Mastitis control

Hovi M and Roderick S (2000), Mastitis and mastitis control strategies in organic milk , Cattle Practice, 8, 259-264. 

Renau J K, (1986), Effective use of dairy herd improvement somatic cell counts in mastitis control , Journal of Dairy Science, 69, 1708-1720. 

In actuality, this has been far from the case. Antibiotic therapy, although an important component of mastitis control strategy, is much less effective than could be desired. Farm advisors uniformly stress the principle that treatment must not be relied upon to redress the disease promoting effects of bad animal husbandry, unsanitary milking practices and defective milking machinery. 

In the use of dry cow therapy (DCT) for mastitis control, we have a model situation where antibiotics are introduced into the milk compartment at high concentration and undergo slow dissipation for up to 3 weeks (21,22,23) In mass dry cow therapy (DCT), all cows in a herd are infused in all mammary quarters with an antibiotic... 

In addition to DCT, recommended mastitis control in the U.S. includes the dipping of the cow s teats in a germicide immediately after each milking. This strategy commonly results in a lowered prevalence of IMI in a dairy herd, but also a shift in pathogen... 

IDF Group of Experts on Mastitis. "Principles of Mastitis Control" International Dairy Federation Dpc. 76 Brussels, 1973 p. 67. 

IDF Group A.2 (Bovine Mastitis) "International Progress in Mastitis Control 1983" International Dairy Federation Bull. 

Sischo W.M., L.E. Hieder, G.Y. Miller, and D.A. Moore (1993). Prevalence of contagious pathogens of borne mastitis and use of mastitis control practices. Journal of the American Veterinary Medical Association 202 595-500. 

Hovi, M. 2003. Approaches to Mastitis Control in Well-Established Organic Dairy Herds in England and Wales. PhD thesis. Veterinary Epidemiology and Economics Research Unit. University of Reading, Reading. 

Separation and identification of 14 different antibiotic residues in milk (which are used for mastitis control) by means of TLC were described by Bossuyt et al. The limits of detection ranged from 0.1 to 3 jag/ml except for neomycin which had a minimum detectable level of 15 jag/ml. 

Hayton, A.J. and Bradley, AJ. (2004), The control of mastitis on organic units , in British Mastitis Conference 2004, Stoneleigh, Oct 13th. 

Livestock projects have focused on UK dairy, beef, sheep and pig production systems and have targeted improvements in feeding regimes and preventative health management systems (e.g. for the control of mastitis and endo-parasites and gastrointestinal diseases). 

Mastitis is a complex of infections, caused by a variety of microorganisms with inherent differences in sensitivity to antimicrobial agents. Furthermore, sensitivity vitro does not assure efficacy vivo. Additionally, pathogens have the capacity to gain resistance to antibiotics, particularly under conditions of heavy and poorly controlled use. 

Nowadays, one stated objective of much of the more imaginative mastitis research is the reduction in our dependence on antibiotics and other exogenous chemicals to control bovine mastitis. Achievement of this goal is nowhere in sight. And so, we are left dependent upon antimicrobial therapy, despite its many limitations, as a major element in control strategy for bovine mastitis. 

Ziv, G. In Progress in Control of Bovine Mastitis IDF Seminar, Kiel" Kieler Milchwirtschaftl. Forschungsber. 1986 (In Press). 

The presumed significance of this control mechanism is to enable mammals to terminate the synthesis of lactose when necessary, i.e. to regulate and control osmotic pressure when there is an influx of NaCl, e.g. during mastitis or in late lactation (lactose and NaCl are major determinants of the osmotic pressure of milk, which is isotonic with blood, the osmotic pressure of which is essentially constant). The ability to control osmotic pressure is sufficiently important to justify an elaborate control mechanism and the wastage of the enzyme modifier. 

Novobiocin (Fig. 3.9) is a narrow-spectrum antibiotic with antibacterial activity against many gram-positive pathogens. It is frequently used, in combination with penicillin, for treatment of bovine mastitis by intramammary infusion of 200 mg/ quarter in two quarters, and to control fowl cholera and staphylococcal infections in chickens and turkeys at a level of 200-350 g/ton in feed. 

Nonsteroidal anti-inflammatory drugs are widely used in veterinary practice and are, therefore, of growing interest to the residue control of animal-derived food. Veterinarians are seeing an increased use of anti-inflammatory agents, administered with or without antibiotics, for treatment of mastitis because of the increase in efficiency of these agents over antibiotics alone. 

Novobiocin (NBC) is used for the treatment of mastitis in dairy cattle. In 1982, the tolerance level was set at 100 pg/kg in milk from dairy animals. An HPLC assay was developed for NBC determination in bovine milk at a tolerance level (214). The milk sample was diluted with buffer, the proteins were precipitated with MeOH, and the solution was filtered. The filtrate was injected directly into an HPLC system with UV detection. The interlaboratory study was realized for the analysis of two concentrations of NBC in fortified control milk samples. Recoveries of NBC reported by the participating laboratories were 89-99% at 50 pg/kg, 93-101% at 100 pg/kg, and 89-100% at 2 mg/kg. The CVs ranged from 2.0% to 6.2%. All laboratories described the procedure as rapid and simple, allowing the preparation of 20 samples in less than 2 hours. 

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