Prevention of Calf Diarrhea with Vaccines Prepared from Egg Yolk: Immunoglobulin Y Technology

PROJECT NAME: Prevention of Calf Diarrhea with Vaccines Prepared from Egg Yolk: Immunoglobulin Y Technology
PROJECT MANAGER:  Assistant Prof. Dr. Sibel HASIRCIOĞLU
PROJECT SUBJECT:
It is known that calf diseases (especially calf diarrhea) and deaths cause significant economic losses. Diarrhea causes significant economic losses due to calf deaths, medication and treatment costs, increased care expenses, and low performance. It costs American beef and dairy cattle breeders $250 million annually. Although there are no exact numerical data on economic losses due to calf diarrhea in Turkey, the disease rates determined in studies reveal that economic losses are at a significant level.

In this project, it is aimed to develop a domestic product as an alternative to imported vaccines and immunoglobulins used in the prevention and protection of calf diarrhea, which causes significant economic losses in cattle breeding enterprises, to reduce vaccine costs with the developed product, to ensure its widespread use in our country, and ultimately to prevent calf deaths due to diarrhea. To create the prototype of the vaccine, first, the viral agents causing diarrhea (all viruses) and the antigenic determinant (peptide) stimulating the host's immune system will be immunized in hen's eggs, and immunoglobulins (Ig Y) formed against these viral agents will be extracted from egg yolks. After evaluating the specificity of the extracted Ig Y against Bovine Coronavirus (BCV) and Bovine rotavirus (BRV) with various tests, they will be used in challenge tests. After administering these antibodies to calves through milk to assess their protective effect, the calves that received the antibodies and developed immunity to the viruses will be challenged via oral and nasal routes using a known DKID50 dose of BCV/BRV. Thus, the protective effects of IgY against BCV/BRV infections in calves will be evaluated. The obtained egg yolk immunoglobulins will be compared with the immunoglobulins (IgG) found in bovine colostrum against these viral agents in terms of antibody titers and efficacy. Efficacy studies will be conducted on experimentally infected calves. Additionally, the product to be obtained will be compared with imported vaccines available in the market in terms of their capacity to form immunoglobulins. The produced immunoglobulins can also be used in the treatment of rotavirus and coronavirus infections in calves. The product (vaccine-antibody) to be produced will make a significant contribution to preventing economic losses due to calf diarrhea in our country. If the antibodies are successfully produced with this project, it is predicted that the product to be produced will be preferred in the world market due to Turkey's proximity to the Middle East and the sensitivity of the product. Companies familiar with our project topic have requested meetings with project managers for cooperation due to the market size and sensitivity of the topic.

Another benefit of the project is that it will prevent the loss of foreign currency caused by the purchase of vaccines and immunoglobulins used in the treatment of rotavirus and coronavirus diarrhea, which are obtained from abroad. It is possible to create an alternative to imported vaccines, which will be obtained at a lower cost, and to find more widespread use.

PROJECT OBJECTIVE:
The costs of treatment for diarrhea and labor cause significant economic losses. The most rational approach to this is to take preventive measures. In general, adverse environmental factors, weak immunity, and infectious agents in diarrhea reduce the efficiency of enterprises. The difficulty of treatment and the economic losses caused by neonatal calf diarrhea are the best indicators of the importance of preventive medicine.

There are two basic principles to protect newborn calves from diarrhea. These are;

Improving the defense system of calves, 
Reducing environmental factors that contribute to the development of infection in newborn calves.
 

Vaccines against E. coli, Rotaviruses and Corona viruses, which are involved in the etiology of calf diarrhea, are a very effective method in preventing diseases. Passive immunization of calves through colostrum by vaccinating pregnant cows is important in dairy enterprises. Especially in enterprises where vaccination is not practiced, immunoglobulin treatment to be given to calves within the first 12 hours after birth is very important when an outbreak related to the disease is observed.

