42. Analysis of reproduction management in boars as a prevention of infertility (boars‘ insemination ability, sperm production, fertility)

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?

1. Breeding system

2. Selection of breeding boars

3. Breeding methods

4. Examination for breeding soundness

What factors affect breeding in boars?

1. Location

2. Environment

3. Nutrition

4. 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?

1. High occurrence of low litter sizes

2. Low adaptability

3. Metabolic diseases

4. Organ diseases

5. Infectious diseases

6. 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?

1. Pen mating

2. Hand mating

3. 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?

1. Single sire mating for genetic traits

2. 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?

1. History

2. General examination

3. Reproductive examination

4. Observation of copulation (libido testing)

5. 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?

1. Season: libido falls in summer & increases in winter

2. Maturity age & experience: young or old age

3. Poor service management: slippery floors, large females, poor handling

4. 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?

1. Individually: movement of head and tail resulting in productive forward movement (no circling, etc.)

2. 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