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Simple Summary: Phytoestrogens are secondary plant metabolites that are structurally similar to endogenous estrogens and may result in adverse reproductive effects in grazing livestock. This study evaluated the key phytoestrogens in legume pastures and their effect on superovulation, embryo quantity and embryo quality. Cows grazed on legume and ryegrass pastures for a duration of 7 weeks at two timed treatments and were subjected to a conventional estrus synchronization and superovulation protocol. Coumestrol and formononetin were identified as the dominant phytoestrogens. The results from the grazing trial suggest that grazing potential estrogenic legume pastures less than 20 days before artificial insemination may affect oocyte developmental competence and contribute to early embryonic loss. Ovulation and artificial insemination rates have been observed to decrease in sheep and cows when exposed to dietary phytoestrogens at concentrations greater than 25 mg/kg DM. A grazing trial was undertaken to investigate the effects of coumestrol and other key phytoestrogens on the superovulatory response, embryo numbers and quality in beef cows grazing legume pastures. A 7-week controlled grazing trial was conducted with legume and ryegrass pasture treatments, with cows exposed to legumes at two timed treatments, 4 and 7 weeks. Twenty Angus cows were subjected to a conventional estrus synchronization and superovulation protocol. Embryos were recovered via conventional uterine body flushing 7 days post artificial insemination (AI). Numerous phytoestrogens were identified in both pasture and plasma samples, including coumestrol and formononetin. Concentrations of phytoestrogens in the pasture ranged from 0.001 to 47.5 mg/kg DM and 0 to 2.6 ng/mL in plasma. Approximately 50% of cows produced viable embryos 7 days post AI. A significant interaction between the effect of treatment groups on the embryo stage was observed (p < 0.05). The results suggest that concentrations of >25 mg/kg DM of phytoestrogens less than 20 days preceding AI may negatively affect oocyte developmental competence, reduce progesterone production and thus contribute to early embryonic loss. [ABSTRACT FROM AUTHOR]

Simple Summary: Insects, including dung beetles, rely on volatile cues to locate food and mates. However, the antennal responses of dung beetles to dung headspace volatiles have received minimal attention. To address this gap, we conducted a scanning electron microscopy study to examine the density distribution of three types of antennal sensilla in three introduced dung beetle species found in Australia: Geotrupes spiniger, Bubas bison and Onitis aygulus. The gross morphology of the antennal sensilla of these species is described here for the first time. Notably, we observed distinct patterns of sensilla trichodea, sensilla basiconica and sensilla chaetica on the proximal and distal surfaces of three lamellae in their antennal clubs. Furthermore, using electroantennography, we investigated the olfactory responses of these dung beetles to ten selected dung volatiles and mixtures of the same volatiles. The test chemicals evoked differential antennal responses in all three test species. The results are discussed in relation to the distribution and density of the antennal sensilla and the potential role of dung headspace volatiles in dung preference by these dung beetles. Overall, our findings indicate the possibility of using EAG-active compounds to attract dung beetles in the field. Locating sporadically distributed food resources and mate finding are strongly aided by volatile cues for most insects, including dung beetles. However, there is limited information on the olfactory ecology of dung beetles. We conducted a scanning electron microscopy study on the morphology and distribution of the antennal sensilla of three introduced dung beetle species in Australia: Geotrupes spiniger (Coleoptera: Geotrupidae), Bubas bison and Onitis aygulus (Coleoptera: Scarabaeidae). Three main morphological types of antennal sensilla were identified: sensilla trichodea (ST), sensilla basiconica (SB) and sensilla chaetica (SCh). Distinct variations of SB distribution were observed in B. bison and G. spiniger and on different lamellar surfaces in both sexes of all three species. Sexual dimorphism in antennal sensilla distribution or their abundance was not evident. To complement the morphological characterisation of sensilla, electroantennography (EAG) was carried out to construct EAG response profiles of the three species to selected dung volatiles. An initial study revealed that antennae of all species were sensitive to a mix of phenol, skatole, indole, p-cresol, butanone and butyric acid, common components of livestock dung headspace. In addition to these six compounds, dimethyl sulfide, dimethyl disulfide, eucalyptol and toluene were tested for antennal activity. All compounds evoked measurable EAG responses, confirming antennal sensitivity. Geotrupes spiniger exhibited significant responses to all the compounds compared to the control, whereas B. bison and O. aygulus only responded to a subset of compounds. A comparison of relative EAG amplitudes revealed highly significant responses to p-cresol in G. spiniger and to skatole in B. bison. Geotrupes spiniger displayed differential responses to all the compounds. Pooled EAG data suggest highly significant differences in responses among the three species and among compounds. Our findings suggest that a blend of volatiles may offer potential for the trapping of dung beetles, thereby avoiding the use of dung baits that are inconvenient, inconsistent and may pose a threat to farm biosecurity. [ABSTRACT FROM AUTHOR]

Abstract: Mikania micrantha Kunth, commonly known as bitter vine, American rope, or mile-a-minute, is a rapidly growing vine, native to tropical America. Mikania micrantha is present in 20 Pacific island [...]

Elevated concentrations of manganese (Mn2+) can persist after drainage in soil following wetland rice production, leading to toxicity in subsequent legume crops. To evaluate Mn2+ concentration causing adverse impacts on crop establishment and growth, a controlled environment experiment using hydroponics was designed. Germination and growth of field pea, faba bean and mung bean were evaluated over 21 d with an increase in Mn2+ (0 − 50 mg Mn2+L−1). Germination of all crops was impacted significantly with an increase in concentration of Mn2+. Leaf chlorophyll content as well as all plant growth parameters assessed (dry weight, height) were negatively impacted (p < 0.05) by increasing concentrations of Mn2+. Field peas and faba beans proved more sensitive to Mn2+ than did mung beans at concentrations of 5 − 10 mg L−1. Field pea and faba bean specifically exhibited reduced height (30 − 60% and 4 − 41%, respectively), root length (12 − 30% and 20 − 25%, respectively), and shoot weight (41 − 69% and 47 − 81%, respectively). Mung bean was less impacted in terms of plant height with 23% reduction at 25 mg Mn2+ L−1 and shoot dry weight reduced by 48% at 50 mg Mn2+ L−1. Total chlorophyll content of mung bean was severely affected (86% reduction at 50 mg Mn2+ L−1), with field pea least impacted. Our findings suggest that significant Mn2+ toxicity could potentially occur in terms of legume germination and overall growth if legume crops are sown into post-rice soils with ≥5 mg Mn2+L−1. Soil Mn2+ level must be considered when developing cropping strategies following flooded rice. [ABSTRACT FROM AUTHOR]