Study points to olive leaf powder as quail feed additive: full analysis

A new Frontiers in Veterinary Science paper reports that olive leaf powder may improve growth performance, antioxidant status, meat quality, and gut microbial balance in growing Japanese quail, adding fresh data to the push toward plant-based feed additives in poultry systems. In the six-week trial, researchers placed 375 one-day-old chicks into five groups and compared a basal diet with diets containing 3%, 4%, 5%, and 6% olive leaf powder. The top inclusion level, 6%, produced the clearest gains in live body weight and carcass-related measures, while also shifting blood lipids and cecal microbiota in what the authors describe as a favorable direction. The article was published May 22, 2026. (frontiersin.org)

The study lands in a familiar but still unsettled area of poultry research: finding natural feed additives that can support performance and gut health as producers move away from antibiotic growth promoters. In the paper, the authors frame olive leaf powder as a candidate because of its anti-inflammatory, antioxidant, and antibacterial properties. That rationale is consistent with prior literature. A 2023 review of olive oil co-products in monogastric nutrition summarized evidence that olive leaf extracts and related polyphenol-rich ingredients can reduce coliform bacteria, increase lactobacilli, and in some broiler studies improve body weight gain and feed conversion. (frontiersin.org)

In the new quail study, the reported effects extended beyond growth. According to the abstract, olive leaf powder supplementation significantly improved carcass yield and total edible meat, increased antioxidant enzyme activity, and improved meat quality measures including cooking loss, water-holding capacity, pH, and color. The bloodwork findings were mixed but directionally notable: the authors reported improved protein and lipid profiles, lower total cholesterol, triglycerides, LDL, and VLDL, and higher HDL, while also noting increased liver enzyme activity. On the microbiology side, the cecal analysis showed higher Lactobacillus counts and lower total bacterial count, coliforms, E. coli, and Salmonella, with no significant change in Bacillus counts. (frontiersin.org)

This paper also appears alongside related 2026 quail research suggesting olive leaf powder is gaining momentum as a phytogenic additive of interest. A separate Poultry Science report indexed by ScienceDirect described olive leaf powder as a “promising natural feed additive” for improving growth performance, health status, gut microbial balance, and economic efficiency in growing Japanese quail. Taken together, these studies suggest researchers are moving from broad claims about olive-derived polyphenols toward more dose-specific, production-oriented testing in quail. That said, the available search results did not surface independent expert commentary or a company-backed announcement tied to this new Frontiers paper, which may mean industry reaction is still limited or simply not yet published. (sciencedirect.com)

Why it matters: For veterinarians and poultry nutrition professionals, the practical signal here is less about immediate adoption and more about where formulation research is heading. If olive leaf powder can reliably improve gut microbial balance while also supporting growth and oxidative status, it could become one more tool in feed strategies aimed at resilience, performance, and reduced pathogen pressure. But several caveats matter: this was a single published study, the article page currently shows the final formatted version is still pending, and the reported “best” result at 6% inclusion raises real-world questions about ingredient sourcing, diet formulation constraints, consistency of active compounds, palatability, and cost. Those are the issues that determine whether a phytogenic additive is clinically and commercially useful, not just statistically interesting. (frontiersin.org)

There’s also a broader veterinary relevance in the microbiota findings. In poultry medicine, additives that shift intestinal populations toward more beneficial bacteria and away from enteric pathogens are attractive, especially when they may also support antioxidant defenses. But microbiota outcomes can be highly context-dependent, varying with housing, baseline diet, pathogen exposure, processing of the plant material, and the phenolic content of the additive itself. The 2023 review on olive co-products makes that clear by showing benefits in some species and formulations, but not uniformly across all studies. (frontiersin.org)

What to watch: The next important step is replication, ideally in larger and more commercial quail settings, with clearer economic modeling and standardized characterization of the olive leaf powder itself. Veterinary readers should also watch for peer commentary, follow-on trials comparing olive leaf powder with other phytogenics, and any work testing whether the microbiota shifts translate into measurable disease-resilience or food safety benefits. (frontiersin.org)