Breeding Flashcards
Puberty definition
- Transition from immature to sexually mature and capable of reproduction
- Characterized by hormones, physical characteristics, and sexual behavior
Relative onset of puberty in females vs males
Occurs earlier in females
What hormone controls the onset of puberty?
Hypothalamic release of GnRH
Relative onset of puberty in small vs large dogs and animals
- Occurs sooner in small size animals and breeds
- Small species and breeds have a steeper growth curve, which is why this occurs sooner
What determines when puberty will occur?
- Percent of adult body weight
- In cats and dogs, likely when they hit about 70% of adult body weight
Does body height factor at all into onset of puberty?
- No
- Estrogen produced AFTER puberty leads to closure of epiphyseal growth plates
What will happen to bone growth if an animal is spayed or neutered prior to puberty?
- Prolongs bone growth
Other factors that impact onset of puberty
- Genetics, BCS, gender, environment, presence of mature animals
Average inter-estrus interval
- 4.8-18 months
- Larger breed dogs tend to have longer intervals (with the exception of German Shepherds
Serum progesterone levels during different events in the estrous cycle and pregnancy
- SEE the other flashcards that you made
LH surge relative to different events in estrous cycle and early pregnancy
SEE the other flashcard set
How long can sperm survive in the uterus?
- 9-11 days in a non-capacitated state
Are sperm capacitated or non-capacitated for fertilization?
Capacitated
How long do sperm survive after capacitation?
- <1 day
Where does the stricture occur with vestibulo-vaginal narrowing?
Right above the urethral tubercle
What are alternatives to natural cover breeding?
- Fresh collected side-by-side artificial insemination
- Insemination with chilled shipped semen
- Insemination with frozen thawed semen
Processes involved in inseminating with chilled shipped semen?
- Requires accurate ovulation timing and coordination with persons collecting and shipping semen
- Hard to do over weekend and holiday periods
Insemination with frozen thawed semen - how long are sperm capable of fertilization
Only 1 day
What type of insemination is required with frozen thawed semen?
- Intrauterine insemination due to low quality
- Either surgical insemination or transcervical catheterization
- Highly precise ovulation timing required
How can either fresh side-by-side or chilled shipped semen be inseminated via AI?
- Can use a special pipette to deposit it right outside of the cervix
- Intravaginal Mavic Catheter from Minitube
- Insert up the anterior vagina and inflate the tube
- Place the sperm forward and take an extender like fluid to act like the third fraction of the semen
- Valve on the end to put the semen in
- Wrap with gauze, but no pressure on the belly
- butt to butt time frame for 15-20 min
Where can blood contamination in semen come from?
- Surface of penis, prepuce, or anywhere in the urinary tract (kidneys, epididymis, prostate, bladder, abdomen, penis, sheath)
- Blood could be due to infection or inflammation
How does blood impact semen quality?
- Diminishes it, as sperm adhere to RBCs
What to do if there is blood contamination in the semen?
- Repeat physical examination with prostate examination
- Urinalysis
- Cytology of semen
- Check ratio of RBC:WBC to differentiate inflammation from peripheral blood (if it’s similar, likely just peripheral blood contamination)
- Degenerative leukocytes or leukocytes with intracellular bacteria are highly suggestive of infection
Surgical intrauterine insemination process
- Semen deposited in uterine horns with IV catheter
- Sx more simple than OVH
- Surgical risks include routine anesthesia and wound healing concerns
Can you see the cervix with an otoscope cone?
No
Fertile period for thawed frozen semen
- Has to be about 5-6 days from LH surge
LH tests
- Can use when you think the LH surge is happening, but generally much cheaper and easier to measure progesterone
Transcervical insemination - when do you thaw the semen?
- When you’ve got the bitch catheterized
How long does fresh or chilled semen last in the vagina?
- 4-5 hours
How long does fresh semen last in the uterus?
- 9-11 days
How long does chilled semen last in the uterus?
- 1-2 days or longer
How long does thawed frozen semen last in the uterus?
- Less than 1 day
When is litter size largest?
- Large # of recently capacitated sperm in the presence of mature oocytes
With natural cover breeding, how would you get largest litter size?
- Natural cover breeding every other day
- Days 2, 4, and 6 after LH surge or days 3 and 5 after LH surge
When to get maximum litter size with fresh chilled semen?
- At the start of the fertile period and again 1-2 days later
- From days 3-5 after LH surge
When to get maximum litter size with thawed frozen semen?
- Day 5 and 6 following LH surge
- Must use intrauterine insemination
