The Bacteriostatic Action Of Cecropin-XJ To The Pathogenic In The Dairy Cow Mastitis And The Correlation With Ketosis

With the rapid development of the animal husbandry, esp. the dairy farming in Xinjiang dairy cattle diseases manifest the tendency of increase, consequently causing the great economic loss, among which the dairy cattle mastitis is one of the most harmful, costly diseases hard to be controlled, particularly, the rate of dairy cow subclinical mastitis is increasing year by year. Hence the research to seek novel techniques and methods to cure dairy cattle mastitis is highly expected to decrease the economic losses in dairy farming.The infection of subclinical mastitis was researched through epidemiology investigation in two cattle farms located in the north part of Xinjiang. The bacteria that caused subclinical mastitis were isolated, identified and categorised; The drug susceptibility to the pathogens in vitro was tested, and the bacteriostatic effect of Cecropin-XJ on pathogens was compared with that of traditional antibiotics; and the antibacterial spectrum of Cecropin-XJ was summarised; the main drug resistant and sensitive strains of causing subclinical mastitis were screended. The relationship between subclinical mastitis and ketosis of dairy cows was analysed.The samples from 50 cows were randomly collected and investigated,the ratio of subclinical mastitis was 54.0%. The 88 positive milk samples were identified and isolated, 18 strains of Streptococcus bovis(13.85%), 10 strains of Enterococcus faecalis(7.77%), 41 strains of Staphylococcus aureus(31.54%), 30 strains of Epidermidis Staphylococcus(23.08%), 10 strains of Micrococcus (7.77%), 6 strains of Corynebacterium bovis (4.61%), 6 strains of Bacillus cereus (4.61%) and 7 strains of Bacillus subtilis (5.38%) were isolated, respectively. The main pathogens causing subclinical mastitis were Streptococcus and Staphylococci.Cecropin-XJ had better bacteriostatic action on Gram-positive cocci and Gram-positive bacillus, and had no obvious bacteriostatic effect on Gram-negative bacillus. Among the 12 antibacterials, Ciprofloxacin and Enrofloxacin Base and Streptonivicin had better bacteriostasis effect on pathogenic bacterium in cow subclinical mastitis. The rate of ketosis in two dairy cattle was 5.9%(2/34), the rate of subclinical ketosis in first dairy farm was 11.76% and no subclinical ketosis found in second dairy farm. And the rate of E.coli mastitis in two dairy cattle was 1.53%, the low rate of E.coli mastitis may be related to the less ketosis occurred, thus it was speculated that the E.coli cow mastitis and ketosis had some certain correlation.