Flushing and altrenogest affect litter traits in gilts

Area of Science:

• Animal Science
• Reproductive Biology
• Swine Production

Background:

• Optimizing gilt reproductive performance is crucial for efficient swine production.
• Flushing and hormonal treatments are strategies used to enhance gilt fertility.
• Understanding the synergistic effects of these treatments is essential for maximizing litter size and weight.

Purpose of the Study:

• To evaluate the effects of flushing and altrenogest treatment on gilt reproductive performance.
• To determine the impact of these treatments on estrus interval, ovulation rate, and subsequent litter characteristics.
• To identify optimal strategies for improving gilt reproductive efficiency.

Main Methods:

• A 2x2 factorial arrangement of treatments was used, with 267 gilts assigned to flushing, altrenogest, or control groups.
• Altrenogest (15 mg/gilt/day) was administered for 14 days.
• Flushing (1.55 kg/day additional grain sorghum) began on day 9 of altrenogest treatment and continued until estrus detection.

Main Results:

• Flushing significantly increased ovulation rates (14.5 vs. 13.4 corpora lutea) and litter size (.9 pigs/litter) and weight (1.43 kg/litter).
• The combination of altrenogest and flushing shortened the interval to estrus post-treatment (6.6 days) compared to flushing alone (7.6 days).
• Altrenogest + flushing resulted in more pigs born alive and heavier live pigs when gilts were inseminated at pubertal estrus.

Conclusions:

• Flushing is an effective strategy to increase gilt ovulation rates, litter size, and litter weight, especially when gilts are bred at pubertal estrus.
• Altrenogest combined with flushing can optimize the estrus interval.
• These findings highlight the importance of nutritional and hormonal interventions for enhancing gilt reproductive potential.