# May the Extensive Farming System of Small Ruminants Be Smart?
## 1 Introduction
Therefore, adding PLF systems would inevitably increase production costs and add another layer of technological complexity to farm management, causing delays in implementing PLF systems in small ruminants compared to those in dairy cows [15]. The unit prices of sensors for small ruminants are higher than those developed for large animals due to miniaturisation and higher production costs associated with lower production numbers. Sheep and goat farms are often located in mountainous and marginal areas, with poor technological infrastructure and unreliable electricity, telephone, and internet services. They are associated with advanced age in farmers, contributing to poor local initiatives and delays in PLF implementation [16]. Nevertheless, developing and applying small ruminant grazing technologies are particularly interesting for economic and environmental sustainability. PLF system results and artificial intelligence (AI) are fundamental for farmers for animal control [19]. Indeed, interest has grown in the past five years, and several PLF applications have been developed. Efforts have focused primarily on systems designed for managing grazing animals. These have included virtual fences, drones [26, 27], collar-mounted devices connected to each animal, and software to define the locations of enclosures. A collar emits a warning sound when an animal approaches a virtual fence. A mild electric shock is given if it crosses the fence, which is harmless but uncomfortable [28]. The development in precision grazing technologies ranges from image analysis for grazing measurements [29, 30, 31] to systems for the electronic identification of animals such as RFID tags [25], multiple motion detection sensors such as accelerometers [24], and GPS [15], helpful for health status and well-being assessment [32, 33]. Precision technologies bring significant advantages in extensive rearing systems but require continuous improvements and updates to support farmers in management decisions [34]. According to [PERSON] et al. [35], PLF can pose threats to farms such as direct damage to animals from technical failures of hardware components, inaccurate predictions by the farmer, and negative effects on the animal's welfare state. Using sensors and technologies to rear small ruminants also presents challenges related to various factors such as farmers' reluctance to adopt new technologies, the high cost of these instruments, and the strong attachment to traditional practices. Additionally, customizing these tools for small ruminants and validating their use for sheep and goat species is a complex and time-consuming process that hinders the widespread adoption of these technologies. According to [PERSON] et al. [24], these limiting factors for the broader adoption of innovative technologies in extensive farming may be overcome considering the emerging economic and environmental trends allowed by the more innovative part of the farmer population. This study aimed to conduct an investigation of PLF application in the extensive small ruminant sector based on a review of the literature from the past 5 to 7 years. The focus here will be on both wearable and non-wearable sensors that provide insights into animal behaviour in extensive farming systems, specifically regarding feeding, resting, and walking activities. We focused on these devices because we believe they are more easily usable in extensive small ruminant farms.