A Field Trial Of Cyadox In Swine

Cyadox, a new quinoxaline antimicrobial promotor in animal husbandry, had the traits of obvious growth promotion and good safety on food-producing animals. The dose of study the effect on growth in pigs was not higher than 100 mg/kg intemal. In order to study the Effects and safety on growth in pigs, a 115-day feeding study of pigs and antibacterial activity in vitro of cyadox was conducted to. And dose levels of drugs tested include the recommended use level-0, 1X, 3X, and 5X.210 Large White barrows, weaned at 40 days of age, were randomLy allotted to 7 treatments with 3 replicates. The treatments were: one control fed the basal diet without any antimicrobial, one group fed the diet containing 50 mg/kg olaquindox, one group fed the diet containing 50 mg/kg quinocetones, one group fed the diet containing 50 mg/kg aureomycin, and the other three groups fed the diets containing 50, 150, 250mg/kg cyadox, respectively. The animals at the start of the 7-day adaptation period were fed a basal diet containing no antibiotics. At the age of 47d the piglets entered the experiment. The experiment period lasted 115d in 3 phases. (1, from d 0 to 40; 2, from d 41 to 85; 3, from d 86 to 115). Average daily gain (ADG), Average daily feed intake(ADFI)and Feed/Gain(F/G)were determined in each phase. The serum were collected on days 0, 40, 115, to determined the biochemistry characters. At the end of phase, five pigs of each control, 50 mg/kg olaquindox, 50, 150, 250mg/kg cyadox were slaμghtered to determine the weight of heart, liver, spleen, lung and kidneys. And determination the quinoxaline-2-carboxylic acid (QCA) as the marker resides for the cyadox in swine muscle and liver. Determination the methyl-3-quinoxaline-2-carboxylic acid (MQCA) as the marker resides for the olaquindox in swine muscle and liver.Determination the in vitro antibacterial activity of cyadox, olaquindox, quinocetones and aureomycin against Escherichia coli, salmonella and Serpulina innocens, by microdilution.Three does of cyadox(50, 150 and 250 mg/kg)improved ADG and depressed F/G by 7.1%(P＜0.05),35.3%(P＜0.05),46%(P＜0.05) and 7.1%(P＜0.05),12.3%(P＜0.05), 13.7%(P＜0.05) in phase 1(d 0 to 40), by 3.2%(P＞0.05),6.5%(P＜0.05),8.5%(P＜0.05) and 2.0%(P＞0.05),2.7%(P＞0.05),3.1%(P＜0.05) in phase 2 (d 41 to 85), by 3.0%(P＞0.05),5.1%(P＜0.05),7.2%(P＜0.05) and 0.3%(P＞0.05),1.2%(P＞0.05),2.5%(P＜0.05)in phase 3 (d 86 to 115), respectively.In addition, no obvious effects of cyadox on relative organ weights and characters of physiology and biochemistry were observed in all treatment groups. The correlation analysis of blood physiology and serum biochemistry with cyadox dose, diarrhoea frequency and ADG showed that, there were feebleness correlation about the blood physiology and cyadox dose (0＜r＜0.3). There were significant correlation about the WBC, RBC of blood physiology with diarrhoea frequency,ADG (P＜0.05). There were significant correlation about the TP, ALP, BUN, K⁺, Na⁺ of serum biochemistry with cyadox dose (P＜0.05). There were significant correlation about the TP, ALP, BUN, Na⁺ of serum biochemistry with diarrhoea frequency (P＜0.05). There were significant correlation about the ALP, BUN, Na⁺ of serum biochemistry with ADG (P＜0.05). Otherwhile, the multiple regression analysis showed some multivariate regression equation about the blood physiology and serum biochemistry with significant correlation about cyadox dose, diarrhoea frequency and ADG. The multivariate regression equation about WBC, RBC was, Y=2.102＋O.55X_WBC-0.096X_RBC. The multivariate regression equation about TP, ALP, BUN, K⁺ with cyadox dose was, Y=2.987X_TP＋0.69X_ALP-36.417X_BUN＋58.915X_K⁺-390.109. The multivariate regression equation about TR, ALP, BUN with diarrhoea frequency was Y=10.685-0.061X_TP-0.008X_ALP＋0.14X_BUN. The multivariate regression equation about ALP, BUN with ADG was Y=753.104＋0.072X_ALP-2.818X_BUN.Then HPLC method was used to determine the residues of QCA, MQCA in muscle and liver in pigs of 50, 150, 250mg/kg cyadox and 50 mg/kg olaquindox. After a withdrawal time of 24h, the concentrations of QCA in muscle and liver were 2.0 to 3.5μg/kg and 13.1 to 29.2μg/kg below the MRL (5μg/kg, 30μg/kg), and the concentrations of MQCA in muscle and liver were 6.0 to 10.0μg/kg and 75.7 to 105.1μg/kg above the MRL (4μg/kg, 50μg/kg).The results showed that cyadox less than 250mg/kg in-feed can improve the growth performance effectively with no obvious toxic reactions and low metabolite residue after long term administration, which indicated that cyadox was safe enoμgh to pigs. The in vitro antibacterial activities of cyadox on 3 species of clinical pathogeric bacteria in pigs were tested by microdilution method. The results showed that cyadox was active to Escherichia coli and Salmonella, The Minimal Inhibitory Concentration (MIC) is 40～80μg/mL and 40～80μg/mL. The Minimal Inhibitory Concentration (MIC) of olaquindox is 80 to 160μg/mL and 80 to 320μg/mL. The Minimal Inhibitory Concentration (MIC) of quinocetone is 40 to 80μg/mL and 80μg/mL. The Minimal Inhibitory Concentration (MIC) of aureomycin is 40 to 160μg/mL and 80 to 160μg/mL. The results showed that cyadox was active to Serpulina innocens. The Minimal Inhibitory Concentration (MIC) is 2 to 4μg/mL. The Minimal Inhibitory Concentration (MIC) of olaquindox is 8μg/mL.The antibacterial activity of cyadox and was stronger than that of olaquindox and aureomycin. And the MIC was not rise up after long term administration. Indicated that cyadox could be used as an antibacterial agent clinically.In conclusion, this paper studied the effects and safety on growth in pigs on field experiment. Results in these experiments were consistent with other studies. These results give scientific guidances for the resonable and safe use of cyadox in pigs. As a conclusion, cyadox is a safe for pigs with excellent growth promotion effect and antimicrobial activity.