ブロイラーにおける精巣嚢胞：慢性ナトリウム中毒と病原性相乗効果に関する研究

Testicular cysts in poultry are pathologic conditions with significant implications for reproductive health and flock performance. This study investigated the clinical, molecular, and pathologic impacts of chronic sodium toxicity and its interplay with infectious agents in broiler chickens. In a flock of 22,600 Ross broiler chickens, a severe mortality rate (88.3%) was reported after showing signs of disease such as reduced feed intake, diarrhea, and lethargy. At necropsy, hydropericardium and testicular cysts, with no evidence of ascites, were observed. Severe intestinal necrosis, renal lesions characteristic of membranoproliferative glomerulonephritis, and in the testes, atrophy with no epithelial germ cells or seminiferous tubules were observed during histopathologic examination. Analysis of the feed revealed high levels of sodium in the feed (0.64% in the starter feed and 0.65% in the finisher feed). PCR assays detected adenovirus DNA, with positive results on day 15 and negative results on day 35, while bacterial cultures identified Escherichia coli exhibiting multidrug resistance. Symptoms and mortality did not improve with antibiotic treatment. Although adenoviral DNA was detected, the histopathologic findings supported sodium toxicity as the primary causative factor. Histopathologic examination, alongside PCR assays, is crucial for achieving a comprehensive and accurate understanding of the underlying causes in such cases. These findings show that there can be an interaction between an imbalanced diet and pathogens in broilers and thus the need for accurate feed formulation and diagnostic approaches to manage multiple causes of disorders in poultry production systems.