7. Light Stimulation
At the beginning of the estrus induction period, increase the daily light duration to 14 hours.
Install incandescent lamps in the gilt housing to supplement light intensity to above 150 LUX (approximately 4–6 W/m²) — equivalent to the brightness level where one can clearly read a newspaper in the pen.
However, simply extending the light duration without boar stimulation may delay or even prevent gilts from showing heat. Light management should always be combined with boar exposure for optimal results.
8. Isolation Between Boars and Gilts
During the growing and development phase, gilts should be raised separately from boars.
They should neither see nor smell boars in daily management, as overexposure to boar stimuli may cause them to lose sensitivity and interest during the heat detection stage.
Some farms keep gilts and teaser boars together for convenience, which is an incorrect practice.
Instead, changing pens, providing sunlight exposure, and regular outdoor exercise can help stimulate estrus by introducing new environmental factors.
9. Human–Animal Interaction
During the induction process, caretakers can simulate boar mounting behavior by slowly approaching and gently touching the gilt’s back and flanks, gradually increasing intensity over time. This should be done once or twice daily for about a week.
Such close interaction not only mimics the effect of a boar’s presence but also builds trust between the gilt and handler, reducing fear and resistance during heat detection and insemination procedures.
10. Heat Detection
Compared with multiparous sows, gilts often show milder estrus symptoms with shorter standing reflex durations, making initial detection more challenging.
The vulva changes are typically more obvious in gilts and can serve as a key indicator. The onset of estrus should be recorded when vulvar redness and swelling begin to subside.
During the detection process, caretakers should focus on observing gilt behavior rather than only the teaser boar.
If lighting conditions are poor, ensure adequate illumination to allow accurate observation.
11. Record Keeping and Group Management
Establishing a comprehensive estrus record is the first step in tracking the reproductive performance of breeding females.
Records should include gilt ear number, pen number, dates of the first three observed heats, changes in vulva appearance, and back-pressure responses.
Color marking using different spray paint (red, green, blue) each week helps identify gilts by estrus period.
Grouping gilts that come into heat on the same day also allows for batch management, improving synchronization and breeding efficiency.
12. Staff Training and Time Management
Farm managers must attach great importance to gilt stimulation programs.
A clear and measurable work plan should be implemented, and the most responsible and patient personnel should be assigned to gilt estrus induction tasks.
Their workload should be reasonable to ensure adequate time for careful boar exposure and behavioral observation.
Consistent management, good communication between handlers, and attention to detail are key to achieving reliable estrus detection and successful artificial insemination.
Each of the above steps—ranging from light control, boar stimulation, and environmental management to record keeping and staff training—plays an essential role in improving gilt reproductive performance.
While optimizing estrus induction and detection can significantly enhance artificial insemination success rates, farms should also focus on gilt quality selection. Gilts with poor leg structure or underdeveloped teats should be eliminated early to ensure a healthy, productive breeding herd.
Post time: Nov-04-2025