Resumen

MEZA-VILLALVAZO, Víctor et al. Metabolic profile of conjugated linoleic acid isomers and oocyte quality in hair ewes. Nova scientia [online]. 2014, vol.6, n.12, pp.287-303. ISSN 2007-0705.

Polyunsaturated fatty acids are modified in rumen, given rise to isomers of conjugated linoleic acid (CLA), which, under in vitro conditions, has been shown to improve the resistance to manipulation and embryo survival. However, under these conditions is not exposed to the metabolism of the animal, which could affect their physiological potential, being necessary the study of the intrinsic aspects of the animal consuming, diets rich in polyunsaturated fatty acids. The aim of the present work was to determine the presence of most biologically important CLA isomers in rumen fluid in vitro conditions, the presence of these in blood, follicular fluid and oocyte quality of Pelibuey ewes in vivo. The study was conducted in two phases: Phase 1, three isoenegetic and isoproteic diets were formulated including three levels of corn oil in the diet (0 %, 3% and 6%), which were incubated in a culture medium with ruminal fluid for 24 h. Phase 2, Twenty one Pelibuey ewes, with a live weight of 35.7 ± 1.92 kg, were divided into three groups (n = 7) and fed with the diets described in phase 1 for a period of 28 days, estrous cycles were synchronized with three aplications of PGF2α and Flourogestone acetate (FGA) impregnated intravaginal device for 12 days. At the day 29 of the experiment the animals were slaughtered, oocytes were aspirated by puncture from follicles ≥ 2.00 mm and classified as excellent, good, fair and poor quality, the determination of proportion of fatty acid in rumen fluid and blood plasma follicular blood was determined by gas chromatography. The fatty acids (16:0, 16:1, 18:0, 18:1, 18:2 and 18:3) in rumen fluid and blood were unaffected by the oil level, in follicular fluid, C16:0, C18:0 and C18: 3 (P ≤0.01) decrease linearly as the oil level increased in the diet. The isomers Cis -9, Trans -11 (P ≤0.05) and Trans -10, Cis -12 (P ≤0.001) in ruminal fluid showed a linear trend, and plasma blood a quadratic effect (P ≤0.014) and linear (P ≤0.004 ) respectively. In the follicular fluid Cis -9, Trans -11 (6 to 12 %) and Trans -10, Cis-12 (2 to 4 %) increases linearly as increased the oil level in the diet. The oocyte quality improved as increased the level of corn oil in the diet. The addition of 6% of corn oil in the diet of Pelibuey ewes increases the presence of the Cis -9, Trans -11 and Trans -10, Cis -12 isomers in rumen and follicular fluid and improve the quality of oocytes.

Palabras llave : CLA; biohidrogenation; follicular liquid; oocytes; tropical hair sheep.

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