Southern Agricultural Region Research Articles

A novel method to assess the integrity of frozen archival DNA samples: Alpha‐diversity ratios of short‐ and long‐read 16S rRNA gene sequences

Abstract Archival DNA samples collected and analysed for a range of research and applied questions have accumulated in the laboratories of universities, government agencies and commercial service providers for decades. These DNA archives represent a valuable, yet largely un‐tapped repository of genomic information. With lowering costs of, and increasing access to, high‐throughput sequencing, we predict an increase in retrospective research to explore the wealth of information that resides in these archival samples. However, for this to occur, we need confidence in the integrity of the DNA samples, often stored under suboptimal conditions and their fitness of purpose for downstream genomic analysis. Here, we borrow from a well‐established concept in ancient DNA to evaluate sample integrity, defined as loss of information content in recovered amplicons, of frozen DNA samples and based on the ratio of ⍺‐diversity of short‐ and long‐read 16S rRNA gene sequences. The 16S rRNA variable region of 87 stored DNA samples, extracted from soil, collected from western and southern agricultural regions of Australia between 2001 and 2021 were sequenced using both PacBio full length reads (V1–V9, 1.5 kbp) and Illumina short‐reads (V3–V4, 200–450 bp). When ⍺‐diversity ratios were calculated between the long and short reads to assess DNA degradation, the ratio of ⍺‐diversity did not decrease in older samples versus younger samples. We suggest this as a novel method to confirm integrity of DNA before embarking on large‐scale diversity profiling projects using archival DNA.

A genome-wide perspective on the diversity and selection signatures in indigenous goats using 53 K single nucleotide polymorphism array.

Tibetan goats, Taihang goats, Jining grey goats, and Meigu goats are the representative indigenous goats in China, found in Qinghai-Tibet Plateau, Western pastoral area, Northern and Southern agricultural regions. Very few studies have conducted a comprehensive analysis of the genomic diversity and selection of these breeds. We genotyped 96 unrelated individuals, using goat 53 K Illumina BeadChip array, of the following goat breeds: Tibetan (TG), Taihang (THG), Jining grey (JGG), and Meigu (MGG). A total of 45 951 single nucleotide polymorphisms were filtered to estimate the genetic diversity and selection signatures. All breeds had a high proportion (over 95%) of polymorphic loci. The observed and excepted heterozygosity ranged from 0.338 (MGG) to 0.402 (JGG) and 0.339 (MGG) to 0.395 (JGG), respectively. Clustering analysis displayed a genetically distinct lineage for each breed, and their Fst were greater than 0.25, indicating that they had a higher genetic differentiation between groups. Furthermore, effective population size reduced in all four populations, indicating a loss of genetic diversity. In addition, runs of homozygosity were mainly distributed in 5-10 Mb. Lastly, we identified signature genes, which were closely related to high-altitude adaptation (ADIRF) and prolificity (CNTROB, SMC3, and PTEN). This study provides a valuable resource for future studies on genome-wide perspectives on the diversity and selection signatures of Chinese indigenous goats.

Urban Trees in the Arctic City: Case of Nadym

Trees in Arctic cities perform not only important provisional and regulating ecosystem services, but also bring predominantly settler population closer to the visual images and household standards of their home southern regions. However, maintenance of green infrastructure in the Arctic has specific difficulties associated with the harsh climatic and environmental conditions. This paper focuses on state and dynamics of vegetation in the city of Nadym, Russia, with a particular focus on native and introduced trees as the main ecosystem service providers and an articulation of local values towards green spaces. The research is based on interdisciplinary approach which includes interviews with local residents, geobotanical survey and analysis of remote sensing data. The results of the study show that maintaining of natural vegetation requires specific measures due to environmental the critical impact of anthropogenic activity. The active introduction of plants from more southern regions is manifested both in the deliberate practice of landscaping the city’s streets and courtyards, and in spontaneous attempts to introduce plants from more southern (not Subarctic) agricultural regions of Russia, which are privately brought by city residents from other regions.

