Presented at a Horse SA Seminar, Murray Bridge June 2011 by Abdelsalam Talafha DVM, Diplomate American College of Theriogenologists School of Animal and Veterinary Sciences The University of Adelaide, SA 5371 Australia

1. Selection and Preparation of the Mare and
Stallion for Breeding
Abdelsalam Talafha
DVM, Diplomate American College of Theriogenologists
School of Animal and Veterinary Sciences
The University of Adelaide, SA 5371
Australia

2. Introduction - selection criteria
Criteria and techniques used in selection for
reproductive competence
Goal: To produce healthy offspring with minimal
danger to life and well-being of dam

3. Selection of the Mare
Breeding Soundness Examination “BSE”

4. Components of BSE
Reproductive and general history / Records
General physical examination
Reproductive tract examination

5. Reproductive history : Age
Puberty
• 18 - 24 months
Breeding at puberty
• Higher embryo mortality rates
• Demands of maintenance, growth,
pregnancy

6. Reproductive history: Age
Maiden mares over 12 y of age
• Reduced fertilization & embryo survival rates
• Poor ova viability
• Embryonic defects
• Increase in age-related endometritis
• Exposure to uterine infections

7. Reproductive history: Age
Mares in peak athletic condition demonstrate
• Abnormal estrous cycles
• Corticosteroids and anabolic steroids
effects
• 6-18 months rest period to settle
down into non-athletic state

8. Reproductive history : Age
Ideal age to breed a
maiden mare
5–6 y. old
Not normally
advisable to breed
Over 20 y. old

9. Reproductive history / Records
Length of estrous cycle / estrus
Regularity of estrous cycles
Showing characteristic signs of estrus
Beginning and length of breeding season

10. Reproductive history / Records
• Early embryonic death
• Abortion
• Twins
• Dystocia
Problems during
previous
pregnancies
• Rejection of foals
• Foal birth weight / growth
rates
• Uterine infection
• Mammary gland inflammation
Post foaling
problems

11. General history
Vaccination
Parasite control
Umbilical hernia
Respiratory problems
Vaginal prolapse
Laminitis
Navicular disease
Tendonitis

12. General physical examination
All body systems
Blood analysis
Urinalysis
Fecal egg count
Evaluation of conformation

13. Reproductive tract examination
Perineal conformation
Vaginal speculum exam
Rectal palpation
Ultrasound examination
Uterine cytology
Uterine culture
Uterine biopsy

14. Reproductive tract examination of
Uterine biopsy: category and
predicted foaling rate (%)
I: 80–100%
II A: 50–80%
II B: 10–50%
III: < 10%

15. Selection of the Stallion
Breeding Soundness Examination

16. Components of Stallion BSE
Reproductive and general history
General physical examination
Reproductive tract examination
Observation of libido and mating ability
Examination for venereal disease
Semen collection and evaluation

17. Reproductive history / Records
Start and end of his season
Previous breeding performance
Results of prior fertility evaluations
Reproductive-tract infections

18. General history
Hind limbs injuries
Injuries to genitalia
Systemic infections
Vaccination
Parasite control

19. General physical examination
All body systems
Blood analysis
Urinalysis
Fecal egg count
Evaluation of conformation

20. Reproductive tract examination
Examination of the external and internal genitalia

21. Libido and mating ability
Immediate interest and interaction with a
mare in estrus
Erection within 2 min.
Mount readiness within 5 to 10 sec. after
erection
Ejaculation on 1st mount
Total breeding time of 2 to 5 min.

