Mycoplasma hyopneumoniae (Mhyo) is the primary agent involved in enzootic pneumonia (EP) and one of the leading agents involved in Porcine Respiratory Disease Complex (PRDC). EP directly impacts the productive and economic performance of swine farms, reducing the average daily weight gain and increasing the conversion ratio, and consequently increasing the days that the pigs have to stay on the farm to reach the final slaughter weight1 .
The aim of this study was to compare lung lesions associated with Mhyo at slaughter when applying different Mhyo/PCV2 vaccines in pigs from Peru.
Material & methods
A farrowing-to-finish farm of 1,500 sows in Peru, with circulation of Mhyo that was using an intramuscular vaccine against Mhyo of 2 ml per dose (Vaccine A) and switched to Mhyosphere® PCV ID (Vaccine B), an intradermal vaccine against Mhyo and PCV2, all in one, in 0.2 ml per dose. Apart from the change in the vaccine used, there were no other notable changes in management or treatment on the farm.
The lung lesions of pigs given Vaccines A and B were monitored at the slaughterhouse. The assessment of the lesions was done by the same person and with a blinded method, so that the evaluator did not know which vaccine had been administered in each case. The following parameters were analyzed: lesion incidence (lungs [%] with lesion), mean lesion (mean lesion grade among all lungs), and lesion rate (mean grade among all affected lungs). The modified Madec system was used to evaluate the lung lesions2,3 . Moreover, the economic cost was calculated based on the number of lungs on each grade based on Straw et al.4
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