Varel Vincent H, Wells James E
USDA, Agricultural Research Service, U.S. Meat Animal Research Center, P.O. Box 166, Clay Center, NE 68933-0166, USA.
J Environ Qual. 2007 Apr 5;36(3):773-9. doi: 10.2134/jeq2006.0394. Print 2007 May-Jun.
Pathogens, ammonia, odor, and greenhouse gas emissions are serious environmental concerns associated with swine production. This study was conducted in two manure pits (33,000 L each) to determine the influence of 1.5 or 3.0 g thymol L(-1) and 80 mg L(-1) urease inhibitor amendments on urea accumulation, coliform bacteria, odor, and methane emission. Each experiment lasted 18 or 19 d, during which time 30 to 36 250-mL samples (six per day) were withdrawn from underneath each pit and analyzed for urea, thymol, volatile fatty acids, coliform bacteria, and Campylobacter. At the end of each experiment, six 50-g samples from each pit were placed in serum bottles, and gas volume and composition were determined periodically for 28 d. Compared with the control pit, volatile fatty acids production was reduced 64 and 100% for the thymol amendments of 1.5 and 3.0 g L(-1), respectively. Viable coliform cells were reduced 4.68 and 5.88 log10 colony-forming units kg(-1) of slurry for the 1.5 and 3.0 g thymol L(-1), respectively, and Escherichia coli were reduced 4.67 and 5.01 log10 colony-forming units kg(-1) of slurry, respectively. Campylobacter was not detected in the pits treated with thymol, in contrast to 63% of the samples being positive for the untreated pit. Urea accumulated in the treated pits from Day 3 to 6. Total gas production from serum bottles was reduced 65 and 76% for thymol amendments of 1.5 and 3.0 g L(-1), respectively, and methane was reduced 78 and 93%, respectively. These results suggest that thymol markedly reduces pathogens, odor, and greenhouse gas emissions from a swine production facility. The urease inhibitor produced a temporary response in conserving urea.
病原体、氨气、气味和温室气体排放是与养猪生产相关的严重环境问题。本研究在两个粪坑（每个33000升）中进行，以确定1.5或3.0克百里酚/升以及80毫克/升脲酶抑制剂添加物对尿素积累、大肠菌群、气味和甲烷排放的影响。每个实验持续18或19天，在此期间，从每个粪坑下方抽取30至36个250毫升的样本（每天6个），并分析其中的尿素、百里酚、挥发性脂肪酸、大肠菌群和弯曲杆菌。每个实验结束时，从每个粪坑中取六个50克的样本放入血清瓶中，在28天内定期测定气体体积和成分。与对照粪坑相比，1.5和3.0克/升百里酚添加物分别使挥发性脂肪酸产量降低了64%和100%。对于1.5和3.0克百里酚/升的添加物，每千克粪浆中存活的大肠菌群细胞分别减少了4.68和5.88个对数10菌落形成单位，大肠杆菌分别减少了4.67和5.01个对数10菌落形成单位。在使用百里酚处理的粪坑中未检测到弯曲杆菌，而未处理的粪坑中有63%的样本呈阳性。在处理过的粪坑中，尿素从第3天到第6天开始积累。对于1.5和3.0克/升的百里酚添加物，血清瓶中的总气体产量分别降低了65%和76%，甲烷分别降低了78%和93%。这些结果表明，百里酚可显著减少养猪场设施中的病原体、气味和温室气体排放。脲酶抑制剂在保存尿素方面产生了暂时的效果。
