[Preservation of bioresource potential of dairy cattle under oil gas technogenesis (influence of sorbents adding to rations for heavy metals content in milk)]
2009
Akhmetzyanova, F.K.
Agroecological evaluation of contamination of agricultural lands, feeds and cow milk with heavy metals (HM) has been done. The peculiarities of HM migration from different types of soils into grain and forage crops, in rations of lactating cows and milk under different conditions of keeping and feeding animals have been found. The methods to reduce the content of HM in cow milk have been developed and their economical efficiency has been determined. The study covered 3 areas of the Republic of Tatarstan which are the most contaminated with oil and oil products. high concentrations of copper, zinc and lead exceeding the MAC were found in the soil of each area. The feed contamination exceeding the normative values of lead and cadmium says about deteriorated ecological safety of animal products, milk in particular. as the age of plants increases, the concentration of lead grew in awnless brome by 15.9%, in natural herbs - by 44.4% and the content of copper and zinc decreased by 19.4 and 62.3%, respectively. The high concentrations of TM were detected in cow molk of priviate and public sectors. The MAC is exceded in wintewr stable period by 27.0-130.0%, in summer pasture period - by 50.0-100.0%. The change-over of cows from the pasture for stable system in summer period and feeding green feed lowersrriving lead in animal organism 1.6 times, cadmium and zinc - 2 times. High efficacy of reducing the content of HM in milk in using natural sorbents: zeolytes, sodium bentonitem ferrocyte and bifezh in the cow rations was established. using zeolyte allows geeting net profit from milk per 1 head in an amount of 108.5-138.8 rub, ferrocine - 26.2-62.2 rub, salt briquetts with ferrocyne and microelements - 588.5 rub, with ferrocine abs food sulfur - 208.4 rub, with microelements - 393.9 rub
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