Cattle and sheep breeding technology: promoting the popularization of independent and rapid detection of infectious diseases in cattle and sheep

Arthritic encephalitis in goats and leukemia in cattle (cattle do not have CAE). Common infectious diseases in two cattle and sheep often cause economic losses to breeders, but dairy farmers and sheep farmers often do not know how to develop an independent and rapid detection technology for infectious diseases in cattle and sheep without plug-in and on-the-spot screening. this has become the goal of the joint efforts of Wang Peihua, a teacher and teacher in the Department of Animal Science and Technology of National Taiwan University.

Goat Arthritis Encephalitis (Caprine arthritis-encephalitis; CAE) is a chronic virus, which can cause chronic arthritis and mastitis in adult dairy or meat goats and leukoencephalomyelitis (leukoencephalomyelitis) in young goats. Most of goat arthritis encephalitis is transmitted vertically from female goats to their offspring through milk and colostrum, and some of them are transmitted horizontally through contact with each other.

"this virus affects the lactation and health of cattle and sheep animals, and the most direct cause is the invisible economic loss of animal husbandry." Professor Wang Pei-Hua, Department of Animal Science and Technology, National Taiwan University.

No treatment, no prevention of   threatening the health of cattle and sheep

Clinically, the symptoms of infected cattle and sheep vary greatly. In terms of arthritis, some cattle and sheep can develop severe claudication within a few months or one or two years, while others only have intermittent claudication or joint stiffness, which can be maintained for several years without deterioration. In addition, the breast cells of infected cows and ewes will be infiltrated by monocytes, resulting in hard breasts and no milk, which can be said to be one of the major diseases deeply troubling the animal husbandry industry.

As the interval between infection and symptoms of cattle and sheep is long, and even some of them do not have obvious clinical symptoms, it is not easy to detect, and there is no drug treatment or vaccination at present. If you want to prevent the infection of this disease, first of all, strictly isolate the postpartum sheep so that they do not eat the colostrum and milk of the infected ewes, cut off the route of transmission, and then gradually eliminate the infected sheep.

Subvert the traditional   to make the inspection technology faster and more accurate

In the past, the practice of preventing and testing goat arthritis encephalitis virus was mainly through the testing unit arranging personnel to the pasture to assist in drawing blood, taking it back to the laboratory for testing through the traditional enzyme combined with immunosorbent assay ELISA, and then providing the test report, waiting for a long process of personnel and report output (usually about a week), often unable to cooperate with the screening of young sheep that could not be tracked and carried out quickly.

To this end, Professor Wang Peihua led a research team led by Dr. Bai'an, and teachers and students joined hands in the research, hoping to come up with a simpler and portable alternative solution, just like quick flu screening, which will enable livestock husbandry to conduct rapid CAE testing of sheep directly on the spot in the future.

Gui Baian, an associate researcher who devoted himself to the research and also worked in the Hsinchu Branch of the Animal production Research Institute of the Council of Agriculture, said that from testing on goats to the detection of bovine leukemia this year, the experimental team used to detect CAE disease in sheep, mainly by using constant temperature nucleic acid amplification reaction to amplify the CAEV virus sequence, and by directly detecting the nucleotide sequence of CAEV virus. In order to confirm whether the goat carries CAE virus, under rigorous inspection and verification, this technique can be operated not only in the laboratory, but also directly and quickly in the livestock breeding site.

No need for expensive equipment, no plug in   to help reduce morbidity

With the efforts and continuous attempts of the research team, a set of goat blood test processing process was established, and the constant temperature nucleic acid amplification fluorescent primer of goat arthritis encephalitis virus and the design of detection probe were completed, so that more people can use this rapid detection kit for goat arthritis encephalitis virus to conduct rapid screening in animal husbandry sites.

During the operation, it is only necessary to collect the blood of the sheep first, and the obtained blood sample is extracted by simple DNA, then the sample DNA to be tested is subjected to a constant temperature increase of viral nucleic acid, the product is reacted with the probe placed on the test paper, and the color reaction is carried out with the phenomenon of fluid capillarity. finally, with the naked eye to determine the result, it is judged to be positive if there is a reaction line.

"the whole testing process can be completed within 1.5 hours, requiring no expensive equipment and almost no plug-in equipment, making it very suitable for preliminary screening and detection of animal diseases on site." Bo-an said with a smile.

This technology is not only easy to operate and easy to carry, but also can be operated directly in the laboratory or in the livestock breeding site, and can be diagnosed quickly. It can help the industry reduce the cattle and sheep with bad CAE virus year by year, help operators effectively judge and isolate the cattle and sheep that have not been attacked by the CAE virus, reduce the incidence of disease, and improve the economic loss of the goat industry. This technology for rapid on-site detection of sheep CAE has been patented by both Taiwan and the United States, and some manufacturers have expressed interest in technology transfer.

In addition to effectively helping cattle and sheep reduce the risk of disease, Professor Wang Peihua also hopes that this innovative technology can be widely applied to more animal husbandry-related disease prevention and screening procedures in the future, such as pig farming, which has a larger economy in Taiwan. to help more animal husbandry effectively reduce the risk of animal disease and create higher benefits and output values.

Related information

For more details on the R & D results of this project, please contact Mr. he of Agricultural Science and Technology Research Institute, a legal person of the consortium, Tel: 03-5185049, email: 1072086@mail.atri.org.tw