STUDY ON THE EFFICACY OF AN INACTIVATED M YCOPLASMA-HYOPNEUMONIAE VACCINE (STELLAMUNE(R) MYCOPLASMA) AT DIFFERENT TIMES OF VACCINATION

In a field study, an inactivated Mycoplasma-hyopneumoniae vaccine was tested in 1 810 pigs of various age groups (suckling and weaned piglet s and fattening pigs). Records of the antibody concentration in the se rum over a certain time period showed a significant faster rise in the antibody titer and a significant increase in the concentration up unt il the end of the fattening period for those pigs that had been vaccin ated, as compared to those of the control group. A post-slaughter insp ection of the lungs of the vaccinated groups versus the control groups revealed a significantly higher percentage of lungs without any patho logical changes and a significantly lower percentage of lungs with bro nchopneumonia and pleuritis in the vaccinated unweaned piglet and the fattening pig groups. A significant difference between the weaned pigl ets and their control group was only seen in the occurrence of pleurit is. The vaccinated animals of the suckling and weaned piglet groups sh owed an significantly higher average daily weight gain until the end o f the fattening period compared to the average daily weight gain of th eir corresponding control group. The average daily weight gain was 36 g/day for the unweaned piglet group and 26 g/day for the weaned piglet group. The criteria flesh score, back-fat thickness and amount of val uable meat cuts were calculated for the determination of meat quality rating, The criterion named flesh score showed significantly better re sults for the vaccinated groups compared to the control groups. The cr iteria back-fat thickness and amount of valuable meat cuts, respective ly, showed no significant differences between the vaccinated and the c ontrol groups.