Reduced progesterone concentration during growth of the first follicular wave affects embryo quality but has no effect on embryo survival post transfer in lactating dairy cows.
Reproduction
; 141(3): 333-42, 2011 Mar.
Article
em En
| MEDLINE
| ID: mdl-21177956
ABSTRACT
Fertility of lactating dairy cows is associated with reduced progesterone (P(4)) concentration compared with nonlactating animals. The objective of the current study was to determine whether P(4) during growth of the first follicular wave (FFW) affects embryo quality. Lactating Holstein cows at 33±3 days post partum were allocated to one of three treatments. Cows in the FFW and FFW with P(4) (FFWP) treatments started the superstimulation protocol on day 1 of the estrous cycle and second follicular wave (SFW) cows started the superstimulation protocol on estrous cycle day 7. Cows were superstimulated with 400â mg of NIH-FSH-P1 (FSH) given twice daily for 5 days, two prostaglandin F(2α) (PGF(2α)) injections given with the ninth and tenth injections of FSH, GNRH given 48 âh after the first PGF(2α) injection, and timed insemination 12 and 24 âh after the GNRH injection. Cows in the FFWP treatment received two intravaginal P(4) inserts during the superstimulation. Embryos were recovered 6.5 days after artificial insemination and excellent/good and fair embryos were frozen and transferred. Blood was sampled daily from estrous cycle day 0 until insemination from donor cows. During the superstimulation protocol, P(4) was (P<0.01) greatest for SFW cows followed by FFWP and FFW cows respectively. The percentage of embryos-oocytes from SFW and FFWP cows classified as excellent/good and fair embryos was (P=0.02) greater than those of FFW cows. Pregnancy per embryo transfer was not (P≥0.73) affected by embryo donor treatment. Reduced embryo quality of cows induced to ovulate the follicles from the first follicular wave is a consequence of reduced P(4) during follicle growth.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Progesterona
/
Bovinos
/
Embrião de Mamíferos
/
Transferência Embrionária
/
Folículo Ovariano
Tipo de estudo:
Guideline
Limite:
Animals
/
Pregnancy
Idioma:
En
Revista:
Reproduction
Assunto da revista:
MEDICINA REPRODUTIVA
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Estados Unidos