Herd health programs and working with commercial goat dairies (Proceedings)


Herd health programs and working with commercial goat dairies (Proceedings)

Nov 01, 2009

Herd health programs developed by veterinarians in cooperation with producers strive to maximize health and production while decreasing the incidence of a variety of economically important diseases. Biosecurity programs reflect the interaction between the animal and its ability to resist disease, a variety of infectious agents and the environment. Producers need to be educated that changes in management practices can be very cost effective in reducing the incidence of preventable diseases and decreasing the need for pharmaceuticals. Insidious diseases such as caprine arthritis-encephalitis, mycoplasma, caseous lymphadenitis and Johne's disease do not respond to treatment regimens and are best prevented through adoption of specific pathogen prevention programs. Lastly, cleanliness and good nutrition cannot be over-stressed to prevent disease and increase productivity.

Commercial goat dairymen agree that one of the greatest challenges they face is finding a food animal veterinarian that has a working knowledge of goats and their diseases. One producer suggested dairymen purchase copies of Smith and Sherman's Goat Medicine and share it with interested veterinarians. Another producer commented that there is a general lack of information about management strategies, and another commented that the information is available but is not readily accessible. The dairy goat industry is expanding quickly in some areas and new producers often have minimal background or education in livestock prior to buying goats and starting a dairy. There is obviously a demand for veterinarians willing to work with goats.

Good herd health programs assume that certain general management practices are performed. Vaccination of young stock and pregnant does against Clostridium perfringens types C & D and tetanus decreases the incidence of these two common diseases. Providing newborns with one ounce of colostrum per pound of body weight three times in the first 24 hours of life provides antibodies against pathogens in their specific environment. Providing feed off the ground and keeping water sources clean help prevent parasitism. Separating newborns from the adult population at birth prevents transfer of microbes and parasites from infected adults to immunologically naïve young. Addition of coccidiostats to milk, milk replacer, water or creep feeds markedly decreases the incidence of coccidiosis.

No vaccine or drug can replace keeping the environment clean. Removing dirty bedding and opening a closed barn prevent parasitism, pneumonia and paratuberculosis. The incidence of scours in kids is markedly reduced when their pens and feeding devices are cleaned frequently. In certain environments, the use of raised floors or dry lots can decrease parasitism. Encouraging exercise by housing animals in large paddocks or pastures reduces the incidence of ketosis, hypocalcemia and obesity. Adequate amounts of nutritious feeds appropriate for the type and number of animals present prevents nutrient deficiencies and allows livestock to maximize productivity. Well-fed goats with adequate trace minerals appropriate to the local feeds are more likely to mount an effective immune response when challenged.

Eradication and control programs prevent major disease problems such as caprine arthritis-encephalitis, mycoplasma, caseous lymphadenitis, and Johne's disease. Many producers utilize test and cull programs for CAE and Johne's disease. Producers remove kids from the adult population at birth, feed heat-treated colostrum and pasteurized milk, and permanently separate the clean herd to decrease the incidence of these four diseases. The new clean herd and the adult population should be separated by at least a ten foot alley, and the two populations should not share shelter, feed or water devices. Closed herds do not purchase animals from other herds, attend shows, board outside animals, share transportation, or allow any contact of their animals with other livestock. Encouraging commercial producers to raise all female kids on a specific pathogen prevention program increases the sale value of extra replacements and can provide an extra source of income for the herd.

While many producers see the benefit of developing herds free of these insidious diseases, not all are convinced that the effort involved in developing a clean herd will provide an increased economic return. Does with chronic wasting diseases do not live as long and do not produce as much milk on a yearly basis as does under the same management without chronic disease. Animals infected with these chronic diseases are permanently infected and serve as a source of contagion to other livestock. Many progressive commercial herds enjoy greater productivity and sales of healthy stock after adopting a prevention program and eliminating these chronic diseases.

In order to prevent introduction of new diseases into the commercial herd, goats should be tested for brucellosis, caprine arthritis-encephalitis, mycoplasma, caseous lymphadenitis, paratuberculosis, parasites, mastitis and tuberculosis prior to purchase. Vaccination status and nutritional history should be determined. If possible, young goats that have not been previously bred should be purchased to decrease exposure to pathogens transmitted through breeding. Milk from lactating does should be cultured prior to purchase to prevent introduction of new mastitis pathogens into the herd. As necessary, herd additions should be treated for internal and external parasites upon arrival. When transporting incoming stock, a clean vehicle should be used and it should be cleaned again before being used for another purpose.