期刊
JOURNAL OF DAIRY SCIENCE
卷 84, 期 1, 页码 292-298出版社
AMER DAIRY SCIENCE ASSOC
DOI: 10.3168/jds.S0022-0302(01)74479-7
关键词
total bacterial count; bulk tank milk; Petrifilm aerobic count
The bacterial composition of bulk tank milk from 13 farms was examined over a 2-wk period to characterize sudden elevations in the total bacterial count referred to as spikes. Bulk tank milk samples collected at each pick-up were analyzed for standard plate count, Petrifilm aerobic count, somatic cell count, Gram-negative organisms, and streptococci. Twenty standard plate count spikes were observed: 12 associated with streptococci, 4 associated with Gram-negative organisms, 2 associated with streptococci and Gram-negative organisms, and 2 that were not definitively characterized. Spikes ranged from 14,000 to 600,000 cfu/ml. Streptococcus uberis was isolated as the predominant organism from 11 spikes, and Escherichia coli was isolated from 4 spikes. Statistical analysis of total bacterial counts indicated a high correlation (r = 0.94) between standard plate counts and Petrifilm aerobic count. Regression analysis of standard plate counts and Petrifilm aerobic counts yielded the equation log(10) (standard plate count) = 0.73 + 0.85log(10) (Petrifilm aerobic count), indicating that the correlation, although strong, is not one to one. In a related pilot study, triplicate bulk tank milk samples were collected and analyzed for total bacterial count and presumptive streptococcus, Gram-negative, and staphylococcus counts. Two-way ANOVA of these triplicate data indicated a lack of significant variation among the triplicate samples, suggesting that one sample can reliably gauge the microbial status of the entire bulk tank.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据