Caracterización de biomarcadores de estrés oxidativo en fluidos biológicos y biopsias hepáticas de vacas lecheras como indicador de potenciales enfermedades metabólicas

Abstract

During the transition period, dairy cows must make metabolic and endocrine adjustments that are often critical for the animal. Nutrient requirements increase postpartum and the liver must adapt to contribute to the increased glucose demand. In addition, liver tissue must respond to the increased flow of non-esterified fatty acids originating from lipomobilization. With increased metabolic demand, the imbalance between oxidizing species and the antioxidant system leads to oxidative stress, which can increase the susceptibility of animals to new infections, impacting the efficiency of livestock systems. In recent years, interest in the administration of antioxidants has grown, demonstrating the benefits of supplementation on animal health. The objective was to characterize biomarkers of oxidative stress in biological samples, and their possible association with alterations in lipid metabolism in the liver of high-producing dairy cows during the transition period. The development and validation of analytical techniques using LC-MS/MS for determining biomarkers in different biological matrices has been documented. It was shown that animals with births under mild heat stress conditions could have a higher concentration of these biomarkers along with alterations in liver function parameters. In addition to these findings, encouraging results were observed after parenteral supplementation with vitamins and minerals important for the antioxidant system, demonstrating a decrease in the hepatic concentration of 3-nitrotyrosine in supplemented animals, in accordance with possible beneficial effects on the metabolism of fatty acids in the liver.