100.Methods of searching for gilts and sows in heating

Question 1

Background of topic?

Answer 1

• The length of the estrus cycle is normally 21 days and occurs regularly until the sow or gilt becomes pregnant.
• Gilts tend to have a shorter cycle of 18–20 days.
• It is more easily detected in sows compared to gilts
• After weaning, early estrus may occur around day 3/4, normal estrus occurs at day 5 and late estrus occurs

around day 6/7

• It is important when conducting estrus checks that gilts/sows are taken close to a mature boar and his

pheromones so that the important stimuli of sight, smell and sound are most intense

Question 2

Pre-mating behaviour in pigs?

Answer 2

Pre-mating behaviour in pigs: Head detection

• Increased activity
• Head to head contact –> sniffing and nosing –> mounting attempts –> standing reaction –> copulation
• Standing reflex test takes around 10 mins, and return 45-60 minutes later to try again, as not all gilts/sows

will show a positive response in the absence of a boar

• Farmers should back check again even after synchronisation
• Physical

o Vulval reddening and swelling

o Clear vaginal discharge –> changes to an oil like consistency 12-24 hours

o Proestrus is slightly swollen/red

o Oestrous is very swollen and red