Authors: Ana María Higueras Ortega, Miguel Ángel Sanz Franco, Marina Solé Berga, Antonio Villodres Ramírez, Tania Perálvarez Puerta

Ovine respiratory syndrome (ORS) is an emerging pathology, largely due to the new Veterinary Medicinal Products Regulation ((EU) 2019/6), that makes the restriction of the use of antibiotics necessary. This situation makes the implementation of prophylactic measures crucial. Vaccines containing the leukotoxin of Mannheimia haemolytica appear to be the best option for controlling ORS.

The aim of this study was to evaluate the profitability of two vaccines against M. haemolytica through the study of production parameters on a lamb feedlot, such as average daily gain (ADG), mortality, feed conversion rate (FCR), and number of animals in the sick pen. The return on investment (ROI) of vaccination with a leukotoxoid-based vaccine (Pasterbact®) was also calculated.