Anatomical Distribution of Subcutaneous Fat and its Relationship with Body Condition Score in Pack Mules from the Central Andean Area of Colombia

Introduction: In the Colombian Andean mountain areas, mules are the basis for the development of agricultural activities of smallholders. In the management of mules, the empirical knowledge of farmers predominates for the nutritional aspect, which implies having the animals in optimal body condition for the task of pack loading. One of the important aspects of management related to animal welfare is the determination of body condition (level of fatness), which is calculated via subjective (visual) and objective techniques such as real-time ultrasound fat thickness measurement. Aims: The aim of the present study was to determine the fatness using ultrasound in different anatomical regions of the body and its association with body condition scores (BCSs) in working mules. Methods: Mules (n = 43) aged 5-30 years, from four municipalities in the western area of Cundinamarca, were measured in each sample. Mules were assigned a BCS value (1-9) based on visual appraisal and palpation of the dorsal and lumbar areas, area behind the shoulder, withers, and tail head as well as by measuring the subcutaneous fat thickness using ultrasound in five anatomical sites [back fat thickness (BFT), loin fat thickness (LFT), hearth fat thickness (HFT), wither fat thickness (WFT), and hip fat thickness (FHT)]. Results: The mean BCS in the mules was 5.2 +/- 1.1 and the mean subcutaneous fat thickness for the sites BFT, LFT, HFT, WFT, and FHT were 5.2 +/- 2.1 mm, 3.9 +/- 0.8 mm, 7.0 +/- 2.2 mm, 4.7 +/- 1.5, and 4.2 +/- 1.2 mm, respectively. Correlation coefficient between BCS and BFT was r = 0.39 (p <0.01), that between BCS and HFT was 0.49 (p <0.01), and that between BCS and HFT was r = 0.43 (p < 0.01). Conclusion: We concluded that the distribution of subcutaneous fatness is different for the five anatomical sites evaluated, demonstrating a greater fatness in the hearth region followed by the back region.