Ultrasonography: A Window into Hen Performance

In the precision-driven world of modern egg production, a novel application of ultrasonography is
revolutionizing how producers evaluate laying hen potential. This non-invasive technology offers
quantifiable insights into physiological parameters directly correlated with productivity, enabling
producers to optimize performance while maintaining high welfare standards.

Keel bone fractures affect up to 90% of hens in aviary systems, significantly compromising welfare and
laying performance. These injuries – often the result of collisions with equipment or long-term pressure
from perching – are exacerbated in modern layers, which are selectively bred for high egg output at the
expense of muscle mass and bone strength.

Figure 1 : Pectoralis muscle thickness in a well-muscled hen (left: thicker) and in an hen lacking muscle (thinner: right) obtained by ultrasonography. The keel bone is barely detected on palpation (left) or protruding (right).

Beyond the Surface: Quantitative Tissue Assessment

Traditionally, producers rely on body weight measurements and manual palpation to assess pullet and hen development. While useful, these methods are subjective and lack precision. Fleshing score—already a benchmark in broiler breeder management—is increasingly recognized for its relevance to layers, as muscle development and protein retention are essential to sustaining a productive laying curve.

Necropsy remains the most accurate method of evaluating keel bone integrity, but it’s invasive and terminal. Ultrasonography, already used in poultry science to assess egg freshness and shell thickness, now offers a reliable, on-farm alternative for R&D investigation. Lallemand Animal Nutrition has pioneered a real-time, portable ultrasound application for evaluating both breast muscle thickness and keel bone condition.

Using a standardized scanning protocol, the device captures pectoralis muscle thickness (Figure 1) and identifies keel bone deviations or fractures offering consistent tracking across production stages. ¹

The Muscle-Bone-Egg Connection

Recent research ² has established clear connections between breast muscle development, skeletal health,
and egg production quality. The pectoralis muscle serves as a critical protein reserve for egg synthesis,
while the skeleton provides essential minerals like calcium and phosphorus for eggshell formation.

In a 2024 field study conducted by Lallemand Animal Nutrition in Italy, hens with well-developed muscles
showed 28-40% thicker pectoralis measurements compared to under-developed counterparts – clear
evidence of the technology’s diagnostic value.

Nutritional Strategy Validation

This ultrasound method also opens the door to validating nutritional strategies such as probiotic supplementation. In controlled trials, supplementation with Pediococcus acidilactici CNCM I-4622 (BACTOCELL) demonstrated significant physiological improvements over specific timeframes. ³

Figure 2 : Muscle Thickness Increase with Probiotic Supplementation

In the same field trial in Italy, these improvements corresponded with dramatic differences in keel bone
integrity – 50% of probiotic-supplemented hens maintained undamaged keel bones versus just 15% in
control groups (Figure 2). Furthermore, when fractures occurred, their severity was substantially reduced
(0% severe fractures in supplemented birds compared to 25% in control groups).

“This methodology represents an intersection of diagnostic imaging science and production physiology.” notes Chevaux. “The high-frequency sound waves generate detailed tissue mapping that correlates strongly with metabolic efficiency indicators. Ultrasonography gives us that insight without sacrificing birds for examination.”

The adoption of this technology represents a forward-thinking approach to poultry management where science meets practicality to optimize production while supporting bird welfare.