Body weight optimization of broiler breeder hens. 2. Reproductive performance.

Area of Science:

• Animal Science
• Poultry Science
• Reproductive Biology

Background:

• Broiler breeder hen reproductive performance is crucial for the poultry industry.
• Growth trajectories, including early growth (EG) and the timing of maximum pubertal growth (I2), can influence physiological development and productivity.

Purpose of the Study:

• To evaluate the impact of shifting growth gain from the pubertal to prepubertal phase (EG) and altering the timing of maximum pubertal growth (I2) on broiler breeder hen performance.
• To assess effects on body weight (BW), feed efficiency, carcass composition, and reproductive outcomes.

Main Methods:

• A 6x2 factorial experiment utilized twelve body weight (BW) target trajectories created by modifying Gompertz model coefficients for Ross 308 hens (0-60 weeks).
• Treatments included six I2 levels and two EG levels (EG0: standard gain; EG20: 20% of phase 2 gain shifted to phase 1).
• Data were analyzed using three-way ANOVA and analysis of covariance.

Main Results:

• Earlier I2 was associated with a decrease in dorsal feather score.
• Egg production, egg weight, and egg mass increased with earlier I2.
• Total eggs produced and estimated chick numbers per hen also increased with earlier I2.

Conclusions:

• Advancing body weight gain to the prepubertal phase (EG) and earlier timing of maximum pubertal growth (I2) in broiler breeder hens positively impacts reproductive efficiency.
• Earlier I2 significantly enhanced egg and chick production, highlighting the importance of growth phase optimization for breeder hen productivity.