Feedlot diets containing increasing starch levels and different feed additives changes cecal proteome profile involved on energy metabolism and inflammatory response of Nellore cattle

Abstract

Background Diets for feedlot cattle require higher energy density, thus contributing to the high rate of fermentable carbohydrate. The use of feed additives is necessary to reduce possible metabolic disorders. The objective of this study was to analyze the post-rumen effects of different levels of starch (25, 35, and 45%) and additives (Monensin, Blend of essential oil + exogenous α-Amylase) in diets for Nellore cattle feedlot. The cecum tissue proteome was separated by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), and then, with the verification of differentially expressed protein SPOTS, these were characterized by electrospray ionization mass spectrometry (ESI-MS/MS).Results The expression of nine enzymes participating in the Steps of the glycolysis pathway was verified, such as: Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), Glyceraldehyde-3-phosphate dehydrogenase like-17 protein, Triosephosphate isomerase (Step 1); Phosphoglycerate mutase and Phosphoglycerate mutase 2 (Step 2); Alpha-enolase (ENO1), Beta-enolase (ENO3) and Fructose-bisphosphate aldolase (ALDOB) (Step 4); and Pyruvate Kinase (PKM) (Step 5). There was expression of three enzymes linked to catalytic activities participating in the synthesis of lactate from pyruvate: L-lactate dehydrogenase B, L-lactate dehydrogenase A chain and L-lactate dehydrogenase. The ATP synthase subunit beta and ATP synthase subunit beta_mitochondrial participate in the electron transport chain, producing ATP from ADP in the presence of a proton gradient across the membrane. Due to the manipulation of diets, the expression of the Leukocyte elastase inhibitor protein, associated with the inflammatory response.Conclusions The use of blends of essential oil associated with α-amylase as a feed additive promoted the greater expression of enzymes in the pathway of glycolysis and gluconeogenesis (and the absence of proteins linked to inflammation (Leukocyte elastase inhibitor) in cecum tissues. On the other hand, the increase in starch in the diets promoted a reduction in enzymes linked to carbohydrate degradation with increased responses linked to inflammatory injuries.