Gossypol disrupts embryo development in heifers

Area of Science:

• Animal Science
• Reproductive Biology
• Toxicology

Background:

• Gossypol, a compound found in cottonseed meal, is known to have toxic effects.
• Understanding the impact of dietary free gossypol (FG) on reproductive parameters in cattle is crucial for livestock management.

Purpose of the Study:

• To investigate the effects of varying dietary free gossypol (FG) levels on plasma and uterine gossypol concentrations.
• To assess the impact of FG on early embryo development and viability in Holstein heifers, both in vivo and in vitro.

Main Methods:

• Fifty Holstein heifers were fed diets with controlled FG content (0, 17.8, or 36.8 mg/kg BW) for 70 days.
• Embryos were collected post-superovulation and assessed for quality, cell number, and viability, or cultured in vitro with gossypol (10 µg/mL).
• Plasma and uterine tissue samples were analyzed for gossypol concentrations.

Main Results:

• Plasma and uterine gossypol concentrations increased dose-dependently with dietary FG intake.
• Heifers on the high FG diet produced fewer high-quality embryos, characterized by lower cell numbers and smaller diameters.
• In vitro exposure to gossypol (10 µg/mL) reduced blastocyst development and increased embryo degeneration.

Conclusions:

• Dietary free gossypol intake, particularly at high levels (36.8 mg/kg BW), significantly compromises early embryo development and viability in dairy heifers.
• Gossypol concentrations above 7 µg/mL in plasma, uterine fluid, or culture media negatively affect embryo quality and development.
• These findings suggest a mechanism for the reduced fertility observed in dairy cows consuming gossypol-containing diets.