Development of an index based on ultrasonographic measurements for the objective appraisal of body condition in Andalusian horses

Abstract

Body condition scoring (BCS) is an indirect measure of the level of subcutaneous fat; however, by measuring the subcutaneous fat thicknesses (SFT), the precision of the degree of fatness assessment is improved. The aims were: 1) to develop an alternative body fat scoring index (BFSI) based on ultrasonographic measurements; 2) to assess the agreement between BCS and the new index applied to Andalusian horses; 3) to adjust the BCS cut-off values (if necessary) for overweight and obesity in this breed. One hundred and sixtysix Andalusian horses were included in this cross sectional study. On each horse, BCS, body fat percentage (BF%) and ultrasonography of SFT at localized deposits were evaluated. According to BFSI five possible body categories were established. Only one horse (0.6%) was classified as emaciated, 9.0% as thin, 74.7% as normal, 11.4% as overweight and 4.2% as obese. Despite higher BCS and SFT values were observed compared to other breeds, most of the horses evaluated presented a normal body condition under the new BFSI. BCS and BFSI were significantly associated (p<0.001), however, the concordance was low (weighted Cohen's kappa coefficient, 0.262 ± 0.071; p=0.004). Using BFSI, obese horses had significantly greater BF% than the rest of categories (p<0.001). BCS showed a good diagnostic accuracy for detection overweight (AUC = 0.759 ± 0.055; p<0.001) and obese (AUC = 0.878 ± 0.050; p=0.001) horses; redefining the cut-off values for overweight and obesity condition as 7.5/9 and 8.5/9 respectively in Andalusian horses.Additional keywords: ultrasonography; subcutaneous fat deposits; objective score; adiposity; obesity; index. Abbreviations used: AUC (area under the curve); BMI (body mass index); BCS (body condition score); BFSI (body fat scoring index); ROC (receiver operating characteristic curve); SFT (subcutaneous fat thickness); SFT-N25% (SFT over the first third of the neck-length); SFT-N50% (SFT over the second third of the neck-length); SFT-N75% (SFT over the last third of the neck-length); SFT-S (SFT behind the shoulder); SFT-Rb (SFT over the ribs); SFT-R (SFT over the rump); SFT-TH (SFT over the tailhead); BF% (body fat percentage).

Body fat evaluation in Colombian Paso horses: body condition score and morphometric and ultrasound measurements

“…Then, measurements were taken using antiseptic alcohol on clean hair. Ultrasonographic images were taken at three defined points, according to previous reports in other breeds (Martin-Giménez et al, 2018). Anatomic landmarks were identified by palpation and visual assessment, as follows: 1) SFT-75% of neck length (from the base of the ear towards the dorsal edge of the scapula, in a straight line in the anatomical demarcation formed by the trapezius muscle and the nuchal ligament laminar portion); 2) SFT-lumbar region (3-cm laterally, at the L6); and, 3) SFT-gluteal region (50% of the path between the coxal tuberosity and the greater trochanter of the femur and 5 cm in the direction of the sacrum).…”