Comparison of some somatic cell counting methods in sheep, goat and cow milk

In this study, it is aimed to evaluate some common somatic cell counting methods in milk samples of different species comparatively. For this purpose, milk samples collected from 41 head Simental cows, 41 head Akkaraman sheep and 41 head Maltese goat; Somatic cell counts (SCC) were determined by using DeLaval Cell Counter (DCC) device, methylene blue staining and methyl green pyronine staining methods. The average SCC values in cow milk samples obtained by DCC, methylene blue and methyl green pyronine staining method are; 164.098, 1.120.355 and 102.398 cells/ml respectively, and the difference between the methods is statistically significant (p<0.05). SCC values in sheep milk samples are; 494.463, 3.094.314 and 1.029.143 cells/ml (p<0.05) respectively, and SCC in goat milk samples are; 985.732, 5.456.353 and 2.038.496 cells/ml respectively and the difference between the methods is statistically significant (p<0.05). The difference between SCC in cow, sheep and goat milk samples obtained by DCC device is statistically significant (p<0,05). Likewise, the difference between the species was also found to be statistically significant (p<0,05) when the methylene blue staining and the methyl green pyronin staining methods were used. The average DNA numbers obtained by the methyl green pyronine staining method in cow, sheep and goat milk samples were 102.398 1.029.143 and 2.038.496 DNA/ml, and RNA numbers were 116.166, 493.920 and 438.849 RNA/ml, respectively. When mast cell granules (MCG) numbers are examined; the average values determined in cow, sheep and goat milk were found as 1.004.189, 1.440.457 and 681.506 MCG/ml, respectively. When comparing DNA and MCG mean values for cow, sheep and goats, the difference between the species is statistically significant (p<0.05). However, although the difference between the average RNA numbers was insignificant between sheep and goat milk samples, it was found to be higher than cow milk samples (p<0.05). When the correlations between DNA, RNA and MCG numbers were examined, positive correlation (r=0.533) between RNA and MCG values of sheep milk was found to be statistically significant (p<0.01). When all the data obtained from the study were evaluated it was concluded that, the methyl green pyronine staining method can be recommended in sheep and goat for the detection of SCC in milk, and the methylene blue staining method can be recommended for cow milk. However considering the generally low SCC values obtained by DCC, it is thought that more new studies are needed to be done.