Reproduction of Pig
Selection of boars for
- They must be offspring of better
producing gilts and sows.
- They must belong to a litter with size
and weight of not less than 8 and 72 kg respectively at weaning.
- Boars satisfying above stipulations
are subjected to preliminary selection at 5 months of age provided they
have a body weight of at least 60 kg.
- Final selection of boars should be
undertaken at 7 months provided it has attained a body weight of at
least 90 kg.
- Must be free from physical defects.
- Breeding males and females should be
selected from different litters and boars should be changed periodically
– preferably once in two years – for avoiding inbreeding.
Management of boars
- Although boars reach sexual maturity
at 7 months of age, it is generally recommended that they must be at
least 10-12 months (100 kg body weight) before being put to regular use.
- Boars should be fed after service
rather than before.
- Boar: sow ratio may be 1:25.
- Outdoor exercise is good for keeping
the boar thrifty and virile. He should neither be over fat nor run down.
The boar may be handled firmly but gently, keeping in mind that he can
- Each boar should be housed separately.
- Number of services for boars: 2 - 4
per week depending on the age of boar.
- Boars should be tested for brucellosis
and leptospirosis periodically.
- Gilts: Breeding pigs are selected from
mother pigs having good mothering ability as shown by large litter size
and weight at weaning. Gilts should have 12-14 evenly spaced sound
teats, good growth rate and feminity.
- Weaned sows: Sows are usually weaned
at 8 weeks after farrowing. The weaned sows come into heat in 3-10 days
after weaning. They may be bred on the first post-weaning heat itself
since this period is most fertile. She may respond to nutritious diet
and pick up fast if the condition is poor.
- Pregnant sows and gilts: In addition
to having proper nutrition, the pregnant animals should be provided with
regular exercise. Forced exercise may be brought about by feeding some
distance away from the house or inducing the animal for moderate walk.
Sows of the same size and condition can be run together. The bred and
gilts may be housed separately. Do not house boars along with pregnant
stock. Avoid overcrowding, mixing of new and old stock, slippery ground
and overexciting of pregnant pigs.
Breeding chart for
|1. Age at puberty (months)
||6 – 8
|| 5 - 7
|2. Age at which the pigs can
be bred (months) Approximate body weight (kg)
|10 – 12
80 – 110 kg
|8 – 10
80 – 100 kg
|3. Oestrous cycle
||18 – 24 days
|4. Oestrous period (days)
||2 – 3 days
|5. Signs of heat
grunting, champing of jaws, swollen vulva, mounting on other
pigs, standing still when mounted or pressed on the back.
|6. Apt time for mating
||24 hours after the
onset of heat symptoms. Second mating is advised 8-12 hours
after the first mating
|7. Gestation period
||111 – 117 days
|8. Farrowing time
||2 – 12 hours
|9. Litter size at birth
||6 – 12 no.
|10. Birth weight
||1 – 2.5 kg
|11. Suckling period
|12. Post-weaning heat in sows
||3 – 10 days
Kerala Agricultural University. 2001. Package
of Practices- Recommendations: Veterinary and Animal Husbandry, Kerala
Agricultural University, Trichur. .