AW0521 - Determining potential impacts of Precision Breeding on Animal Welfare FINAL REPORT

1. Introduction of the Genetic Technology (Precision Breeding) Act in 2023 paved the way for the use of precision breeding technologies (e.g., genome editing) in livestock in England. However, while recognising that there may be major benefits inferred by increased disease resistance and other traits, concern has been raised about the possible wider effects of the use of the technology on animal welfare. This project aimed to understand the current situation with respect to level of use and development of precision-bred animals and to consider what welfare indicators should be used to assess welfare in general, and for specific types of edits.2. A mapping and scoping phase indicated that few companies have initiated data collection or development of precision-bred animals that might be present in/be imported into England. The pig and fish sectors were the only sectors to indicate that development has commenced. Mapping suggested that the first animals are bred in research/university environments where animals are kept under the auspices of ASPA. Apart from the fish and pig sectors, the chicken, cattle and sheep sectors also expressed some interest in developing precision-bred animals in the near future (I.e.., in the next 5 years). For the equine sector, only a few stakeholders expressed some interest in using precison-breeding technologies to improve specific traits such as disease resistance or resilience to environmental stress, but there is no intention to use PB in equine breeding practice in the immediate future. 3. Expert consultation and a review of the literature indicated that the Five Domains Model was the most appropriate of current animal welfare models to use to build indicator lists. This model includes nutritional state, health, environmental responses, behavioural interactions and mental state. While most animal welfare assessment protocols assess the effects of housing and management on welfare outcomes for animals, it is biological functioning that is the most important aspect to assess in the precision breeding context.4. Welfare assessment indicator lists were drawn up for the three main species that are in the most advanced stage of use of precision breeding. These were pigs, poultry and salmon. Indicator lists were constructed that drew on industry handbooks, current animal welfare assessment schemes and relevant literature. These indicator lists aimed to facilitate a holistic assessment of overall animal welfare to detect changes in functioning across the Five Domains. The indicator lists contain welfare indicators that assess the animal across its EVID4 Evidence Project Final Report (Rev. 06/11) Page 3 of 21lifetime, compared with a control group of the same breed and same age and sex ratio. Three levels of assessment were considered: basic, enhanced and enhanced plus. The basic level of assessment does not fully cover the five domains in all three species, so SRUC strongly recommends that the enhanced level of assessment is adopted.5. In addition to the overall welfare assessment indicator lists, three cases studies were considered to determine how and when to add additional welfare indicators to these lists. The aim was to cover welfare-related traits and production-relate traits. To this end, the specific traits considered were PRRS virus, avian influenza and the hypothetical case of myostatin in fish. As animals carrying these edits are not available for inspection, a risk assessment was limited to ‘consequence characterisation’: ie., identifying possible consequences of gene editing on welfare. These case studies showed that a wider consideration of the edit and the pathways involved needs to be investigated. In addition to the overall holistic assessment using the Basic, Enhanced or Enhanced Plus levels, assessment using additional welfare indicators that are relevant to the specific edit may be required.6. Three webinars/workshops were held to present results to stakeholders. In addition, a meeting was held with equine stakeholders and numerous discussions were held with individual stakeholders to gain information on aspects of precision breeding

Genetic and context-specific effects on individual inhibitory control performance in the guppy (Poecilia reticulata)

Among-individual variation in cognitive traits, widely assumed to have evolved under adaptive processes, is increasingly being demonstrated across animal taxa. As variation among individuals is required for natural selection, characterizing individual differences and their heritability is important to understand how cognitive traits evolve. Here, we use a quantitative genetic study of wild-type guppies repeatedly exposed to a ‘detour task’ to test for genetic variance in the cognitive trait of inhibitory control. We also test for genotype-by-environment interactions (GxE) by testing related fish under alternative experimental treatments (transparent vs. semi-transparent barrier in the detour-task). We find among-individual variation in detour task performance, consistent with differences in inhibitory control. However, analysis of GxE reveals that heritable factors only contribute to performance variation in one treatment. This suggests that the adaptive evolutionary potential of inhibitory control (and/or other latent variables contributing to task performance) may be highly sensitive to environmental conditions. The presence of GxE also implies that the plastic response of detour task performance to treatment environment is genetically variable. Our results are consistent with a scenario where variation in individual inhibitory control stems from complex interactions between heritable and plastic components

AW0521 - Determining potential impacts of Precision Breeding on Animal Welfare FINAL REPORT

1. Introduction of the Genetic Technology (Precision Breeding) Act in 2023 paved the way for the use of precision breeding technologies (e.g., genome editing) in livestock in England. However, while recognising that there may be major benefits inferred by increased disease resistance and other traits, concern has been raised about the possible wider effects of the use of the technology on animal welfare. This project aimed to understand the current situation with respect to level of use and development of precision-bred animals and to consider what welfare indicators should be used to assess welfare in general, and for specific types of edits.2. A mapping and scoping phase indicated that few companies have initiated data collection or development of precision-bred animals that might be present in/be imported into England. The pig and fish sectors were the only sectors to indicate that development has commenced. Mapping suggested that the first animals are bred in research/university environments where animals are kept under the auspices of ASPA. Apart from the fish and pig sectors, the chicken, cattle and sheep sectors also expressed some interest in developing precision-bred animals in the near future (I.e.., in the next 5 years). For the equine sector, only a few stakeholders expressed some interest in using precison-breeding technologies to improve specific traits such as disease resistance or resilience to environmental stress, but there is no intention to use PB in equine breeding practice in the immediate future. 3. Expert consultation and a review of the literature indicated that the Five Domains Model was the most appropriate of current animal welfare models to use to build indicator lists. This model includes nutritional state, health, environmental responses, behavioural interactions and mental state. While most animal welfare assessment protocols assess the effects of housing and management on welfare outcomes for animals, it is biological functioning that is the most important aspect to assess in the precision breeding context.4. Welfare assessment indicator lists were drawn up for the three main species that are in the most advanced stage of use of precision breeding. These were pigs, poultry and salmon. Indicator lists were constructed that drew on industry handbooks, current animal welfare assessment schemes and relevant literature. These indicator lists aimed to facilitate a holistic assessment of overall animal welfare to detect changes in functioning across the Five Domains. The indicator lists contain welfare indicators that assess the animal across its EVID4 Evidence Project Final Report (Rev. 06/11) Page 3 of 21lifetime, compared with a control group of the same breed and same age and sex ratio. Three levels of assessment were considered: basic, enhanced and enhanced plus. The basic level of assessment does not fully cover the five domains in all three species, so SRUC strongly recommends that the enhanced level of assessment is adopted.5. In addition to the overall welfare assessment indicator lists, three cases studies were considered to determine how and when to add additional welfare indicators to these lists. The aim was to cover welfare-related traits and production-relate traits. To this end, the specific traits considered were PRRS virus, avian influenza and the hypothetical case of myostatin in fish. As animals carrying these edits are not available for inspection, a risk assessment was limited to ‘consequence characterisation’: ie., identifying possible consequences of gene editing on welfare. These case studies showed that a wider consideration of the edit and the pathways involved needs to be investigated. In addition to the overall holistic assessment using the Basic, Enhanced or Enhanced Plus levels, assessment using additional welfare indicators that are relevant to the specific edit may be required.6. Three webinars/workshops were held to present results to stakeholders. In addition, a meeting was held with equine stakeholders and numerous discussions were held with individual stakeholders to gain information on aspects of precision breeding