Effects of glyphosate, antibiotics and an anticoccidial drug on pancreatic gene expression and blood physiology in broilers

Drugs and pesticide residues in broiler feed can compromise the therapeutic and production benefits of antibiotic (ANT) application and affect gene expression. In this study, we analyzed the expression of 13 key pancreatic genes and blood physiology parameters after administering one maximum residue limit of herbicide glyphosate (GLY), two ANTs, and one anticoccidial drug (AD). A total of 260 Ross 308 broilers aged 1‍–‍40 d were divided into the following four groups of 65 birds each: control group, which was fed the main diet (MD), and three experimental groups, which were fed MD supplemented with GLY, GLY+ANTs (enrofloxacin and colistin methanesulfonate), and GLY+AD (ammonium maduramicin), respectively. The results showed that the addition of GLY, GLY+ANTs, and GLY+AD caused significant changes in the expression of several genes of physiological and economic importance. In particular, genes related to inflammation and apoptosis (interleukin 6 (IL6), prostaglandin-endoperoxide synthase 2 (PTGS2), and caspase 6 (CASP6)) were downregulated by up to 99.1%, and those related to antioxidant protection (catalase (CAT), superoxide dismutase 1 (SOD1) and peroxiredoxin 6 (PRDX6)) by up to 98.6%, compared to controls. There was also a significant decline in the values of immunological characteristics in the blood serum observed in the experimental groups, and certain changes in gene expression were concordant with changes in the functioning of the pancreas and blood. The changes revealed in gene expression and blood indices in response to GLY, ANTs, and AD provide insights into the possible mechanisms of action of these agents at the molecular level. Specifically, these changes may be indicative of physiological mechanisms to overcome the negative effects of GLY, GLY+ANTs, and GLY+AD in broilers.