CIRCULAR 03 – 2008. La “CIRCULAR” es el mecanismo de comunicación oficial entre los titulares del Ministerio de Educación y los centros educativos del país, a fin de orientar el desarrollo de las actividades administrativas y pedagógicas, de conformidad al marco jurídico y a las normas vigentes. Según sea oportuno, el MINED emitirá una o varias circulares
Farm dataMASTITIS BASICS
Categories of Mastitis
Mastitis can be divided into different categories: clinical and subclinical
contagious and environmental
Clinical mastitis is when there are obvious changes to the udder tissue and / or the
milk. The milk may appear watery or full of clots, but will have an abnormal secretion. The udder may appear normal or may be hot and swollen. Depending on the severity of the infection, the cow may appear normal and behave accordingly or toxic mastitis can
Subclinical mastitis is when there are no visible changes to the milk. A milker will be
unable to identify subclinical mastitis unless he carries out tests, such as individual cow cell counts, or the California mastitis test. The cell count of quarters with subclinical mastitis will always be elevated above 200,000.
Contagious mastitis: the udder and teats are the reservoir of infection. Transmission
occurs during the milking process from udder preparation by contaminated hands,
udder cloths and liners. Infection establishes on the teat and teat canal. Bacteria may then penetrate the mammary gland. Most infections are subclinical and result in raised
cell counts. Control measures include post milking teat disinfection, dry cow therapy and culling. Contagious bacteria include Staphylococcus aureus, Streptococcus agalactiae and dysgalactiae. If your herd cell count is over 200,000 then this indicates that there is a problem with contagious mastitis.
Environmental mastitis: the environment is a reservoir of infection. Infection is
transmitted on to the teats between milkings or during udder preparation.
Organisms are forced up through the teat canal during the milking process or after milking if cows are allowed to lie down immediately following milking. Most infections cause clinical mastitis. Subclinical infections are less common. Environmental mastitis is controlled by provision of a clean environment, adequate accommodation for cows, milking through a correctly functioning machine, good udder preparation and pre- milking teat disinfection. Environmental organisms include E coli, Streptococcus uberis (straw bedding), Klebsiella (sawdust and shavings) and Bacillus. THE THREE STAGES TO REDUCE HERD CELL COUNTS:
Identify the high cell count cows and the bacteria responsible for the high cell count Take specific action for high cell count cows, this will depend on your herd SCC, milk price penalties and your youngstock availability
OPTIONS FOR HIGH CELL COUNT COWS
a) Cull ~ Cost is about $800 – 1,200
Permanent solution and irreversible Take into account full mastitis history (SCC and clinical mastitis records and bacteriology) and also consider other factors lameness, production, other problems Costly decision Is it really necessary?
b) Dry off the cow ~ $8 - 12
Retains cow in the herd
Allows treatment with dry cow therapy
You can check the cows cell count at next lactation and keep the calf
You may still need to cull cow, but allows this option later
You could dry off the cow early or stop milking her and put a calf with her to suck out
c) Antibiotic treatment during lactation ~ $125 +
Treatment success is poor, treat three cows and cure one Not recommended
d) UdderMint treatment during lactation ~ $5-8
Massage UdderMint into the udder for a five to seven day period This helps to improve circulation and the number of white blood cells and can help
e) Separate and milk last
Put your problem high cell count cows into a separate group and always milk last. You can always disinfect clusters between uses as an additional measure Shepton Veterinary Group, Allyn Saxon Drive, Shepton Mallet, BA4 5QH Not to be reproduced without written permission.
HIGH SCC MASTITIS ORGANISMS
Micro-abscesses within the udder tissue Treatment success during lactation varies between 10 and 25% with intramammary Treatment success decreases with increasing age of the animal Many strains of Staph aureus are resistant to Penicillin Response with dry cow therapy can be up to 70%, or as low as 5-10% in older and Can be difficult to isolate from bacteriology as there is intermittent shedding Cell counts highly variable in infected cows Treatment success for cows in lactation 4 and above are very poor indeed Infection associated with poor teat skin and / or teat injuries Very difficult to eliminate from a dairy herd Strep uberis
Bacteria is environmental in origin and associated with straw bedding and yards Outbreaks at pasture and also in dry period Subclinical infections are common and may be associated with poor mastitis identification and/or poor treatment regimes Response to treatment during lactation may be 60% or less Response to dry cow therapy is generally good This organism lives both in the udder and the environment Control measures will involve reducing the level of contagious and environmental Shepton Veterinary Group, Allyn Saxon Drive, Shepton Mallet, BA4 5QH Not to be reproduced without written permission. Strep dysgalactiae
Associated with poor teat condition due to milking machine problems and/or poor A less common cause of high cell counts
4. Strep agalactiae
Causes cell counts up to 20,000,000 with no changes to the milk Highly contagious, and up to 100,000,000 bugs per cc of milk Can cause fluctuating Bactoscan or TBC Responds very well to treatment during lactation Treatment success in old cows is very good Can be eradicated from a dairy herd using dry cow therapy, treatment during lactation
CAUSES OF CLINICAL MASTITIS
Coliforms and E coli
70% cases eliminated by the cow without signs of clinical mastitis Clinical cases often have a watery secretion Subclinical E coli is uncommon and is very unlikely to cause a high herd cell count Vaccine available to reduce severity and incidence Strep uberis
Shepton Veterinary Group, Allyn Saxon Drive, Shepton Mallet, BA4 5QH Not to be reproduced without written permission.
Title A Handbook of Statistical Analyses Using R (2nd Edition)Author Brian S. Everitt and Torsten HothornMaintainer Torsten Hothorn <Torsten.Hothorn@R-project.org>Description Functions, data sets, analyses and examples from the second edition of the book`A Handbook of Statistical Analyses Using R' (Brian S. Everitt and TorstenHothorn, Chapman & Hall/CRC, 2008). The first chapterof th