Hartwig Samantha, Burron Scarlett, Richards Taylor, Rankovic Alexandra, Ma David W L, Pearson Wendy, Ellis Jennifer, Trevizan Luciano, Seymour Dave J, Shoveller Anna K
Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada N1G 2W1.
Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada N1G 2W1.
J Anim Sci. 2025 Jan 4;103. doi: 10.1093/jas/skaf025.
Camelina sativa is an oilseed crop rich in α-linolenic acid (ALA), an n-3 fatty acid (FA), and is resistant to harsh climates and pests. Previously, supplementation with camelina oil (CAM) in horses had no adverse effects on basic health parameters and had comparable skin and coat parameters as both flaxseed oil (FLX) and canola oil (OLA). Further, the plasma FA profile of horses was reflective of their respective treatment oil. The objective of this study was to assess the effects of dietary CAM supplementation on skin FA profile, immune, and inflammatory responses as compared to 2 commonly used oils in the equine industry, OLA and FLX, in healthy adult horses. Twenty-four adult horses, from 2 separate herds, were enrolled in this experiment. The horses underwent a gradual 4-wk fat acclimation period to sunflower oil (approximately 0.28% ALA), then were supplemented with either CAM (approximately 34.9% ALA), OLA (approximately 12.0% ALA), or FLX (56.0% ALA) at an inclusion rate of 0.37 g/kg body weight (BW) per day for an additional 16 wk. Immune and inflammatory responses were assessed by measuring antibody concentrations across time after sensitization to keyhole limpet hemocyanin (KLH) at weeks 10 and 12, and a subsequent delayed-type hypersensitivity (DTH) challenge. Skin biopsy samples were collected at weeks 0, 8, and 16, and FA composition was determined using gas-chromatography. All data were analyzed as a repeated measures ANOVA using PROC GLIMMIX in SAS. Antibody and DTH responses to KLH did not differ among groups (P = 0.262 and 0.813, respectively), and no treatment by time effects were observed (P = 0.764 and P = 0.817, respectively). Most FA in the skin changed in composition across time, with the sum of n-3 FA increasing (P < 0.001) and the sum of n-6 FA and skin n-6:n-3 ratio decreasing over time (P < 0.001 and P < 0.001, respectively). Only dihomo-γ-linolenic acid (P = 0.025) and the sum of n-3 FA (P = 0.031) had treatment-by-week effects. At week 16, the composition of eicosapentaenoic acid in the skin was greater in FLX than OLA, but neither differed from CAM (P = 0.049). These results suggest that ALA supplementation may beneficially impact skin FA profile. However, due to the small differences in n-3 FA and n-6:n-3 ratio among CAM, FLX, and OLA, a comparable skin FA profile, immune, and inflammatory response was observed among treatments at a dose of 0.37 g oil/kg BW. Therefore, CAM may be a suitable alternative to FLX in equine diets for the delivery of ALA.
荠蓝是一种富含α-亚麻酸（ALA）的油料作物，α-亚麻酸是一种n-3脂肪酸（FA），并且荠蓝对恶劣气候和害虫具有抗性。此前，给马匹补充荠蓝油（CAM）对基本健康参数没有不良影响，并且在皮肤和被毛参数方面与亚麻籽油（FLX）和菜籽油（OLA）相当。此外，马匹的血浆脂肪酸谱反映了它们各自所摄入的油。本研究的目的是评估与马产业中常用的两种油（OLA和FLX）相比，在健康成年马的日粮中补充CAM对皮肤脂肪酸谱、免疫和炎症反应的影响。来自2个不同马群的24匹成年马参与了本实验。这些马经历了为期4周的逐渐适应葵花籽油（约含0.28% ALA）的脂肪适应期，然后以每天0.37 g/kg体重（BW）的添加比例补充CAM（约含34.9% ALA）、OLA（约含12.0% ALA）或FLX（56.0% ALA），持续16周。在第10周和第12周对钥孔戚血蓝蛋白（KLH）致敏后，通过测量不同时间的抗体浓度以及随后的迟发型超敏反应（DTH）激发来评估免疫和炎症反应。在第0周、第8周和第16周采集皮肤活检样本，并使用气相色谱法测定脂肪酸组成。所有数据使用SAS中的PROC GLIMMIX进行重复测量方差分析。对KLH的抗体和DTH反应在各组之间没有差异（P分别为0.262和0.813），并且未观察到处理与时间的交互作用（P分别为0.764和0.817）。皮肤中的大多数脂肪酸组成随时间变化，n-3脂肪酸的总量增加（P < 0.001），n-6脂肪酸的总量以及皮肤中n-6:n-3比值随时间下降（P分别< 0.001和P < 0.001）。只有二高-γ-亚麻酸（P = 0.025）和n-3脂肪酸总量（P = 0.031）有处理与周数的交互作用。在第16周时，皮肤中二十碳五烯酸的组成在FLX组中高于OLA组，但两者与CAM组均无差异（P = 0.049）。这些结果表明补充ALA可能对皮肤脂肪酸谱有有益影响。然而，由于CAM、FLX和OLA之间n-3脂肪酸和n-6:n-3比值差异较小，在0.37 g油/kg BW的剂量下，各处理之间观察到了相当的皮肤脂肪酸谱、免疫和炎症反应。因此，在马的日粮中，CAM可能是FLX提供ALA的合适替代品。
