NAVLE (North American Veterinary Licensing Examination) · USA / Canada · International Council for Veterinary Assessment (ICVA); scored by NBME, delivered by Prometric
Original practice questions written to the published syllabus · not past papersMale reproduction and fertility, semen collection, evaluation and freezing, artificial insemination, embryo transfer, IVF, cloning and sexed semen, and reproduction in the non-bovine species.
In the exams: ICAR AICE-JRF core group 07; ICAR AIEEA-PG 13 (ARGO); RPSC (ETT, IVF, cloning)
NAVLE, RCVS SME, Australasian AVE, SAVC registration
Clinical reasoning: classifying a bull from BSE findings, venereal disease control, mare breeding management with cooled and frozen semen, canine ovulation timing and Brucella canis.
How our questions for NAVLE spread across the units of Veterinary Andrology & Assisted Reproductive Techniques. Difficulty: 5 easy, 32 medium, 2 hard.
| Reproduction in companion animals | 8 | |
| Reproduction in equines | 6 | |
| Breeding soundness examination | 4 | |
| Semen collection | 4 | |
| Male infertility | 4 | |
| Reproduction in small ruminants and swine | 3 | |
| Semen evaluation | 2 | |
| Artificial insemination | 2 | |
| Multiple ovulation and embryo transfer | 2 | |
| Male reproductive physiology | 1 | |
| Frozen-semen technology | 1 | |
| Ovum pick-up and in-vitro fertilisation | 1 | |
| Sexed semen | 1 |
Choose an answer, then open the working. Each explanation says why the right answer is right and why the others are not.
Under the Society for Theriogenology (SFT) bull breeding soundness standard, the semen minimums for a satisfactory classification are:
A. At least 30% progressively motile and at least 70% morphologically normal sperm
SFT requires ≥30% progressive motility and ≥70% normal sperm, plus a scrotal circumference meeting the age minimum and a satisfactory physical examination. Reversing the two figures (70% motile, 30% normal) is the commonest slip. Other national systems use their own thresholds, which is why the standard is named in the stem.
Further reading: Society for Theriogenology, Manual for Breeding Soundness Examination of Bulls
Using the SFT minimum scrotal circumference table, what is the minimum for a bull aged 20 months?
D. 32 cm
SFT minimums: 30 cm at ≤15 months, 31 cm over 15–18 months, 32 cm over 18–21 months, 33 cm over 21–24 months and 34 cm over 24 months. A 20-month bull falls in the over-18-to-21-month band, so 32 cm. 31 cm is the next band down and 34 cm is the adult value.
Further reading: Society for Theriogenology, Manual for Breeding Soundness Examination of Bulls
In bulls, haematoma (fracture) of the penis usually results from rupture of the tunica albuginea at the:
D. Dorsal aspect of the distal bend of the sigmoid flexure
During a vigorous thrust, cavernous pressure ruptures the tunica albuginea on the dorsum of the distal bend of the sigmoid flexure, producing a swelling cranial to the scrotum. The other sites are not the classic location.
Further reading: Noakes, Parkinson & England, Veterinary Reproduction and Obstetrics
A 9-year-old male dog with an abdominal retained testis has gynaecomastia, a pendulous prepuce, symmetrical alopecia and attracts other male dogs. The most likely cause is:
A. Sertoli cell tumour secreting oestrogen
Retained testes are at higher risk of Sertoli cell tumour, which can produce oestrogen and cause feminisation and, in severe cases, bone-marrow suppression. Excess testosterone would not feminise; prostatic hyperplasia and Brucella infection do not cause this syndrome.
Further reading: Johnston, Root Kustritz & Olson, Canine and Feline Theriogenology
Rams are introduced to anoestrous ewes after several weeks of complete separation, late in the transition season. What is the typical response?
B. Ovulation within days, often silent first, then heat about 17–24 days later
Ram (male) pheromones raise LH pulse frequency, causing ovulation within a few days; the first ovulation is often silent and may be followed by a short cycle, so most ewes show oestrus about 17–24 days after introduction. The effect works on anoestrous ewes near the season, without a progestagen, though priming tightens the response.
Further reading: Hafez & Hafez, Reproduction in Farm Animals; Senger, Pathways to Pregnancy and Parturition
To advance the breeding season in mares in a temperate climate, artificial lighting commonly provides:
B. About 16 hours of light daily, begun 60–90 days before breeding
Mares are long-day breeders; extending total daylight to about 16 hours, starting some 60–90 days before the target date, brings forward the first ovulation of the year. Short days or long nights suppress cyclicity, as in sheep. A week of light is far too short to take effect.
Further reading: McKinnon et al., Equine Reproduction
A mare scanned 14 days after ovulation has two embryonic vesicles. The usual management is to:
A. Crush one vesicle manually before fixation at about day 16
Twin pregnancy in the mare usually ends in abortion or weak foals, so one vesicle is crushed transrectally, ideally while they are mobile or soon after, and before fixation at about day 16. PGF2α ends the whole pregnancy, not one twin, and waiting loses the easy window.
Further reading: McKinnon et al., Equine Reproduction
The queen (female cat) is described as an induced ovulator because:
A. Mating stimulation triggers the LH surge that leads to ovulation
In the queen, vaginal stimulation at coitus triggers LH release, and several matings are often needed for enough LH to cause ovulation; some queens ovulate spontaneously. She is a long-day seasonal breeder, so falling daylight ends rather than starts her season.
Further reading: Johnston, Root Kustritz & Olson, Canine and Feline Theriogenology
Before a stud dog is used on a new bitch, both dogs should be screened for which venereally transmitted, zoonotic infection?
D. Brucella canis
Brucella canis causes abortion, epididymitis, discospondylitis and infertility; it is zoonotic and difficult to eliminate, so serological testing before breeding is standard. Canine herpesvirus causes neonatal deaths but is not screened in the same way, Mycoplasma is part of the normal flora, and Toxocara is a roundworm.
Further reading: Johnston, Root Kustritz & Olson, Canine and Feline Theriogenology
A bitch's serial progesterone tests place her LH surge on 10 March. Using 65 days from the LH surge, when should whelping be expected?
C. 14 May
10 March + 65 days = 14 May (21 days left in March, 30 in April, then 14 into May). 12 May uses 63 days, the figure often quoted from mating; 6 May uses 57 days, which is counted from the first day of cytological dioestrus, not from the LH surge; 21 May is the upper end of gestation measured from a single mating.
Further reading: Johnston, Root Kustritz & Olson, Canine and Feline Theriogenology
Ten here, 39 in the app. The Laisha app has every practice question we have written to NAVLE in this subject, marked as you go, with timed papers, a jump-to-unanswered list and a certificate when you pass at 70 per cent.
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