A succession of pulmonary microbiota in broilers during the growth cycle.

Respiratory health problems in poultry production are frequent and knotty and thus attract the attention of farmers and researchers. The breakthrough of gene sequencing technology has revealed that healthy lungs harbor rich microbiota, whose succession and homeostasis are closely related to lung health status, suggesting a new idea to explore the mechanism of lung injury in broilers with pulmonary microbiota as the entry point. This study aimed to investigate the succession of pulmonary microbiota in healthy broilers during the growth cycle. Fixed and molecular samples were collected from the lungs of healthy broilers at 1, 3, 14, 21, 28, and 42 d of age. Lung tissue morphology was observed by hematoxylin and eosin staining, and the changes in the composition and diversity of pulmonary microbiota were analyzed using 16S rRNA gene sequencing. The results showed that lung index peaked at 3 d, then decreased with age. No significant change was observed in the α diversity of pulmonary microbiota, while the ß diversity changed regularly with age during the broilers' growth cycle. The relative abundance of dominant bacteria of Firmicutes and their subordinate Lactobacillus increased with age, while the abundance of Proteobacteria decreased with age. The correlation analysis between the abundance of differential bacteria and predicted function showed that dominant bacteria of Firmicutes, Proteobacteria and Lactobacillus were significantly correlated with most functional abundance, indicating that they may involve in lung functional development and physiological activities of broilers. Collectively, these findings suggest that the lung has been colonized with abundant microbiota in broilers when they were just hatched, and their composition changed regularly with day age. The dominant bacteria, Firmicutes, Proteobacteria, and Lactobacillus, play crucial roles in lung function development and physiological activities. It paves the way for further research on the mechanism of pulmonary microbiota-mediated lung injury in broilers.

Effect of in ovo glyphosate injection on embryonic development, serum biochemistry, antioxidant status and histopathological changes in newly hatched chicks.

This study aimed to investigate the potential toxic effects of pure glyphosate or Roundup® on hatchability, serum biochemistry and histopathological observation of the liver and kidney of newly hatched chicks. On day six, a total of 225 fertile eggs were obtained from Huafeng breeder hens. The eggs were randomly divided into three treatments: (a) the control group injected with deionized water, (b) the glyphosate group injected 10 mg pure glyphosate/Kg egg mass and (c) the Roundup group injected 10 mg the active ingredient glyphosate in Roundup® /Kg egg. The results showed a decrease of hatchability rate in chicks treated with Roundup® (66%). In addition, no significant change was observed in body weights, yolk sac weight and relative weight organs except the liver and kidney were significantly increased with groups treated with glyphosate and Roundup® compared to the control group. The results showed that serum protein profiles were linearly significantly increased of serum phosphor, uric acid, aspirate aminotransferase, alanine transaminase and alkaline phosphatase in groups treated with Roundup® , as well as the serum concentrations of triglyceride altered after treatment with glyphosate. Furthermore, oxidative stress was observed in the treated chicks, the glyphosate and Roundup® induced changes of the content of malondialdehyde in both the liver and kidney, moreover decrease of glutathione peroxidase, total superoxide dismutase and catalase activity in the kidney tissue and serum. Additionally, changes also happened in the histomorphology of the liver and kidney tissue of the treated chicks. It can be concluded that Roundup® as a probable decrease of hatchability. Exposure to glyphosate alone or Roundup® caused liver and kidney histopathological alterations, serum parameters imbalances and oxidative stress, also induced a variety of liver and kidney biochemical alterations that might impair normal organ functioning in newly hatched chicks.