Number of piglets born and their survival upto weaning age determine the amount of economic return from pig rearing. Proper breeding is necessary for obtaining maximum number of piglets. Knowledge of the farmers on signs and duration of heat, time of breeding and number of breeding during one heat period is very important for obtaining good and healthy litter size in pig rearing.
What is heat period?
An Adult female pig if not served or bred by male shows some external signs of heat at 21 days interval. The female accepts the boar and allows service only during the heat period. The signs of heat extend for a period of 2 to 3 days which is called heat period.
Signs of heat
- Swelling of vulva and mucous discharges.
- Sows in heat show restlessness and less appetite.
- Emits low grunting sound.
- The female in heat allows mounting by a male or other female.
- She mounts on the other females which are either in heat or approaching heat.
- When pressed on the back, the female stands motionless. This is known as standing reflex.
- Nuzzling/sniffing the flank region of the other pigs.
- Length of heat period is for 2 to 3 days.
Important points to remember while breeding female pigs
- Do not breed the gilts at first two or three heat periods since the reproductive organs are not fully developed.
- Do not breed the nursing sows (mother pig) even if they come to heat within 2 to 3 days after delivering of piglets.
- Do not breed the sow at first heat after weaning so as to allow sufficient time for the general health recovery of the sow before rebreeding.
Veterinary Hospital Kohima