Elmoslemany A M, Keefe G P, Dohoo I R, Dingwell R T
Department of Health Management, University of Prince Edward Island, Charlottetown, Canada.
J Dairy Sci. 2009 Sep;92(9):4239-48. doi: 10.3168/jds.2008-1751.
The objectives of this study were to evaluate microbiological quality of bulk tank milk in Prince Edward Island, to evaluate correlation among milk quality criteria, and to determine seasonal effects on milk quality parameters. Bulk tank raw milk quality was evaluated on all Prince Edward Island dairy herds (n = 235) over a 2-yr period (March 2005 to March 2007). Biweekly total aerobic (TAC), preliminary incubation (PIC), laboratory pasteurization, and coliform (CC) counts were determined using a Petrifilm culture system. Additionally, bulk tank somatic cell count was determined weekly. The mean and median values were 12.8 x 10(3) and 4.9 x 10(3) cfu/mL for TAC, 29.6 x 10(3) and 13 x 10(3) cfu/mL for PIC, 87 and 12 cfu/mL for laboratory pasteurization count, 21 and 5 cfu/mL for CC, and 218 x 10(3) and 187 x 10(3) cells/mL for somatic cell count. There was moderate correlation (0.57) between TAC and PIC. All other correlation coefficients were low (<0.26). Correlation results suggest that a single quality parameter could not predict others used in this study. Seasonal data indicate that 1) in general, all counts tended to be low in winter, 2) the CC and somatic cell count were always high in summer, and 3) TAC tended to be high during summer.
本研究的目的是评估爱德华王子岛散奶罐牛奶的微生物质量，评估牛奶质量标准之间的相关性，并确定季节对牛奶质量参数的影响。在2年期间（2005年3月至2007年3月），对爱德华王子岛所有奶牛场（n = 235）的散奶罐原料奶质量进行了评估。使用Petrifilm培养系统每两周测定一次总需氧菌（TAC）、初步培养菌（PIC）、实验室巴氏杀菌菌数和大肠菌群（CC）数。此外，每周测定一次散奶罐体细胞数。TAC的平均值和中位数分别为12.8×10³和4.9×10³ cfu/mL，PIC为29.6×10³和13×10³ cfu/mL，实验室巴氏杀菌菌数为87和12 cfu/mL，CC为21和5 cfu/mL，体细胞数为218×10³和187×10³ 个细胞/mL。TAC与PIC之间存在中等相关性（0.57）。所有其他相关系数均较低（<0.26）。相关结果表明，单个质量参数无法预测本研究中使用的其他参数。季节性数据表明：1）总体而言，所有菌数在冬季往往较低；2）CC和体细胞数在夏季始终较高；3）TAC在夏季往往较高。
