Does modern broilers need less energy for better growth and intestinal development?

Area of Science:

• Animal Science
• Poultry Nutrition
• Avian Physiology

Background:

• Dietary energy is a critical factor influencing broiler performance and health.
• Current recommendations for metabolisable energy (ME) may not be optimized for modern broiler genetics.

Purpose of the Study:

• To evaluate the response of broiler chicks to varying dietary energy levels.
• To determine if reducing dietary ME impacts growth, feed efficiency, carcass characteristics, and intestinal morphology.

Main Methods:

• 11,400 Ross-308 broiler chicks were fed diets with 95% to 101.25% of the recommended ME for 42 days.
• Evaluated parameters included body weight (BW), feed intake, feed conversion ratio (FCR), carcass yield, and jejunal morphometrics.
• Statistical analysis included linear and quadratic effects of dietary treatments.

Main Results:

• Reducing dietary ME by up to 5% linearly improved FCR without affecting final BW or carcass yield.
• Significant improvements in jejunal villus height and surface area were observed with 2.5% and 3.75% ME reduction.
• Higher ME levels (101.25%) did not enhance performance compared to the positive control.

Conclusions:

• The optimal dietary energy level for modern broilers may be lower than primary breeder recommendations.
• Reducing dietary ME by up to 5% can improve FCR without compromising broiler performance.
• Dietary energy reduction positively influences intestinal morphology, suggesting enhanced nutrient absorption.