Levels of luteinizing hormone (LH), follicle stimulating hormone (FSH), progesterone and estradiol-17 beta were measured in five Polled Hereford cows. Blood samples were collected once or twice daily for 5 d, then every 6 h from 1 d before weaning (d 28 to 38 postpartum) until 10 d after the second postweaning estrus. Blood samples were again collected at daily intervals until the third postwea...

Introduction Yaks are seasonal breeders and the breeding season lasts from July to October. If the females do not show obvious estrus in a particular breeding season, they will express estrus in the next breeding season or in some cases not until several breeding season later. The observed estrus rate of yaks is rather low, and the postpartum period is long. Most females deliver calves once eve...

Twelve healthy and not pregnant local cows, aged 3-6 years, 1-3 parity. The cows were synchronized using the PGF2α of 5 ml/cow intramuscularly, twice at 11 days intervals. Estrus detection based on scoring van Eerdenburg was conducted 24 hours after second prostaglandin injection three times daily for days. changes in cervical dilatation observed 0, 6, 12 from onset estrus. result showed that 8...

Characterization of factors influencing estrus and ovulation in sows may facilitate development of procedures for improving reproductive performance. The experiment was conducted in confinement during 1997 to 1999 using 174 Large White x Landrace sows. After weaning, sows were checked for estrus twice daily. In the 1st yr, transrectal ultrasound was performed once daily and in the 2nd yr twice ...

The experiment was conducted on 14 postpartum mithun (Bos frontalis) cows to establish the preovulatory LH and FSH surge patterns during estrus in peripheral circulation. Blood samples from jugular vein were collected every 2 h until 72 h and on alternate days till day 22 (day 0 = day of estrus) following the day of estrus onset. Plasma progesterone (P4), LH and FSH levels were estimated. Plasm...

In postpartum cows, ovulatory follicle size at time of insemination (GnRH/TAI) influenced pregnancy rates following TAI, but had no effect on pregnancy rates when cows spontaneously ovulated. Furthermore, cows that exhibited estrus (± 24 h of GnRH/TAI) had higher pregnancy rates compared to cows not in estrus. The objective was to assess the relationship between ovulatory follicle size and estr...

The objectives of the first experiment were to characterize the pattern of protein secretion by 1) porcine follicles before and after the preovulatory gonadotropin surge and 2) corpora lutea on d 4 and 11 after estrus (d 0 = estrus). Gilts were ovariectomized 1) on d 20 after estrus and before the preovulatory gonadotropin surge (pre-estrus group; n = 3), 2) 18 to 36 h after the onset of estrus...

This study aimed to determine the length of estrus period in Aceh cows based on changes characteristics cervical mucus observed using a camera-equipped artificial insemination (AI) endoscope. used twelve healthy and reproductively sound aged 4-6 years. All were synchronized prostaglandin F2α (PGF2α) injected intramuscularly twice, 11 days apart. Estrus detection was conducted 24 hours following...

Here, we report a new method for measuring behavioral patterns during estrus in goats based on video tracking analysis. Data were collected from cycling goats, which were in estrus (n = 8) or not in estrus (n = 8). An observation pen (2.5 m × 2.5 m) was set up in the corner of the female paddock with one side adjacent to a male paddock. The positions and movements of goats were tracked every 0....