Abstract
A commercial field trial conducted in Andhra Pradesh, India, evaluated the efficacy of an oregano essential oil supplement in improving growth performance and flock uniformity among layer pullets. The study, which involved 20,300 pullets over a four-week period, demonstrated significant improvements in body weight gain, reducing the growth gap between commercial and standard weights by 67%.
Introduction
The global poultry industry faces numerous challenges, including the rise of antimicrobial resistance, increasing demands for feed efficiency, and growing consumer preferences for naturally raised poultry. Oregano essential oil—containing over 30 bioactive compounds—hasemerged as a promising alternative to conventional growth promoters.
Layer production remains a crucial protein source for the world’s expanding population. However, modern layer farming is increasingly affected by:
- Growing antimicrobial resistance and the need to reduce antibiotic use
- Rising feed costs and pressure to enhance efficiency
- Variability in production performance and flock uniformity
- Environmental stressors negatively affecting bird health
- Economic pressures on producers
- Stringent egg quality standards for both domestic and export markets
Among natural feed additives, oregano essential oil has gained particular attention due to
its multifunctional benefits, including:
- Natural antimicrobial and anti-coccidial properties
- Appetite stimulation and support for digestive health
- Antioxidant effects that reduce oxidative stress
- Anti-stress benefits during heat exposure or handling
- Immune system modulation
Flock Uniformity: Importance and Challenges
Flock uniformity, a key performance indicator, is achieved when 80% of birds fall within ±10% of the average body weight. In India, several factors contribute to poor uniformity, impacting both productivity and profitability.
Impacts of Poor Uniformity
A flock with 60% uniformity (compared to an optimal 85%) may experience a 5-10% decline in egg production and a 10-15% increase in feed conversion ratio (FCR), significantly reducing profit margins over a standard 60-week laying cycle.
Reduced Egg Production
- Inconsistent Laying Rates: Non-uniform birds reach sexual maturity at varying times, resulting in uneven production peaks and lower overall output.
- Smaller Egg Sizes: Underweight or underdeveloped hens lay smaller eggs, reducing market value and revenue.
- Prolonged Production Gaps: Birds maturing late delay the flock’s peak production, extending the non-productive period.
Poor Egg Quality
- Variable Shell Quality: Non-uniform hens may produce eggs with inconsistent shell thickness or strength, increasing breakage and waste.
- Internal Quality Issues: Variations in hen health or nutrition can affect yolk and albumen quality, impacting consumer satisfaction and grading standards.
Feed Efficiency Challenges
- Wasted Feed: Uniform flocks consume feed more efficiently. In non-uniform flocks, underweight or overweight birds may underutilize or overconsume feed, increasing costs.
- Nutritional Imbalance: Standard feed formulations may not meet the needs of all birds. Smaller birds may struggle to compete for feed while and larger birds may overeat.
Increased Health Risks
- Stress and Competition: Smaller or weaker birds may be bullied or outcompeted for feed and space, increasing stress and susceptibility to disease.
- Disease Spread: Non-uniform flocks may have varying immune responses, making disease control (e.g., avian influenza, coccidiosis) more difficult.
- Higher Mortality: Underdeveloped birds are more prone to health issues, resulting in higher mortality rates.
Economic Impacts
- Lower Profitability: Reduced egg production, poor feed efficiency, and higher culling rates decrease overall revenue.
- Market Challenges: Inconsistent egg sizes and quality can result in penalties or rejections in markets with strict standards.
- Increased Costs: Additional labor, feed, and health interventions required to manage non-uniform flocks raise operational expenses.
Causes of Poor Uniformity
- Inconsistent chick quality (e.g., variable hatchery conditions)
- Poor nutrition or uneven feed distribution
- Poor lighting or temperature control
- Stress or disease during rearing
- Overcrowding and competition for resources
Mitigation Strategies
- Source high-quality chicks
- Implement stage-appropriate feeding programs
- Monitor weights regularly and sort birds as needed
- Maintain optimal environmental conditions
- Use additives like yeast cell walls to improve gut health
- Vaccinate and follow strict biosecurity protocols
Trial Overview
In India, a commercial trial was conducted to assess the impact of 100% natural oregano essential oil on Layer performance and its uniformity improvement:
Materials and Methods
Location: Commercial grower farm, Andhra Pradesh
Trial Period: July 2024
Flock Size: 20,300 pullets
Intervention: Oregano Essential Oil supplementation at 250 g/ton of feed
Duration: 4 weeks (Weeks 13–16 of rearing)
Results and Discussion
Following supplementation, birds showed consistent weekly improvement in body weight, with the deficit narrowing from -130g in week 13 to -50g in week 16. This highlights the effectiveness of the supplement in improving growth rate and approaching target weights.
Mechanisms of Action and Bioactive Compounds
Antimicrobial and Anti-Coccidial Effects
- Carvacrol and thymol exhibit strong antimicrobial properties
- Natural control of pathogenic bacteria and coccidia
- Improved gut health through selective antimicrobial action
- Enhanced nutrient absorption due to healthier intestinal environment
Digestive System Enhancement
- γ-Terpinene and p-Cymene stimulate digestive enzyme production
- Improved nutrient digestibility and absorption
- Enhanced gut barrier function
- Better feed conversion efficiency
Antioxidant Properties
- Phenolic compounds neutralize free radicals
- Reduced cellular oxidative stress
- Protection of cellular membranes from lipid peroxidation
- Improved tissue integrity and function
Anti-stress Mechanisms
- Polyphenols and other compounds modulate stress response
- Reduced cortisol levels during heat stress
- Improved resistance to environmental stressors
- Better energy utilization under stress conditions
Conclusion
Oregano essential oil supplementation significantly improved growth performance and flock uniformity in commercial layer pullets. The reduction in growth gap and consistent weight gains suggest that oregano oil is a viable natural alternative for enhancing productivity in layer operations.
Disclaimer: The Oregano Essential Oil used in the trial is DOSTO-O’gano powder. For further information, please contact Dr. Sarwar Ali at sarwar@immeureka.com.
by Dr. Lee Hock Hee, Algebra Bio and Sarwar Ali, Immeureka Animal Health
