Effects On The Growth Promotion, Target Animal Safety And Residues Elimination Of BMD Premix In Ducks

Bacitracin methylene disalicylate (BMD) is one of the polypeptide antibiotics, in veterinary medicine, it is used in the management of necrotic enteritis (NE) and the improving of the growth of livestock and poultry. Bacitracin and its related products had been used in Chickens, pigs and fish farming, but the target animal safety, efficacy of the growth promotion and the detection of Bacitracin residues in the target animal of duck has not been reported. By studying the efficacy of the growth promotion, the target animal safety and the residues elimination of BMD in duck, these studies would help to draw up a dosing regimens by ensuring the recommended dose, the target animal safety and the withdrawal time in duck.1. The growth promotion of Bacitracin methylene disalicylate for duck100healthy Muscovy duck of15days old were divided into5groups. The duck in the first group were fed without any medicated premix as the controller, another group were fed25mg/kg bacitracin zinc(BZ) of feed, the other3groups were fed5、25、50mg/kg BMD of feed, respectively. The trial period is56days. Assessment criteria include Symptoms, survival rate, Average daily weigh-gain (ADG), feed conversion ratio and the carcass traits. The results showed that BMD have little impact on the carcass traits, but it can improved the survival rate, Average daily weigh-gain (ADG) and feed conversion ratio. The results indicated that the recommended dose were25-50mg/kg BMD of feed (calculate by bacitracin).2. The target animal safety of BMD in duck80healthy Muscovy duck of15days old were divided into4groups. The duck in the first group were fed without any medicated premix as the controller. The ducks in the other3groups were fed50、150、250mg/kg BMD of feed, respectively. The parameters of hematology and biochemical of blood were detected at21and42days, respectively. All the ducks were weight and dissected at21and42days, respectively. The consumption of food for all groups was recorded during the period of21and42days.The results showed that no duck died during the test, and all the ducks were healthy and the result of dissection showed no. abnormal symptoms. This test confirmed that BMD can increase the appetite and the feed intake of Muscovy ducks, as well as improve the feed utilization rate. The parameters of blood hematology and biochemical were not found significantly except only a few parameters such as alkaline phosphatase, aspartate transaminase and glucose had significant difference between each group without dose relation. The results confirmed that the BMD is safe in the target animal of duck.3. The residues elimination of BMD in duck tissuesA microbiological method for determining BMD residues in duck tissues was developed. BMD residues in duck tissues were extracted by methyl alcohol, the extracts were defatted by n-hexane, detected by cylinder plate method. The concentrations, logarithm of BMD had a good linear coefficient relation (R2>0.99) with the square of the diameter of inhibition zone in the range of0.05～0.8IU/mL. When spiked BMD concentration in tissues were0.025,0.05, and O.lIU/g, the recoveries were over80%. The limit of detection was0.025IU/g (410μg/kg). The method established can be used for residue analysis of BMD in duck tissues.24ducks were fed with250mg/kg BMD of feed for successive20days, six ducks were respectively slaughtered at12hours,1,3,5days. BMD in duck tissues were determined by cylinder plate method established above. The result showed that no BMD residues were detected in the tissues. This experiment showed that the withdrawal period of BMD in duck was0day.