Effects of active immunization against androstenedione or oestrone on oestrus, ovulation and lambing in Merino ewes

Martin, G.B.; Scaramuzzi, R. J.; Cox, R.I.; Gherardi, P.B.

doi:10.1071/ea9790673

Cited by 23 publications

(6 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Also it has shown that the improvement in ovulation rates after long-term immunisation compares favourably with those reported for the other breeds of sheep immunised for a shorter time interval (Scaramuzzi et al 1977;Martin et al 1978;Smith et al 1981). The primary and secondary immunisation regime produced a wide range of antibody titres at the time of mating.…”

Section: Discussionsupporting

confidence: 56%

Long-term active immunisation of Romney ewes with an androstenedione-protein conjugate — effects on oestrus, ovulation, and lambing

Gibb

Hudson

Kieboom

et al. 1982

New Zealand Journal of Experimental Agriculture

View full text Add to dashboard Cite

The aim of the present study was to determine the effects of primary and secondary immunisation with an androstenedione-protein conjugate 11 and 3 months before mating on oestrous activity, ovulation rate, and lambing performance in Romney ewes. No significant differences in prevalence of oestrous activity were observed between the immunised and control groups, although the onset of oestrus was significantly earlier in the former group (P<0.05). The immunised ewes had a higher ovulation rate (P<0.01) and produced more lambs than the controls (P

show abstract

Section: Discussionsupporting

confidence: 56%

Long-term active immunisation of Romney ewes with an androstenedione-protein conjugate — effects on oestrus, ovulation, and lambing

Gibb

Hudson

Kieboom

et al. 1982

New Zealand Journal of Experimental Agriculture

View full text Add to dashboard Cite

show abstract

“…Ovulation rate responds in a curvilinear manner to increasing titre levels, with ovulation being inhibited at high antibody titres (Martin et al 1979;Smith et al 1983;Scaramuzzi and Radford 1983;Webb et al 1984). In PMSG-treated oestradiol-immune ewes, Boland et al (1985) observed similar increases in ovulation rate and total ovarian response to superovulatory (1500 i.u.…”

Section: Discussionsupporting

confidence: 50%

Effect of Anti-oestradiol-17B Antibodies on the Reproductive Response of Ewes Superovulated with PMSG

Eppleston¹,

Nancarrow²,

Battye³

et al. 1988

Aust. Jnl. Of Bio. Sci.

View full text Add to dashboard Cite

A field experiment was conducted to examine the effect of anti-oestradiol-17B antibody titre on the oestrous and ovulatory responses of ewes to low (600 i.u.) or high (1200 i.u.) doses of pregnant mare's serum gonadotrophin (PMSG). Merino ewes were treated with intravaginal sponges and were subsequently used as vehicle-treated controls or were immunized to produce reciprocal anti-oestradiol-17B antibody titres of < 1000 or > 1000. Ewes were then treated with PMSG and the incidence of oestrus and ovulation, ovulation rate, and yield of embryos recorded.Treatment of immune ewes with 1200 i.u. PMSG resulted in both a higher proportion of ewes ovulating and a higher ovulation rate than in immune ewes treated with 600 i.u. (86% v. 67% and 13·4 v. 6·0 respectively).As anti-oestradiol-17B titres increased there was a reduction in the proportion of ewes exhibiting oestrus. The proportion of ewes ovulating decreased as antibody increased in ewes treated with 600 i.u. PMSG but not in those treated with 1200 i.u., suggesting an increased positive feedback of oestradiol with high PMSG doses. Fertilization rates were highest at the lower PMSG dose (68% v. 42%) and increased with increasing titre. Overall, there was no increase in ovulation rate or in yield of embryos over control values from either low « 1000) or high (> 1000) antibody titres.

show abstract

“…Higher ovulation rates have been observed in ewes immunized against oestradiol, oestrone and androstenedione (Van Look et al 1978;Martin et al 1979;Scaramuzzi et al 1980) and it was thought that the increased ovulation rates were caused by the increased secretion of gonadotrophins observed in immunized animals (Martensz et al 1976Scaramuzzi et al 1980). Similarly, the increased release of LH after immunization against progesterone may play a role in regulating ovulation rate in these animals.…”

Section: Methodsmentioning

confidence: 97%

Effect of Immunization against Progesterone on Oestrus, Cycle Length, Ovulation Rate, Luteal Regression and LH Secretion in the Ewe

Thomas¹,

Oldham²,

Hoskinson³

et al. 1987

Aust. Jnl. Of Bio. Sci.

Self Cite

View full text Add to dashboard Cite

The effects of active immunization against progesterone on reproductive activity were studied in Merino ewes. Immunization against progesterone caused a shortening (P < 0'01) of the interval between ovulations from 17-18 days (controls) to between 6 and 10 days (immunized group); this was associated with a corresponding reduction in the interval between LH surges. The immunized ewes also had higher (P < O· 05) ovulation rates (1' 72) than controls (I. 25) and exhibited a reduced (P < 0'01) incidence of oestrus (26% v. 95%). Many immunized ewes continued to ovulate despite the persistence of corpora lutea from earlier ovulations which led to an accumulation on the ovaries of many corpora lutea of different ages. The frequency of LH pulses in ewes immunized against progesterone (1'8 ± 0·2 pulses/4 h) was significantly (P < 0'001) higher than that of control ewes (0'3 ± 0·1 pulses/4 h). This study highlights the importance of progesterone in the control of oestrus, ovulation, ovulation rate, luteal regression and the secretion of LH in the ewe.

show abstract

Effects of active immunization against androstenedione or oestrone on oestrus, ovulation and lambing in Merino ewes

Cited by 23 publications

References 0 publications

Long-term active immunisation of Romney ewes with an androstenedione-protein conjugate — effects on oestrus, ovulation, and lambing

Long-term active immunisation of Romney ewes with an androstenedione-protein conjugate — effects on oestrus, ovulation, and lambing

Effect of Anti-oestradiol-17B Antibodies on the Reproductive Response of Ewes Superovulated with PMSG

Effect of Immunization against Progesterone on Oestrus, Cycle Length, Ovulation Rate, Luteal Regression and LH Secretion in the Ewe

Contact Info

Product

Resources

About