城市绿色空间可达性与居民分布的空间匹配与影响因素

PDF HTML阅读 XML下载 导出引用 引用提醒 城市绿色空间可达性与居民分布的空间匹配与影响因素 DOI: 10.5846/stxb202106151586 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 浙江省哲学社会科学规划课题青年项目（20NDQN294YB）；国家社会科学基金项目（20FYB054）；浙江省自然科学基金项目（LQ20D010004）；宁波市社会科学研究基地课题（JD5-ZD41） Spatial match between urban residents' distribution and green space accessibility and its driving force Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:城市居民的绿色空间可达性是衡量城市基础设施公平分配的指向标，关乎城市民生福祉。以宁波为研究区，基于高德地图路径规划Application Programming Interface （API）测度了绿色空间可达性，融合多源数据模拟了人口空间分布，分析了绿色空间可达性与人口分布的空间匹配状态，并采用地理探测器探讨其影响因素。研究表明：①宁波绿色空间可达性由各区中心向郊区衰减，高可达性空间占比不高，反映了绿色服务供给不足的现状。高可达性空间集中于三江口、鄞州新城、北仑城区和镇海老城区，低可达性空间则主要分布在东部郊区、西部山区和南部农业区。②宁波居民的绿色空间可达性在空间上表现为市中心高人口密度-高可达性和郊区低人口密度-低可达性的空间匹配特征，在规模上仅不及半数的居民享有15min绿色空间可达性，在乡镇尺度上呈现显著的城区-郊区二元类型分异。③城市居民绿色空间可达性受多重影响因子驱动，按照重要性依次为区位特征、人类活动、开发强度、社会经济和地形条件。 Abstract:The accessibility of urban residents to green spaces is not only an essential indicator of equitable distribution of urban infrastructure but also a basic component to build livable city, which is linked with urban resident's well-being. In this study, taking Ningbo urban area as a case, we calculated the accessibility of urban green space using the Amap route planning Application Programming Interface. We also simulated the spatial distribution of urban resident based on multi-source data, including land use, nightlight, Normalized Difference Vegetation Index (NDVI), Point of Interest (POI), and road network. The spatial match between green space accessibility and urban residents' distribution was thus analyzed on the grid scale with a resolution of 100 m. Furthermore, the drivers for the accessibility of urban residents to green spaces was explored using the GeoDetector. The results show that the accessibility of green space in Ningbo is descending from each district's downtown to peripheral area, with a large proportion of poor accessibility coverage, indicating the weak green service on the whole. The area with good accessibility to green space is concentrated in the confluence of Yao River, Fenghua River and Yong River, Yinzhou new city, Beilun downtown, and Zhenhai old urban area, while the area with poor accessibility is distributed in the eastern and western mountainous area and the southern agricultural region. The accessibility of urban residents to green spaces in Ningbo shows two characteristics:high-density population and good green space accessibility in the downtown and low-density population and poor green space accessibility in the urban periphery. Also, it tends to evolve into an urban-rural dual structure at sub-district scale, which can be classified as three types including downtown, urban periphery, and industrial cluster/agricultural region/ecological conservation area. The proportion of urban residents living with green space accessibility within 15 min is less than 50%, reflecting the limited green service for urban residents in Ningbo. The drivers for the accessibility of urban residents to green spaces analyzed by the GeoDector show that five indicators as proxies for drivers are both significant. The ranking of drivers for the accessibility of urban residents to green spaces is location, human activity, development intensity, social economy, and terrain condition. 参考文献 相似文献 引证文献

Sustainability of nutrient management in grain production systems of south-west Australia

