Buserelin in a superovulatory regimen for Holstein cows. I. Pituitary and ovarian hormone response in an experimental herd

Hj, Voss; Se, Allen; Rh, Foote; P, Im; Ck, Kim; Aquadro, P.

doi:10.1016/0093-691x(89)90543-8

Cited by 9 publications

(1 citation statement)

References 29 publications

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“…at various times relative to the onset of oestrus or to the injection of PG (36-54 h after PG treatment) that is, at about the time the spontaneous LH surge was expected, either for the practical purpose of synchronization of the cows with regard to the ovulation period (Foote et al, 1989;Voss et al, 1989) or to enhance the release of LH, on the assumption that the spontaneous LH surge would be insufficient to induce ovu¬ lation of mature oocytes of all stimulated follicles (Guay and Bedoya, 1981; Wubishet el al, 1986). Although improvement of oocyte quality at ovulation (Laurincik et al, 1991) and embryo yield (Wubishet et al, 1986) (Walton and Stubbings, 1986).…”

Section: Discussionmentioning

confidence: 99%

Effects of suppression by a progesterone-releasing intravaginal device and subsequent induction by GnRH of the preovulatory LH surge on follicular function in PMSG/PG-treated heifers

Vos¹,

Bevers²,

Willemse³

et al. 1994

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After synchronization of oestrus, normally cyclic heifers (n = 31) received 2500 iu pregnant mares' serum gonadotrophin (PMSG) i.m. and had a progesterone-releasing intravaginal device (PRID) without the oestradiol capsule inserted on day 10 of the oestrous cycle and received 15 mg prostaglandin(PG) i.m. 48 h later. PRIDs were removed 96 h after insertion and 16 heifers received 1.0 mg GnRH i.m. while the controls (n = 15) received 10 ml saline i.m. All heifers were injected with anti-PMSG i.v. 10 later. Peripheral blood concentrations of PMSG, progesterone, oestradiol and LH were compared. Ovaries were collected on death 7 days after the GnRH or saline injection and the number of corpora lutea counted. Heifers were considered to have responded well (> 60 pmol l-1) or poorly (< 60 pmol l-1) to superovulation on the basis of the oestradiol concentration 24 h after PG administration. During PRID treatment, LH concentrations remained at basal values. In the heifers treated with GnRH, a single LH surge occurred 2.3 +/- 0.1 h (SD) after the GnRH injection with a maximum concentration of 14.6 +/- 2.3 (SEM) micrograms l-1 and a duration of 6-8 h. In 12 of the 15 control heifers, LH concentrations remained low (range 0.10-1.94 micrograms l-1) during the 72 h following the saline injection; three controls showed a spontaneous LH surge at 18, 23 and 23 h after the saline injection, respectively, with a maximum concentration of 6.0-12.5 micrograms l-1 and a duration of 10-12 h.(ABSTRACT TRUNCATED AT 250 WORDS)

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