Micronúcleo e Alterações Metanucleares em Células de Mucosa Oral em Bovinos em Área de Controle de Pragas em Pastagens

Abstract

The use of pesticides, such as the herbicide 2,4-Dichlorophenoxyacetic acid (2,4-D), is essential in modern agriculture, but its genotoxic effects on non-target organisms like cattle remain poorly understood. This study investigated nuclear alterations in oral mucosa cells of cattle exposed to 2,4-D in pest control areas, correlating them with physiological stress parameters including body temperature, weight, and Body Condition Score (BCS). Thirty-six adult cattle from a farm in Piracanjuba-GO, exposed to pesticides during the 2023 production cycle, were analyzed. Oral mucosa samples were collected using cytological brushes, fixed in Carnoy's solution, and stained with basic fuchsin and fast green to identify micronuclei and other nuclear abnormalities (binucleation, karyorrhexis, karyolysis, and "broken egg"). Physiological parameters (temperature, weight, and BCS) were recorded and statistically analyzed using ANOVA and Chi-square tests. Although 61.1% of animals showed elevated temperature (≥38.0°C) and 75% had BCS ≥3.5 - indicators of thermal and metabolic stress - no statistically significant association (p > 0.05) was found between these variables and nuclear alterations. Despite the higher frequency of micronuclei (61%) and "broken eggs" (71%) in cattle with elevated temperature, the differences were not significant. The results suggest that while cattle showed signs of physiological stress, no significant genotoxicity was detected during the study period. The lack of correlation may be related to adaptive mechanisms or the short exposure duration. Long-term studies are recommended to assess cumulative effects. This work highlights the importance of continuous monitoring in areas with intensive pesticide use