Nutritional interventions to improve fertility in male broiler breeders

Fertility in broiler breeder flocks depends on both males and females, but each rooster is responsible for fertilizing approximately 1,000 to 1,800 eggs or more, making male reproductive performance a critical factor for hatchability and flock productivity.

Stress, aging, mycotoxicosis, toxicosis, and poor nutritional management can significantly reduce semen quality, sperm motility, testosterone production, and overall reproductive efficiency in roosters.

Aging and Male Fertility Decline

Roosters older than 40 to 45 weeks commonly experience reproductive decline, including:

• Testicular regression
• Reduced testosterone levels
• Lower sexual behavior
• Reduced semen volume
• Lower sperm concentration
• Reduced viability and forward motility

These age-related changes are associated with increased lipid peroxidation, reduced antioxidant capacity, and altered seminal fluid composition.

Male Diets vs Female Diets

Roosters have lower amino acid and calcium requirements than hens, which creates ongoing debate about the use of male-specific diets during the production phase.

Many farms use only female diets due to management limitations such as lack of feed bins or automatic feeders. However, excessive calcium intake can negatively affect sperm motility by causing mitochondrial degeneration in sperm cells.

PUFAs and Antioxidant Support

Rooster sperm membranes contain high concentrations of polyunsaturated fatty acids (PUFAs), especially docosatetraenoic acid, which makes them highly susceptible to oxidative damage and lipid peroxidation.

Supplementation with omega-3 fatty acids from:

• Salmon oil (4%)
• Tuna oil (3%)
• Menhaden oil (2%)
• Linseed oil (2–6%)

can improve sperm motility, testosterone synthesis, semen volume, sperm viability, and total sperm count.

Key Antioxidants for Fertility

Several antioxidants have shown positive effects on rooster fertility:

• Betaine (1,000 mg/kg)
• CoQ10 (300 mg/kg)
• Selenium-methionine
• Organic Zinc (100–110 mg/kg)

These additives improve sperm production, motility, membrane integrity, testicular development, testosterone production, and seminal antioxidant status.

However, excessive vitamin C and vitamin E supplementation may negatively affect sperm morphology and fertility, showing that dosage precision is critical.

Functional Amino Acids

Functional amino acids and metabolites also improve fertility in roosters older than 55 weeks:

• L-arginine (0.14%)
• D-aspartic acid (200 mg/kg BW)
• L-carnitine (150 mg/kg)
• Guanidinoacetic acid (GAA) (1,200 mg/kg)

These compounds improve libido, testosterone levels, Sertoli and Leydig cell development, sperm concentration, membrane integrity, and sperm penetration capacity.

Avoiding Mycotoxins and Glyphosate Exposure

Mycotoxins such as aflatoxins, fumonisins, zearalenone, ochratoxins, and trichothecenes can damage reproductive organs, reduce testicular size, and impair semen quality.

Glyphosate-based herbicide (GBH) exposure through feed ingredients can also negatively affect testicular histopathology and sperm mobility, two critical fertility indicators.

Conclusion

Male fertility is a major factor influencing hatchability and overall broiler breeder productivity. Nutritional precision becomes even more important as roosters age and become more vulnerable to oxidative stress and reproductive decline.

Combining male-specific diets, omega-3 supplementation, antioxidants, functional amino acids, and toxin control creates a strong strategy to maintain fertility and reproductive longevity.