Balancing nutrient inputs and exports is essential to maintaining soil fertility in rainfed crop and pasture farming systems. Soil nutrient balances of land used for crop and pasture production in the south-west of Western Australia were assessed through survey data comprising biophysical measurements and farm management records (2010–15) across 184 fields spanning 14 Mha. Key findings were that nitrogen (N) inputs via fertiliser or biological N2 fixation in 60% of fields, and potassium (K) inputs in 90% of fields, were inadequate to balance exports despite increases in fertiliser usage and adjustments to fertiliser inputs based on rotations. Phosphorus (P) and sulfur (S) balances were positive in most fields, with only 5% returning losses >5 kg P or 7 kg S/ha. Within each of the three agroecological zones of the survey, fields that had two legume crops (or pastures) in 5 years (i.e. 40% legumes) maintained a positive N balance. At the mean legume inclusion rate observed of 20% a positive partial N budget was still observed for the Northern Agricultural Region (NAR) of 2.8 kg N/ha.year, whereas balances were negative within the Central Agricultural Region (CAR) by 7.0 kg N/ha.year, and the Southern Agricultural Region (SAR) by 15.5 kg N/ha.year. Hence, N budgets in the CAR and SAR were negative by the amount of N removed in ~0.5 t wheat grain, and continuation of current practices in CAR and SAR fields will lead to declining soil fertility. Maintenance of N in the NAR was achieved by using amounts of fertiliser N similar to other regions while harvesting less grain. The ratio of fertiliser N to legume-fixed N added to the soil in the NAR was twice that of the other regions. Across all regions, the ratio of fertiliser N to legume-fixed N added to the soil averaged ~4.0:1, a major change from earlier estimates in this region of 1:20 under ley farming systems. The low contribution of legume N was due to the decline in legume inclusion rate (now 20%), the low legume content in pastures, particularly in the NAR, and improved harvest index of lupin (Lupinus angustifolius), the most frequently grown grain legume species. Further quantifications of the effects of changing farming systems on nutrient balances are required to assess the balances more accurately, thereby ensuring that soil fertility is maintained, especially because systems have altered towards more intensive cropping with reduced legume production.

Consumption of cropland with high yield and low irrigation water intensity by urban expansion in China during 2000–2015

• We developed new spatially explicit datasets for constant food crop yield and constant food crop water intensity in China. • The proportion of cropland area lost by urban expansion to the total area of cropland loss equaled 63.48% during 2000–2015. • Urban expansion was preferentially occurring on cropland that was both high-yield and low-BWI in China. • The preference was more centralized in three southern agricultural regions, including the YRR, SER, and SWR. Cropland is fundamental for food production, which consumes a considerable amount of fresh water in the production process. Cropland with a high yield and low water intensity is extremely precious for realizing the sustainable and environmentally friendly utilization of cropland. However, urban expansion often occurs on cropland, and there is not enough scientific understanding of the features of cropland lost by urban expansion. Here, combining land use data, agricultural statistical data, the China-AEZ model and the GIS spatial analysis method, a spatially explicit constant food crop yield and “colorful” water intensity datasets were developed and preference indices were estimated, aiming to identify the features of cropland lost by urban expansion in China. The results showed that urban expansion played an increasingly dominant role in cropland loss in China during 2000–2015, with the area of cropland lost by urban expansion accounting for 63.48% of the total area of cropland loss. Urban expansion preferred to consume cropland with high yield and cropland with low blue water intensity (BWI), and the corresponding preference indices equaled 1.57 and 1.33, respectively. In addition, a coupling index was introduced to estimate the coupling relationship between the food crop yield and BWI of cropland, and the preference index of high-coupling-index cropland lost by urban expansion was 1.61 during 2000–2015, indicating that urban expansion was preferentially occurring on cropland that was both high-yield and low-BWI. In terms of the temporal and spatial variations, the degree of preference for cropland of high yield and/or low BWI lost by urban expansion all increased slightly at the national scale, while the preferences were more centralized in three southern regions, including the middle and lower reaches of the Yangtze River (YRR), southeastern China (SER), and southwestern China (SWR). In contrast, there were no such preferences in other regions. The preference of urban expansion consuming cropland with low total water intensity and green water intensity was also not significant at the national scale during 2000–2015.

Hydrogeochemical investigation of groundwater quality in the hard rock terrain of South India using Geographic Information System (GIS) and groundwater quality index (GWQI) techniques

