Spotty liver disease (SLD) is characterized by multifocal liver lesions, mortality, and drop in egg production. The disease is emerging in Europe and Australia, particularly in free-range and floor-raised layer flocks. Campylobacter hepaticus has been recently identified as the causative agent of SLD. We report the isolation and characterization of C. hepaticus from livers of laying hens affected with SLD in the United States. Two isolates were characterized and found to be highly similar to those described from SLD cases in the United Kingdom and Australia. Initial isolation of C. hepaticus from liver samples required microaerophilic and thermophilic conditions and incubation for a particularly long duration (approximately 7 days). Morphologic and phenotypic properties of the isolates were typical for Campylobacter spp. Phylogenetic analysis based on 16S ribosomal RNA gene sequences and detection of a glycerol kinase gene confirmed the identity of the isolates as C. hepaticus. To the authors' knowledge, this is the first report of C. hepaticus isolation from layer chickens with SLD in the United States. With the increasing changes in the egg industry from conventional cages to cage-free housing systems, the incidence and economic impact of SLD could become significant.

Salmonella Enteritidis (SE) has been the most common Salmonella serotype associated with foodborne infections in the last several years. Dietary applications of yeast-based preparations in feed have shown to reduce Salmonella colonization in chickens augmenting SE control strategies. This study was conducted to evaluate the effects of a mannan-rich yeast cell wall-derived preparation (Actigen^®) administered in feed at a rate of 400 g/ton on SE colonization in the cecum and internal organs of commercial layer chickens. Sixteen week-old layer pullets were orally challenged with a selected nalidixic acid resistant SE strain at a dose of 1.7×10^9 colony forming units (CFU) per bird. SE colonization was assessed by evaluating isolation rates from ovary and pooled liver/spleen samples as well as enumeration of SE in cecal pouches one week post-challenge. Recovery rates of SE from the ovaries of directly challenged birds receiving Actigen^® were significantly lower (P <0.02) than those in directly challenged birds fed an unsupplemented control diet. Recovery rates of SE from pooled liver/spleen samples were not significantly different between Actigen^®-treated pullets and controls (P = 0.22). Using direct plate count methods, cecal SE concentrations were 1 log₁₀ lower (P <0.001) in challenged pullets in the Actigen^®-supplemented group than in the challenged controls. The SE concentration distributions in the ceca were similar in groups testing positive and groups testing negative for SE in the ovaries and liver/spleens tissues. As a result, SE concentrations in the ceca could not be directly related to the occurrence or prevalence of SE in these tissues. In conclusion, Actigen^® supplementation appears to decrease the prevalence of SE in ovarian tissue and concentrations of SE in cecal contents and may be useful as a tool for reducing the risk of eggshell contamination and transovarian transmission of SE in eggs.

Determining the efficacy of feed-additive technologies utilized as pre-harvest food-safety interventions against Salmonella enterica may be influenced by factors including, but not limited to, mechanism of action, experimental design variables, Salmonella serovar(s), exposure dose, route, or duration in both controlled research and real-world field observations. The purpose of this study was to evaluate the dietary inclusion of a Saccharomyces cerevisiae fermentation-derived postbiotic (SCFP) additive (Diamond V, Original XPC^®) on the colonization of cecal and ovarian tissues of commercial pullets directly and indirectly exposed to Salmonella Enteritidis (SE). Four hundred and eighty commercial, day-of-age W-36 chicks were randomly allotted to 60 cages per treatment in two identical BSL-2 isolation rooms (Iowa State University) with four birds per cage and fed control (CON) or treatment (TRT) diets for the duration of study. At 16 weeks, two birds per cage were directly challenged via oral gavage with 1.1 × 10⁹ CFU of a nalidixic-acid-resistant SE strain. The remaining two birds in each cage were thus horizontally exposed to the SE challenge. At 3, 7, and 14 days post-challenge (DPC), 20 cages per group were harvested and sampled for SE prevalence and load. No significant differences were observed between groups for SE prevalence in the ceca or ovary tissues of directly challenged birds. For the indirectly exposed cohort, SE cecal prevalence at 7 DPC was significantly lower for TRT (50.0%) vs. CON (72.5%) (p = 0.037) and, likewise, demonstrated significantly lower mean SE cecal load (1.69 Log₁₀) vs. CON (2.83 Log₁₀) (p = 0.005). At 14 DPC, no significant differences were detected but ~10% fewer birds remained positive in the TRT group vs. CON (p > 0.05). These findings suggest that diets supplemented with SCFP postbiotic may be a useful tool for mitigating SE colonization in horizontally exposed pullets and may support pre-harvest food-safety strategies.

The objective of the present study was to determine the effects of feeding diets containing grains naturally contaminated with Fusarium mycotoxins to fryer rabbits. The efficacy of a glucomannan mycotoxin adsorbent (GMA) was also examined. Thirty 5-wk-old male New Zealand White rabbits were fed a control diet, a contaminated diet, or a contaminated diet + 0.2% GMA for 21 d. Experimental diets contained deoxynivalenol (DON; vomitoxin) at a concentration of 0.25, 4.3, and 4.9 μg/g, respectively. Feed intake was measured daily and water intake was measured every 3 d. At the end of the feeding period, blood was collected for evaluation of serum chemistry and hematology. Visceral organs were excised, weighed, and processed for histopathological examination. Body weight gain and water intake were greater in rabbits fed the contaminated diet (P = 0.075 and 0.020, respectively) and those fed the contaminated + GMA diet (P = 0.026 and 0.002, respectively) compared with controls. Rabbits fed the contaminated + GMA diet had significantly increased serum urea concentrations (P = 0.023) and decreased serum alkaline phosphatase activity (P = 0.020) compared with controls. Increase in BW gain of rabbits fed the contaminated diets was caused by increased water consumption. There was no effect (P > 0.05) of diet on relative organ weights, but decreased infiltrations with eosinophilic granulocytes were observed in different regions of the intestine in rabbits fed the contaminated or the contaminated + GMA diet. It was concluded that rabbits could be adversely affected by feed-borne Fusarium mycotoxins but appear to be less sensitive than other mammalian species. Supplementation with GMA did not reduce many of the effects of feed-borne mycotoxins. Copyright © 2013. American Society of Animal Science .

The high pathogenicity avian influenza virus H5N1, which first emerged in the winter of 2021, has resulted in multiple outbreaks across the American continent through the summer of 2023 and they continue based on early 2025 records, presenting significant challenges for global health and food security. The viruses causing the outbreaks belong to clade 2.3.4.4b, which are descendants of the lineage A/Goose/Guangdong/1/1996 (Gs/Gd) through genetic reassortments with several low pathogenicity avian influenza viruses present in populations of Anseriformes and Charadriiformes orders. This review addresses these issues by thoroughly analysing available epidemiological databases and specialized literature reviews. This project explores the mechanisms behind the resurgence of the H5N1 virus. It provides a comprehensive overview of the origin, timeline and factors contributing to its prevalence among wild bird populations on the American continent.