Relationships among fertility, sperm storage, and shell quality

Area of Science:

• Poultry Science
• Reproductive Biology
• Animal Science

Background:

• Eggshell quality is crucial for poultry production and fertility.
• Variations in eggshell characteristics, such as thin shell (TS) and shell-less (SL) eggs, can affect hen reproductive efficiency.
• Understanding the relationship between shell quality, sperm storage, and fertility is essential for optimizing breeding programs.

Purpose of the Study:

• To investigate the correlations between eggshell quality (hard shell - HS, thin shell - TS, shell-less - SL), fertility, and sperm storage in White Leghorn hens.
• To determine if specific gravity (SG) of HS eggs is indicative of fertility parameters.
• To histologically examine sperm distribution in uterovaginal sperm-host glands (UV-SHG) of hens laying HS versus SL eggs.

Main Methods:

• 109 White Leghorn hens were artificially inseminated (AI) over 2 days.
• Eggs were collected for 17 days and categorized by shell quality (HS, TS, SL); SG was measured for HS eggs.
• Fertility was assessed after 3 days of incubation; histological analysis of UV-SHG was performed on selected hens.

Main Results:

• Hens producing eggs with SG < 1.070 exhibited significantly lower fertility rates and duration.
• Specific gravity showed significant positive correlations with fertility percentage, duration, and fertile egg production.
• Histological examination revealed a higher percentage of empty UV-SHG in SL hens compared to HS hens, suggesting impaired sperm storage.

Conclusions:

• Eggshell quality, particularly low specific gravity, is strongly associated with reduced fertility and duration of fertility in hens.
• Shell-less egg production is linked to compromised sperm storage within the uterovaginal sperm-host glands.
• These findings highlight the importance of maintaining adequate eggshell quality for successful artificial insemination and overall reproductive performance in poultry.