Gilt Selection in Commercial Swine Operations: A Strategic Foundation for Reproductive Longevity and Herd Efficiency

In modern commercial swine production systems, strategic gilt selection plays a pivotal role in shaping the reproductive efficiency and long-term productivity of the sow herd. A recent expert review cited by PigProgress underscores the importance of combining biological, structural, and management-based criteria to ensure consistent, high-level performance.

📊 Optimal Biological Markers at First Breeding

Scientific literature identifies the ideal window for gilt breeding between 230–250 days of age, corresponding to a live body weight of 130–155 kg and backfat thickness between 12–15 mm.

These physiological parameters reflect not only physical maturity but also endocrine readiness, particularly regarding leptin levels, a hormone derived from adipose tissue known to regulate the hypothalamic-pituitary-ovarian axis and support regular estrous cycling.

🥗 Tailored Nutritional Management and Flushing Strategy

From approximately 60 kg body weight, nutritional protocols should be adjusted to achieve a daily gain of 750–800 g, balancing lean tissue accretion and fat deposition.

During the three weeks prior to first insemination, gilts should be fed ad libitum (a flushing phase), stimulating:

• Follicular recruitment
• Ovulation rate
• Conception success

This practice optimizes reproductive output without compromising gilt health or longevity.

🧬 Structural Soundness and Physiological Integrity

Selection criteria must also account for:

• Limb and joint conformation
• Gastrointestinal health
• Overall robustness and metabolic stability

Gilts with well-balanced frame and structural integrity are less prone to lameness, chronic disorders, or early culling due to subclinical stress or poor adaptation to the herd environment.

🐗 Estrus Stimulation and Hormonal Priming

Early estrus detection is critical for breeding synchronization. From 24–26 weeks of age, gilts should be exposed daily to stimulus boars, ensuring:

• Activation of neuroendocrine pathways
• Visual and olfactory stimulation
• Predictable and pronounced estrus behavior

This enhances reproductive predictability and improves the efficiency of artificial insemination timing.

📈 Long-Term Implications for Herd Performance

Well-selected gilts are more likely to complete multiple productive parities, reducing early removals and replacement costs. A science-based selection strategy:

• Increases farrowing rates
• Enhances sow lifetime performance
• Stabilizes the farm's reproductive economy

✅ Conclusion: Gilt Selection Is a Scientific Investment, Not a Random Process