## 3 Results and Discussion  
### Study of Pathogenic Microfora Growth Process in Milk Hoses  
Milk was transported from the farm to the laboratory, where it was tested for total microbial count and _Staphylococcus_ count within 2.5 h.  
Figure 3a,b show a raw milk sample from a healthy animal and a milk sample from a cow treated for mastitis. Figure 1c shows a Gram staphylococcal smear microscopy. According to the research results, it was found that the total microbial count in raw milk was within the specified limits (1.2 \(\times\) 10\({}^{4}\) CFU/mL), but the number of staphylococci was exceeded by 1.4 \(\times\) 10\({}^{3}\) CFU/mL. This indicates that in the case of low-quality rinsing of milking hoses, bacterial growth occurs on residual milk and in hard-to-reach places of the milking system, which reduces the quality of the output product. When examining milk obtained from cows treated for mastitis (with the high somatic cell count (SCC)) with antibiotics (their list is not specified by farm workers), the total microbial count is higher than in raw milk and is 9.2 \(\times\) 10\({}^{4}\), but the number of staphylococci is multiple times lower--5.0 \(\times\) 10\({}^{1}\) CFU/mL. The presence of pathogenic microboracteria even in the milk of healthy animals confirms the need for sanitary treatment of milking equipment. Contamination of milk with pathogenic microorganisms could be caused both by the violation of hygienic treatment of udders as described in [6] and the possible adhesion of pathogen colonies on stainless steel, rubber and plastic as described in [16]. Details of the results are presented in Table 1. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Type of Sample** & **Determined Value** & **Result** & **Normal Value** & **Measurement Standard** \\ \hline Raw & Total microbial count, CFU/mL & 1.2 \(\times\) 10\({}^{4}\) & Not more than & GOST 32901-2014 \\ cow’s & Staphylococci, Total microbial & 1.4 \(\times\) 10\({}^{3}\) & Not allowed & GOST 30347-2016 \\ milk & count, CFU/mL & 9.2 \(\times\) 10\({}^{4}\) & Not more than & GOST 32901-2014 \\ Milk with & Total microbial count, CFU/mL & 9.2 \(\times\) 10\({}^{4}\) & Not more than & GOST 32901-2014 \\ high SCC & Staphylococci, Total microbial & 5.0 \(\times\) 10\({}^{1}\) & Not allowed & GOST 30347-2016 \\  & count, CFU/mL & 10.0 \(\times\) 10\({}^{1}\) & Not allowed & GOST 30347-2016 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Results of a study of pathogenic microflora growth in milk hoses. Figure 3: Staphylococcus aureus growth on selective medium: (**a**) sample on raw milk; (**b**) sample on milk from a cow treated for mastitis; (**c**) Gram smear microscopy on sample b.  
Simulation Modeling of Milk Flow in of the Milk Hoses and Measuring Chamber of the Light-Scattering Sensor  
The developed model of the milking system is shown in Figure 4.  
According to the simulation results, it was found that after 120 s of flushing, the temperature in the teat cups reached 79.35 \({}^{\circ}\)C, the temperature in the collector was 79.01 \({}^{\circ}\)C, the temperature before the light-scattering sensor was 78.73 \({}^{\circ}\)C and after the light-scattering sensor was 78.41 \({}^{\circ}\)C. The lowest liquid temperature recorded in the end section of the milk pipe was 20.06 \({}^{\circ}\)C. Since it is known that _S. aureus_ and _S. epidermidis_ die at a temperature of 70 \({}^{\circ}\)C in 10 min, the pathogenic microflora is definitely destroyed in all hoses of the milking system. Consequently, quality rinsing ensures staphylococci disinfection throughout the entire line from the teat cups to the milk line due to a flow temperature of 79.35 \({}^{\circ}\)C to 76.28 \({}^{\circ}\)C.  
Figure 5 presents the pattern of milk flow in the light-scattering sensor. The interpretation of Lines 1, 2, 3 is described in Section 2.2. Figure 4: Results of modeling the temperature of the rinsing mixture at the milking system.