Immune fitness as a measure of animal health, welfare and productivity in the feedlot

Abstract

Abstract Background Animals have long been bred for production traits that enable high-yield, but this does not consider the overall immunological ‘fitness’. What is the physiological basis that enables some animals to thrive or fail when exposed to production stresses, are there any measures of the immune component to identify these animals? Further, are there commonly related genes associated with immune fitness? Methods 50 mixed breed beef cattle were randomly selected at feedlot intake. Blood and saliva samples were collected at arrival (high stress), post- acclimatization and pre-slaughter (60 days post intake or ≥400kg). Body condition and other measures (weight, height, disposition, coat colour) were collected at each sampling and at slaughter. Samples were processed for cell counts, RNA (transcriptomics analysis) and serum (protein analysis). Transcriptomic and proteomic analysis was by 24k Bovine Affymetrix ST1 GeneChip and RayBiotech Bovine Cytokine Array Q30. Results and conclusion Analysis correlated to outcome measures identified genes and proteins associated with immune fitness including those correlated to animals with susceptibility to disease and/or low weight gains. These results suggest that immune measures may be utilized to identify animals at risk of poor production performance facilitating improved animal management to optimize animal health and welfare.