Enzyme deep dive: protein utilization in poultry

Exploring enzyme application to maximize protein utilization

Protein utilization is a critical factor of efficiency in poultry production, influencing feed conversion ratios (FCR), growth performance, and sustainability. As the costs of production rise - both feed and environmental - optimizing protein digestion has become paramount. 

Protein is one of the most limiting components in poultry diets due to the variability in ingredient digestibility. The digestibility of lysine, for instance, varies between 75% and 90% depending on the protein source. 

Modern poultry genetics have increased protein demands. Broilers require a higher protein-to-energy ratio, while laying birds need optimal protein intake to sustain high egg production. However, a significant portion of dietary protein will remain undigested, thanks to anti-nutritional factors. Additionally, elements such as feed processing methods, gut health, and individual bird variability can also influence protein absorption.

Role of enzymes in protein digestion 

The primary functions of enzymes include:

Protein Hydrolysis: Exogenous proteases enhance the breakdown of high-molecular-weight proteins into peptides and free amino acids, increasing bioavailability.

Reduction of Anti-Nutritional Factors: Proteases neutralize trypsin inhibitors, while NSP-degrading enzymes such as xylanases and pectinases improve gut viscosity and nutrient absorption.

Gut Health Modulation: Enzymes influence the gut microbiota by reducing fermentable protein availability to pathogenic bacteria, thereby mitigating the risk of dysbiosis.

Gene Expression Regulation: Recent studies have shown that enzymes can upregulate genes responsible for mucin production, strengthening the gut barrier function and improving intestinal health.

Reduction in Endogenous Protein Losses: By improving protein digestion efficiency, enzymes help minimize the loss of endogenous proteins, including digestive enzymes and mucins, ensuring better protein retention in the bird.

Advancements in protease technology 

dsm-firmenich’s second-generation protease, ProAct 360™, has been developed to enhance both the speed and completeness of protein digestion. 

Broad Substrate Specificity: Unlike traditional proteases, ProAct 360™ targets a wide range of protein sources, including those resistant to endogenous digestive enzymes.

Optimized pH Profile: It remains active across varying pH conditions, ensuring protein breakdown occurs throughout the digestive tract.

Enhanced Trypsin Inhibitor Degradation: Improved efficacy against protease inhibitors mitigates pancreatic hypertrophy and enhances protein digestibility.

Faster Hydrolysis: Compared to earlier protease formulations, ProAct 360™ accelerates protein breakdown in the small intestine, minimizing nitrogen excretion and improving FCR.

Increased Enzyme Stability: Advances in enzyme coating and formulation technology ensure proteases remain effective throughout feed processing and storage, preventing degradation during pelleting.

Practical considerations in enzyme application 

When incorporating enzymes into poultry diets, nutritionists must evaluate several factors:

Diet Composition: High NSP diets benefit from carbohydrase inclusion, while soybean-based diets require proteases to mitigate trypsin inhibitors.

Age of Birds: Enzyme efficacy tends to be higher in younger birds due to their immature digestive systems.

Processing Stability: Enzymes must withstand pelleting and conditioning processes to retain activity.

Formulation Adjustments: Accurate matrix values should be applied to account for enzyme-induced improvements in amino acid digestibility.

Feed Ingredient Variability: The quality of protein sources, such as soybean meal and alternative protein ingredients, must be considered when determining enzyme requirements.

Dosage Optimization: The inclusion rate of enzymes should be carefully determined to balance cost-effectiveness with performance benefits.

Environmental and Welfare Implications: Improved protein utilization reduces nitrogen excretion, leading to lower ammonia emissions and improved litter quality, which in turn minimizes footpad lesions (increasing feet value to sale) and respiratory issues.

What’s Next?

The future of protein utilization in poultry nutrition will likely involve continuous improvements in enzyme formulations and precision nutrition strategies. Emerging research in enzyme biotechnology is expected to yield more efficient enzyme variants tailored to specific feed formulations. Additionally, advancements in feed processing technologies, such as precision feed additive delivery systems, will further enhance enzyme efficacy. Sustainability initiatives will also drive the adoption of enzyme solutions that minimize the environmental footprint of poultry production.