204 Fatty Acid Composition of Follicular Fluid From Dairy Cows Fed Tropical Forage-Based Diets Supplemented With Increasing Levels of Soybean Oil

Abstract

Recent studies have shown that dietary supplementation with sources rich in polyunsaturated fatty acids (PUFA) can improve reproductive perfor-mance of lactating dairy cows. However, no studies have reported the fatty acids composition of follicular fluid (FF) from dairy cows fed high-PUFA diets. This study aimed to evaluate the fatty acids composition of FF from dairy cows fed tropical forage-based diets containing different levels of soybean oil (SO). Four multiparous Holstein-Zebu cows in midlactation (90 ± 25 days in milk) were assigned to 1 of the following dietary treatments (on a dry matter basis): (1) T1 (control) = no SO; (2) T2 = diets containing 1.5% of SO; (3) T3 = diets containing 3.0% of SO; and (4) T4 = diets containing 4.5% of SO. Diets were composed of chopped elephant grass and a concentrate mixture and the forage concentrate ratio was 55 : 45 (dry matter basis). The experimental design was a 4 × 4 Latin square in which each period lasted 21 days. All cows received intravaginal progesterone-releasing devices and follicular waves were synchronized with 0.5 mg of gonadorelin. The FF from dominant follicles was collected by transvaginal ultrasound-guided aspiration on the last day of each period (Day 21) and centrifuged (10000 × g, 1 min) and the supernatant was frozen at -80°C until fatty acid analysis. Extraction and methylation of fatty acids in FF were performed according to the 1-step simplified method described by Masood A et al. (2005 J. Lipid Res. 46, 2299-2305). The fatty acid profile from FF was determined by gas chromatography as described by Cruz-Hernandez C et al. (2007 J. Dairy Sci. 90, 3786-3801). Treatment effects were determined by regression analysis using the REG procedure of SAS (SAS Institute, Cary, NC, USA) and declared significant at P < 0.05. Nearly 30 different fatty acids (70% of the total area) were identified in the FF samples. The most representative fatty acids (% total area) for the 4 dietary treatments (T1, T2, T3, and T4, respectively) were C18 : 2 cis - 9, cis - 12 (19.8, 20.3, 16.1, and 24.2), C18 : 0 (17.7, 16.6, 19.5, and 16.8), C16 : 0 (12.2, 10.7, 11.3, and 17.8), and C18 :1 cis - 9 (6.5, 7.3, 5.5, and 7.7). Inclusion of SO in the diet linearly reduced (P < 0.05) concentrations of C16 : 1 cis - 9 (0.8, 0.7, 0.4, and 0.5) and C20 : 3 (1.2, 1.1, 0.5, and 0.7), but linearly increased (P < 0.05) concentrations of C18 : 1 trans - 11 (0.4, 0.4, 0.6, and 1.4), C18 : 1 cis - 11 (0.4, 0.5, 0.4, and 0.9), and C18 : 1 cis - 12 (0.2, 0.5, 0.5, and 0.7) isomers in FF. The increase in the concentration of C18 : 1 trans - 11 in FF from cows fed higher levels of SO was not accompanied by an increase in the proportion of CLA cis - 9, trans - 11 (0.9, 1.0, 0.7, and 0.9 for T1, T2, T3, and T4, respectively). It suggests the absence or low activity of A9-desaturase enzyme in the follicular environment, unlike that observed in the mammary gland. In general, our results indicate that fatty acid composition of follicular fluid from lactating dairy cows is sensitive to changes in dietary supply of PUFA. Financial support: FAPEMIG (CVZ1815/06).

49 Effects of Dietary Conjugated Linoleic Acid Supplementation on Bovine Oocyte Lipid Metabolism, Lipid Composition, and Embryo Cryotolerance

“…Feeding ewes diets high in polyunsaturated fatty acids (PUFA) altered fatty acid composition of follicular components (Wonnacott et al, 2010) and improved membrane integrity after chilling (Zeron et al, 2002a). Fatty acid composition of follicular fluid in dairy cows is sensitive to dietary supply of polyunsaturated fatty acids (PUFA) using soybean oil (Batista et al, 2010) and flaxseed oil (Zachut et al, 2010). In vivo-produced embryos from Nellore heifers were more sensitive to cryopreservation when diets included rumen-protected PUFA Guardieiro et al, 2014).…”

“…Significantly greater doses of CLA were fed in the mouse study by Harris et al (2001) compared with most CLA studies reported in ruminants. Additionally, a significant portion of the lipid-encapsulated supplement was likely biohydrogenated in the rumen in the study by Castañeda-Gutiérrez et al 2007a Fatty acid composition of follicular fluid is sensitive to changes in dietary supply of PUFA using soybean oil (Batista et al, 2010). Heifers fed fish oil had grater proportions of EPA and DHA in follicular fluid (Childs et al, 2008).…”

“…Reproductive responses after feeding supplements high in polyunsaturated fatty acids (PUFA) has been investigated in both dairy and beef cows. The composition of bovine follicular fluid is sensitive to changes in dietary supply of PUFA (Batista et al, 2010). However, feeding PUFA failed to influence oocyte quality in lactating Holstein cows, suggesting that benefits of PUFA are a result of other biological mechanism (Bilby et al, 2006).…”

“…Oocytes from ewes fed fish oil had a lower temperature of lipid phase transition, leading to superior membrane integrity after chilling (Zeron et al, 2002a). Fatty acid composition of follicular fluid in dairy cows is sensitive to dietary supply of polyunsaturated fatty acids (PUFA) using soybean oil (Batista et al, 2010).…”

“…Castañeda-Gutiérrez et al (2007a) reported very few alterations in follicular fluid fatty acid composition after CLA supplementation in cows. However, fatty acid composition of bovine follicular fluid was sensitive to changes in dietary supplementation of PUFA using soybean oil (Batista et al, 2010) and fish oil (Childs et al, 2008). Feeding dairy cows a rumen-protected flaxseed oil altered the fatty acid composition of plasma, follicular fluid, COC and granulosa cells (Zachut et al, 2010).…”