The Safety And The Clinical Effects Of Enteric-coated Tilmicosin Pellets In Swine Infected With Procine Contagious Pleuropneumoniae

Tilmicosin is one of the macrolide antibiotics for animals especially.It is a broad-spectrum antibacterial.It can kill most of bacteria,for example,all the gram positive bacteria,part of gram negative bacteria,mycoplasma,and leptospira.Tilmicosin is widely used for preventing and treating porcine infectious pleuropneumonia?cow mastitis and respiratory syndrome and mycoplasma galliscepticum.They have defects in clinics,although Tilmicosin injection,Tilmicosin nanoemulsion and Tilmicosin premix are principally used at home and abroad.For instance,Tilmicosin injection shows poor solubility in water so that it is hard to be prepared and cost,and also the injection cause stress reaction.Tilmicosin nanoemulsion is unstable in nature,the emulsifier used in the constituent has toxic and would cause allergy to animals,Tilmicosin premix is too bitter to taste for animals.Furthermore,Tilmicosin is acid-labile and easy to be destroyed in stomach.To overcome the shortage of Tilmicosin mentioned above,enteric-coated Tilmicosin pellets were developed.The enteric-coated Tilmicosin pellets will not be degraded by stomach acids,and it can cover up bad odor and bitterness to improve the palatability.Also,the enteric-coated Tilmicosin pellets can reduce damage caused by direct contact and reduce the interaction between drug and feed ingredient.This experiment is designed to evaluate the safety of the enteric-coated tilmicosin pellets used in swine.Forty 25-day old piglets were selected and were devided into 4 groups randomly,10 piglets each group.One of the groups was designed as control,the piglets from others were fed with one fold(400 g/1000kg feed),three folds(1200 g/1000kg feed)and five folds(2000 g/1000kg feed)of recommended dose of the enteric-coated tilmicosin pellets which were added into pig feed for 45 consecutive days,respectively.The complete blood count,blood coagulation test,blood biochemical test,urinalysis,gain in body weight,ratio of feed to body gain,ratio of organ weight to body weight and histopathological examinations were tested during the experiment.The results showed that no significant difference was found in all measured parameters between the enteric-coated tilmicosin pellets groups and the control group,indicating that the enteric-coated tilmicosin pellets have low toxicity and are safe to be used in swine minimum under the five folds of recommended dosage(2000 g/1000kg feed).Compared to the clinic effects on swine infected with actinobacillus pleuropneumoniae by using of the enteric-coated tilmicosin pellets(300 g/1000kg feed)and tilmicosin premix(300 g/1000kg feed)respectively,the mortality from the enteric-coated tilmicosin pellets group is lower than that of the tilmicosin premix group.The effective rate and cure rate of the enteric-coated tilmicosin pellets group are much higher than those of tilmicosin premix group.The average weight gain of the enteric-coated tilmicosin pellets group is higlher than that of tilmicosin premix group,and the standards of pulmonary lesion score in the enteric-coated tilmicosin pellets group is also lower than that of the tilmicosin premix group.The results indicate that the enteric-coated tilmicosin pellet has much better effect on the disease treatment of porcine contagious pleuropneumoniae.