Improvement of sheep fecundity by treatment with antisera to gonadal steroids

Land, R. B.; Morris, Brian; Baxter, G. Andrew; Fordyce, Marjorie; Forster, J. R. M.

doi:10.1530/jrf.0.0660625

Cited by 56 publications

(29 citation statements)

References 14 publications

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“…In this study androstenedione binding activity was lower than that obtained in sheep (Land, Morris, Baxter, Fordyce and Forster, 1982). The immunization protocol used in the present study was similar to that reported previously in cattle, in which there was an increased ovulation rate.…”

Section: Discussionsupporting

confidence: 89%

Follicle populations, ovulation rates and profiles of gonadotropins, inhibin and insulin-like growth factor-1 of heifers actively immunized against androstenedione and inhibin, separately or in combination

Rhind¹,

Schemm

Schanbacher

1993

Anim. Sci.

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Link to this article: http://journals.cambridge.org/abstract_S0003356100006607How to cite this article: S. M. Rhind, S. R. Schemm and B. D. Schanbacher (1993). Follicle populations, ovulation rates and proles of gonadotropins, inhibin and insulin-like growth factor-1 of heifers actively immunized against androstenedione and inhibin, separately or in combination. Abstract Four groups of 20 Simmental cross heifers were actively immunized against human serum albumin (control, (Q), androstenedione (A), a 30 amino acid synthetic fragment of porcine inhibin alpha (I) or A and I in combination (AI). At the time of the third and final antigen injection and again 2 weeks later, all animals were injected with synthetic prostaglandin F 2a (PG) to synchronize oestrus. Concentrations of LH, FSH, insulin-like growth factor-1 (IGF-1) and inhibin (C and A heifers only) in serum samples collected twice daily during 3 days before the second PG injection and at 15-min intervals from 24 to 32 h after PG injection were determined. Two weeks later, all heifers were administered PG and ovariectomized 24 h later.Ovarian follicles were dissected from the stroma, measured and cultured in medium 199 for 2h at 37°C. Numbers of small (3-0 to 7-9 mm diameter) and large (>8-0 mm diameter) follicles were not significantly altered by any of the immunization treatments. Intrafollicular concentrations and secretion rates of oestradiol, testosterone, progesterone and inhibin, determined in vitro, were not affected by immunization. Intrafollicular IGF-1 concentrations were not affected; this hormone was not detectable in the culture medium. Intrafollicular concentrations of oestrogen and testosterone and secretion rates of all three steroids were greater (P < 0-05) in animals which had regressing corpora lutea at the time of ovariectomy. Of the animals that had dominant follicles, one of 17, one of 13, four of 19 and six of 15 in the C, A, I and AI groups, respectively, had two or more. Only the difference between AI and C cows in the incidence of dominant follicles was statistically significant (P < 0-05). Mean circulating concentrations of LH, and inhibin (C and A groups only) and mean LH pulse frequency and pulse amplitude were unaffected by treatment but FSH concentrations were higher in A (P < 0-001) and lower in AI and I heifers (P < 0-001) compared with C animals while IGF-1 concentrations were lower in A heifers (P < 0-001) and higher in AI heifers (P < 0-05) compared with C heifers. It is concluded that immunization against inhibin, either alone or in combination with immunization against androstenedione increased the incidence of multiple dominant follicles in heifers but did not increase their ovulation rate.

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Section: Discussionsupporting

confidence: 89%

Follicle populations, ovulation rates and profiles of gonadotropins, inhibin and insulin-like growth factor-1 of heifers actively immunized against androstenedione and inhibin, separately or in combination

Rhind¹,

Schemm

Schanbacher

1993

Anim. Sci.

