Influence of reproductive stage at PRID™ insertion on synchronization of estrus and ovulation in mares

Handler, Johannes; Schönlieb, Sabine; Hoppen, H. O.; Aurich, Christine

doi:10.1016/j.anireprosci.2006.02.012

Cited by 13 publications

(23 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Mare reproduction is characterized by its seasonality (i.e., autumn and winter), when the ovaries become inactive (anestrus) and the uterus has low uterine tonus and decreased endometrial edema (Newcombe 2002, Handler et al 2007). …”

Section: Discussionmentioning

confidence: 99%

“…Animals were assigned to one of two groups. In GP4 (n = 6), animals received intravaginal P4; these mares were in anestrus and had no CL, their follicles were < 25.0 mm (Handler et al 2007), and they had poor uterine tonus and no endometrial edema (Newcombe Two administrations of an intravaginal progesterone device on the induction of ovarian cyclicity in anestrous mares G. Polo et al…”

Section: Mare Selectionmentioning

confidence: 99%

“…However, the results of using P4 in anestrous mares are inconsistent. Different responses were observed after its use, which may be due to variation in the anestrus stage of each animal at the beginning of the protocol (Handler et al 2007). The hypothesis of this study is that the intravaginal P4 administration will induce ovarian cyclicity in mares in anestrus.…”

Section: Introductionmentioning

confidence: 99%

“…Mares are seasonally polyestrous animals that are influenced by photoperiod, with a restricted number of cycles and ovulations throughout the year (Palmer andGuillaume 1992, Guerin andWang 1994). The anestrus phase is characterized by a relatively relaxed cervix, lack of uterine tonus or endometrial edema, ovaries with follicles < 25 mm, and no corpus luteum (CL) (Newcombe 1994, Newcombe 2002, Handler et al, 2007. Mares carrying follicles smaller than 10 mm are characterized as being in the deep anestrus phase (Handler et al 2006).…”

Section: Introductionmentioning

confidence: 99%

“…Advantages of the intravaginal method are that the device is easy to handle, safe (with the exception of the risk of mild localized vaginitis), and inexpensive (Newcombe 2002). The P4 released by the device suppresses the secretion of luteinizing hormone (LH), levels of which rises quickly when the device is removed, thus stimulating follicular growth and ovulation (Arbeiter et al 1994, Handler et al 2007). …”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Two administrations of an intravaginal progesterone device on the induction of ovarian cyclicity in anestrous mares

Polo¹,

Weiss²,

Bertol³

et al. 2016

PHK

View full text Add to dashboard Cite

Summary:The study aimed to evaluate the effect of double administration of a progesterone (P4) intravaginal device on induction of ovarian cyclicity in mares. Twelve crossbred mares were assigned to one of two groups. The first group (GP4; n = 6; 100 % in anestrus phase) underwent the following protocol: day (d) 0, 1.9 g of P4 + ultrasound of the uterus and ovaries (US); d 7, US; d10, first P 4 removal + US; d10 -d 24, US daily; d 28, second P4; d 35, US; d 40, second P4 removal + US; d 40 -d 54, US daily; and d 54 -d 76, US every other day. The second group (GNP4; n = 5; 100 % in transition phase) underwent the same protocol as GP4, but without the administration of the P4 device. From d 55 -d 76, 100.0 % of the mares in both groups held uterine tonus and 83.3 % had endometrial edema; after the first and second P4 removal, 66.7 % and 83.3 % of GP4 mares, respectively, reached the transition phase. By d 76, 50.0 % and 80.0 % of the GP4 and GNP4 animals, respectively, had ovulated; the average size of the largest follicle increased from d 0 -d 76 in both groups, but was significant only in GP4. Four to five days after the first and second P4 removals in GP4, follicles showed an average growth of 9.0 mm. At the end of the study, both groups had follicular medium diameters greater than 34 mm (P > 0.05). Ovulations correlated with body condition scores (P < 0.05). In conclusion, two administration of P4 affected ovarian cyclicity in anestrous mares, and synchronized follicular waves and ovulation.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Mare Selectionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%