Research For Relevant Index Of Rumen Acidosis And LPS Concentration In Blood, Milk, And Faeces Of The Dairy Cows In Different Milking Condition

Studies on diet composition, blood parameters, milk routine index, fecal pH, and the concentration of lipopolysaccharide (LPS) in blood, milk, and feces with winter and spring high-producting dairy cows were conducted, to find out the sensitive index of ruminal acidosis. The comprehensive and systematic research was carried out on50-90days’lactation period Holstein cows from a Mengniu Dairy milk base, to provide some reference data and scientific evidence on subacute ruminal acidosis (SARA) diagnosis and treatment to high-producting dairy cow. Thus, not only increases the milk productivity, but also avoids ruminal acidosis, keeps rumen health, and improves economic returns. The results are as follows:1. In the survey on the diet composition, nutritional level, and feeding and management, the author found the forage to concentrate ratio is a reasonable ratio of40:60, among which silage feed accounts for the highest proportion of45%, following by lactation feed accounts for28%. Therefore, for high-producting dairy cows, it is significant to lay emphasis on quality of silage feed and reasonable mixed feeding of hay and alfalfa; a long period of corn silage over-fed may also leads to ruminal acidosis.2. Study the blood routine index and biochemical index relevant to SARA. Blood WBS, RBC, and HGB in high-producting dairy cow compared with medium-producting dairy cow, the difference was not obvious (P>0.05); however, the content of LD, GLU in high-producting dairy cow is higher than the content in medium-producting dairy cow, and the difference was significant (P<0.05); and the ionic index content of Cl in high-producting dairy cow is lower than the content in medium-producting dairy cow, the difference was significant (P<0.05); there’s no obvious difference in the other SARA related blood and biochemical indexes. Hence, we could use these blood indexes, which are sensitive to SARA, to make judgement on SARA in future studies. Providing more defined landmark to judging SARA.3. Study the productivity and health index of dairy cow. The milk fat percentage of high-producting dairy cow is commonly lower than the medium-producting dairy cow, but it’s not obvious; there is great difference in the number of somatic cells, some reach up to1.0×106/ml while some are only1×103/ml. Somatic cell number detection can be applied to prevent from the mastitis of dairy cows.4. Study fecal pH. The fecal pH of both high-producting dairy cow and medium-producting dairy cow is in the normal range, and there’s no obvious variation.5. After detecting the content of LPS in blood, milk, and feces, the author found that the content of LPS in blood is a quite low figure of0.08-1.20EU/ml. However, the blood LPS in high-producting dairy cow is higher than the content in medium-producting dairy cow. The content of LPS in milk has little change, but the milk samples from the cows which are at the risk of mastitis have a high content of LPS, even up to113EU/ml. The difference in feces LPS content between high-producting dairy cow and medium-producting dairy cow is not obvious, it’s in the normal range of7-12.78EU/ml.