Effects of dietary camelina, flaxseed, and canola oil supplementation on transepidermal water loss, skin and coat health parameters, and plasma prostaglandin E2, glycosaminoglycan, and nitric oxide concentrations in healthy adult horses.

Camelina oil is derived from a low-input, high-yield crop and, in comparison to many other dietary fat sources currently used in equine diets, provides a greater amount of α-linolenic acid [ALA; (n-3)], than linoleic acid [LA; (n-6)]. However, no research exists assessing the effects of feeding camelina oil to horses in contrast to other commonly used oils. The objective of this study was to compare the effect of supplementing camelina oil to that of flaxseed and canola oil supplementation, on outcomes related to skin and coat health in horses. Thirty adult horses [23 mares, 7 geldings; 14.9 years ±â€…5.3 years; 544 ±â€…66 kg body weight (BW) (mean ±â€…SD)] underwent a 4-week wash-in period consuming hay and sunflower oil. Following the wash-in period, horses were blocked by location, age, and BW, and assigned to one of three treatment oils for 16 weeks (370 mg oil/kg BW): camelina (CAM), canola (OLA), or flaxseed (FLX) oil. Blood samples were collected and plasma prostaglandin E2 (PGE2; ELISA), nitric oxide (NO; Griess Reaction), and glycosaminoglycan (GAG; DMMB) concentrations were measured on weeks 0 (n = 30), 14 (n = 24), and 16 (n = 30). On weeks 0, 2, 4, 8, and 16, transepidermal water loss (TEWL) was measured pre- and post-acetone application using a VapoMeter (n = 26), and a 5-point-Likert scale was used to assess skin and coat characteristics on the side and rump of the horses (n = 30). All data were analyzed with repeated measures ANOVA using PROC GLIMMIX in SAS. Independent of treatment, coat color, and quality increased from baseline. There were no differences in the outcomes assessed between the horses supplemented camelina oil and those supplemented canola or flaxseed oil. These results suggest that independent of treatment, all oil supplements improved coat color and quality in horses. This provides indication that camelina oil is comparable to existing plant-based oil supplements in supporting skin and coat health and inflammation in horses.

Horses cannot produce omega-3 α-linolenic acid or omega-6 linoleic acid in the body, and as a result, these fatty acids are required in the diet. Camelina oil contains a lower ratio of omega-6 to omega-3 fatty acids (1:1.8) in comparison to alternative fat ingredients commonly included in many horse diets, such as soybean oil (1:0.12). Omega-3 fatty acids from flaxseed oil or marine-based oils can support skin and coat health and lower inflammation in horses; however, there is a lack of research investigating camelina oil supplementation and its benefits in horses. Thus, the objective of this study was to determine the effects of camelina oil on skin and coat health in horses. Horses were supplemented with sunflower oil for 4 weeks before being assigned to one of three treatment oils (camelina, canola, or flaxseed) for 16 weeks. Skin barrier function was assessed by measuring the transepidermal water loss of the chest, inner elbow, withers, and rump. Blood markers, including prostaglandin E2, nitric oxide, and glycosaminoglycan, were measured. Skin and coat parameters, including shine, softness, hair quality, color intensity, and moisture, were assessed using a 5-point scale on the rump and side of the horses. No differences in transepidermal water loss, blood markers, or skin and coat parameters were observed among treatments. Our results suggest that camelina oil is comparable to existing oil supplements in supporting skin and coat health and inflammation in horses.