Bioassay responses of ewes to legume swards.   II. Uterine weight results from swards

Bennett, D.; Morley, F. H. W.; Axelsen, A

doi:10.1071/ar9670495

Cited by 24 publications

(20 citation statements)

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“…Pasture containing~1000 mg/kg will inhibit oestrus and ovulation [24] but pasture containing 200-400 mg/kg will only depress ovulation [27]. Smith et al (1980) [140] reported that a coumestrol concentration of 25 mg/kg DM was sufficient to suppress the ovulation rate of ewes, a claim supported by earlier work [22,141].…”

Section: Tolerance Levelssupporting

confidence: 57%

Fertility of Herbivores Consuming Phytoestrogen-containing Medicago and Trifolium Species

Reed¹

2016

Agriculture

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Despite their unrivalled value in livestock systems, certain temperate, pasture, legume species and varieties may contain phytoestrogens which can lower flock/herd fertility. Such compounds, whose chemical structure and biological activity resembles that of estradiol-17α, include the isoflavones that have caused devastating effects (some of them permanent) on the fertility of many Australian sheep flocks. While the persistence of old 'oestrogenic' ecotypes of subterranean clover (Trifolium subterraneum) in pasture remains a risk, genetic improvement has been most effective in lowering isoflavone production in Trifolium species; infertility due to 'clover disease' has been greatly reduced. Coumestans, which can be produced in Medicago species responding to stress, remain a potential risk in cultivars susceptible to, for example, foliar diseases. In the field, coumestrol is often not detected in healthy vegetative Medicago species. Wide variation in its concentration is influenced by environmental factors and stage of growth. Biotic stress is the most studied environmental factor and, in lucerne/alfalfa (Medicago sativa), it is the major determinant of oestrogenicity. Concentrations up to 90 mg coumestrol/kg (all concentrations expressed as DM) have been recorded for lucerne damaged by aphids and up to 600 mg/kg for lucerne stressed by foliar disease(s). Other significant coumestans, e.g., 4'-methoxy-coumestrol, are usually present at the same time. Concentrations exceeding 2000 mg coumestrol/kg have been recorded in diseased, annual species of Medicago. Oestrogenicity of some Medicago species is also influenced by maturity and senescence. Studies in Israel, North America, Europe, New Zealand and Australia have confirmed that coumestans in lucerne, represent an acute or sub-acute loss of reproductive efficiency in herbivores, e.g., sheep, cattle, and possibly horses. When sufficiently exposed peri-conception, coumestrol, sometimes present in lucerne, be it as pasture, hay, silage, pellets, meal, and sprouts, is associated with what can be an insidious, asymptomatic, infertility syndrome. Most livestock research with oestrogenic lucerne has been conducted with sheep. Ewes may be at risk when the coumestrol concentration in their diet exceeds 25 mg/kg. In studies where lambing was compared for lucerne and a phytoestrogen-free treatment, the mean decrease in lambs born/ewe was 13%; ewes on lucerne, exhibited a lower frequency of multiple births.

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Section: Tolerance Levelssupporting

confidence: 57%

Fertility of Herbivores Consuming Phytoestrogen-containing Medicago and Trifolium Species

Reed¹

2016

Agriculture

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“…However, there is no pattern in isoflavone distribution, either as single compounds or total contents among the different plant parts (Cook et al, 1995;Vetter, 1995;Wu et al, 2003;Table 4). There are some large differences between cultivars (Bennet et al, 1967;Carlsen et al, 2008;Sachse, 1974), while some show no differences (Saloniemi et al, 1993). The formononetin content can differ between resistant and susceptible populations (Cook et al, 1995).…”

Section: Isoflavones/isoflavanones In White Clovermentioning

confidence: 99%

“…Many isoflavones show antifungal properties (Ingham, 1982;Van Etten, 1976;Virtanen and Hietala, 1958;Weidenbçrner et al, 1990) and estrogenic effects in ruminants (Bennet et al, 1967;Pettersson et al, 1984;Saloniemi et al, 1993;Shutt and Braden, 1968;Shutt and Cox, 1972). The isoflavones formononetin and biochanin A stimulate colonization by one AM fungus (Glomus intraradices) and white clover growth (Siqueira et al, 1991a), while biochanin A inhibit the growth of another AM fungus (Gigaspora margarita) (BØcard et al, 1992).…”

Section: Biological Effects Of Isoflavones and Isoflavanones And Theimentioning

confidence: 99%

Biologically active secondary metabolites in white clover (Trifolium repens L.) – a review focusing on contents in the plant, plant–pest interactions and transformation

Carlsen

Fomsgaard

2008

Chemoecology

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To exploit biologically active compounds from white clover (Trifolium repens L.) for suppressing weeds and soil-borne diseases, either as isolated products (biopesticides) or through cultivars with enhanced production of these compounds, the biologically active compounds must be identified, plant content measured, and their fate in soil known. The present review summarizes the published knowledge needed for such exploitation; providing essential information on structure and concentration of flavonols, flavones, condensed tannins, isoflavones, isoflavanones, pterocarpans, coumestans, cyanogenic glucosides, and saponins in healthy and stressed white clover plants. Various stresses and particular cultivars affect the concentrations of several of the compounds. Information on biological effects and the degradation/transformation of these compounds in plants or by microorganisms is available. There is no information on the degradation pathway in soil, the mechanisms of exudation and leaching of compounds from plants, and soil sorption properties of the compounds. The clover soil fatigue problem is increasing in grasslands and causes problems especially in organic farming. Research efforts focused on biological elements of clover soil fatigue have not explained it, and the influence of secondary metabolites has not been investigated. There are few investigations into the interaction between beneficial fungi/fungal-diseases and the occurrence of biologically active secondary metabolites in white clover plants. Such studies are critical to better understand beneficial fungi and pathogens.

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“…1964).· However, oestrogenic effects of this clover in sheep and cattle have occasionally been reported in the U.S.A. (Sanger and Bell 1961;Wright 1960), Japan (Ochi et at. 1964), Australia (Bennett et at. 1967), andBritain (Newton et at.…”

Section: Introductionmentioning

confidence: 99%

The oestrogenic activity of white clover (Trifolium repensL.)

Wong¹,

Flux

Latch

1971

New Zealand Journal of Agricultural Research

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Bioassay responses of ewes to legume swards. II. Uterine weight results from swards

Cited by 24 publications

References 0 publications

Fertility of Herbivores Consuming Phytoestrogen-containing Medicago and Trifolium Species

Fertility of Herbivores Consuming Phytoestrogen-containing Medicago and Trifolium Species

Biologically active secondary metabolites in white clover (Trifolium repens L.) – a review focusing on contents in the plant, plant–pest interactions and transformation

The oestrogenic activity of white clover (Trifolium repensL.)

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