Short-Term Effects of Dietary Selenomethionine Supplementation on Hepatic and Renal Transcriptomic Alterations Induced by Ochratoxin a in Broiler Chickens

Ochratoxin A (OTA), a mycotoxin commonly found in poultry feed, induces oxidative stress and disrupts redox homeostasis in vital organs such as the liver and kidneys. Selenium (Se), an essential trace element, may mitigate OTA-induced toxicity by supporting the antioxidant defense systems. This study investigated the short-term effects of dietary selenomethionine (SeMet) supplementation on OTA-induced oxidative and transcriptional responses in broiler chickens. Fifty-four 3-week-old birds were fed diets containing 2 mg/kg OTA, a target supplementation of 0.5 mg/kg Se (measured as 0.59 mg/kg as SeMet), or a combination of the two for five days. Liver and kidney samples were collected on Days 1 and 5 for biochemical and gene expression analyses. Exposure to OTA significantly modulated the expression of redox-sensitive transcription factors (<i>NRF2</i>, <i>KEAP1</i>), selenoproteins (<i>GPX3</i>, <i>GPX4</i>, <i>SELK</i>), and detoxification-related genes (<i>AHR</i>, <i>AHRR</i>, <i>CYP1A2</i>). SeMet alone enhanced selenoenzyme expression and antioxidant capacity, while co-exposure partially attenuated OTA-induced oxidative stress, resulting in more pronounced <i>NRF2</i> activation in the kidneys and <i>CYP1A2</i> induction in the liver. This is the first study to characterize the transcriptomic responses to OTA exposure in poultry within the first five days, providing novel insight into organ-specific mechanisms and emphasizing the epidemiological relevance of Se supplementation in mitigating the risk of feed contamination.