Precision that protects: in ovo accuracy supports flock performance
In commercial poultry production, precision is a necessity. Broiler operation success is rooted in the hatchery, where accuracy of in ovo vaccination technology has implications for flock health, labour and economic performance. At the centre is a critical metric: site of injection (SOI) accuracy.
From Zoetis, Embrex biodevice technology leads in precision and has demonstrated performance advantages compared with other in ovo vaccination offerings. Backed by decades of data, this technology helps hatcheries consistently deliver vaccines to the right location in the embryo, enabling early immune protection and helping optimise results from vaccine investment.
Why in ovo vaccination accuracy matters
Accurate in ovo vaccination delivers vaccines into either the amnion or embryo – two locations shown to trigger optimal immune response (Figure 1).
Off-target injections — into the air cell, allantois or yolk — can reduce both vaccine efficacy and protection and injure developing chicks. In a high-throughput environment, small mistakes add up.
“Poultry is a business of scale,” said Dr Tarsicio Villalobos, global biodevice technical services director at Zoetis. “A fraction of a cent lost per chick translates into major losses over millions of birds. Site of injection is a foundation of vaccine performance. If site of injection is not accurate, it affects everything downstream.”
Embrex versus others – a measurable advantage
A study showed a performance gap between Embrex and other in ovo technologies. In SOI studies, this technology has consistently achieved up to 100% accuracy, delivering the vaccine precisely to the amnion or embryo in viable embryos with device throughput up to 70,000 eggs per hour. In 2025, studies comparing the performance of two other in ovo vaccination brands revealed notable differences in accuracy and consistency.
Device brand A averaged 92.9% SOI accuracy with 3.5% of viable embryos receiving no vaccine at all. The vaccine was injected into 7.3% of clear embryos. Device brand B performed worse, averaging 77.4% accuracy, 3.7% of viable embryos receiving no vaccine. Of the clear eggs, 1.3% received the vaccine.
With these results, a significant number of chicks didn’t receive the vaccine in a location that triggers an effective immune response, and the vaccine was wasted on clear eggs.
These results have meaningful biological outcomes. As Villalobos explained: “If you start with a healthy animal, everything else can improve — feed conversion, weight gain, livability. If you start with a compromised chick, no amount of management can compensate.”
Early protection = real-world performance
The high level of Embrex system accuracy stems from its engineering, which is backed by industry-leading service. “Through our hatchery health teams, we provide pre-installation assessments, operator training and continuous support, including preventive maintenance and emergency service, to help ensure every injection lands where it should,” Villalobos said.
Economics of accuracy
When a vaccine is delivered to the correct site within an embryo, the chick can gain early immunity and higher livability. When a vaccine isn’t delivered accurately, the risk is inconsistent protection, waste and higher costs.
That’s why the SOI metric matters. For hatcheries processing millions of eggs per month, accuracy gaps can mean a significant loss in vaccine cost, chick quality and downstream performance.
As the poultry industry pushes for greater efficiency, precision becomes more valuable. This technology has evolved through the inovoject platform and feedback-driven improvements, helping the technology meet standards for biosecurity, performance and return on investment.
“For the poultry industry, SOI needs to be a key factor when making decisions about in ovo technology,” Villalobos said. “If the technology isn’t accurate, what value is it really delivering?”
References are available on request.
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