Mobility And Bioaccumulation Of Heavy Metal Along Manure-Maggot-Broiler Food Chain

With the rapid development of livestock and poultry industry in China, manure pollution and shortage of protein supplement have become an urgent problem to be solved. In the test we have researched effects on growth performance and slaughter performance of broilers supplemented with maggots bred in pig manure in daily feed, also studied mobility and bioaccumulation of heavy metal along pig manure-maggot-broiler food chain to build a pig manure-maggots-poultry circulation industry chain and settle the worsening pollution of livestock and poultry manure to promote the sustainable development of our economy, the main research results are as follows:1. There were no differences observed for average daily gain, feed conversion ratio, survival, eviscerated rate, heart and spleen weight, moisture of broiler with feeding diets containing maggots, adding 15% maggots to the daily feed can raise slaughtering rate of broilers. Diets supplemented with 5.0, 10.0, 15.0 % maggots can ensure normal growth of broiler, adding 5% housefly maggot powder was the most appropriate.2. The fresh manure treated with maggots decreased 38.5% in wet weight, 22.0% in dried weight. Contents of chrominum(Cr) and lead(Pb) were significantly lower than the original manure(p<0.05), only nickel(Ni) and arsenic(As) contents had no significant change(p>0.05), zinc(Zn), copper(Cu), nickel(Ni), selenium(Se), cadmium(Cd) in pig manure extremely significantly decreased( p<0.01). After bioconversion by maggot, the sum of water soluble state, ion exchange state, carbonate bound state of Cu and Zn were upward, water soluble state and ion exchange state forms of Cd content decreased, residual state rised, carbonate fractions and humic acid bound of more content and the total amount of both trended rise, the sum of strong organic bound state and residual state of Cr increased, but the sum of Pb kept unchanged basically, the potential bioavailability of Zn and Cu increased after maggot conversion, the forms of Cd and Cr turned steadily, fraction of Pb ultimately remained invariable.3. When maggot dealing with manure, from the age of 3 day to 5 day, with the age increasing, heavy metals of maggots of per unit of weight decreased due to the presence of heavy metals in pig manure. On the 5-day-old larvae, Zn, Cu, Cr, Ni, As, Pb, Se, Cd contents were significantly lower than the other days. There were different heavy metal enrichments of maggots at different age, with the increase of the age, the heavy metal enrichment abated, the 5-day-old maggots were at the least.4. Adding 15% maggots to the daily feed, heavy metal contents of chicken and liver had no significant difference(p > 0.05), all detections of heavy metal have been tested in chicken feces except Cr, moreover, contents of Zn, Cu, Cd and so on were significantly higher than the adding 10% group(p<0.05),but there were no difference between the adding 10% group and adding 15% group(p>0.05).