Effects of Dietary Unsaturated Fatty Acids on Oocyte Quality and Follicular Development in Lactating Dairy Cows in Summer

• Published in: Journal of dairy science Vol. 89; no. 10; pp. 3891 - 3903
• Main Authors: Bilby, T.R., Block, J., do Amaral, B.C., Sa Filho, O., Silvestre, F.T., Hansen, P.J., Staples, C.R., Thatcher, W.W.
• Format: Journal Article
• Language: English
• Published: Savoy, IL Elsevier Inc 01.10.2006; American Dairy Science Association; Am Dairy Sci Assoc
• Subjects: Animal productions; Animals; artificial insemination; Biological and medical sciences; Body Temperature - drug effects; Caspases - metabolism; Cattle - embryology; Cattle - physiology; corpus luteum; cow; cow feeding; Dairy cattle; dairy cows; Dairying; dietary fat; Dietary Fats - administration & dosage; Dietary Fats - analysis; Dietary Fats - pharmacology; dry period; early lactation; embryo; Embryo, Mammalian - drug effects; Estrus - physiology; fatty acid; Fatty Acids, Unsaturated - administration & dosage; Fatty Acids, Unsaturated - pharmacology; Female; Fertilization in Vitro - veterinary; follicular development; Food industries; Fundamental and applied biological sciences. Psychology; Graafian follicles; Hormones - blood; In Situ Nick-End Labeling - veterinary; in vitro fertilization; Insulin-Like Growth Factor I - analysis; Lactation; linseed oil; Milk and cheese industries. Ice creams; omega-3 fatty acids; omega-6 fatty acids; oocyte; oocytes; Oocytes - drug effects; Oocytes - physiology; Ovarian Follicle - drug effects; Ovarian Follicle - physiology; ovulation; Pregnancy; protected fat; Seasons; summer; sunflower oil; Terrestrial animal productions; vegetable oil; Vertebrates; Florida; fatty acid; embryo; cow; oocyte; Embryo; Farming animal; Lactation; Dairy cattle; Lipids; Summer; Fatty acids; Vertebrata; Mammalia; Quality; Dairy industry; Development; Unsaturated fatty acid; Artiodactyla; Ungulata; Oocyte
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.s0022-0302(06)72432-8

Dietary sources of fatty acids were evaluated for their influence on oocyte quality and follicular development using 54 lactating cows in summer. Fat supplements were 1) sunflower oil (80% cis 18:1), 2) Ca salt of transoctadecenoic acids (57% trans 18:1), 3) Ca salt of vegetable oils (30% 18:2), and 4) linseed oil (56% 18:3 and 16% 18:2). Fats were fed at 1.35% of dietary dry matter beginning at 5 wk prior to expected calving date and at 1.5% (oils) and 1.75% (Ca salts) of dietary dry matter for 15 wk after parturition. Four days following a programmed induced ovulation, 5 transvaginal oocyte aspirations were performed 3 or 4 d apart. Three days after the last aspiration, PGF2α was injected, followed 3 d later by a GnRH injection and a timed artificial insemination (d 0) 16 to 20h later. For the first 4 aspirations, oocytes grading 1 or 2 were used for in vitro embryo production. Total cell number and the proportion of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)–positive blastomeres were analyzed at d 8. At the fifth aspiration, the occurrence of metaphase II, group II caspase activity, and TUNEL labeling were determined after oocyte maturation. A total of 1,011 oocytes were collected. The proportion of oocytes with high caspase activity was greater for grade 3 compared with grades 1 and 2 (37.5 vs. 1.54 and 1.61%). Feeding polyunsaturated fatty acids, as compared with monosaturated fatty acids, failed to affect oocyte quality, as demonstrated by subsequent embryo development. Cows fed 18:2- or 18:3-enriched diets had a larger preovulatory follicle at insemination and subsequent volume of the corpus luteum compared with those fed cis 18:1 or trans 18:1 diets (16.8, 16.2 vs. 15.0, 14.9±0.7mm; 7,323, 8,208 vs. 6,033, 5,495±644mm3, respectively). The previously documented benefits of polyunsaturated fatty acids on reproductive performance appear to reflect actions at alternative biological windows in lactating dairy cows.