Preparation of breeder rams Flashcards
How long is Spermatogenesis in sheep ?
7 weeks
What do we expect from the ram?
Clinically healthy
Normal genital system
Good quality semen
Libido
Mating dexterity
Free from venereal disease
Name the 5 condition Ts
Teeth
Toes
Tassel
Testes
Temperament
Before onset of breeding season, breeder rams must:
Undergo a complete breeder fitness test - to ensure fertility
Be free of any sexual diseases
Have mating skills and a high libido
How many sperms are necessary for successful conception ?
125 – 500 million
What is considered a highly fertile ram ?
Rams with a scrotum circumference of >30
Perform >4 successful matings in a 20 min
HF rams mated with 95% of ewes on heat > 3 times
What is considered a medium fertile ram ?
Rams with a scrotum circumference <30 cm and <3 matings in a mating test
What is the advantages of using HF rams ?
Up to 10% more adult ewes will reproduce
Ewes with multiple births will increase with 5-20% and ± 5% more maiden ewes will be fertilized as a result of multiple matings
Ewe lambs from HF rams are more fertile - longer periods of estrus.
Rams with large testes produce ewe lambs that will have an earlier onset of their breeding season and have more twins/multiple births
The use of HF rams tend to increase the future fertility of a herd at a higher rate than using multiple birth ewes
When must we start with breeder ram preparation ?
At least 2 months before onset of mating season due to sperm production cycle being 7-8 weeks long, but preferable 3 months before start of mating, to have enough time to acclimatize in new surroundings
To what is testes circumference positively correlated ?
Sperm production
Male hormone production
Ovulation rate
Multiple births
Age of sexual maturity of female offspring
Breeder rams should be injected, 3 months before beginning of mating season with …
Zinc
Manganese
Selenium
Vit A
Vit E
What must happen to the breeding rams 8 weeks before mating ?
Rams are fed flushing diet to increase condition score from 3.5 – 4
Rams must obtain exercise
How many sperm are produced daily per gram testes ?
± 20 million
Why must high levels of grain in ram diet prior to mating be avoided?
It will have a negative effect on sperm production because of increased fat deposits in scrotum
What should be fed to breeding rams to maximize testes growth and sperm production?
Rams must be fed extra energy and especially a high-level bypass protein (16% protein)
What happens to the breeding rams 6 weeks before mating ?
Evaluating and examining of semen sample
Measurement of scrotal circumference
Mating skills test
What should the scrotal circumference be 15 moths of age - 6 weeks before mating ?
35 cm
What sign do we find in the groin of a breeding ram 6 weeks before mating ?
Groin must be purple with a lot of wax present
What is the maximum amount of years we keep a ram in the flock ?
5 years
What is the effect of Brucella ovis in breeding rams ?
Leads to contagious form of epididymitis which leads to overall
infertility in rams
How does nutrition effect spermatogenic tissues
Total mass of testicular tissue
Increase the diameter and length of the seminiferous tubules
Increase the number of Sertoli cell nuclei per testis
How does nutrition effect testicular interstitial tissues ?
Increase the total volume of Leydig cells per testis
Increase the rate of testosterone production
