Content of Heavy Metals in Animal Feeds and Manures from Farms of Different Scales in Northeast China

Abstract

To determine the contents of heavy metal (Cu, Zn, As, Cr, Cd and Pb) in animal feeds and manures, 104 livestock feeds and 118 animal manure samples from farms of different herd size and located in northeast China were collected and their heavy metal concentrations were determined. The content of Cu, As and Cd ranged from 2.3–1,137.1 mg/kg dm, 0.02–13.03 mg/kg dm and non-detectable (nd)−31.65 mg/kg dm in pig feeds, 2.88–98.08 mg Cu/kg dm, 0.02–6.42 mg As/kg dm and non-detectable (nd)–8.00 mg Cd/kg dm in poultry feeds, and their content in cattle feeds was similar to that in poultry feeds. The typical content in pig manures was 642.1 mg Cu/kg dm, 8.6 mg As/kg dm, and 15.1 mg Cd/kg dm, which reflected the metal contents in feeds. The typical contents in poultry manures were 65.6 mg Cu/kg dm, 3.3 mg As/kg dm and 1.6 mg Cd/kg dm while the contents in cattle manures were 31.1 mg Cu/kg dm, 2.5 mg As/kg dm and 0.5 mg Cd/kg dm. Animal manure is an important source of heavy metals to the environment in Northeast China.

Review: Nutritional ecology of heavy metals

“…According to Dai et al (2016) more than half of the Wisconsin (USA) dairy farms used feed rations containing Cu above the recommended levels. Zhang et al (2012) reported that in north-east China Cu, Zn and As were found in all feed samples. According to Wang et al (2013) in China (Jiangsu Province), median concentrations of Zn were the highest heavy metals found, followed by Cu.…”

“…The contents of trace elements in animal manures increased over a decade, with the use of feed additives (Luo et al, 2009). Zhang et al (2012) showed that in north-east China, the contents of Cu and Zn in manures of different size farms (small, medium and large farms) were significantly higher than other metals detected. In cattle and chicken manure, there was no significant difference in the content of heavy metals from farms of different sizes (Table 8).…”

“…Considering the different kinds of farms and different species, swine and poultry represent the most important sources of Zn and Cu pollution. This is also linked to the additives used in animal feed (Nicholson et al, 2003;Luo et al, 2009;Zhang et al, 2012, Jakubus et al, 2013. Consequently, swine and poultry farms may have the highest risk for agricultural lands.…”

“…Consequently, swine and poultry farms may have the highest risk for agricultural lands. In terms of environmental protection, animal feed additives should be monitored based on the legal limits in each country (Zhang et al, 2012). Different approaches are also needed for reducing heavy metal inputs to agricultural land and to target policies for preserving long-term soil quality (Nicholson et al, 2003).…”

Chromium and lead contamination in commercial poultry feeds of Bangladesh

“…The maximum chromium content of the solid waste was found to be 3.2%. Zhang et al (2012) found that poultry feed had high concentrations of heavy metals in China. Similarly, high levels of heavy metals were found in poultry feed in Pakistan (Iftikhar et al, 2014).…”