Necrotic enteritis (NE) is a recognized multifactorial disease that cost annually to the poultry industry around $2 billion. However, diverse aspects related to its presentation are not completely understood, requiring further studies using known induction experimental models. Therefore, the purpose of this study was to measure the changes occurring in performance, intestinal integrity and ileal microbiome using a previously established NE-challenge model. Chickens were assigned to a negative control group (NC) or a positive control group (PC). In the PC, broilers were orally gavaged with Salmonella Typhimurium (ST) (1 × 107 cfu/chick) at day 1, Eimeria maxima (EM) (2.5 × 104 oocyst/chick) at day 18 and Clostridium perfringens (CP) (1 × 108 cfu/chick/day) at 23–24 days of age. Weekly, body weight (BW), body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR) were evaluated. Morbidity and mortality were determined throughout the study, and NE lesion scores were recorded at day 25. Additionally, blood and liver samples were collected to measure gut permeability as determined by levels of serum fluorescein isothiocyanate-dextran (FITC-d) and bacterial translocation (BT). Ileal contents were processed for 16S rRNA gene-based microbiome analysis. Performance parameters and intestinal permeability measurements were negatively impacted in the PC resulting in elevated serum FITC-d and BT with a −6.4% difference in BWG. The NE lesion score in PC (1.97 vs. 0.00) was significantly higher in comparison to NC, although there was no difference in mortality. The microbiome analysis showed a dramatic shift of ileal microbiomes in PC groups as compared to NC (ANOSIM: R = 0.76, P = 0.001). The shift was characterized by reduced abundance of the phylum Actinobacteria (P < 0.01), and increased abundance of the genera Butyrivibrio, Lactobacillus, Prevotella and Ruminococcus in PC compared to NC (P < 0.05). Expectedly, Clostridium was found higher in PC (2.98 ± 0.71%) as compared to NC (1.84 ± 0.36%), yet the difference was not significant. In conclusion, results of the present study showed the different intestinal epithelial and microbiological alterations occurring in an established NE-challenge model that considers paratyphoid Salmonella infections in young chicks as an important predisposing factor for presentation of NE.

Fluorescein isothiocyanate dextran (FITC-d) is a 3–5 kDa marker used to measure tight junction permeability. We have previously shown that intestinal barrier function can be adversely affected by stress, poorly digested diets, or feed restriction (FR), resulting in increased intestinal inflammation-associated permeability. However, further optimization adjustments of the current FITC-d methodology are possible to enhance precision and efficacy of results in future. The objective of the present study was to optimize our current model to obtain a larger difference between control and treated groups, by optimizing the FITC-d measurement as a biomarker in a 24-h FR model to induce gut permeability in broiler chickens. One in vitro and four in vivo independent experiments were conducted. The results of the present study suggest that by increasing the dose of FITC-d (8.32 versus 4.16 mg/kg); shortening the collection time of blood samples (1 versus 2.5 h); using a pool of non-FITC-d serum as a blank, compared to previously used PBS; adding a standard curve to set a limit of detection and modifying the software’s optimal sensitivity value, it was possible to obtain more consistent and reliable results.

Photoperiod is essential in manipulating sexual maturity and reproductive performance in avian species. Light can be perceived by photoreceptors in the retina of the eye, pineal gland, and hypothalamus. However, the relative sensitivity and specificity of each organ to wavelength, and consequently the physiological effects, may differ. The purpose of this experiment was to test the impacts of light wavelengths on reproduction, growth, and stress in laying hens maintained in cages and to determine whether the retina of the eye is necessary. Individual cages in 3 optically isolated sections of a single room were equipped with LED strips providing either pure green, pure red or white light (red, green, and blue) set to 10 lx (hens levels). The involvement of the retina on mediating the effects of light wavelength was assessed by using a naturally blind line (Smoky Joe) of chickens. Red and white lights resulted in higher estradiol concentrations after photostimulation, indicating stronger ovarian activation, which translated into a significantly lower age at first egg when compared with the green light. Similarly, hens maintained under red and white lights had a longer and higher peak production and higher cumulative egg number than hens under green light. No significant difference in BW gain was observed until sexual maturation. However, from 23 wk of age onward, birds exposed to green light showed higher body growth, which may be the result of their lower egg production. Although corticosterone levels were higher at 20 wk of age in hens under red light, concentrations were below levels that can be considered indicative of stress. Because no significant differences were observed between blind and sighted birds maintained under red and white light, the retina of the eye did not participate in the activation of reproduction. In summary, red light was required to stimulate the reproductive axis whereas green light was ineffective, and the effects of stimulatory wavelengths do not appear to require a functional retina of the eye.

The microbiome has entered the vernacular of the consumer as well as broiler production and is, therefore, becoming increasingly important to poultry producers to understand. The microbiome is, by definition, compositional and relates to how the microbiological organisms within the gut inhabit that ecological niche. The gut is diverse, flexible, and data acquired requires a greater understanding of the host-microbiome axes, as well as advanced bioinformatics and ecology. There are numerous microbial populations that define the gut microbiome; however, there are even more effects that can influence its composition. As management practices vary between producers, documenting these influences is an essential component of beginning to understand the microbiome. This review targets broiler production and concatenates the currently understood compositional ecology of the broiler gastrointestinal tract microbiome as well as its influences.

In the present study, in vitro assays were conducted to evaluate the solubility of curcumin (CUR) alone or with polyvinylpyrrolidone (PVP) at different pH, as well as its permeability in Caco-2 cells. Results confirmed that the solid dispersion of CUR with PVP (CUR/PVP) at a 1:9 ratio, significantly increased (P < 0.05) solubility and permeability compared to CUR alone. Then, the antimicrobial activity of CUR/PVP, boric acid (BA), and a combination of 0.5% CUR/PVP and 0.5% BA (CUR/PVP-BA) against Salmonella Enteritidis (SE) was determined using an in vitro digestion model that simulates crop, proventriculus, and intestine. The results revealed that in the proventriculus and intestinal compartments significant reductions of SE were observed in all the experimental treatments, but 1% BA eliminated SE in the intestinal compartment and CUR/PVP-BA showed a synergistic effect on antimicrobial activity against SE. To complement these findings, two independent in vivo trials were conducted to determine the effect of 0.1% CUR/PVP; 0.1% BA; or the combination of 0.05% CUR/PVP (1:9 ratio) and 0.05% BA (CUR/PVP-BA) on the antimicrobial activity against SE, intestinal permeability and inflammatory responses in broiler chickens. BA at 0.1% had no significant in vivo effects against SE. However, the combination of 0.05% BA and 0.05% CUR/PVP and 0.05% BA was sufficient to reduce crop and intestinal SE colonization in broiler chickens in two independent trials, confirming the synergic effect between them. A similar antimicrobial impact against SE intestinal colonization was observed in chickens treated with 0.1% CUR/PVP at a 1:9 ratio, which could be due to the increase in solubility of CUR by PVP. Furthermore, 0.1% CUR/PVP reduced the intestinal permeability of FITC-d and total intestinal IgA, as well as increase the activity of SOD when compared to control, while, CUR/PVP-BA only decreased SOD activity. Further studies to confirm and expand the in vivo results obtained in this pilot study, adding intestinal microbial commensal groups and more inflammatory biomarkers to get a complete description of the effects of BA and CUR deserves further investigation.