CHancwtw Farming, Saturday, June 3, 1995 GEORGE F.W. HAENLEIN Extension Dairy Specialist University of Delaware NEWARK, Del.—Mastitis is gone. How we wish this was so! As a boy milking cows by hand, I learned about mastitis. People often said then that milking machines caused mastitis. Yet even though we milked by hand, our cows had mastitis, too. When I went to a school for professional milkers, I learned that mastitits is the reaction to many different causes, including bacteria, yeasts, injuries, heat stress and hormonal effects. I also lean ed how to operate milking machines properly so that they do not contribute to mastitis. This was still in the times before antibiotics, when in addi tion to sulfa drugs, frequent milking-out was usually the prim ary treatment. Even in today’s mastitis control, frequent milking out is still very effective. Then antibiotics—the panacea for most anything—arrived on the scene, and vaccinations were used effectively against mastitis. It soon became apparent that identifying a specific cause from the multiple of mastitis-causing possibilities was required. Cultur ing of samples was necessary in order to supply specific treatments rather than a “shotgun” approach. Today, we are much more inter ested in prevention than in treat ments, not only because of the expense, but because of the level of resignation and frustration with the many causes of mastitis. This situation is compounded by the variety of only partially effective treatments and treat ments that are effective for only a limited time. This is still the case although we have the most sophisticated milking machines ever, with diffe- A Alfa Laval Agri™ JUNE DAIRY MONTH SPECIAL • Synthetic Rubber Mat has Thousands of “Air Cells” to Cushion Cow’s Hocks, Knees • Mat Surface will not Absorb Manure, Urine, Etc • Use A Minimum of Bedding Material. • 5 Year Warranty in Tie-Stall Barns •10 Year Warranty in Free-Stall Bams rential pulsation speeds, quatro milk hoses, automatic take-offs, different size teat lines and auto mated disinfection between cows. We also have ever-new and varied antibiotics. Still mastitis costs the U.S. dairy farmer approximately $2OO/cow/year on average, and it remains die number-one disease on the dairy farm. We have learned the hard way that for every one case of clinical mastitis with visibly abnormal milk, we have at least four other so-called subclinical cases that do not have visibly abnormal milk, but that exhibit beginning inflammations. These inflammations, which are being fought by the cow’s defense system, can break out into clinical cases at any time and have already reduced normal levels of milk production. The new powerful tool giving us all this information is the mea surement of “somatic cell counts” in milk, an indication of the state of the cow’s defense activities. Not all somatic cell counts are the result of inflammation. Older cows typically have more than young cows. Milk at the beginning and end of lactation is normally high in somatic cell counts, and so is foremilk and after strippings, in particular. Also, cows in estrus have high er somatic cell counts in their milk, and summer heat stress will also elevate somatic cell count levels. Nonetheless, monthly testing of every cow in a herd has become a powerful tool for reducing masti tis incidence. It has even led to reducing some typical pathogenic bacteria as causes of mastitis because they arc encountered less frequently. The recent issue of the newslet ter of the National Mastitis Coun- immerman rF^sons Since 1931 DAIRY EQUIPMENT DIVISION 1044 Main Street, P.O. Box 337, Blue Ball, PA 17506 Phone: 800-758-8030 or 717-354-8030 Recent Findings About 5% OFF. Available From: cil (February-March 1995) gi/es some disconcerting information in this direction. Typically found mastitis-causing bacteria are Streptococcus agalactiae and Sta phylococcus aureus. Now it is reported that in “well managed” herds other so-called coagulase-negative staphylococ cus species are the most prevalent causes of mastitis. They used to be considered “minor” pathogens and were ignored in control programs. Now it is fournd that these bacteria cause “mild” mastitis in 5-15 per cent of udder quarters and raise somatic cell counts significantly. They occur more frequently in first-lactation cows than in older cows, and more in the beginning of lactation. They are neither con tagious nor “environmental,” but are called “skin opportunists.” Fortunately, these pathogens are controllable with teat dip prog rams as was fourd in studies of prepartum heifers in very cold weather when teat dipping was interrupted during the dry period. Different teat-dip preparations are now available to make preven tion more effective. lodine or chlorine have been the logical choices, but other chemical prepa rations are also useful. A new compound, sodium dicholoroisocyanurate, provides hypocholorcus acid. Tested in Louisiana studies on 140 cows, Staphylococcus aureus was reduced by 74 percent and Streptococcus agalactiae by 65 percent without irritating teat ends or milker’s hands. But what about the stubbornly remaining 26 or 35 percent? This is where we get the next generation of resistance to our treatments. Other preventive mea sures Hhve to be found. For some time the idea of disin fecting the teat end and actually HER COMFORT THE SOFT. NEW EVA IW MAT PLUS FREE FASTENERS! (Cash Only) Mastitis sealing it against pathogenic inva sions has been pursued by researchers, only to find that the ideal sealant material has not yet been discovered. lowa research with sealant anti biotic wax significantly prevented new infections, and even cured existing infections, during the dry period if the sealant stayed in place for several weeks. Industry still needs to meet this challenge with new inventions. Meanwhile, let’s get back to what can be done during the dry period. ALUMINUM GRAIN BODIES & ALUMINUM REPAIRS by _> •'////// *s<v W> These ultra-light bodies are designed for strength through engineering, not strength with bulk. For example, a 16' grain body with tailgate and 48" sides weighs only 1490 lbs, complete. We'll build you any length or any side height up to 60". Also available: • Double swinging hay • Diamond flooring hauling tailgate • Pull out panel tailgates • Barn door type tailgate • Any size grain chute • Slide out cattle chutes HEWEY WELDING Box 2312, RD4 Lebanon, PA 17042 (717)867-5222 There is news from New Zealand —that highly successful dairy land—about their new prog ram called SAMM, under which they treat all dry cows if the herd bulk tank test is above 400,000 somatic cell counts. Below that level, only selective dry-cow treatment is recommended. I wish that National Mastitis Council Newsletter could reach each dairy farmer regularly. For a small membership fee, much can be learned, especially in the area of dairy farm profits.
Significant historical Pennsylvania newspapers