Prevention of mastitis (inflammation of the udder which can result in abnormal milk) in dairy goats begins long before a producer of milk even considers it to be a problem. Feeding caprine kids milk, without the benefit of pasteurization, from does who are infected can spread mastitis to doelings months before they are mature enough to breed and develop a functioning mammary system of their own. Allowing kids to nurse dams, or to steal milk from their mother’s affected herd mates, presents vectors for transmission that a herdsman may be unaware of in sub-clinical cases-long before the diseased udder becomes acute and is presented for treatment. Spread of infectious bacteria from dam to daughter and laterally by kids nursing multiple milkers is a high consideration in determination of heard health practices. In addition to the spread of mastitis causing bacteria by these methods, examination of milking practices in the parlor causes us at Nickel’s Dairy Goats, Clark, Missouri, to be very careful in the procedures and products we use to safeguard the udders of does in our herd.
The teat is designed to be wonderfully effective in prevention of the entry into the udder of bacteria from the environment. It has a small opening in the end, which is supple enough to allow the passage of milk out while closing small enough to prevent dirt from coming in. The skin of the teat remains elastic and smooth under most conditions, presenting a surface that is resistant to bacteria. The waxy plug at the end, and waxy canal lining is somewhat germicidal, so after an hour or so from milking it has reformed an impenetrable barrier to most pathogens. That this is true, and that it creates a system that works well, is evident in the number of mammaries that are milked and the number of days that we milk them in comparison with the few cases of mastitis needing treatment over time.
Preserving the elasticity and smoothness of the teat skin is considered when man-made products are used to prevent chapping and sunburn. Bag Balm is useful and easily applied when needed after milking in times of adverse weather. Cracked and flaking skin on teats and udder harbors bacteria and dirt which may be introduced during the milking process. Prewashing when milking lowers the bacteria gathered from the environment. We like to use a germicidal wash in warm water applied with a single use paper towel. Nolvasan is gentle on the skin and effective against bacterial agents as well. The thought of the udder as a large reservoir which is kept at a perfect temperature to grow bacteria, helps us see that it is essential to prevent contamination.
The waxy surface on teat ends and in the teat canal must be undisturbed if it is to do its job. Nolvasan is an effective cleaning agent that does not disturb the continuity of this barrier. Over the years we have had people tell us that they make their own prewash usually incorporating bleach or iodine as the germicidal. While I have no doubt that these chemical agents are germicidal, I also know that they are caustic to skin and the wax of the teat plug. In the vigorous manner in which bleach and iodine destroy cells they are likely to destroy the doe’s natural defenses against environmental bacteria as well. The end result is often a case of mastitis instead of the prevention one is hoping for.
The careful dairy goat manager should draw milk only from clean udders. Likewise, only sanitized udders should be milked. Milk only with clean, sanitized hands. Using single-use paper towels for washing and drying udders prior to milking, minimizes the lateral spread of bacteria in the milk room. The milker not only dips the paper towel into the udder wash to prepare each doe but dips his or her hands as well. Human skin is porous and a good vector of disease if not properly disinfected. Each doe should be dried completely before she is milked by machine or by hand. Milking only until the flow of milk stops is also an important part of udder health.
When the udder is empty, a final massage by hand helps to prevent growth of any bacteria introduced. Over-milking can be a factor in destroying the waxy layer of the teat canal or teat end and create stress on the skin which might allow bacteria to enter. Even when letting a machine do the work the milker must be aware of when the udder is empty. Paying strict attention to the amount of vacuum actually delivered to the inflation is an essential part of machine maintenance for mastitis prevention.
Following milking, an application of uncontaminated teat sealant is suggested. The process of using a teat spray is superior to using a dip cup. It has been found in University study that some teat dips are actually able to grow bacteria and that the dip cup is capable of spreading these bacteria from one doe to the next. The product chosen to spray must have the ability to coat the teat orifice and encourage the teat skin to remain smooth and supple. At Nickel’s Dairy Goats, we like to use a spray that contains glycerin for this purpose. Glycerin can seal the teat orifice temporarily until the wax can be recreated and the natural seal formed.
We make sure we clean all equipment between each milking, using chemicals and soaps specifically designed for the cleaning of dairy equipment. Milk stone build up can provide a place for bacteria to grow. The dairy industry in general based on cow production, has benefited the goat keeper who has the ability to share the research and knowledge accumulated over many years. It is far more economical to make use of this information than it is to risk experimentation and perhaps develop mastitis in even one doe.
Cattle research shows that the younger members of the milking string have come in contact with less bacteria than the older individuals. Therefore, it is beneficial to milk in the same order, youngest to oldest based on number of lactations, every milking. The does should be milked in the same stanchion day after day. We visited a cow dairy in which ten rounds of cows came into a 12-stall parlor. Stanchion number four on the right had four cows with uneven mammaries, the result of bacteria picked up during milking and spread to the cows who used that milker. The infection of only four cows of over a hundred herd mates was due to the fact that the cows did not share equipment within the herd. The uneven cows were then marked and milked last, from that day until culture showed that the mastitis had been cured and bacteria was no longer being shed.
It is important to keep the environment for dairy animals dry and clean. The natural inclination of the goat to remain dry and avoid dirty surroundings is a great aid in achieving this goal. At shows, bed pens deep and always choose pens on the outside rows of the barn. Avoid high traffic areas to prevent does from walking where others may have spilled milk. At home keep lounging areas clean and dry. The use of lime screenings as a base is a good idea. Here in Missouri the quarry sometimes calls this "chat" as well. Lime from this source is not anti-bacterial, in that it will not kill bacteria as Barn Lime or caustic lime can. However lime screenings as a base will not harm skin and is effective in that it does not present a medium where bacteria will grow. Keeping areas around feeders and waterers free of build up or mud is a good step in prevention of bacteria as well.
Natural sunlight disinfects without adding chemicals to the environment. Choosing to pen at shows and at home where the sun can shine on the ground or floor is a very good strategy. Ultraviolet light does kill bacteria and the drying effect of the sun prevents moisture conducive to bacterial growth as well.
When the lactation is over, we always dry treat all does. To dry treat helps to reduce the production of milk. It is done with the hope that the addition of antibiotics into the mammary will be effective against the growth of bacteria during a time when milk is allowed to sit in the udder. Dry treating always twice, a week apart, has proven to be effective for us. However in cases where the doe was difficult to dry off a third treatment might be needed.
In choosing replacement does for any dairy goat herd, take care not to buy into trouble. Personally assess the udders of any prospects for lumps, unevenness, or skin abnormalities.
Milk all new additions last and separately, until convinced they are indeed as healthy as the home team. In purchasing dry stock and kids we are sure to ask how they were raised and what the source of milk and colostrum was. When assessing the risks of exposure to harmful bacteria, keep in mind the possibility that pathogens in the milk fed to kids can live in the forming mammary tissue of that kid and come to life as a full blown case of mastitis when she freshens or even before.
Over the years we have managed a dairy goat herd our goal has been high production as well as longevity in the show ring. While a case of mastitis may not always be life threatening, it would signal the end of usefulness to our breeding program. To ensure the continuity of the genetics in our herd, prevention is not the best choice-it is the only choice, economically as well as for the health of our does.