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When can boars begin breeding?
At 6-7 months of age with occasional service
What should happen to boars before breeding age, and why?
Exposed to females as much as possible to stimulate male mating behaviour
What is essential for the first mating of a boar?
A small, quiet sow or gilt in oestrus
When can boars be used regularly for breeding?
From 7-8 months of age
How often can boars be used for breeding up to 1 year of age?
2-4 times weekly
How many services can mature boars perform per week?
6-10 services
What is the maximum number of natural services a boar should perform daily?
2 times daily
What are important factors when analysing reproduction management in boars to prevent infertility?
Breeding system
Selection of breeding boars
Breeding methods
Examination for breeding soundness
What factors affect breeding in boars?
Location
Environment
Nutrition
Infectious diseases
What is the best location for mating boars?
In the boar’s pen to avoid distraction
What type of flooring should be avoided in breeding areas?
Slippery floors
What environmental factor should be prevented to enhance breeding performance?
Thermal stress
What type of diet should be provided to breeding boars?
A diet with plenty of protein, amino acids, vitamins, and minerals to keep them fit, not fat
Why are vigorous vaccination programs essential for boars?
To prevent reproductive diseases, as boars are bred to multiple females and can become carriers
Why should breeding records be maintained for boars?
To determine reproductive performance
How long should newly purchased boars be quarantined?
3-6 weeks unless certified free from disease
Why should boars be allowed 3-4 weeks in a new environment before use?
To settle into the new environment
What should be done with boars lacking fertility or sex drive?
They should be culled
What factors disqualify a boar from breeding selection?
High occurrence of low litter sizes
Low adaptability
Metabolic diseases
Organ diseases
Infectious diseases
Low reproductive performance
What traits should boars be selected for?
Ability to sire gilt lines producing large, healthy, rapidly growing litters
Why are 2-3 breeds usually mixed in breeding programs?
To complement selective traits
What factors are considered when selecting boars?
Reproductive performance of dams and sires and the average litter size of the sire's origin
What are the types of breeding methods?
Pen mating
Hand mating
Artificial insemination
What is pen mating?
Boar is kept with females in smaller farms, with sows in different stages of the cycle
What is the recommended boar-to-sow ratio for pen mating?
1:4 for mature boars, 1:2 for young boars
What is hand mating?
Supervised natural mating, usually 2-3 times during oestrus. Individual female mated to individual boar.
When should the first service occur in hand mating?
On the first day of standing oestrus
How frequently should hand mating services occur?
At 24-hour intervals
What is the boar-to-sow ratio for hand mating?
1:15 to 1:25
What is artificial insemination used for?
Single sire mating for genetic traits
Pooled mating for market hog offspring
What is the boar-to-sow ratio in artificial insemination?
1:150 to 1:1250
What is the typical volume and sperm count in extended semen used for artificial insemination?
60-80 ml with 2-3 billion sperm
What are the purposes of a breeding soundness examination?
To ascertain normal fertility and diagnose infertility
What are the requirements for a breeding soundness examination?
History
General examination
Reproductive examination
Observation of copulation (libido testing)
Semen collection and evaluation
What is evaluated for the history for examination of breeding soundness in boars?
Normal environment, handling, housing, feeding, cleaning, service area, age, sexual experience
What is evaluated during a general examination of boars for reproductive soundness?
Body condition, TPR, nutritional deficiencies (protein), systemic illnesses
What does poor body condition affect in boars?
Spermatogenesis and reproductive performance
What concurrent health conditions can affect breeding performance?
Locomotor dysfunction, caudal abdominal pain, and prolonged pyrexia
What does the reproductive exam of a boar involve?
Examination of visible and palpable parts, including prepuce, penis, sigmoid flexure, and internal genitalia for size, texture, content and temperature
What should be assessed during copulation observation?
Stability on hind limbs, willingness to mount, and conditions preventing copulation
What factors may affect libido of boars?
Season: libido falls in summer & increases in winter
Maturity age & experience: young or old age
Poor service management: slippery floors, large females, poor handling
Locomotor dysfunction: impair ability & willingness to copulate – back & hind limbs are most important, but also lesions on carpus & trunk
What does semen examination ascertain?
Number, motility, and morphology of sperm
What is the typical volume and density of boar semen?
Volume: 125-500 ml; Density: 200-1000 x 10⁶/ml
What is the normal colour of semen?
Milky white
What could abnormal semen colour indicate?
Presence of urine/blood/pus
How is sperm count determined?
Haemocytometer, diluted in saline
What is the ideal sperm motility percentage?
70%
How is sperm motility assessed?
Individually: movement of head and tail resulting in productive forward movement (no circling, etc.)
Group: waves of concentrated regions
What are common sperm abnormalities?
Defects in the head, midpiece, or tail, and protoplasmic droplets
What is the maximum percentage of primary sperm defects allowed?
20%
What is the maximum percentage of secondary sperm defects allowed?
10%
What is the ideal pH range for boar semen?
6.8-7.2
What test measures resistance to dilution in boar semen?
Resistance to dilution by saline
How is live and dead sperm differentiated in boars?
Eosin-nigrinosin staining
What is the difference between bull and boar semen (volume, concentration)?
Bull:
Volume: 4-8 ml
Concentration: 1-1.5 billion/ml
Boar:
Volume: 125-500 ml
Concentration: 0.2-1 billion/ml
How are sperm abnormalities classified according to time?
Primary: during spermatogony
Secondary: during transport
Tertiary: during copulation
