EurekaMag.com logo
+ Site Statistics
References:
52,725,316
Abstracts:
28,411,598
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Progesterone and estradiol in biodegradable microspheres for control of estrus and ovulation in mares


Theriogenology 40(3): 465-478
Progesterone and estradiol in biodegradable microspheres for control of estrus and ovulation in mares
Progesterone and estradiol 17-beta in poly (DL-lactide) microspheres were used to control estrus and ovulation in mares after luteolysis was induced by prostaglandin F-2 infin . Mares were given a single intramuscular injection of biodegradable poly (DL-lactide) microspheres, 1 day following prostaglandin treatment, containing no hormones (control), 0.625 g progesterone and 50 mg estradiol (low dose), 1.25 g progesterone and 100 mg estradiol (medium dose), or 1.875 g progesterone and 150 mg estradiol (high dose; n=15 mares per group). Mares treated with the low dose had significantly longer intervals (P lt 0.05) to estrus and ovulation than the control mares; however, low dose mares had shorter intervals (P lt 0.05) to estrus than high dose mares and shorter intervals to ovulation than medium and high dose mares. Regression analysis indicated that the medium dose was sufficient for maximizing interval to ovulation while the high dose maximized interval to estrus. All groups of mares exhibited similar (P gt 0.05) post-treatment estrus lengths. A clinical response scoring system based on synchrony of both estrus and ovulation within a treatment group was also used to measure the effectiveness of treatments on control of estrus and ovulation. Clinical response scores did not differ (P gt 0.05) among treatment groups. Mares were randomly assigned for insemination at the beginning of the first post-treatment estrus. Rates for embryo recovery performed by uterine lavage 7 days post-ovulation did not differ (P gt 0.05) among groups. Concentrations of serum progesterone increased in mares receiving progesterone and estradiol microspheres. At 10 to 14 days post-injection of microspheres, progesterone concentrations were higher (P lt 0.05) and remained above 1 ng/ml in the mares receiving the high dose. Progesterone concentrations were also higher (P lt 0.05) on Days -3 to -1 (Day 0 = day of post-treatment ovulation) in mares receiving the high dose when compared to control mares. Gonadotropin concentrations were suppressed (P lt 0.05) in the medium and high dose groups.

Accession: 002468633

PMID: 16727330

DOI: 10.1016/0093-691x(93)90400-y

Download PDF Full Text: Progesterone and estradiol in biodegradable microspheres for control of estrus and ovulation in mares



Related references

Regulation of estrus and ovulation in mares with progesterone or progesterone and estradiol biodegradable microspheres with or without PGF2alpha. Theriogenology 38(6): 1091-1106, 1992

Regulation of estrus and ovulation in mares with progesterone or progesterone and estradiol biodegradable microspheres with or without PGF2 alpha. Theriogenology 38(6): 1091-1106, 1992

Regulation of estrus and ovulation in cyclic mares with progesterone and estradiol biodegradable microspheres: effects of different doses of estradiol. Journal of Equine Veterinary Science 13(9): 525-528, 1993

Evaluation of biodegradable microspheres for the controlled release of progesterone and estradiol in an ovulation control program for cycling mares. Journal of Equine Veterinary Science 13(9): 521-524, 1993

Regulation of estrus and ovulation in cyclic mares with progesterone or progesterone plus estradiol biodegradable microsphere with or without pgf2 alpha. Journal of Animal Science 70(SUPPL 1): 268, 1992

A preliminary report on the efficacy of biodegradable microspheres for the controlled release of progesterone and estradiol for synchronization of ovulation in mares. Theriogenology 33(1): 202, 1990

Use of microspheres of progesterone and estradiol for ovulation control in mares. Journal of Animal Science 70(SUPPL 1): 127, 1992

Biodegradable estradiol microspheres do not affect uterine involution or characteristics of postpartum estrus in mares. Theriogenology 42(2): 371-384, 1994

Estrus, ovulation, and serum progesterone, estradiol, and LH concentrations in mares after an increased photoperiod during winter. American Journal of Veterinary Research 38(2): 203-207, 1977

Estrus ovulation and serum progesterone estradiol and luteinizing hormone concentrations in mares after an increased photoperiod during winter. American Journal of Veterinary Research 38(2): 203-207, 1977