A total of 194 groundwater samples were collected from hard rock terrain of Medak, a fast urbanizing region of Telangana State, South India to assess the groundwater quality using Geographic Information System (GIS) and groundwater quality index (GWQI) techniques. Groundwater samples were analyzed for pH, electrical conductivity (EC), total dissolved solids (TDS), total hardness (TH), calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), bicarbonate (HCO3−), chloride (Cl−), sulfate (SO42−), nitrate (NO3−) and fluoride (F−). The minimum and maximum values of pH (6.6–8.79), electrical conductivity (168–3170 μS/cm), total hardness (50–1550 mg/L), bicarbonate (18–527 mg/L), sulfate (21–328 mg/L), calcium (10–164 mg/L), magnesium (2.4–680 mg/L), sodium (14–145 mg/L) and potassium (1–24 mg/L) were recorded in the hard rock terrain of Medak region. About 32% and 22% of groundwater samples exceeded the maximum desirable limit of Cl− and SO42− for drinking purposes as prescribed by the World Health Organization (WHO) standards. The total dissolved solids classification divulges that the 182 groundwater locations are within the enviable for drinking uses. The analytical data reveals that the nitrate concentrations vary from 4 to 440 mg/L, with a mean of 73 mg/L. It is noted that the maximum value (440 mg/L) is one of the highest value found in Medak district, and 50% of the total samples show nitrate concentrations exceeding the maximum permissible limit recommended by WHO. The high fluoride concentration (>1.5 mg/L) in about 57% of the groundwater samples are beyond the recommended limit of drinking purposes. Spatial distribution of high fluoride concentration is noticed in the eastern and also some parts of the western region, while high nitrate concentration is shown in north and southern agricultural regions of the study area. The chemical relationships in Piper diagram identified Ca2+-Mg2+-Cl-, Ca2+-Na+-HCO3- and Ca2+-HCO3- are all most predominant water types, while Gibbs diagrams revealed that groundwater of the study region are mainly controlled by rock weathering dominance and partially evaporation dominance. The GWQI indicates that 37.11% and 57.21% of groundwater samples are excellent and good in water quality for drinking uses, respectively. Geologically, 80% of the study area consists of granites and gneiss, and 20% with basalts and laterites. Eventually, groundwater quality in the Medak region is fettered by geogenic and anthropogenic activities, therefore, people are advised to maintain a groundwater management strategy to protect further sustainability.

Divergent breeding values for fatness or residual feed intake in Angus cattle. 1. Pregnancy rates of heifers differed between fat lines and were affected by weight and fat

The pregnancy rate of heifers affects the efficiency and profitability of beef herds. Heifers extreme in rib fatness (Fat) or post-weaning residual feed intake (RFI) estimated breeding values (EBVs) were evaluated for their pregnancy rates at two locations in the southern agricultural regions of Australia (Struan and Vasse) as part of the Beef Cooperative Research Centre Maternal Productivity Project. Heifers divergent in Fat (High-Fat and Low-Fat) had differences in fat depth pre-joining at the 12/13th rib (4.4 mm vs 3.5 mm) and P8 rump site (6.1 mm vs 4.8 mm). This was associated with significant differences in pregnancy rates over a 9-week joining period (91.5% vs 83.0%) and an even larger difference when calculated over a 6-week joining period (77.3% vs 65.0%). Heifers divergent in RFI (Vasse only) also differed in rib fat (7.6 mm vs 6.4 mm) and P8 fat (11.0 vs 9.2 mm), but not significantly in pregnancy rates between the two RFI (High-RFI and Low-RFI) genotypes following a 9-week (92.4% vs 88.5%) or 6-week (81.2% vs 73.7%) joining period. The phenotypic analysis of the Fat and RFI heifers together indicated that weight and fat depth were the largest contributing factors to variation in pregnancy rates, and age and pre-joining weight gain were not significant. These phenotypic characteristics indicated that producers can manage heifers to particular weight and fat combinations to improve heifer conception rates. Associations of BREEDPLAN EBVs with heifer fertility showed that a shorter days-to-calving EBV had the biggest impact (P < 0.001) on heifer pregnancy rates and rib fat and scrotal size EBVs were close to significant (P < 0.10).

Crop sequences in Western Australia: what are they and are they sustainable? Findings of a four-year survey

A survey was conducted of commercial broadacre paddocks in the south-west cropping zone of Western Australia from 2010 to 2013. In total, 687 paddock years of data were sampled from 184 paddocks. The land use of each paddock was recorded together with measurements of weed density, the incidence of soilborne pathogen DNA, and soil inorganic nitrogen (nitrate and ammonium). The dynamics of these biophysical variables were related to the crop and pasture sequences employed. Wheat was the most frequent land use (60% of paddock years), followed by canola and pasture (12% each), and lupins and barley (6% each). Four crop species, wheat, canola, barley and lupins, accounted for 84% of land use. By region, wheat, canola, barley and lupin accounted for 90% of land use in the Northern Agricultural Region (NAR), 83% in the Central Agricultural Region (CAR) and 78% in the Southern Agricultural Region (SAR). Conversely, pasture usage in the SAR was 21%, compared with 12% in the CAR and 7% in the NAR. Over the surveyed paddocks, weed density, soilborne pathogens and soil N were maintained at levels suitable for wheat production. The inclusion of land uses other than wheat at the frequency reported maintained the condition of these biophysical variables.

