Study On The Correlativity Of Heavy Metals Concentration In Cattle And Rearing Environment In Guizhou

Guizhou Province has taken animal husbandry as an important pillar industry,the cadmium elements level of Guizhou Province is exceeding the stipulated standard,which has a serious impact on beef exports and pose a threat to food safety and hygiene,it is a urgent need to make clear why the level of cadmium in beef is exceeding the stipulated standard.For this we carried out field surveys and analysis in the native mountain areas in Guizhou,researching the environment factors related to the animal life,the distribution of heavy elements in the ecological food chain and the migration laws & features in the organizations within the plot of livestock,and analyzing the relationship between the heavy metals in the cattle organizations and the breeding environment.We have chosen 3 Counties respectively of different levels of environmental pollution, including Pingtang county,Weining county and Hezhang County.The collecting samples are:the kidneys,liver and muscle of the cattle,the samples of environmental soil,pasture,water and cattle fecal waste,with a total of seven types,290 samples.We tested three elements of each sample:Zn, Pb and Cd.The results were as follows:(1)the highest average level of Zn,Pb and Cd in cattle were 1100.4 mg/kg,467.7mg/kg and 10.19mg/kg;in soil were 53.58mg/kg,1.0mg/kg and 38.32mg/kg respectively.(2)The zinc content of kidney,liver,muscle and feces of the cattle has a clear correlation with that of in the soil,grass,water.Hezhang country had the highest average level of Zn in the soil,grass, water of the range of 633.43～1782.69 mg/kg,335.17～1874.67mg/kg,68～6556μg/L.This region had a higher zinc content of kidney,liver,muscle and feces of the cattle.The range is 24.18～52.92 mg/kg,23.56～230.25mg/kg,25.77～71.48 mg/kg and 453.47～1079.60 mg/kg respectively. The zinc content in cattle muscle are still lower than the national standard.(3)The lead content of kidney,liver and muscle of the cattle has not correlation with that in environment.Hezhang country had the highest average level of Pb in the soil,grass,water of the range of 211.47～886.15 mg/kg,56.72～206.63mg/kg,1.36～9.41μg/L.The lead content of kidney,liver and muscle of the cattle is in the range of 0.14～2.53 mg/kg,0.05～4.46mg/kg and 0.005～0.019 mg/kg respectively in this region.The lead content of feces of the cattle has a clear correlation with that of in environment.The average level of Pb is 170.76 mg/kg in this region.(4)The cadmium content of kidney,liver,muscle and feces of the cattle has a clear correlation with that of in the soil,grass,water.In the selected three regions,the cadmium content of different Cattle organizations are very different:Hezhang＞Weining＞Pingtang.The indigenous zinc smelting in Hezhang has caused serious heavy metal pollution.The cadmium content in soil,feed,cattle kidney,cattle liver is seriously exceeding the national standard.In Hezhang country,Cd in the soil, grass,water of the range of 7.68～15.71 mg/kg,2.34～15.34 mg/kg,0.025～1.538μg/L and in kidney 2.65～73.62 mg/kg,liver 0.13～6.84mg/k,muscle0.0007～0.0293 mg/kg and feces 9.51～15.21 mg/kg of the cattle respectively.Cd in muscle fit national standard.the heavy metal content is always the highest in the kidney,so the bovine kidney can be taken as a biological indicator of the heavy metal contamination environment.