# Application of Ultrasonic Nondestructive Testing for Breeding of Meat Pigeons
## 1 Introduction  
China is the largest producer of meat pigeons, accounting for about 80% of global production [1]. The meat pigeon is currently the fourth most commonly bred poultry species in China after chickens, ducks, and geese [2]. In recent years, the global demand for meat pigeons has continued to grow. The meat pigeon industry in China not only meets domestic market needs but also holds an important position in international exports. Its industry chain involves various aspects such as feed processing, disease prevention and control,breeding technology promotion, product processing, and brand establishment, resulting in significant economic stimulation [3]. Pigeon meat is rich in nutrients, various amino acids, high-quality proteins, and trace elements [4,5]. An old Chinese saying states that \"one pigeon is better than nine chickens\". The breast muscle (BM) of meat pigeons is the main edible part and the most valuable. Breast muscle weight (BMW) is the most important economic indicator of the production performance of meat pigeons [6]. BMW and carcass weight are established indicators for breeding high-quality BM traits of meat pigeons. However, the measurement of BMW requires slaughtering, which is time-consuming and increases production costs [7]. Moreover, high-quality birds selected after slaughter can no longer be used for breeding [8].  
Ultrasonic nondestructive testing (UNDT) was recently developed for non-invasive measurements of poultry and other livestock [9]. The main advantages of UNDT include safety, reliability, and non-invasive measurement [10], which can be repeated and observed in real time [11], making it particularly advantageous for preserving breeding stock. By contrast, traditional methods, such as manual palpation or destructive sampling, are limited by precision, cost, and the inability to retain high-value breeding stock. UNDT was introduced in the 1980s in China for use in animal husbandry and veterinary medicine [12], and is currently widely applied in clinical and biological research [13]. In livestock breeding, UNDT has been used to evaluate the composition of rabbit carcass [14], the backfat thickness of live lambs [15], the correlation between the live and carcass weights of beef cattle [16], and the gestational age of Korean black sheep [17]. UNDT has also been widely applied in poultry breeding. [PERSON] et al. used UNDT to identify correlations between the fat content and carcass traits of Peking ducks, which provided the basis for the application of UNDT in the breeding of meat ducks [7]. [PERSON] et al. reported a significant positive correlation between breast muscle thickness (BMT) and body weight (BW), keel length, and BMW for the selection of Yangzhou geese [8]. However, with the rapid development of meat pigeon breeding, new requirements for testing production efficiency and accuracy have emerged. Additionally, a comprehensive review of the limitations of these applications and the rationale for extending UNDT to meat pigeons has yet to be detailed. Therefore, it is necessary to accelerate the utilization of measurable traits to evaluate the breeding performance of meat pigeons [6].  
The aim of the present study was to assess the feasibility of UNDT to measure the traits of meat pigeons and identify potential correlations of BMT with BMW, dressed weight, live BW, breast width, and breast depth (BD) to improve breeding production, and to attempt to address the high time and resource consumption associated with traditional slaughter measurement methods, and promote efficient development in the pigeon meat industry.