114 Effect of Body Condition Score on Fatty Acid Composition of Equine Visceral Adipose Tissues

Abstract Body condition score (BCS) is routinely used to assess overall fat coverage in horses for both management considerations and research studies. However, BCS has not previously been associated with fatty acid (FA) composition of visceral adipose tissues. This study was aimed to determine FA composition of abdominal (leaf– LF) and mesenteric (MF) adipose tissues. Stock type horses with BCS of 4 (n = 5), 5 (n = 9), and 6 (n = 5) were slaughtered and LF and MF samples were collected, directly derivatized to FA methyl esters, and analyzed by gas chromatography (Agilent Technologies, Santa Clara, CA) with internal standard calibration. Statistical analysis was performed by the GLIMMIX procedure of SAS 9.4 (SAS Institute Inc., Cary, NC) and statistical significance was determined at P ≤ 0.05. Percentage of 18:2 n6 in MF was 13.52% for BCS 4 horses, greater than those of BCS 5 and 6 (P = 0.05). The percentage of 16:1 n7 in BCS 6 horses (4.69%) was greatest (P ≤ 0.03), so was that of 18:0 in BCS 5 horses (6.21%, P ≤ 0.01). In the LF of BCS 5, percentages of 17:0, 17:1 n8, and 18:0 were 0.65, 0.88, and 7.1%, respectively, greater than those of BCS 4 and BCS 6 (P ≤ 0.04). Percentage of 16:1 n7 in LF was similarly greatest for BCS 6 horses (4.02%; P = 0.02). Collectively, saturated FA (SFA) percentage (37.6%) was greater in LF than in MF (35%; P = 0.02), leading to greater SFA (37.60%) than monounsaturated FA (MUFA; 32.72%; P ≤ 0.001) in LF but not in MF (MUFA = 34.72%, SFA = 35%; P = 0.60). Both LF and MF had more SFA and MUFA than polyunsaturated FA (PUFA; 29.69 and 30.28%, respectively; P < 0.001). These data indicate that greater BCS increases the saturation of LF more than it does that of MF.