The Milk Producer - April 2011 - (Page 32)

APPLIEDSCIENCE By Kim MacDonald and Greg Keefe Reliable alternative New system to culture mastitis bacteria on-farm lets you know quickly whether you really need antibiotics to treat an infected cow aureus—are something like insects. E. coli, often known for causing acute mastitis, can make a cow sick or toxic. More often, it causes mild to moderate cases that show up simply as abnormal milk without making the cow sick. E. coli belongs to a group of bacteria known as Gram negative or Coliform bacteria along with Klebsiella and Enterobacter. Like some insect pests, Gram negative bacteria have a protective outer shell. It prevents most antibiotics from penetrating a bacterium and killing it. Luckily, this protective armour is no match for the cow’s immune system. In most cases, the immune system can act right away to attack and kill the bacteria. As a result, cows with mild to moderate cases of Coliform mastitis typically cure quickly without treatment. If they don’t get better quickly, consult your veterinarian for a targeted antibiotic regime. Gram positive bacteria are like the mosquitoes—sometimes hard to catch, but when they are exposed, easily squished. Staph. aureus, known for its contagious and persistent nature, belongs to the Gram positive group. Other bacteria in this group are the many different kinds of Streptococci, other Staphs and other minor pathogens. They don’t have an outer protective layer like Coliforms, making it easy for antibiotics to penetrate the cell and destroy it. Some of these types of infections persist due to their ability to hide inside the udder’s cells where neither antibiotics nor the cow’s immune system can find them. If you don’t treat Gram positive infections soon after they are detected, they could persist, reducing the cow’s milk production or serving as infection reservoirs for other cows. Using Petrifilms from 3M Canada offers a payback of $30 in savings for every $10 invested in the technology, according to a new study. I nstead of reaching for antibiotics when you identify mastitis in your dairy cows, you can now reach for an on-farm test that can tell you whether treatment is even needed. The overall result can significantly reduce the estimated $180 cost of every mastitis case you detect in your herd. Mastitis, the most costly of all dairy cow diseases, also results in the most frequent need for antibiotic use. Lost profits can become substantial, largely because you have to dump abnormal-looking and treated milk down the drain. Many producers automatically reach for antibiotic treatments when they detect a mastitis infection. They 32 | April 2011 | MilkPRODUCER hope to cure the cow quickly and prevent reduced long-term milk production. However, the different antibiotics sitting on your shelf are designed to kill specific types of bacteria. If the mastitis case you are trying to treat is caused by an organism other than those bacteria, the antibiotic does nothing to clear up that infection. To understand differences among mastitis-causing bacteria, think about flying insect pests during summer. A quick swat can easily kill some, while exterminating others takes a little more effort because they have hard protective shells. Two common types of mastitiscausing bacteria—E. coli and Staph.

Table of Contents for the Digital Edition of The Milk Producer - April 2011

The Milk Producer - April 2011
Contents
Editor's Notes
DFO Chair's Message
Dairy Update
Industry Roundup
DFC Promotion
Cover Story
Producer Profile
Research
Applied Science
Ruminations
Calf Rearing
Markets
New 'N' Noted
Back Forty

The Milk Producer - April 2011