Analysis of the blood proteome allows identification of proteins related to changes upon certain physiological conditions. The pathophysiology of necrotic enteritis (NE) has been extensively studied. While intestinal changes have been very well documented, data addressing NE-induced alterations in the blood proteome are scant, although these might have merit in diagnostics. Considering recent technological advancements in proteomics and pressing need for tools to access gut health, the current study employs mass-spectrometry (MS) proteomics to identify biomarkers for gastrointestinal health of broilers chickens. Untargeted proteomics investigation was conducted on chicken blood plasma in animals under NE challenge. Two MS-strategies were used for analysis: DDA (Data Dependent Acquisition) and DIA (Data Independent Acquisition). DIA showed superior completeness and quantification of the acquired data, despite high degree of agreement in identification and quantification between both approaches. Identified differentially expressed proteins shared by DDA and DIA represent responses of animals to infection and may serve as potential biomarkers. Experimental validation through ELISA immunoassays for selected regulated proteins confirmed medium-to-high levels of inter-protein correlation, along with positive correlation between the methods. Functional analysis showed enhanced defense, immune, and acute phase responses, alongside reduced signaling, regulatory, and cell adhesion activities in infected animals.