【作者】 金鑫； 张红涛； 李胜利；

【Author】 Jin-xin~1 Zhang-hongtao~2 Li-shengli~1 (1.State Key Laboratory of Animal Nutrition,College of Animal Science and Technology, China Agricultural Uneiversity,Beijing 100193,China 2.Beijing San Yuan LvHe Dairy Cattle Breeding Company)

【机构】 动物营养国家重点实验室中国农业大学动物科技学院国家奶牛产业技术体系； 北京三元绿荷奶牛养殖公司；

【摘要】 由于三聚氰胺含氮量高,添加后可以提高饲料的表观蛋白质含量,并且由于其特殊的理化性质,掺假后不易被常规检测方法检出,所以被少数不法厂商用于饲料掺假。本试验采用三聚氰胺纯品,通过检测不同的添加水平时各样品中三聚氰胺的残留浓度,来衡量奶牛代谢三聚氰胺的能力,进而评定三聚氰胺对奶牛安全的影响;通过研究三聚氰胺在奶牛体内残留规律,探讨三聚氰胺对奶牛产生危害的最小水平。选择5头产奶量和体重相近、健康无疾病、安装有永久性瘤胃瘘管的经产荷斯坦泌乳奶牛作为试验动物。三聚氰胺纯品试验设计为四个添加水平,即用0.1%、0.3%、0.5%、0.7%的纯品分别代替1%、3%、5%、7%的豆粕,每个处理饲喂同一水平的三聚氰胺,由低到高依次改变三聚氰胺的添加水平,全天应采食的三聚氰胺在晨饲时一次性饲喂完毕。试验结果表明,各处理样品中三聚氰胺残留浓度随三聚氰胺纯品的添加水平提高而增加。当三聚氰胺纯品添加水平达到精补料的0.3%时,血浆和粪样中的三聚氰胺残留浓度与添加水平为0.1%时的残留浓度有极显著差异(P<0.01);当添加水平达到精补料的0.5%时,瘤胃液、血浆和牛奶中三聚氰胺残留浓度与添加水平为0.3%时的残留浓度有显著差异(P<0.01),此时粪样中三聚氰胺残留浓度有所上升,但与添加水平为0.3%的残留浓度没有显著差异(P=0.21);当添加水平达到精补料的0.7%时,所有样品中三聚氰胺的残留浓度与此前较低水平时的残留浓度均有极显著差异(P<0.01)。泌尿系统是机体排除三聚氰胺的主要途径,这与三聚氰胺导致肾脏疾病甚至引起宠物死亡的报道相一致。在通过本试验对三聚氰胺进行奶牛安全性评价时要关注两方面的问题:①维持奶牛机体器官正常生理功能的安全,②奶牛提供的动物性产品的安全。精补料中三聚氰胺添加水平不超过0.3%时,奶样中三聚氰胺的残留浓度与添加水平为0.1%时残留浓度相比差异不显著(P=0.58);添加水平不超过精补料的0.5%时,尿样中的残留浓度的处理间差异不显著(P=0.24);而当精补料中三聚氰胺添加水平达0.7%时,尿样、奶样中三聚氰胺残留浓度都与前三个较低的添加水平有极显著的差异(P<0.01)。在试验设置添加水平的前提下,可以看出当精补料中添加三聚氰胺纯品超过0.3%时,牛奶中残留的三聚氰胺浓度会显著上升;超过0.5%时,尿中三聚氰胺残留浓度也会显著上升,奶牛代谢三聚氰胺的功能性器官(尤其是肾脏)的负担会显著加大。更多还原

【Abstract】 Melamine,as a high nitrogen content material,could be used to add in feedstuff to increase the apparent protein,and because of its unique physical and chemical properties, adulteration was not easy to be discovered by the conventional detecting method,and so Melamine was used to adulterate by a few unscrupulous feedstuff manufacturers. The experiments were conducted to evaluate the safety of pure Melamine fed to the dairy cows.During different supplementing levels of pure Melamine or Melamine byproducts,the residual concentration of Melamine in samples were tested to measure the capacity of dairy cattle metabolizing Melamine,hence to assess the safety of supplementing Melamine in dairy cattle feedstuff.By studying the melamine residue changes in the cattle body could determine the minimum level of melamine had negative effect on dairy cattle. Five cannulated multiparous healthy dairy cows with similar milk yield and body weight were assigned to the experiments.There were four levels set in the pure Melamine experiment, adding 0.1%,0.3%,0.5%,0.7%pure melamine to replace 1%,3%,5%,7%soybean meal relatively in the concentration.Feeding the dairy cows with the same concentration of pure Melamine in each part of the experiments,the supplementing level was from low to high,and fed Melamine to the cows with concentration in the morning. The results showed that residual concentration of Melamine in each kind of samples was durative increasing.When the pure Melamine level rose to 0.3%in the concentration,the residual concentration of Melamine in samples of blood and feces were very significantly different from that of 0.1%(P<0.01);when the pure Melamine level rose to 0.5%,the residual concentration in ruminal fluid,blood and raw milk was significantly different from that of 0.3% (P<0.01) while the residual concentration in feces was not significantly different from that of 0.3%(P =0.21),though the concentration of Melamine was durative increasing;when the pure Melamine level rose to 0.7%,the residual concentration in all samples were very significantly different from that of 0.5%(P<0.01).The urinary system is the main way to excrete Melamine took in breakfast,which was consistent with the report that Melamine had negative effect on kidney. When the pure Melamine level rose from 0.1%to 0.3%in the concentration,the residual concentration of Melamine in milk was not significantly different(P =0.58),though durative increasing as the rising level of Melamine.When the level rose to 0.5%,the residual concentration of Melamine in urine was not significantly different(P =0.24).However,when the pure Melamine level rose to 0.7%,the residual concentration in urine and milk were very significantly different from the lower levels(P<0.01). Based on the adding level of experiments set,we could draw such a conclusion,when the level of pure Melamine rose to 0.3%,the residual concentration of Melamine in milk was significantly rising,had significantly negative effect on raw milk quality and safety.When the level of pure Melamine rose to 0.5%,the metabolizing burden of functional apparatus to excrete Melamine,especially kidney,was significantly aggravating.更多还原