Sonomorphology of the reproductive tract in male and pregnant and non-pregnant female Rothschild's giraffes (Giraffa camelopardalis rotschildi)

Niemuller, Cheryl; Pootoolal, Jason; Rich, Peter; Gray, Charlie; Streich, W. Jürgen; Hildebrandt, Thomas B.

doi:10.1016/j.theriogenology.2009.01.016

Cited by 13 publications

(7 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Knowledge regarding the reproductive anatomy and ovarian functional structures in giraffes is derived mostly from postmortem findings [19][20][21]. By training giraffes to enter a restrainer and to accept rectal manipulation, the present study visualized the genital tract and ovarian events in situ by regular ultrasonography, as has been previously reported [22].…”

Section: Introductionmentioning

confidence: 67%

“…Because single values during pregnancy are comparable with peak luteal phase fP4 values, pregnancy cannot be determined by single fP4 measurements [14]. Ultrasonography can provide a first hint by Day 17 after mating that an animal is pregnant by visualization of whether the CL regressed or was now larger than the normal nonconceptive CL [22]. This phenomenon, together with the OVARIAN ACTIVITY IN CYCLING AND PREGNANT GIRAFFES 993 short functional life span of the CL during the cycle, indicates that the blastocyst signals its existence rapidly to induce maternal recognition and thus luteal rescue (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…In the pregnant giraffes, ultrasonography was performed one to two times per week until 13 wk into gestation. All procedures, restrainer, and equipment were described previously in detail [22].…”

Section: Ultrasonographymentioning

confidence: 99%

See 2 more Smart Citations

Ovarian Ultrasonography Correlated with Fecal Progestins and Estradiol During the Estrous Cycle and Early Pregnancy in Giraffes (Giraffa camelopardalis rothschildi)1

Hildebrandt

Pootoolal²,

Rich³

et al. 2009

Biology of Reproduction

Self Cite

View full text Add to dashboard Cite

Fecal and urinary progestin analyses have shown that giraffes express a short reproductive cycle, averaging 15 days, compared with other large ruminants. However, actual ovarian events have not been correlated with the hormonal pattern. In this study, mature cycling female Rothschild giraffes (Giraffa camelopardalis rothschildi) were repeatedly examined by transrectal ultrasonography to correlate ovarian function with changes in fecal progestin (fP4 [n(c) = 6]) and estradiol (fE2 [n(c) = 6]) and serum progestin (n(c) = 2) as measured by enzyme immunoassay. Five females became pregnant and were monitored during early gestation. In this study, we discovered that hormone values for fP4 in cycling giraffes do not correlate with the classic profile of follicular development, ovulation, and luteogenesis. The corpus luteum (CL) and the next dominant follicle were forming simultaneously. A mean +/- SD peak in fE2 of 254.92 +/- 194.76 ng/g and subsequent ovulation occurred as early as 1 day after the fall in fP4. In pregnant giraffes, the CL reached a diameter significantly larger (mean +/- SD, 41.02 +/- 2.70 mm; P = 0.0126) than that during the cycle (33.48 +/- 2.80 mm), while follicular activity and fluctuating fE2 were still present. With this research, we demonstrated that the progesterone profile typically used to characterize the ovarian cycle does not correlate with luteal development in the ovaries of this species. Furthermore, we conclude that the giraffe could have evolved a short reproductive cycle because of the almost parallel order of ovarian events.

show abstract

Section: Introductionmentioning

confidence: 67%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Ovarian Ultrasonography Correlated with Fecal Progestins and Estradiol During the Estrous Cycle and Early Pregnancy in Giraffes (Giraffa camelopardalis rothschildi)1

Hildebrandt

Pootoolal²,

Rich³

et al. 2009

Biology of Reproduction

Self Cite

View full text Add to dashboard Cite

show abstract

“…In other mammals, inadequate CL function has been described under specific circumstances, including puberty, postpartum estrus, and hormonal treatment [38]. In premature giraffes, luteinizing follicles form pseudo-CLs that do not secrete any progesterone [39]. The lack of P m secretion from LUFs in a normal estrous cycle seems reasonable in mature elephants as, in contrast to many other species, P m seems to completely inhibit antral follicle development [1].…”

Section: Discussionmentioning

confidence: 99%

Role of the Double Luteinizing Hormone Peak, Luteinizing Follicles, and the Secretion of Inhibin for Dominant Follicle Selection in Asian Elephants (Elephas maximus)1

