Credit: Creative Age

Next generation livestock technologies: chewable vaccines, super larvae, and rapid fertility tests

New technologies could boost the livestock sector in low-and middle-income countries.

There are enormous opportunities to improve animal health and productivity in low-and middle-income countries, where hundreds of millions of people depend on livestock for income and nutrition. In addition to good management and husbandry practices, new technologies may help unlock or overcome specific barriers to improving health and productivity.

A new array of technologies supported by SEBI-Livestock offers this potential. The technologies, which include innovative vaccine delivery platforms, disease surveillance tools, and high-tech cattle fertility testing, will be presented at this week’s virtual International Symposium on Sustainable Animal Production and Health, hosted by the International Atomic Energy Agency (IAEA) and the Food and Agriculture Organization of the United Nations (FAO).

Innovations in vaccine delivery

In low-and middle-income countries, under-resourced animal health systems and logistical challenges are holding back the livestock sector. Novel solutions are needed, including ways to store, administer and deploy live-saving animal vaccines.

A common bovine parasite may offer a new mechanism to deliver vaccines. Javier Lopez Vidal and colleagues from the University of Edinburgh’s School of Biological Sciences and SEBI-Livestock suggest that a parasite that is already found in more than 80% of cattle worldwide could be mobilised to inoculate cattle with potentially any pathogen. The Trypanosoma theileri parasite causes no ill effects in healthy animals and seems able to induce low-level prolonged immunity against disease. To date, the researchers have used the parasite to inoculate against Babesia divergens, a parasitic blood infection in cattle, and have also used it to deliver an antigen that causes the deadly East coast fever. Early evidence suggests that his approach could be used to tackle several diseases in one shot, making it well-suited to low and middle-income countries.

Other vaccine technologies bypass the need for injections. Jolieke G. van Oosterwijk from US Biologic and SEBI-Livestock Director Prof Andy Peters have tested the use of a chewable vaccine that could be used to combat a range of zoonotic diseases. Oral vaccines are easier to store, transport and administer, making them well-suited for low-and middle-income countries. This technology offers a ‘plug-and-play’ platform that can be adjusted to deliver a range of oral vaccines against different diseases in different species. Early tests have shown encouraging results against Lyme disease in mice, reduced parasites in poultry, and have produced antibodies in goats against the deadly plague peste des petits ruminants (PPR).

Disease-fighting parasite larvae may also be added to the arsenal of new vaccine technologies. Radhika Mendis and colleagues at the University of Peradeniya in Sri Lanka, the IAEA and SEBI-Livestock are developing a new generation of irradiated larval vaccines as a cheap and sustainable means of disease control. Irradiated larvae were first developed for use against cattle lungworm by researchers in Glasgow in the 1950s, but the technology has never been successfully adapted to work with other parasites until now. The researchers used radiation to render a live organism inactive – in this case Haemonchus contortus, a common blood sucking parasite of goats. The irradiated larvae are harmless, and do not cause disease, but can result in immunity when ingested by an animal. Many countries already have centralised irradiation facilities set up for other purposes, such as food safety. “This study proves a concept which could be scaled up, especially if it can make use of existing irradiation facilities” suggests SEBI Director Prof Andy Peters, who took part in the research.

New frontiers for disease surveillance in Nigeria

In addition to vaccines, disease surveillance is critical tool to support animal health. In Nigeria, a newly-established mycoplasma diagnostics laboratory has kick-started routine testing for harmful diseases including Contagious Bovine Pleuropneumonia (CBPP), one of the three great cattle plagues. New findings offer the first laboratory-confirmed estimates for prevalence of CBPP (between 7 and 14%), as well as the first-ever lab-confirmed estimates for contagious caprine pleuropneumonia (CCPP). A serological survey of over 300 goats kept extensively gave an average seroprevalence of 4.4%. The lab, which was supported by SEBI-Livestock, and hosted by the University of Ilorin, has increased Nigeria’s capacity to diagnose and monitor important diseases. The lab will also be used for new collaborations in animal and human mycoplasmology, and for training and teaching purposes.

Cow-side rapid fertility testing in Kenya

P4 Rapid tests show whether a cow is in heat (oestrus)
P4 Rapid tests show whether a cow is in heat (oestrus). Photo: Creative Age

For her PhD research, veterinarian Bridgit Muasa evaluated a rapid cow-side fertility testing tool in different production systems in Kenya. The P4 Rapid tool (now known as P4Gold) was developed in the UK and uses lateral flow technology to evaluate whether an animal is in heat (oestrus). These tests are important for successful conception and reproduction, but they had never been tested before in tropical smallholder conditions. Dr. Muasa found that this test is able to successfully detect oestrus and can also detect non-pregnancy after insemination in these settings. Her next step will be to evaluate the tool with farmers in Nigeria and India.

Development opportunities

These studies and prototypes were carried out under the first phase of the Supporting Evidence Based Interventions (SEBI) Programme, based at the University of Edinburgh’s Royal (Dick) School of Veterinary Studies.

“These early stage technologies show good potential for improving animal health and optimising productivity in low-and middle-income countries,” said Nick Juleff, senior program officer for the Bill & Melinda Gates Foundation, which funded the initial set of studies under the SEBI-Livestock programme.

“These technologies are ripe for further investment,” explained Prof Andy Peters, who is seeking partnerships to continue and scale up development. “We want to keep working to ensure that small-scale livestock keepers can benefit from these innovations in the near future,” he said.

More information

Details about these technologies and author contact information are now available.

Vanessa Meadu, Communications and Knowledge Exchange Specialist, SEBI-Livestock
Page created: 29 Jun 2021 Page last reviewed: 26 Jan 2023