Somatic Cell Count And Bacteria Of Milk Samples From Dairy Cow And Their Influence On Main DHI Indicators

Dairy cow mastitis is one of the high incidence rate, difficult to control, and seriously harmful diseases, which restricting the healthy development of dairy cow industry, especially the subclinical mastitis is more potential hazards to dairy industry. To explore the correlations among SCC in milk samples, other main DHI indicators of milk samples and pathogen infection characteristics. DHI determination was carried out on a dairy farm in Tuoketuo County in near Hohhot, and the different pathogens from subclinical mastitis were isolated and identified, the correlations among the Somatic Cell Count in milk samples and other main indicators of DHI and types of pathogen infection were initially analyzed.Firstly, the4763measured DHI data from the dairy farm following17consecutive months’ detection were statistically analyzed, and found that the milk yield, percentage of milk fat and milk lactose were decreased while the percentage of milk protein was gradually increased (P<0.01) with the increasing of milk sample’s somatic cell count. The tendency of somatic cell count was increased following the increase of Parity and Lactation days.Secondly,79measured DHI milk samples at different ranges were selected to carry out etiological research. The detection rate of bacteria was84.81%(67/79), dominant bacteria group were streptococcus and Gram-negative bacillus, with detection rates of33.93%(38/112) and55.36%(62/112) respectively. Single and mixed infections of two kinds of bacteria were the main infection patterns. Bacterial infection patterns had significant effect on milk yield (P<0.05), while the effects on milk fat, milk protein, and milk lactose were not significant (P>0.05).At last, according to the survey of somatic cell count in the determination of DHI, the incidence of subclinical mastitis from the dairy farm was analyzed. Positive rate of subclinical mastitis was39.95%. The tendency of somatic cell count was increased following the increase of Parity and Lactation days.The clinical characteristic of subclinical mastitis in dairy cow was systemically analyzed, and the correlations among the main indicators of DHI detection and subclinical mastitis in dairy cow, and pathogen infectious characteristics were found out in this study. The results would lay a good foundation for the establishment of subclinical mastitis warning system in dairy cow based on DHI.