Rear sow management profoundly impacts lifetime reproductive performance. Extensive domestic and international research confirms: the earlier a rear sow reaches puberty, the higher its lifetime productivity. Delayed puberty in older rear sows remains a common issue in modern farms, significantly limiting sow reproductive efficiency.

Boar exposure (estrus induction) is a critical, labor-intensive, and technically demanding practice to advance puberty. To achieve optimal results in large-scale operations, the following 12 key steps must be rigorously implemented:

1. Initial Boar Exposure Age & Duration

• Landrace × Yorkshire gilts: Begin at 160–170 days (23–24 weeks)

• Purebred gilts: Begin at 170–190 days (25–27 weeks)

• Continue exposure ≥21 days until 95% exhibit first estrus

70% show estrus within 3 weeks; 95% within 6 weeks

2. Boar Selection for Induction

• Use vasectomized boars >12 months, with strong libido, heavy saliva, and pungent odor

• Must actively “communicate” and detect estrus like a detection dog

• Rotate boars every 7–10 days to prevent familiarity fatigue

Long-term use of one boar per batch yields poor results

3. Boar-Sow Contact Method

• Drive boar into gilt pen for full-body contact and mounting

• Avoid fence-line “nose-to-nose” only

• Preferred: Move persistent non-cycling gilts into boar pen

• On-site supervision required to prevent accidental mating or injury

4. Daily Contact Frequency

• Morning + afternoon, with >8-hour interval

• No exposure before 150 days (ineffective and potentially harmful)

• Best timing: 0.5 hours post-feeding

5. Contact Duration per Gilt

• 4 minutes per gilt (1 boar can test ~100 gilts/day)

• 16 pens × 6 gilts = 96 gilts → complete in 1 hour

• Extend slightly in summer or high-density pens

Pen gates must be easy to operate and secure

6. Space Requirements

• Group housing: 5–8 gilts/pen, ≥2.5 m² per gilt

• Allow chasing and mounting

• Non-slip, dry flooring; properly positioned feeders/waterers to prevent injury

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Recommended Tools for Rear Sow Management

Enhance efficiency with:

• Portable Electrical-Ejaculator Set – Safe, precise semen collection

• Semen Collection Kit – Hygienic, complete solution for AI programs

• Comfort Rubber Cow Mattress – Reduces stress, improves estrus expression