Vaccines and diagnostic kits used in calf diarrhea are imported from abroad. This situation makes us dependent on foreign countries and causes foreign currency loss for our country. In the National Vision 2023 project Biotechnology and Gene Technologies report, it is stated as the 3rd goal to develop and use molecular diagnostics, animal drugs, and vaccines based on biotechnology and gene technologies.

If we briefly list the general objectives of this project:

Minimizing calf deaths due to diarrhea, developing a prototype domestic product that supports passive immunization in calves to increase efficiency in cattle breeding enterprises, and thus providing significant gains to the national economy.
Using the developed vaccine in the immunization of chickens and extracting Ig Y from egg yolk,
Using the produced antibodies in the prevention and treatment of calf diarrhea,
Obtaining and producing field strains of viral agents (Coronavirus, Rotavirus) causing diarrhea,
Encouraging university-private sector cooperation for domestic vaccine production and creating employment in this sector,
Preventing dependence on foreign countries with domestic vaccine production,
Preventing foreign currency loss caused by imported vaccines,
Producing more effective and cheaper vaccines compared to imported products,
Creating an alternative to imported vaccines due to their lower cost and providing widespread use.
Starting vaccine production studies with biotechnological methods in addition to conventional vaccine production techniques.
 

It is aimed to transform the prototype product we will develop into an industrial product with our private sector partner with whom we will cooperate.

Specific objectives of the project:

To provide antibodies transferred to protect against viral agents causing diarrhea in calves from an alternative source: Immunoglobulin Y (a single type of antibody found in egg yolk);

Preparation of inactivated vaccine (Source laying hens)
Antibody production (Protective and therapeutic effect of immunoglobulins obtained from egg yolk)
Offering the produced product to the Turkish and world market

REGIONAL CONTRIBUTION OF THE PROJECT:
Burdur province has great potential in dairy cattle breeding, breeding cattle raising, and milk production in Turkey. Especially in animal production, Burdur province ranks first in the region with a 45% share. 80% of the cattle in the region consist of cultural breed cattle. 95% of these cultural breed cattle are found in Burdur province. Epidemic diseases and health problems are frequently seen in enterprises. Especially calf diarrhea is one of the most important problems seen in cattle enterprises. It has been determined that the use of imported vaccines brought from abroad to protect against the disease is extremely low (an average of 7000 doses per year on a provincial basis). This situation makes it difficult to control the disease and increases economic losses due to calf deaths caused by diarrhea. To prevent these losses, which harm the national economy, it is necessary to start domestic vaccine/antibody production studies, which are predicted to be more effective and cheaper than imported vaccines, and to ensure the widespread use of calf diarrhea vaccines in our region as soon as possible. Thus, dependence on foreign countries and foreign currency loss will decrease. The calf diarrhea vaccine/antibodies to be prepared with local isolates we will develop within the scope of the project will be the first domestic product to be produced with this technique (immunoglobulin Y) in Turkey, and will increase the domestic/international recognition of the region.

SOCIAL CONTRIBUTION OF THE PROJECT:
The product to be obtained as a result of the realization of the project will be transformed into an industrial product in cooperation with a private sector organization that will support our project and want to take part as a producer company. This cooperation will strengthen the relations between our university and the private sector and make significant contributions to the development of the R&D infrastructure. The product to be obtained and developed will reduce economic losses due to calf deaths caused by diarrhea, making significant contributions to the livestock sector in our region and country. In addition, the antibodies to be produced will be offered to the domestic/international market as an alternative to the product produced in South Korea, which has the entire world market. Considering the cost of the product from South Korea per animal (25 dollars + 20% VAT), if the product to be developed within the scope of the project is commercialized, it will make great contributions to the national economy and the sector. In addition, it is foreseen to prepare antibodies to be used both for protection and treatment against other viral agents causing infections in chickens, cats, and dogs with this technology. Meetings have been held with people in this sector, and demands have been received. It is aimed to reduce dependence on foreign countries and prevent foreign currency loss in these matters as well.