title: In vivo embryo production in cows superovulated 1 or 2 days after ovum pick-up.
abstract: The present study evaluated superovulatory responses and in vivo embryo production in cows treated with FSH starting 1 or 2 days after ovum pick-up (OPU). Thirty-three non-lactating Nelore cows were subjected to aspiration of all follicles ≥3mm for OPU. After OPU, cows were randomly divided into two groups in which the follicle superstimulatory treatments with FSH started 1 or 2 days after OPU (Groups D1 and D2, respectively). Data are presented as the least squares mean±s.e.m. The number of follicles ≥3mm before OPU was similar between groups (~34); however, cows in Group D2 had more follicles ≥3mm on the first day of FSH (15.2±2.3 vs 7.6±1.7; P=0.04) and a higher ratio of the number of follicles at first FSH/number of follicles before OPU (0.41±0.04 vs 0.24±0.02; P=0.01). In addition, Group D2 cows had a greater superovulatory response than did cows in Group D1 (18.9±2.8 vs 9.1±1.9 corpora lutea, respectively; P<0.03). However, there was no difference in the total number of recovered ova and embryos from cows in Groups D2 and D1 (5.1±1.4 vs 4.9±1.3, respectively; P>0.10). Nevertheless Group D2 cows had more freezable embryos than Group D1 cows (3.2±1.1 vs 1.3±0.5, respectively; P<0.05). Cows from Group D2 had a much higher proportion (P<0.001) of follicles ≥8mm compared with follicles ≥6mm and <8mm at the time of the last treatment with FSH. In conclusion, to obtain a greater production of viable embryos in superovulated cows after OPU, it is recommended to wait at least 2 days before starting FSH treatment.
authors: Department of Animal Science, College of Agriculture 'Luiz de Queiroz' (ESALQ), University of São Paulo, Av. Pádua Dias, 11, CP 9, Piracicaba, SP 13418-900, Brazil.
authors: Ricardo S
authors: RS
authors: Surjus
authors: Department of Animal Science, College of Agriculture 'Luiz de Queiroz' (ESALQ), University of São Paulo, Av. Pádua Dias, 11, CP 9, Piracicaba, SP 13418-900, Brazil.
authors: Alexandre B
authors: AB
authors: Prata
authors: Department of Animal Science, College of Agriculture 'Luiz de Queiroz' (ESALQ), University of São Paulo, Av. Pádua Dias, 11, CP 9, Piracicaba, SP 13418-900, Brazil.
authors: Marta
authors: M
authors: Borsato
authors: College of Veterinary and Animal Science, São Paulo State University, Distrito Rubião Júnior, Botucatu, SP 18618-970, Brazil.
authors: Fernanda C S Z
authors: FC
authors: Mattos
authors: College of Veterinary and Animal Science, São Paulo State University, Distrito Rubião Júnior, Botucatu, SP 18618-970, Brazil.
authors: Mariana C
authors: MC
authors: Martins da Silveira
authors: Department of Animal Science, College of Agriculture 'Luiz de Queiroz' (ESALQ), University of São Paulo, Av. Pádua Dias, 11, CP 9, Piracicaba, SP 13418-900, Brazil.
authors: Gerson B
authors: GB
authors: Mourão
authors: Department of Animal Science, College of Agriculture 'Luiz de Queiroz' (ESALQ), University of São Paulo, Av. Pádua Dias, 11, CP 9, Piracicaba, SP 13418-900, Brazil.
authors: Alexandre V
authors: AV
authors: Pires
authors: Department of Dairy Science, University of Wisconsin, 1675 Observatory Drive, Madison, WI 53706, USA.
authors: Milo C
authors: MC
authors: Wiltbank
authors: Department of Animal Science, College of Agriculture 'Luiz de Queiroz' (ESALQ), University of São Paulo, Av. Pádua Dias, 11, CP 9, Piracicaba, SP 13418-900, Brazil.
authors: Roberto
authors: R
authors: Sartori
mesh_terms: D000818:Animals; D002417:Cattle; D004334:Drug Administration Schedule; D005260:Female; D005300:Fertility Agents, Female / Q000008:administration & dosage*; D005306:Fertilization / Q000187:drug effects*; D005640:Follicle Stimulating Hormone / Q000008:administration & dosage*; D007315:Insemination, Artificial / Q000662:veterinary; D016018:Least-Squares Analysis; D054315:Oocyte Retrieval / Q000662:veterinary*; D006080:Ovarian Follicle / Q000187:drug effects* / Q000502:physiology; D010062:Ovulation Induction / Q000662:veterinary*; D011247:Pregnancy; D013396:Suction / Q000662:veterinary; D013480:Superovulation / Q000187:drug effects*; D013997:Time Factors
chemical_list: D005300:Fertility Agents, Female; D005640:Follicle Stimulating Hormone