## 1 Introduction  
Globally, there is an increasing demand for animal products (e.g., meat, dairy products, eggs, wool, leather, etc.) [1, 2, 3, 4]. African swine fever [5] and excessive population growth [6, 7] have brought new challenges, requiring pig husbandry to further develop in the direction of intensification, specialization, and refinement [8, 9]. Feed costs account for a major proportion of the total cost of raising pigs [10]. Reducing feed waste helps to mitigate the world food crisis, as well as reduce the costs of pork production [11, 12]. The appropriate feeding allowance should be determined at various gestation stages [13, 14], as inadequate or excessive feeding can compromise the reproductive performance of sows [15]. The gestation period of sows is typically categorized into three stages. During early gestation, there is no clear benefit observed from increased feeding [16], and excessive nutrient intake may lead to higher embryo mortality and lower litter sizes [17]. In mid-gestation, gilts are still growing and developing, and sows need to recover body reserves lost from the previous breeding cycle [18]. Late gestation is a period for improving the birth weight of piglets [19, 20]. Increasing the energy intake of sows has a positive effect on individual piglets, but may also elevate the stillborn rate [21]. The implementation of precision feeding has a positive impact on the sustainability of pig husbandry [22, 23]. Compared with conventional feeding, precision feeding decreasesthe intake of lysine and protein and reduces feed costs without adversely affecting growth and reproductive performance [24; 25; 26]. Additionally, in terms of environmental protection, precision feeding reduces nitrogen and phosphorus excretion [27; 28]. [PERSON] et al. [29] observed that gilts subject to precision feeding ate more and lost less weight during subsequent lactation. [PERSON] [30] found that precision feeding decreased the risk of sows being too fat or too thin, thereby decreasing the risk of impaired narrowing or milk production, and also that there was less variability in backfat thickness when sows narrowed in the same batch. [PERSON] et al. [31] showed that the risk of fetal displacement in sows could be identified early by measuring feed intake and time spent at an ESF. The integrated application of automation and Internet of Things (IoT) technologies in pig husbandry can contribute to more accurate data records [32; 33] which in turn reduce the burden on practitioners, lower the cost of farming, and raise productivity. The IoT connects physical objects and spaces into a local area network or internet and enables efficient monitoring and management by integrating data objects [34; 35; 36]. [PERSON] et al. devised a three-layer wireless sensor network system based on ZigBee to monitor four environmental parameters (temperature, relative humidity, and concentrations of carbon dioxide and ammonia) in commercial gestation units; real-time monitoring of the microclimate and timely intervention were achieved by analyzing the temporal and spatial characteristics of the pigsty [37]. [PERSON] et al. developed a monitoring system using wireless broadband leaky coaxial cable to collect data from Bluetooth Low-energy (BLE) tags attached to individual pigs. These data were used to compute and estimate the position and movement of each pig [38]. Group housing and conventional stall housing have their own advantages and disadvantages [39; 40]; however, because of different degrees of development and economic factors, stalls are still heavily used outside Europe. As part of the transition of intensive pig farms towards automation and informatization, the development of a precision feeding system suitable for stall housing represents a significant step forward. [PERSON] and [PERSON] et al. designed an electronic feeder for the precision feeding of sows housed in stalls [41; 42]. However, there is a scarcity of research examining the shortcomings and defects of precision feeding systems within a real intensive pig farm.