莫能菌素瘤胃代谢动力学特点及育肥牛合理饲喂制度的研究

A KINETIC STUDY ON RUMINAL METABOLISM OF MONENSIN AND RATIONAL RAISING SYSTEM IN STEERS

选用体况良好的4头带有瘤胃瘘管的阉公牛,进行莫能菌素瘤胃代谢动力学特点的研究。结果表明,莫能菌素瘤胃代谢动力学特点符合一室模型C=Co·e-kelt,即C=1.02e-0.003t(t-代谢时间,min;C-莫能菌素浓度,mg/l;e-自然常数)(n=15,r=0.844,P<0.01)。莫能菌素对300～400kg育肥架子牛的合理饲喂制度为:每天饲喂2次,每次间隔720分钟,每次喂量为75mg/头·日,饲喂总数为150mg/头·日。进一步选择体况良好的300～400kg育肥架子牛28头,分成4组,研究莫能菌素水平对日增重和血清中尿素氮、葡萄糖、胆固醇含量的影响。1组,基础日粮+50mg/头·日莫能菌素;2组,基础日粮+150mg/头·日莫能菌素;3组,基础日粮+250mg/头·日莫能菌素;4组(对照组),基础日粮。日粮中分别添加150、250mg/头·日莫能菌素时,育肥牛日增重提高73%和39%,但差异不显著。当莫能菌素添加剂量分别为50、150和250mg/头·日时,能够提高血糖浓度,其中添加量为50mg/头·日时与对照组差异显著(P<0.05);莫能菌素有降低血清中尿素氮的趋势,但差异不显著(P>0.05);莫能菌素对胆固醇含量无规律性影响。

4 steers fitted with permenant ruminal fistula were used in the study o f pharmacokinetics parameters of monensin in rumen.The results indicated that th e concentration-time curve of monensin in the rumen fitted well with a one-compa ntment model.The equation obtained in the present experiment was Ct=1.02EXP(-0.0 03t)(n=15,r=0.844,P<0.01)(t-time,minute)(c-rumen liquid concentration of monensi n,mg/l).Combined with other kinetic parameters measured,we concluded that the ra tional feeding system of steers with a live weight of 300～400kg was 150mg/head ·day,under twice-feeding per day system,and the dosage of monensin per feeding was 75mg.The proper dosage of monensin for steers obtained in the kinetics study was further examined in a ranch experiment.28 fistulated steers with a live wei ght of 300～400kg were randomly arranged into 4 groups:50mg,150mg,250mg or 0mg m onensin per head per day fed respectively.The results indicated that the greates t average daily gain(ADG) was observed when 150mg/head·day monensin were fed,AD G could be raised by 73% and 39% with adding 150 and 250mg/head·day monensin re spectively.Serum glucose concention were raised with the adding of monensin,50mg group was significantly higher than that of control(P<0.05);serum urea-N concen tration was decreased when monension was fed,but the diffenrence was not signifi cant(P>0.05).Monensin supplementation had no influence on the concentration of b lood cholestrerol.