Xu Weiping, Reuter Tim, Inglis G Douglas, Larney Francis J, Alexander Trevor W, Guan Jiewen, Stanford Kim, Xu Yongping, McAllister Tim A
Agriculture and Agri-Food Canada, Lethbridge Research Centre, P.O. Box 3000, Lethbridge, Alberta T1J 4B1, Canada.
J Environ Qual. 2009 Feb 6;38(2):437-50. doi: 10.2134/jeq2008.0168. Print 2009 Mar-Apr.
During outbreaks of infectious animal diseases, composting may be an effective method of disposing of mortalities and potentially contaminated manure. Duplicate biosecure structures containing 16 cattle (Bos taurus) mortalities (343 kg average weight) were constructed with carcasses placed on a 40-cm straw layer and overlaid with 160 cm of feedlot manure. At a depth of 80 cm (P80), compost heated rapidly, exceeding 55 degrees C after 8 d and maintained temperatures of 55 to 65 degrees C for > 35 d. Temperatures at 160 cm (P160) failed to exceed 55 degrees C, but remained above 40 degrees C for >4 mo. To investigate rates of microbial inactivation, Escherichia coli O157:H7, Campylobacter jejuni, and Newcastle disease virus (NDV) were inoculated in manure (E. coli O157:H7 and C. jejuni approximately 10(8) CFU g(-1); NDV, approximately 10(6) EID(50) g(-1)), embedded at P80 and P160 and retrieved at intervals during composting. Escherichia coli O157:H7 and NDV were undetectable after 7 d at both depths. The C. jejuni DNA was detected up to 84 d at P80 and >147 d at P160. To estimate degradation of recalcitrant substrates, bovine brain, hoof, and rib bones were also embedded at P80 and P160 and retrieved at intervals. Residues of soft tissues remained in carcasses after opening at 147 d and bovine tissue decomposition ranked as brain > hoof > bone. More than 90% dry matter (DM) of brain disappeared after 7 d and 80% DM of hoof decomposed after 56 d. High degradation of cattle carcasses, rapid suppression of E. coli O157:H7 and NDV and reduction in viable cell densities of >6 logs for C. jejuni demonstrates that the biosecure composting system can dispose of cattle carcasses and manure in an infectious disease outbreak.
在动物传染病暴发期间，堆肥可能是处理病死动物和潜在受污染粪便的有效方法。建造了两个包含16头病死牛（Bos taurus，平均体重343千克）的生物安全结构，将尸体放置在40厘米厚的稻草层上，并覆盖160厘米厚的饲养场粪便。在80厘米深度（P80）处，堆肥迅速升温，8天后超过55摄氏度，并在35天以上保持55至65摄氏度的温度。160厘米深度（P160）处的温度未超过55摄氏度，但在4个月以上保持在40摄氏度以上。为了研究微生物失活率，将大肠杆菌O157:H7、空肠弯曲菌和新城疫病毒（NDV）接种到粪便中（大肠杆菌O157:H7和空肠弯曲菌约为10⁸CFU g⁻¹；NDV约为10⁶EID₅₀ g⁻¹），埋入P80和P160处，并在堆肥过程中间隔取出。在两个深度处，7天后均未检测到大肠杆菌O157:H7和NDV。在P80处，空肠弯曲菌DNA在84天内均可检测到，在P160处则在147天以上均可检测到。为了估计难降解底物的降解情况，还将牛脑、蹄和肋骨埋入P80和P160处，并间隔取出。在147天打开尸体后，软组织仍残留在尸体中，牛组织的分解顺序为脑>蹄>骨。7天后，超过90%的脑干物质消失，56天后，80%的蹄干物质分解。牛尸体的高降解率、大肠杆菌O157:H7和NDV的快速抑制以及空肠弯曲菌活细胞密度降低超过6个对数，表明生物安全堆肥系统可以在传染病暴发时处理牛尸体和粪便。
