**5. Role of preclinical studies in safeguarding milk production and its properties**

Dairy products are an important part of the human diet for more than 8000 years and are one of the official dietary recommendations for many countries in the world [89]. Daily intake of milk and dairy products has been identified as an important part of a balanced diet [90], because milk serves as a whole range nutrient consumed by humans (**Figure 1**).

### **5.1 Preclinical tests for milk analysis**

## *5.1.1 X-ray fluorescence analysis*

Recently, this technology has become widespread. The XRF method makes it possible to carry out analyses without sample separation. It helps in the quantification of minerals, trace elements, and volatiles which are difficult to determine in other analytical methods [92]. X-ray fluorescence spectroscopy (XRF) is an extension of the milk component analysis domain. Various configurations of XRF spectrometers are commercially available and are designed to provide economical and rapid analysis of milk. XRF is an excellent tool for daily analysis of the milk in dairy industries and research institutes. The results of the analysis can be used to assess nutritional value and evaluate the milk and dairy products [93].

### *5.1.2 Raman spectroscopy-based analysis*

In this method, different types of milk quantity samples are used to classify several classes using reduction techniques in combination with random forest classifiers (RF). Quantitative and experimental analyses are based on locally collected milk samples from various species, including cow, buffalo, goat, and human milk samples. This classification is based on changes in the intensity of Raman peaks in a milk sample. The analysis of principal components (PCA) was used as a reduction technology in combination with RF to emphasize changes in Raman spectra that can differentiate milk samples from different species. The proposed method shows a sufficient opportunity to distinguish samples of cow milk from different species due to an average accuracy of about 94%, a specificity of about 97%, and a sensitivity of about 93% [94].

### *5.1.3 Somatic cell count (SCC) test*

Mastitis is mostly caused by bacterial pathogens invading the mammary gland. Typical pathogens, namely, *Escherichia coli*, a gram-negative bacterium usually associated with acute, clinical mastitis, and *Staphylococcus aureus*, a gram-positive bacterium often associated with chronic mastitis, can cause differential activation of the immune system [95]. Somatic cell count (SCC) is used as key indicator in mastitis screening programs typically applied in the frame of dairy herd improvement (DHI) testing programs [96]. Direct microscopic somatic cell count (DMSCC) is one of the approved methods by FDA (Foss, Hillerød, Denmark). Flow cytometry and Ekomilk Scan® are also used to check the somatic cell count (**Figures 2** and **3**) [97].

### *5.1.4 California mastitis test (CMT)*

The technique, invented in 1957 by Schalm and Noorlander, is used to detect intramammary infection caused by a major mastitis pathogen in early lactation cows

**Figure 1.**  *Gross milk production of different milk-producing species [21].* 

**Figure 2.**  *General composition of milk from different dairy animals [91].* 

**Figure 3.**  *Comparison of the somatic cell score (SCS) using different methods.* 

*Reconnoitering Milk Constituents of Different Species, Probing and Soliciting Factors… DOI: http://dx.doi.org/10.5772/intechopen.82852* 

**Figure 4.**  *Sensitivity and specificity within first week of calving through CMT [100].* 

[98]. They indicated that the degree of precipitation and gel formed by a mixture of the reagent and milk reflected the somatic cell count of the milk (**Figure 4**) [99].

### *5.1.5 Proteomics techniques for mastitis control*

Early detection of mastitis and related pathogenic factors improves animal health status through timely and effective treatment. With the development of related technologies of proteomics, such as 2D-gel electrophoresis (2D-GE) and mass spectrometry (MS), several new proteins associated with mastitis have been identified [101]. The evolution of proteomic profiles of pathogens can help to identify the existing information on enzymes, toxins, and metabolites. However, the successful use of these new biomarkers for detection devices remains a challenge [102].

## **6. Conclusions**

 Fat is higher in bovine specie as compared to others and it is the main source of HDL and cholesterol enhancement in blood. Protein of ovine is higher than other milk-producing animals. Protein from camel milk (lactoferrin, immunoglobulin, lysozyme) is very useful in diabetes, cancer, and autoimmune diseases. High selenium found in caprine milk fortifies immune system, while higher contents of zinc, iron, and manganese in camel milk speak of greater oxygen carrying capacity by helping ion transport exchange. Higher riboflavin, folic acid, B6, and vitamin A in buffalo milk are blessings to enhance immunity and decrease of megaloblastic anemia. Antidiabetic, antioxidant, high vitamin C and niacin, low vitamin A and E are more defined properties that refer as wound healer agent. Heat treatment protocols result in denaturation of lysine, iodine, folate, and vitamins B12, B6, B1, and C, inactivation of enzymes, and change in flavor. Skim milk production often favors increase in biofilm resistance and spread of presence of spore-forming bacteria. Adding to this are the diseases or disease conditions exacerbating compromised soundness of milk. Preclinical studies are effective approaches to avoid deterioration of milk. X-ray fluorescence analysis is effective in evaluation of nutritive values of milk and milk products without decomposition of milk. Raman spectroscopybased analysis successfully differentiate between milk of different species with higher sensitivity and specificity. Somatic cell count and California mastitis tests are fruitful in estimation of intramammary infection. Latest techniques like proteomic protocols are explorable approaches as an effective preclinical study of milk.
