In the dynamic world of animal production, many challenges arise in disease control, animal welfare and the need to meet antibiotic‐free demands. Emerging diseases have a significant impact on the poultry industry. Managing gut microbiota is an important determinant of poultry health and performance. Introducing precision glycans as feed additives adds another dimension to this complex environment. The glycans play pivotal roles in supporting gut health and immunological processes and are likely to limit antibiotic usage while enhancing intestinal well‐being and overall poultry performance. This study explores precision glycan product as a feed additive supplemented at a continuous dose of 900 g per tonne of feed, in a free‐range production system on a large commercial farm. Forty thousand 17‐week‐old pullets were randomly allocated to one of two separated sections of the production shed, with individual silos and egg‐collecting belts. The flock performance, gut microbiota and its functionality were analysed throughout the laying cycle until 72 weeks of age. The results demonstrated that introducing precision glycans improved a range of performance indicators, including reduced cumulative mortality, especially during a major smothering event, where the birds pile up until they suffocate. There was also significantly increased hen‐housed egg production, reduced gut dysbiosis score and undigested feed, increased number of goblet cells and improved feed conversion ratio. Additionally, microbiota analysis revealed significant changes in the composition of the gizzard, ileum content, ileum mucosa, and caecal and cloacal regions. Overall, the findings suggest that precision glycans have the potential to enhance poultry egg production in challenging farming environments.

The poultry industry contributes significantly to the global meat industry but faces many production challenges like high-density housing, welfare issues, and pathogenic infections. While antibiotics have commonly been used to treat many of these issues, they are being removed from poultry production globally due to increased microbial resistance. Precision glycans offer a viable alternative to antibiotics by modulating microbial metabolic pathways. In this study, we investigated the effects of precision glycan supplementation on productivity and gut microbiota in broilers. The experiment was conducted in a commercial setting using 32,400 male Ross chickens randomly divided into three sheds with 10,800 birds each. One shed with 12 pen replicates of 900 birds was used as control, while the other two with an equal number of replicates and birds were assigned to precision glycan supplementation. The treatment significantly improved the average daily weight gain and feed conversion ratio, with a significant modification in the abundance of several bacterial taxa in the caecum, ileum, and ileum mucosa microbial communities. There was increased richness and diversity in the caecum, with a reduction in Proteobacteria and an increase in Firmicutes. Richness remained unchanged in the ileum, with an increase in diversity and reduction in pathogenic genera like Clostridium and Escherichia-Shigella. Ileum mucosa showed a lower abundance of mucin degraders and an increased presence of next-generation probiotics. Supplemented birds showed a high level of disease resistance when the farm experienced an outbreak of infectious bronchitis, evidenced by lower mortality. Histological analysis confirmed improvements in the ileum and liver health, where the precision glycan supplementation reduced the area of congested sinusoids compared to the control group in the liver and significantly improved ileum intestinal morphology by increasing crypt depth and surface area. These results collectively suggest that precision glycans offer substantial benefits in poultry production by improving productivity, gut health, and disease resistance.

The livestock industry faces growing constraints due to antimicrobial resistance, particularly in poultry systems that have historically relied on antibiotic use. These challenges are exacerbated in free-range production, where restrictions on antimicrobial interventions coincide with heightened exposure to infectious diseases, leading to increased mortality and reduced productivity. On-farm disease outbreaks cannot be reproduced in high ethics standards approved animal houses, where they can be modeled to recognize some patterns of pathogen dynamics. While laboratory settings enable rigorous control and monitoring, they lack the environmental, management, production, pathogen pressures and complexity found on industrial farms and therefore cannot realistically recreate disease progression. Here, we present a field study in a layer flock that experienced three disease outbreaks of spotty liver disease (SLD) and fowl cholera (FC). The treatment group was supplemented with a precision biotic, a synthetic glycan product, while weekly performance measures and responses of microbial populations across major gut sections were observed. The precision biotic supplemented birds showed higher cumulative mortality but also higher egg output. However, as this was an unreplicated field study, these differences should be interpreted as descriptive associations. The intestinal microbial community responded differently to supplementation under concurrent environmental and disease pressures. This study provides large-scale field observations during concurrent outbreaks of SLD and FC, offering real-world insights that may inform future controlled studies of disease dynamics and performance management. Key points: • Free-range systems increase disease risk, reducing health and productivity in layer flocks. • Precision biotics were associated with higher egg output and higher cumulative mortality in hens. • Gut microbiota and liver congestion differed between precision biotic supplemented and control groups.