The Relationship Between Somatic Cells And Milk Production And The Pathogen Bacterial Research Caused High Somatic Cell Counts

High SCC is the main indications of bovine subclinical mastitis. In many pastures, a test which can indirect detective SCC is usually used to assess udder health. High SCC is mainly caused by the blood leukocytes get into to the breast tissue to phagocytic invasive pathogens. A large number of inflammatory cells will cause injury. If with high SCC status for a long time, cows may loss part of function of the breast tissue, and this means a loss of part of the milk production for ever. Therefore, to ensure the dairy cows with a low SCC status (<150,000/mL) is one of the ways to keep production. In addition, the low SCC milk can be sold to higher prices. Pastures need to known the objective of the SCC control plan, and they need to known what to do can bring economic benefits. Therefore they also need to understand the types of pathogens caused SCC increased so that the can take the correct prevention and control measures.DHI records were obtained from a dairy farm in Shanghai during2009to2011. While the SMT positive milk samples are taken for subclinical mastitis pathogens isolation and identification every month. The relationship between the daily milk yield and somatic cell will be studied used SCS and SCC. The harm of the different types of the subclinical mastitis pathogen will be evaluated from the SCC increase extent caused by different pathogens.The results show that the SCS can be a very good response with a lot of the somatic cell rising, the daily milk yield declining. The view from the whole group, the average somatic cell linear score and milk yield showed a quadratic correlation (P<0.05), fitted curve is Y=0.0498x2-1.0987x+36.984, R2=0.9096. Average linear score for each increase of1, while the production declines0.56kg/d. The study also shows that, when the somatic cell counts is less than50,000/mL, the daily milk yield has a peak value, more than50,000/mL it begins to decline. The vast SCC of the majority of samples is less than150,000/mL.When SCC increase from100,000to2million, the production fluctuates in a small range. The daily milk yield does not appear a large decline until somatic cell counts in more than2million. Studies have shown that the effect of high SCC on daily production begins form the start of the peak lactation and ends at the late lactation, the difference was not significant (P>0.05).The results of the bacteria isolated and identified showed that the main pathogens of subclinical mastitis are CNS, Staphylococcus aureus and Streptococcus. The CNS has the maximum rate of42%. Usually, Streptococcus agalactiae caused the highest SCC rising; followed by CNS; at last is Staphylococcus aureus. Staphylococcus aureus infection in this pasture just mostly be able to self-healing, individual cases will be converted to persistent infection and lead to phase-out.The results show that the SCC should be less than150,000/mL with health breast in this pasture and milk production will be loss when SCS is more than150,000/mL.In this dairy farm, if SCC level can be reduced to less than150,000/mL, in the case of other measures in the same pasture, the milk production will increase about1kg/d. The pasture need to take measures to reduce the rate of infection of the CNS, Staphylococcus aureus and non-Streptococcus lactis to achieve this goal.