Seasonal dynamics and possible development of total count of microorganisms in sheep’s milk

Anotace: The work is focused on the evaluation of seasonal dynamics of the total count of microorganisms in sheep’s milk and on the proposal of developing cut-off values for standard limitation for the next fifteen years for hygienic safety support. The total count of microorganisms was measured between years 2012–2014 (n = 4,746). The results were statistically evaluated using medians, geometric means, arithmetic means, means of log values (log10) and standard deviations for the cut-off limit determination. This model was patterned on the maximum of total count of microorganisms in the tested percentiles 95 (statistical conventional interval), 91, 90, 80 and 70% and on the result of medians (from 109 to 148 × 103 cfu/ml). These cut-off limits were divided into three classes (I to III) of standard quality, and the model of dynamics for their gradual implementation time was created as follows: initiation period (class I = ≤ 800; II = from 801 to 1,300; III = 1,301 to 4,000; non-standard = > 4,000 × 103 cfu/ml); second period (class I = ≤ 550; II = 551 to 800; III = 801 to 1,300; non-standard = > 1,300 × 103 cfu/ml); third period (standard class = ≤ 800 × 103 cfu/ml); fourth period (standard class = ≤ 550 × 103 cfu/ml); and the last legislative period (≤ 300 × 103 cfu/ml as a real hygienic limit). The limit for milk without heat treatment corresponds to the real value of the median 200 × 103 cfu/ml. The work is important for the procedures in the development of methods for the control and safety of raw food material.