Appeasing Pheromones Against Bovine Respiratory Complex and Modulation of Immune Transcript Expressions

Bovine respiratory disease is still a major concern in feedlots and has major economic impact. Another consequence of respiratory infections is the use of antimicrobial molecules to control bacterial pathogens. This can participate to the emergence and shedding of antimicrobial re-sistance that can threaten animal as well as human health. Appeasing pheromones with their capacity to reduce stress and thus their ability to preserve the functions of the immune system have been proposed to reduce the use of antimicrobial substances. In the current report we as-sessed the effect of appeasing pheromone administration on bovine health and performance during the fattening period. Zootechnical and health parameters as well as whole blood immune transcript expressions were measured over weeks in young bulls to determine the effect of the pheromone. We observed a reduction of clinical signs at day 30 in young bulls who received the pheromone and a higher expression of interleukin 8 transcripts in this group than in the control group. Our results are in line with previous reports in bovine and other mammals and ask for further studies to shed more light on the beneficial impact of appeasing pheromones and to de-cipher their exact mechanisms of action.