22. Examination for venereal disease
Normal
nonpathogenic
bacteria flora
Potentially
harmful
bacteria
Klebsiella
pneumoniae
Pseudomonas
aeruginosa
Venereal
bacteria
Taylorella
equigenitalis
Venereal
viruses
Equine
herpes
virus 3
Equine
viral
arteritis

23. Semen collection and evaluation
Semen collection using artificial vagina
Ejaculate should be filtered
Gel: 10 - 300 ml
Gel free semen: 20 - 80 ml

24. Semen evaluation
• Watery grey
to creamy
white
Color of
normal
ejaculate
• 7·2 - 7·7
Normal
semen
pH

25. Semen evaluation: Motility
Velocity
• Scale of 0 to 4
Progressive motility (PM)
• > 60%
• PM < 40% are likely to compromise
fertility

26. Semen evaluation: Concentration
100 – 500 x 106 sperm /ml
4 – 14 x 109 sperm / ejaculate

27. Semen evaluation: Morphology
Morphologically normal (MN) > 70%

28. Calculation of PM – MN sperm: Example
A stallion produces 90 ml semen
Gel-free sperm = 75 ml
[ Sperm ] = 220 x 106 /ml
• 75 ml x (220 x 106) = 16·5 x 109 / ejaculate
Assuming PM = 75%
• Total # PM = (16·5 x 109) x 0·75 = 12·37 x 109
Assuming MN: 50% of PM
• Total # PM-MN sperm= (12·37 x 109)x 0·50 = 6·18 x 109

29. Daily Sperm Output (DSO)
Number of sperm that a stallion can produce on a daily
basis
To achieve 75%, 45-day pregnancy rate in 40 mares
by natural cover or 120 mares by AI during a typical
breeding season of 135-150 days
• Minimum of 2 x 109 PM-MN sperm in 2nd of 2
sperm collections taken 1 hr apart after 1 week
of sexual rest

30. BSE - Interpretation
Satisfactory • Pass all tests of BSE
• A problem that precludes his
classification as satisfactory
• May pass BSE at a later date
Questionable
• A problem that is not expected to
improve
Unsatisfactory

31. Types of semen
• Intended for AI at premises other
than that on which it was
collected
Transported semen
• Not extended
• Must be used within 10 min
Raw semen
• Extended semen
• Maintained at ~ 22°C
• Used within 4 hrs of collection
Fresh semen

32. Types of semen
• Mixed with extender
• Cooled to between 5-10 °C
• Used within 36 hrs after
collection
Chilled (cooled)
semen
• Processed and maintained in
liquid nitrogen (-196°C) for long
periods
Frozen semen

33. Semen preservation: semen extender
• Protect sperm against cold shock
by stabilizing cellular membranes
Lipoproteins
Glucose • Source of energy for sperm
Antibiotics • Eliminate bacteria growth
Osmolarity • 350 mOsm/L
pH • 6.5 to 7.2

34. Semen preservation: Chilled Semen
• Within 2 - 5 min
after ejaculation
Semen mixed with 37°C extender
• Dilution 1:1
extender : semen
For immediate AI
Semen storage > 2 - 4 hrs • Dilution 4:1
• 25 - 50 x 106
sperm / mL
Finale conc. in extended semen

35. Insemination volume (IV) for fresh extended semen
 IV (mL) = PMS dose ÷ (SCe x %PM)
 PMS dose: 100 – 500 x 106
 SCe: sperm concentration in extended semen
(25 - 50 x 106 )
 %PM: progressively motile sperm in ejaculate

36. Insemination volume (IV) for fresh extended semen
 Example: [ sperm ] = 220 x 106 /ml, PM = 75%
 IV = 500 x 106 ÷ (50 x 106 x 0.75) = 13.3 ml
 (500 x 106 ÷ 220 x 106 ) 2.3 ml semen : 11 ml
extender
 = dilution 1 ml semen : 5 ml extender
 Typical IV 10 – 30 ml

37. Semen preservation: chilled semen
Extended semen fertilizing capacity
• Refrigerated temp: 24 - 48 hrs
• 72 - 96 hrs (highly fertile stallions)
• Room temp: 12-24 hrs
Airport security x-ray at 10 μSv
• No adverse effects of on sperm motility,
morphology, or fertility
• Mares delivered normal foals at term

38. Semen Preservation: Frozen semen
Dilution and centrifugation
Freezing extender
Packaging
Freezing
Storing
Thawing
Insemination

