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

Abstract

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, PGF2alpha was injected, followed 3 d later by a GnRH injection and a timed artificial insemination (d 0) 16 to 20 h 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 +/- 0.7 mm; 7,323, 8,208 vs. 6,033, 5,495 +/- 644 mm3, respectively). The previously documented benefits of polyunsaturated fatty acids on reproductive performance appear to reflect actions at alternative biological windows in lactating dairy cows.

Several fibroblast growth factors are expressed during pre-attachment bovine conceptus development and regulate interferon-tau expression from trophectoderm

“…Conceptuses were harvested on days 11, 14, and 17 post-insemination after superovulation. In brief, growth of a new wave of follicles was induced by ablating large follicles (O10 mm diameter) on ovaries with an ultrasound-guided follicle aspiration device (Bilby et al 2006). A controlled drug intravaginal device containing progesterone (1.38 g; Eazi-Breed CIDR; Pfizer Corp., New York, NY, USA) was inserted after follicle ablation.…”

Impact of contrasting fish oil concentrations in the diet on ovine embryo development <i>in vivo</i> and of corresponding diet-specific derivative sera during <i>in vitro</i> culture

“…In that scenario it was argued that the causal mechanism was the reduction in plasma progesterone concentrations that accompanies high levels of feeding in the ewe (McEvoy et al, 1995). Although progesterone concentrations were not measured in the present study it is unlikely that the fish oil would have reduced them since all the evidence, albeit mostly from dairy cattle studies Bilby et al, 2006;Petit and Twagiramungu, 2006;Thangavelu et al, 2007) but also supported by sheep data (Kuran et al, 1999), indicates that supplementary dietary lipids elevate progesterone. In the Kuran et al (1999) study referred to just now, we found that dietary lipid was associated with significantly enhanced progesterone synthesis in primary explants of ovine luteal tissue in vitro.…”

“…In ewes, Cancino-Arroyo et al (2006) recorded a significant improvement in the quality of oocytes aspirated from gonadotrophin-stimulated follicles and a tendency towards better in vitro maturation, fertilization and embryo development when the diet was supplemented with 4% maize oil. Bilby et al (2005Bilby et al ( , 2006 reported that dairy cows given a diet enriched with linoleic acid tended to yield aspirated oocytes with a subsequently slower rate of in vitro embryo development than those from cows given an oleic acid-enriched diet. Linoleic acid supplementation of an in vitro culture medium (Marei et al, 2010) confirmed its inhibitory effect on bovine oocytes and early embryos.…”

The effect of nutrition and metabolic status on the development of follicles, oocytes and embryos in ruminants

“…In the dairy cow, a diet enriched with long-chain fatty acids increases the number of medium follicles (6 to 9 mm) and the diameter of the preovulatory follicle (Lucy et al, 1991b). These positive effects of long-chain fatty acids on the size of the dominant follicle have been confirmed in several studies (Mattos et al, 2000;Robinson et al, 2002;Ambrose et al, 2006;Bilby et al, 2006). In addition, different effects were observed on the follicular growth between monounsaturated fatty acids (MUFA) and polyunsaturated (PUFA) fatty acids: PUFAs promoted follicular growth to a greater extent than did MUFAs (Bilby et al, 2006).…”