Title: Breeding TB resistant cattle for the beef industry
Funder: Department for Environment, Food and Rural Affairs

Abstract: Description Bovine tuberculosis (bTB) is a zoonotic disease endemic in the UK and other countries, and presents a significant challenge to the UK cattle sector. Defra lists bTB as one of the four most important livestock diseases globally, incurring annual costs of about £175 million in the UK.The key deliverable of the proposed project will be genetic evaluations of beef cattle for bTB resistance. Breeders can use these results to select animals that will breed enhanced resistance to the disease in the following generations. Finishing herds will benefit from rearing animals having a very low probability of becoming infected. The deliverables will contribute to improving the health status of producing animals and herds, which enhances the consumer perception and attitude towards animal products.Results will also offer new insights into the genetic mechanism controlling beef cattle resistance to bTB, thereby contributing to scientific efforts aiming at dissecting the genetic architecture of the trait, leading to its final eradication.The overall aim of the proposed project is co-funding and leverage with the UK Cattle Industry to support new research to develop a genetic scoring system for the breeding of TB-resistant beef cattle. The specific objectives of the project that will help us achieve the overall aim are to:1. Develop a national database of bTB surveillance and pedigree records of beef cattle suitable for the genetic evaluation.2. Define bTB resistance phenotypes based on the health status of individual animals and calculate relevant descriptive statistics.3. Estimate genetic parameters for bTB resistance in beef cattle.4. Estimate breeding values (EBV) of individual animals for bTB resistance.5. Estimate the correlation of bTB EBVs with genetic evaluations for other traits in the breeding goal.6. Develop genomic predictions and evaluations for bTB resistance.7. Integrate results into a system for routine genetic evaluations.Previous Defra research has identified hereditary traits associated with TB-resistant cattle, and this has been further developed by the UK Dairy industry and incorporated into their breeding programme. This programme specifically targets breeds of dairy cattle and the beef industry is now keen to replicate the process. If successful this breeding programme could be incorporated across the UK and at international levels to develop TB-resistant cattle across the globe. Objective The specific objectives of the project that will help achieve the overall aim are to:1. Develop a national database for the genetic evaluation based on bTB surveillance and pedigree records of beef cattle, combining data from the APHA, the British Cattle Movement Service, individual breed societies, BASCO and the Edinburgh Genetic Evaluation Services.2. Define bTB resistance phenotypes for individual animals based on their health status; the latter will be defined from skin test results and post-mortem examination records.3. Estimate genetic parameters for bTB resistance in beef cattle using the phenotypes from step (2) after building and assessing relevant statistical models of analysis.4. Estimate breeding values (EBV) of individual animals for bTB resistance based on phenotypes from step (2) and genetic parameters from step (3).5. Estimate the correlation of bTB EBVs with genetic evaluations for other traits in the breeding goal to assess the impact of selecting for enhanced resistance on beef traits.6. Develop genomic predictions and evaluations for bTB resistance based on results from step (4) and a validation process.7. Integrate all results into a system for routine genetic evaluations ensuring full automation of the process and including safeguards for the quality of the outcome.Co-funding and leverage with the UK Cattle Industry to support new research to develop a genetic scoring system for the breeding of TB-resistant beef cattle. The 2 year research study will be undertaken by Scottish Rural University and College (SRUC) and equally funded (1:1) by Defra (£120k in year 1) and AHDB Beef (£120k in year 2), to support action taken by the cattle industry to reduce and eradicate bovine TB. Defra TB Programme and the Devolved Administrations are keen to support the beef industry in developing their programme to breed more TB-resistant cattle and recognise this time-limited opportunity to co-fund and leverage the research. If successful this breeding programme could be incorporated across the UK and at international levels to develop TB-resistant cattle across the globe.


Research activity codes: 2.2 FACTORS RELATING TO PHYSICAL ENVIRONMENT
Health categories: INFECTION