39. Semen Preservation: Frozen semen
0.5-mL straw labeled with
• Stallion identification
• Breed registry
• Registration number
• Semen-processing location and date
• Freezing extender used

40. Longevity of sperm motility
Raw semen
• Room temp.
• PM > 10% at 6 hrs
Chilled extended semen
• Stored at 5°C
• Examined at 6, 12, 24 and 48 hrs
• PM > 40% when warmed to 37°C after 24 h
Frozen sperm
• Thawed at 38°C
• PM > 15% after 2 hrs

41. Minimum standards for stallion semen for AI by “World
Breeding Federation for Sport Horses (WBFSH)”
Fresh Semen
• Minimum of 300 x 106 PM
Chilled Semen: Extended / Fresh
• Sperm dose: Minimum of 300 x 106 PM at time of
portioning
• AI: within 12 hrs of collection
• PM: > 35%
• Storage conditions maintained

42. Minimum standards for stallion semen for AI by WBFSH
Chilled Semen: Extended / Transported
• Sperm dose: minimum of 600 x 106 PM at
time of portioning
• Max. volume: 40 cc
• AI: 24 - 36 hrs after collection
• PM: > 35%
• Storage conditions maintained

43. Minimum standards for stallion semen for AI by WBFSH
Frozen Semen
• Minimum of 750x106 PM per AI dose post-thawing
• Volume dose: dependent on
manufacturing process (0.5 or 5 ml
straws)
• PM: > 35% post-thawing

44. Back to our Example using WBFSH standards
 Gel-free sperm = 75 ml, [ sperm ] = 220 x 106 /ml,
PM = 75%, Total # PM in ejaculate = 12·37 x 109
 This ejaculate can be used for
 Fresh and fresh extended semen =(12.3 x 109) ÷
(300 x 106 ) = 41 mares
 Chilled transported semen =(12.3 x 109) ÷ (600 x
106 ) = 20 mares

45. Back to our Example using WBFSH standards
 Frozen semen= (12.3 x 109) x 0.35 post-thaw
motility ÷ (750 x 106 ) = 6 mares
 If you want to be more hard on stallion, consider
% MN sperm in your calculations, i.e. 20, 10 and
3 mares, respectively, assuming 50% MN sperm
in ejaculate

46. Timing of insemination
Fresh semen
• 24 - 36 hrs pre-ovulation
Chilled semen
• 12 - 18 hrs pre-ovulation
Frozen semen
• 6 - 12 hrs pre-ovulation
• Up to 6 hrs post-ovulation

47. Preparation of the Mare and
Stallion for Covering

48. Body Condition
Ideal body condition score (BCS) at mating
• 5-6 (scale 1 - 9)
• Good covering of flesh
• Ribs, vertebrae, backbone felt with some
pressure

49. Mare and stallion Preparation - Management
Introduction to breeding surroundings &
procedures
Exercise
Social interaction
Hoof care
Dental care
Parasite control
Vaccination

50. Introducing Stallion to Covering
3 years
• 1st breeding
4 years
• 50 mares / season
• Inconsistent fertility
rates and libido
5 y until his 20s
• 50–100 mares /
season
• Up to 3 mares / day

51. Introducing Stallion to Covering
During 1st season
• Limited to 10 - 15 mares spread out over
season
• Not more than 1 mare / day

52. References
 Juan C. Samper, Jonathan F. Pycock, Angus O. McKinnon. Current
Therapy in Equine Reproduction. 2007. Saunders Elsevier, St. Louis,
Missouri.
 Juan C. Samper. Equine breeding management and artificial
insemination. 2nd edition. 2009. Saunders Elsevier, St. Louis,
Missouri
 Steven P. Brinsko et al. Manual of equine reproduction. 3rd edition.
2011. Mosby Elsevier, Maryland Heights, Missouri
 www.vetmed.lsu.edu/eiltslotus/theriogenology-5361/
 www.equine-reproduction.com
 www.drostproject.org
 www.ivis.org

53. T
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Petra -
JORDAN