Taya

Watanabe

Yamamoto

et al. 2011

Biology of Reproduction

Self Cite

View full text Add to dashboard Cite

Elephants express two luteinizing hormone (LH) peaks timed 3 wk apart during the follicular phase. This is in marked contrast with the classic mammalian estrous cycle model with its single, ovulation-inducing LH peak. It is not clear why ovulation and a rise in progesterone only occur after the second LH peak in elephants. However, by combining ovarian ultrasound and hormone measurements in five Asian elephants (Elephas maximus), we have found a novel strategy for dominant follicle selection and luteal tissue accumulation. Two distinct waves of follicles develop during the follicular phase, each of which is terminated by an LH peak. At the first (anovulatory) LH surge, the largest follicles measure between 10 and 19.0 mm. At 7 ± 2.4 days before the second (ovulatory) LH surge, luteinization of these large follicles occurs. Simultaneously with luteinized follicle (LUF) formation, immunoreactive (ir) inhibin concentrations rise and stay elevated for 41.8 ± 5.8 days after ovulation and the subsequent rise in progesterone. We have found a significant relationship between LUF diameter and serum ir-inhibin level (r(2) = 0.82, P < 0.001). The results indicate that circulating ir-inhibin concentrations are derived from the luteinized granulosa cells of LUFs. Therefore, it appears that the development of LUFs is a precondition for inhibin secretion, which in turn impacts the selection of the ovulatory follicle. Only now, a single dominant follicle may deviate from the second follicular wave and ovulate after the second LH peak. Thus, elephants have evolved a different strategy for corpus luteum formation and selection of the ovulatory follicle as compared with other mammals.

show abstract

“…This technique is considered a safe method because of its minimal bioeffects, as it is repeatable and provides real‐time information, thus generating high‐resolution characterization of soft tissues and bone surfaces. This technique facilitates morphometric studies of organs, implants or other foreign bodies, thus being economically efficient in terms of operation, and it is portable and compatible with zoo and field conditions (Hildebrandt et al., , ; Skajaeraasen et al., ; Lueders et al., ; Place et al., ).…”

Section: Introductionmentioning

confidence: 99%

Abdominal Exploration in Captive Collared Peccaries (Tayassu tajacu) by Ultrasonography

Peixoto

Oliveira

Alves

et al. 2012

Anat Histol Embryol

View full text Add to dashboard Cite

This study determines the morphology and ultrasound features of the abdominal organs in male, nestling and healthy collared peccaries. The bladder wall is hyperechogenic, with a thickness of 0.2 ± 0.08 cm. The kidneys present a well-defined cortex, medulla and pelvis, and the dimensions are 2.56 ± 0.3 × 4.6 ± 0.8 cm for the left and 2.51 ± 0.4 × 4.86 ± 1.1 cm for the right kidney. The spleen has a uniform echotexture over its entire surface. The largest dimensions of the liver are 2.0 ± 0.57 cm for the left lobe and 1.42 ± 0.66 cm for the caudate lobe. The liver presents a homogeneous echotexture in the majority of cases, but sometimes some hyperechoic spots are present. The stomach wall has a thickness of 0.42 ± 0.28 cm. The bowel loops show alternate hyperechoic and hypoechoic layers with a uniform diameter and a wall thickness of 0.19 ± 0.07 cm.

show abstract

Sonomorphology of the reproductive tract in male and pregnant and non-pregnant female Rothschild's giraffes (Giraffa camelopardalis rotschildi)

Cited by 13 publications

References 30 publications

Ovarian Ultrasonography Correlated with Fecal Progestins and Estradiol During the Estrous Cycle and Early Pregnancy in Giraffes (Giraffa camelopardalis rothschildi)1

Ovarian Ultrasonography Correlated with Fecal Progestins and Estradiol During the Estrous Cycle and Early Pregnancy in Giraffes (Giraffa camelopardalis rothschildi)1

Role of the Double Luteinizing Hormone Peak, Luteinizing Follicles, and the Secretion of Inhibin for Dominant Follicle Selection in Asian Elephants (Elephas maximus)1

Abdominal Exploration in Captive Collared Peccaries (Tayassu tajacu) by Ultrasonography

Contact Info

Product

Resources

About