feed / feeding strategy is most efficient for supplemental feed during breeding season?

Answer 25

using meadow hay or alfalfa to supplement

Question 26

What does a typical BSE measure?

Answer 26

1. physical evaluation 2. scrotal evaluation 3. semen testing

Question 27

What are the minimum satisfactory percentages for motility and morphology in a rams BSE?

Answer 27

motility - 30% morphology - 50%

Question 28

What is a part of the physical evaluation section of the BSE?

Answer 28

1. teeth check 2. body condition scoring 3. recording presence of any disease or genital defects/abnormalities

Question 29

What three things do we measure with BSE semen testing?

Answer 29

1. semen motility 2. semen morphology 3. volume and color

Question 30

Why do we synchronize estrus?

Answer 30

shortens the lambing window and allows for lambs and ewes to be managed more uniformly

Question 31

how do we synchronize estrus?

Answer 31

1. the 'Ram Effect" 2. light manipulation 3. hormonal manipulation

Question 32

What is the 'Ram Effect'

Answer 32

introducing a vasectomised ram to a group of ewes and this leads to the initiation of cycling and synchronization

Question 33

What is flushing?

Answer 33

feeding ewes an increased plain of nutrition 2-3 weeks before breeding and 2-3 weeks after initial breeding to increase ovulation and lambing rates

Question 34

How does ewe body condition relate to lamb weight?

Answer 34

The better the body condition score the heavier and healthier the lamb