title: A diet enriched in linoleic acid compromises the cryotolerance of embryos from superovulated beef heifers.
abstract: Dietary rumen-protected fat rich in linoleic acid may affect the superovulatory response and embryo yield; however, its effects on in vivo embryo cryotolerance are unknown in zebu cattle. The present study evaluated the production and cryotolerance after freezing or vitrification of embryos from Nelore heifers supplemented with rumen-protected polyunsaturated fatty acids (PUFA). Forty heifers kept in pasture were randomly distributed into two groups according to the type of feed supplement (F, supplement with rumen-protected PUFA, predominantly linoleic; C, control fat-free supplement with additional corn). Supplements were formulated to be isocaloric and isonitrogenous. Each heifer underwent both treatments in a crossover design with 70 days between replicates. After 50 days feeding, heifers were superovulated. Embryos were evaluated morphologically and vitrified or frozen. After thawing or warming, embryo development was evaluated in vitro. There was no difference between the F and C groups (P>0.10) in terms of embryo production. Regardless of the cryopreservation method used, Group C embryos had a greater hatching rate after 72h in vitro culture than Group F embryos (44.3±4.2% (n=148) vs 30.9±4.0% (n=137), respectively; P=0.04). Moreover, vitrified and frozen embryos had similar hatching rates (P>0.10). In conclusion, dietary rumen-protected PUFA rich in linoleic acid did not improve embryo production and compromised the cryotolerance of conventionally frozen or vitrified embryos from Nelore heifers.
authors: Departament of Animal Science, Luiz de Queiroz College of Agriculture (ESALQ), University of São Paulo, Av. Pádua Dias, 11, Piracicaba, SP 13418-900, Brazil.
authors: Monique M
authors: MM
authors: Guardieiro
authors: Embrapa Genetic Resources and Biotechnology, Parque Estação Biológica, Av. W5 Norte, Caixa Postal 02372, Brasília, DF 70770-900, Brazil.
authors: Grazieli M
authors: GM
authors: Machado
authors: UNESP - University Estadual Paulista, Distrito Rubião Júnior, Botucatu, SP 18618-000, Brazil.
authors: Michele R
authors: MR
authors: Bastos
authors: Departament of Animal Science, Luiz de Queiroz College of Agriculture (ESALQ), University of São Paulo, Av. Pádua Dias, 11, Piracicaba, SP 13418-900, Brazil.
authors: Gerson B
authors: GB
authors: Mourão
authors: Integral Nutrição Animal, GO 070 Km 8. 3, Goianira, GO 75370-000, Brazil.
authors: Luiz H D
authors: LH
authors: Carrijo
authors: Embrapa Genetic Resources and Biotechnology, Parque Estação Biológica, Av. W5 Norte, Caixa Postal 02372, Brasília, DF 70770-900, Brazil.
authors: Margot A N
authors: MA
authors: Dode
authors: Gamete Research Center, Laboratory for Veterinary Physiology and Biochemistry, Department of Veterinary Sciences, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium.
authors: Jo L M R
authors: JL
authors: Leroy
authors: Departament of Animal Science, Luiz de Queiroz College of Agriculture (ESALQ), University of São Paulo, Av. Pádua Dias, 11, Piracicaba, SP 13418-900, Brazil.
authors: Roberto
authors: R
authors: Sartori
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle; D018592:Cross-Over Studies; D015925:Cryopreservation / Q000662:veterinary*; D019587:Dietary Supplements; D046149:Embryo Culture Techniques / Q000662:veterinary; D004622:Embryo, Mammalian / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary*; D008041:Linoleic Acids / Q000494:pharmacology*; D010062:Ovulation Induction / Q000662:veterinary*; D011247:Pregnancy; D013480:Superovulation; D013997:Time Factors; D058989:Vitrification
chemical_list: D008041:Linoleic Acids