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“…The prevention of oestrus and ovulation by circulating antibodies to oestrogens has also been noted in other species (Sundaram, Tsong, Hood & Brinson, 1973;Ferin, Dyrenfurth, Cowchock, Warren & Vande Wiele, 1974;Elsaesser & Parvizi, 1977;Martin, Henricks, Hill & Rawlings, 1978;Elsaesser, 1980). Nevertheless, the increases in ovulation and lambing rates after immunization of sheep against oestrogens have been reported (Smith et ai, 1981 ;Land, Morris, Baxter, Fordyce & Forster, 1982). Since active or passive immunization with steroid hormones is now being considered for practical applications, the objectives of this study were to document the reproductive effects of active immunization of beef cattle against androstenedione and oestradiol-17ß (oestradiol) in relation to ovulation rates, conception rate, blood steroid hormones and ovarian morphology.…”

Section: Introductionmentioning

confidence: 86%

Reproductive effects of immunizing heifers against androstenedione and oestradiol-17

Wise¹,

Schanbacher²

1983

Reproduction

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“…The antiserum (sheep 505) raised in sheep against testosterone-3-carboxymethyloxime (CMO) conjugated to egg albumen (Land et al, 1982) was used at a final dilution of 1:128 000. Gelatin phosphate buffer was used as RIA diluent and dextran-coated charcoal was used to separate the bound from the free testosterone.…”

Section: Methodsmentioning

confidence: 99%

Effect of semen collection frequency on seasonal variation in sexual behaviour, testosterone, testicular size and semen characteristics of tropical hair rams (Ovis aries)

Aguirre

Orihuela

Vázquez

2007

Trop Anim Health Prod

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The purpose of this study was to examine the effect of day length on seminal characteristics, testicular size, sexual behaviour and testosterone (T4) concentration in pelibuey rams subjected to different semen collection frequencies. eighteen intact males were assigned randomly to one of two semen collection frequencies: in the high rate (HR) treatment, two ejaculations per week were obtained from each ram; one ejaculation every two weeks was collected under the low rate (LR) treatment. All animals were housed individually in contiguous 5 m x 5 m wire mesh pens and evaluated over a 12-month period. At the beginning of the experiment rams were 20 months old and 40-50 kg in weight. All rams ejaculated and produced semen throughout the year. Semen volume, sperm per ejaculation, testicular circumference and testicular volume were significantly (p < 0.05) greater during short days in all rams, regardless of the semen collection frequency, with the exception of sperm concentration, for which no variation was found in hr individuals, and reaction time and T4 levels, for which no variation was found in IR males. Rams subjected to HR collection were more affected by the short-day photoperiod than rams collected twice per week, exhibiting greater reduction (p < 0.05) in time to achieve their first ejaculation and in sperm per ejaculation, as well as greater increases (p < 0.05) in T4 concentration than IR rams (14.65 +/- 1.22 vs 23.53 +/- 5.34 s, (3.37 +/- 0.17) x 10(9) vs (3.52 +/- 0.20) x10(9) sperm and 8.68 +/- 0.44 vs 6.85 +/- 0.74 ng/ml, respectively). It was concluded that: (a) the magnitude of the seasonal effects was not sufficient to prevent the rams being used for breeding throughout the year, and (b) seasonal variation within variables was affected differently between semen collection frequencies.

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Improvement of sheep fecundity by treatment with antisera to gonadal steroids

Abstract: T, 1\m=.\5for Group M and 1\m=.\0for the controls. The increase in the number of lambs born was due to a higher proportion giving birth to twins (P < 0\m=.\01); no ewe gave birth to triplets. High conception rates were recorded for all treatments.

Cited by 56 publications

References 14 publications

Follicle populations, ovulation rates and profiles of gonadotropins, inhibin and insulin-like growth factor-1 of heifers actively immunized against androstenedione and inhibin, separately or in combination

Follicle populations, ovulation rates and profiles of gonadotropins, inhibin and insulin-like growth factor-1 of heifers actively immunized against androstenedione and inhibin, separately or in combination

Reproductive effects of immunizing heifers against androstenedione and oestradiol-17

Effect of semen collection frequency on seasonal variation in sexual behaviour, testosterone, testicular size and semen characteristics of tropical hair rams (Ovis aries)

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