Sheep and Goat Reproduction 1 Flashcards
What kind of kidding program is there in:
- Dairy farm?
- Meat farm?
- Year round
2. Controlled program
The Female:
What % of full body weight should they be when they enter the breeding herd?
70-80%
Puberty
- Usually around what age? At what BW?
- 5-15 months. >60% adult body weight
Factors affecting puberty onset:
1.
2.
3.
4.
- Time of lambing
- Nutrition
- Breed (finn > suffolk > rambouillet
- Ram selection (scrotal size)
Selection techniques for increased reproduction:
1.
2.
3.
- Fecundity .04 to .26 is inheritable.
- Increased number of lambs born/ewe/year
Select twins, triplet ewe lambs/rams
Ewes and Does are what kind of breeders?
Short day breeders
The Ewe:
Estrous cycle length?
17 days
The Ewe:
Estrous length?
30 hours
The Ewe:
Gestation length?
147 days
The Ewe:
Method of P4 production?
Placental
The doe
Estrous cycle length?
21 days
The doe
estrus phase length?
36 hours
The doe
gestation length?
150 days
The doe
Method of P4 production?
CL dependent
Describe the physiological steps of why goats and sheep are short day breeders:
1.
2.
3.
4.
- Increasing darkness in the fall as the days shorten
- Increased melatonin release from pineal gland
- Melatonin causes increase pulses from hypothalamus that release GnRH
- Increased GnRH leads to increased release of LH from Adenohypophysos
Estrus in a doe is characterized as the time….
from moment doe stand to be mounted until refusal
Signs of estrus in a doe: 1. 2. 3. 4. 5.
- Tail wagging
- Bleating
- restlesness
- pacing
- vulvar swelling
Signs of estrus in a ewe:
1.
2.
- vulvar swelling
2. anorexia
Metestrus in a sheep and goat =
time period of formation of CL
Diestrus in a sheep and goat =
CL mature and producing progesterone
How many rams / 100 ewes?
2-4
Change the color on the rams marking device how often?
every 14 days
Conception rate for ewes on first service? On second service?
65-80%
90%
Flushing =
Increasing the nutrient uptake by 20-30% 2-3 weeks before breeding
Ways to manipulate the doe during Anestrus:
1.
2.
3.
- Hormonal manipulation (prostaglandin to shorten diestrus phase, progesterone to mimic diestrus phase)
- Manipulation of lights (short day breeders)
- Administration of melatonin
CIDR
- What is it?
Intravaginal implant to increase progesterone levels at 12-14 days (?)