title: Diets enriched in unsaturated fatty acids enhance early embryonic development in lactating Holstein cows.
abstract: We hypothesized that a diet enriched in alpha-linolenic acid would enhance embryonic development relative to diets enriched in linoleic or saturated fatty acids. Twenty-four lactating Holstein cows (86+/-22 d postpartum) were assigned to one of three diets containing saturated fatty acids (SAT; high in palmitic and stearic acids), whole flaxseed (FLX; high in alpha-linolenic acid) or sunflower seed (SUN; high in linoleic acid). Rations were formulated to provide 750 g supplemental fat/cow/d in all dietary groups. Ovulation (Day 0) was synchronized approximately 20 d after diets began. Ultrasound-guided follicular ablation of all follicles >8 mm was performed 5 d after ovulation; super stimulatory treatments began 2 d after follicular ablation, and embryos were collected non-surgically 7 d after AI. Fertilization rate, numbers of follicles and ovulations, and total and transferable embryos did not differ (P>0.05) among dietary groups. Sixty-one transferable embryos were stained and total blastomere number determined. Blastomere number was affected by diet (P<0.01); without regard to stage of development, embryos collected from cows fed SAT had lower (P<0.01) blastomere numbers (mean+/-S.E.M.; 77.1+/-3.9) than those from cows fed FLX (93.4+/-3.3) or SUN (97.2+/-3.5). Differences were most evident in the expanded blastocyst stage; at this stage, embryos of cows fed FLX and SUN diets had more blastomeres (P<0.02) than those of cows fed SAT (115.4+/-6.3, 132.3+/-8.3, and 89.3+/-9.6 cells, respectively). Although our hypothesis was only partially supported, embryonic development was enhanced in Holstein cows fed unsaturated fatty acids compared to those fed saturated fatty acids.
authors.affiliation: Dairy Research and Technology Centre, Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, ALTA, Canada.
authors.forename: G
authors.initials: G
authors.lastname: Thangavelu
authors.forename: M G
authors.initials: MG
authors.lastname: Colazo
authors.forename: D J
authors.initials: DJ
authors.lastname: Ambrose
authors.forename: M
authors.initials: M
authors.lastname: Oba
authors.forename: E K
authors.initials: EK
authors.lastname: Okine
authors.forename: M K
authors.initials: MK
authors.lastname: Dyck
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D001757:Blastomeres / Q000187:drug effects; D002417:Cattle / Q000196:embryology / Q000502:physiology*; D004032:Diet / Q000662:veterinary*; D019587:Dietary Supplements; D004435:Eating / Q000187:drug effects; D047108:Embryonic Development / Q000187:drug effects*; D005227:Fatty Acids / Q000032:analysis; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D019597:Flax / Q000378:metabolism; D006368:Helianthus / Q000378:metabolism; D007328:Insulin / Q000097:blood; D007774:Lactation; D008892:Milk / Q000737:chemistry / Q000378:metabolism; D011374:Progesterone / Q000097:blood; D011897:Random Allocation; D013480:Superovulation / Q000187:drug effects; D013997:Time Factors
chemical_list: D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D007328:Insulin; D011374:Progesterone