Effect Of Ectopic Fermentation System On Treatment Of Meat Duck Manure

Considering the lacking of the basic data of meat duck manure characteristics and the unclear technological parameters in ectopic fermentation process.This study firstly carried out surveys on conventional nutrients,heavy metals and antibiotics in meat duck manure in different seasons and under different breeding methods,and clarified the basic properties and parameters of meat duck manure.The effects of the ventilation rates and bedding types on the treatment of meat duck manure in ectopic fermentation system were studied based on the manure from mesh breeding mode.The physicochemical properties,main nutrient contents,and carbon and nitrogen concentration were monitored and analyzed,respectively.The results can provide references for treating the meat duck manure by ectopic fermentation efficiently.The main innovative results and research conclusions of this paper are as follows:1)The contents of total nitrogen（TN）,total phosphorus（TP）and potassium（K）in meat duck manure were（2.47%±0.14%）,（1.22%±0.11%）and（1.73%±0.59%）,respectively.The main heavy metals in feed and manure were Cu and Zn.And there was a significant positive correlation between Zn in feed and manure（P<0.01）.This indicated that the heavy metals in meat duck manure were mainly come from the feed.According to the rules in“German Limitation Standard for Heavy Metals in Rotten Composting”,the contents of the Cu,Zn and Cr in the duck manure have exceeded the limitations.Antibiotics in manure were mainly tetracyclines and quinolones,while sulfonamides and macrolides were not detected.And the contents showed a trend of ground breeding>online flat breeding>bedding breeding.The results indicated that bedding breeding is an environmentally friendly mode of meat duck farming with less pollutants emissions.2)The extopic fermentation of duck manure experiments were conducted with the bedding of sawdust and rice husk in 6:4.Three ventilation rates of 0.02（A₁）,0.05（A₂）and 0.10（A₃）m3·min^-1·m^-3were selected to investigate the treatment effects with 25 kg of duck manure added daily.The temperature under different ventilation rates were A₂（51.29±4.65°C）>A₁（49.98±3.81°C）>A₃（49.36±5.21°C）,respectively.The number of days with high temperature（>50°C）presented A₂（28 d）>A₁（23 d）>A₃（20 d）.And the oxygen consumption rate were A₂（0.26±0.13）>A₃（0.24±0.09）>A₁（0.20±0.10）ΔO₂%·min^-1.At the end of the three treatment experiments,the GI value,the number of fecal coliforms,the mortality of roundworm eggs and the contents of Cu and Zn were all met the safety requirements.Taking the treatment group with the highest cumulative gas emissions as the reference,the emission reduction efficiencies of CH₄,CO₂,N₂O and NH₃ in A₂ treatment were 77%,33%,23%,and 22%,respectively.There was no significant difference in the main nutrient contents between the whole three treatments.Comprehensively,the extopic fermentation of the duck manure can achieve the best results under the ventilation interval of 5 min and 10 min with the ventilation rate of 0.05 m3·min^-1·m^-3.3)The ventilation rate of 0.05 m3·min^-1·m^-3 was adopted,and 20 kg of duck manure was added daily.Three different kinds of bedding were studied to compare the treatment effects of extopic fermentation of duck manure with the following method:sawdust:corn stalk（5:5）（B₁）,sawdust:rice husk（6:4）（B₂）,and sawdust:rice husk（4:6）（B₃）.The results showed that the temperature of the three kinds of bedding presented the trend of B₁（53.20±2.0°C）>B₂（51.53±2.89°C）>B₃（47.05±2.34°C）.The number of days with high temperature（>50°C）showed B₁（36 d）>B₂（28 d）>B₃（3 d）,and the oxygen consumption rate showed B₁（0.23±0.06）>B₂（0.17±0.07）>B₃（0.12±0.04）ΔO₂%·min^-1.At the end of the experiments,the GI value,the number of fecal coliforms,the mortality of roundworm eggs,and the contents of Cu and Zn of the three treatments were all met the safety requirements.The B₂ treatment had a better nutrient preservation and gas emission reduction effect,and the growth rates of TN,P₂O₅ and K₂O were1.8,1.74and 3.0,respectively.Taking the treatment group with the highest cumulative gas emission as the reference,the emission reduction efficiencies of CH₄,CO₂,N₂O and NH₃ by B₂ treatment was 45%,19%,49%and9%,respectively.In conclusion,the bedding with the sawdust and rice husk in 6:4 has the best treatment effect on duck manure.