## 5 Discussion  
As the literature review indicates, the DTs trend that has recently emerged is still in the early stages of development in a number of application domains related to livestock production systems, but due to the increased research interest in this field, they have the potential to transform the industry. By providing farmers with a real-time view of their animals' health, well-being, and productivity, digital twins can assist farmers in making better decisions about animal care, feed management, and disease prevention. Some of the potential benefits of incorporating the DTs technology in livestock production systems have been identified as follows:  
* **Improved animal health and welfare:** As indicated in [52; 60; 61; 62; 63; 64; 65; 66], DTs can be used to monitor animals' vital signs, feeding behavior, and activity levels. They can also analyze data from multiple sources, such as animal health records, as well as weather and environmental data, to identify patterns and trends that may indicate an increased risk of disease outbreak so that farmers can take preventive action;
* **Increased productivity:** As indicated in [52; 60; 61; 62; 63; 64; 65; 66], DTs can be used to optimize feed relations and feeding schedules and to identify and address environmental factors [67; 68] that may be impacting animal productivity;
* **Reduced costs:** DTs can help farmers to reduce costs by identifying and eliminating inefficiencies in their operations. For example, digital twins can be used to optimize energy use in livestock barns [67; 68] and reduce the amount of food waste;  
Figure 5: Distribution of the works included in the literature review according to (**a**) the year of publication, (**b**) the type of the contribution, (**c**) the presentation of the use case results, and (**d**) the animal species of interest. * **Improving food safety and quality:** DTs can be used to track the movement of animals and food products through the supply chain [69], ensuring that they are safe and of high quality. * **Design and manage more sustainable farming operations:** Digital twins can be used to simulate the impact of different farming practices on the environment. This can help farmers to design and manage more sustainable farming operations that reduce their impact on water quality, greenhouse gas emissions, and other environmental factors. An interesting finding indicated by the literature review was the fact that most of the DTs applications for livestock production systems are still at the concept and prototype stages. This might be due to the agricultural sector being a slow adopter of technology, partly because the advanced technologies in the context of Agriculture 5.0 are growing in complexity. Based on this, what must be highlighted is the need for the interoperability and standardization of the DTs models in the food industry. This challenge is also applicable to livestock production systems, as different farms may incorporate diverse sensors, data formats, and management systems. Standardization efforts are required to ensure seamless integration and data exchange between different digital twin systems. Another open issue is the ethical implications of digital livestock farming, as discussed in [70]. Responsible technological innovation is crucial to ensure that the benefits of the DTs technology in livestock production are realized while avoiding any unintended consequences that might negatively impact animal welfare and the resilience of the livestock industry. Ethical considerations, such as data privacy, animal welfare, and the social implications of automation, need to be carefully addressed in the development and implementation of digital twin systems. Further open issues and challenges that must be addressed to realize the full potential of the DTs technology in livestock production systems are identified as follows:  
* **Data Management and Integration:** DTs require vast amounts of data from various sources, including sensors, farm equipment, and animal monitoring systems.