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

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

Effects of warm climatic periods on dairy cow behaviour and production in Scotland

Global warming is resulting in an overall increase in temperatures and in the frequency of extreme weather events. In dairy cattle, thresholds within the temperature-humidity index (THI) have been used to indicate points at which cattle will likely experience thermal stress (e.g., a THI threshold of 75 predicts thermal stress). However, high-yielding dairy cows that reside in temperate maritime climates may experience some degree of thermal discomfort below this threshold particularly when they are housed. Housing often results in high levels of humidity. The use of technology such as activity monitors and automated intake measures allow us to monitor responses. The aim of this study was to use technological solutions to assess behavioural changes in response to moderate increases in THI levels. Data from dairy cattle on an experimental unit were used. Data on daily lying times, lying bout frequency, step count, feed and water intake and milk yield were extracted for 8 pairs of warmer (THI<65) and 8 matching cooler (THI=43 to 60) periods. Warm and cool periods were no more than 5 weeks apart to ensure that the data from the same animals were being compared. The first three days from each period were analysed. Results showed that total daily lying time was shorter during warmer periods than cooler periods (P<0.05; means and SEMs (h): warm: 11.3±0.06h; cool: 11.8±0.06h). However, there was no effect of THI level on the no. of steps taken by cows (P>0.05 (counts) warm: 868±8 steps; cool: 878±9 steps). Water intake was higher during warm periods (P<0.05: (l) = warm: 81.2±0.7l; cool: 72.1±0.6), but there was no difference in feed intake (warm: 57.6±0.5kg; cool: 57.1±0.3kg). Milk yield was lower during warm periods than cool periods (P<0.05; (l): warm: 31.8±0.3; cool: 32.7±0.2). This suggests that behaviour and milk yield are mildly adversely affected even in conditions that are not traditionally regarded as exceeding cows’ ability to cope with thermal challenge

Effects of warm climatic periods on dairy cow behaviour and production in Scotland

Global warming is resulting in an overall increase in temperatures and in the frequency of extreme weather events. In dairy cattle, thresholds within the temperature-humidity index (THI) have been used to indicate points at which cattle will likely experience thermal stress (e.g., a THI threshold of 75 predicts thermal stress). However, high-yielding dairy cows that reside in temperate maritime climates may experience some degree of thermal discomfort below this threshold particularly when they are housed. Housing often results in high levels of humidity. The use of technology such as activity monitors and automated intake measures allow us to monitor responses. The aim of this study was to use technological solutions to assess behavioural changes in response to moderate increases in THI levels. Data from dairy cattle on an experimental unit were used. Data on daily lying times, lying bout frequency, step count, feed and water intake and milk yield were extracted for 8 pairs of warmer (THI<65) and 8 matching cooler (THI=43 to 60) periods. Warm and cool periods were no more than 5 weeks apart to ensure that the data from the same animals were being compared. The first three days from each period were analysed. Results showed that total daily lying time was shorter during warmer periods than cooler periods (P<0.05; means and SEMs (h): warm: 11.3±0.06h; cool: 11.8±0.06h). However, there was no effect of THI level on the no. of steps taken by cows (P>0.05 (counts) warm: 868±8 steps; cool: 878±9 steps). Water intake was higher during warm periods (P<0.05: (l) = warm: 81.2±0.7l; cool: 72.1±0.6), but there was no difference in feed intake (warm: 57.6±0.5kg; cool: 57.1±0.3kg). Milk yield was lower during warm periods than cool periods (P<0.05; (l): warm: 31.8±0.3; cool: 32.7±0.2). This suggests that behaviour and milk yield are mildly adversely affected even in conditions that are not traditionally regarded as exceeding cows’ ability to cope with thermal challenge