Methods for reproductive tract scoring as a tool for improving sow productivity

Area of Science:

• Animal Science
• Reproductive Biology
• Swine Production

Background:

• Improving sow lifetime productivity is crucial for farm profitability.
• Gilt selection impacts overall herd performance and economic returns.
• Early identification of high-potential gilts can optimize breeding programs.

Purpose of the Study:

• To evaluate the accuracy of different vulva scoring methods for assessing gilt reproductive potential.
• To determine if pre-pubertal vulva width scoring can serve as a gilt selection criterion.
• To correlate vulva scoring with subsequent sow lifetime productivity.

Main Methods:

• 958 prepubertal gilts were scored using digital calipers, visual farm assessment (FS), and two calibrated scoring tools (VSA, VSB).
• Vulva width (VW) and body weight (BW) were recorded at approximately 15 weeks of age.
• Gilt reproductive performance through two parities was tracked and analyzed in relation to VW scores.

Main Results:

• All three scoring methods (VSA, VSB, FS) effectively categorized gilts by vulva width (P < 0.01).
• Higher vulva scores correlated with increased gilt success in reaching first parity (P = 0.02-0.03).
• Gilts with higher scores (VSA M/L, VSB 2-5, FS 2-3) demonstrated improved litter performance (total born, born alive) over two parities.

Conclusions:

• Vulva width assessment at 15 weeks of age is a viable method for predicting gilt reproductive success.
• Scoring methods like VSA, VSB, and FS can identify gilts with enhanced lifetime productivity through two parities.
• This pre-pubertal assessment aids in selecting breeding herd females for improved farm profitability.