EFFICACY OF FEED ADDITIVES IN PRODUCTION PERFORMANCES AND CONTROL OF INFECTIOUS PNEUMONIA IN SWINE.

บทคัดย่อ

Thirty Large White x Landrace barrows and 30 similarly bred gilts were used in a randomized complete block design to determine the efficacy of different levels of lincomycin plus sulphamethazine (LS) in preventing infectious pneumonia.

Six barrows and 6 gilts were assigned at random to one treatment with three replications. These hogs were fed ad libitum with a 16% protein growing ration medicated with LS 44/110, 44/110, 44/110, 22/55 ppm and Tylan Sulpha (TS) 110/110 ppm as treatments I, II, III, IV and V, respectively. Medication continued for 60kg liveweight and then the hogs were fed ad libitum with a 14% protein finishing ration medicated with LS 44/110, 22/55, 0/0, 22/55 ppm and TS 55/55 ppm for treatments I to V for another period up to 94 feeding days.

After 94 feeding days all hogs were fed unmedicated finishing ration for another 15 days to reduce hazards of antibiotics to consumers. Then 12 hogs (6 barrows and 6 gilts) from treatment I and six hogs (3 barrows and 3 gilts) from treatments II to V were slaughtered to determine the extent of lung lesions.

No significant differces (P> 0.05) were found in all production traits among the treatments. The percentage of the incidences of hogs affected with apparent infectious pneumonia and the area of lung affected of treatments I to V were 16.6 / 40.0, 33.3 / 35.0, 50.0 / 55.0, 33.3 / 40.0 and percent, respectively.

Mortality, morbidity and skeletal defects were not found in any experimental hogs.