Delineation of Sclerotinia sclerotiorum pathotypes using differential resistance responses on Brassica napus and B. juncea genotypes enables identification of resistance to prevailing pathotypes

Sclerotinia stem rot caused by the fungus Sclerotinia sclerotiorum is one of the most damaging and difficult-to-manage diseases of oilseed rape (Brassica napus) and mustard (B. juncea). Identifying oilseed Brassica genotypes with effective resistance offers the best long-term prospect for improved management of the disease. Despite some significant interactions between oilseed Brassica genotypes and S. sclerotiorum isolates reported in earlier studies, mostly a single pathogen isolate has been used to identify resistant genotypes. This paper reports the results of studies involving 53 isolates of S. sclerotiorum from the northern and southern agricultural regions of Western Australia where Sclerotinia stem rot is a serious disease of oilseed rape. Colony characteristics of isolates on potato dextrose agar were determined, and two field virulence (i.e., levels of disease severity) studies conducted. The first field study included 14 Brassica genotypes against three S. sclerotinia isolates and the second had eight Brassica genotypes against 50 S. sclerotinia isolates. Only colony diameter of isolates growing on potato dextrose agar was correlated with stem lesion length in the field. In both field experiments, there were significant effects of isolates and host genotypes, as well as a significant interaction between isolates and genotypes in relation to stem lesion length. In the first field experiment, mean stem lesion length ranged from 1cm in the highly resistant B. napus ZY006 to at least 9cm for susceptible genotypes Brassica juncea #2 and B. juncea Montara. The latter genotype was the most susceptible with a mean stem lesion length of 11.1. Expression of high-level resistance in B. napus ZY006 was largely independent of S. sclerotiorum isolate. In contrast, responses in B. napus genotypes, Zhongyou 821, 06-6-3792, RT108 and Charlton were much more isolate-dependent. In the first field experiment, with a greater number of host genotypes than S. sclerotiorum isolates, a higher variance ratio occurred for isolates (VR=158.4) than for host genotypes (VR=10.7). In the second field experiment, with a larger number of S. sclerotinia isolates than hosts, host genotypes had a higher variance ratio (VR=458.9) compared to the isolates (VR=71.2). Increasing the number of isolates greatly improved the capacity to differentiate levels of resistance among test genotypes. In this experiment, some genotypes showed more consistent resistant reactions (e.g., B. napus Mystic and B. juncea Xinyou 9) across different isolates and these are ideal targets for commercial exploitation of this resistance in oilseed Brassica breeding programs. From this experiment, a standardized set of three B. napus and three B. juncea genotypes were shown to be suitable for use as universal differentials to characterize pathotypes of S. sclerotiorum using octal nomenclature. Eight distinct pathotypes of S. sclerotiorum were delineated and characterized and these six host differential genotypes can now be utilized to identify and monitor the incidence and distribution of current and future pathotypes of S. sclerotiorum. Further, by providing a reliable means to characterize pathotypes of S. sclerotiorum, for the first time not only allows identification of resistance(s) against the predominant pathotype(s) of S. sclerotiorum prevailing in a particular region, but also now allows oilseed rape breeding programs to combine host resistances against several specific pathotypes of S. sclerotiorum into future cultivars.

Evaluating the influence of different aspects of habitat fragmentation on mating patterns and pollen dispersal in the bird‐pollinated Banksia sphaerocarpa var. caesia

Habitat fragmentation can significantly affect mating and pollen dispersal patterns in plant populations, although the differential effects of the various aspects of fragmentation are poorly understood. In this study, we used eight microsatellite loci to investigate the effect of fragmentation on the mating system and pollen dispersal within one large and eight small population remnants of Banksia sphaerocarpa var. caesia, a bird-pollinated shrub in the southern agricultural region of Western Australia. The large population had a much larger neighbourhood size and lower selfing rate, maternal pollen pool differentiation and within-plot mean pollen dispersal distance than the small populations. Outcrossing was consistently high and ranged from 85.7% ± 2.6 to 98.5% ± 0.9, and mating patterns suggested nearest-neighbour pollination. Pollen immigration into small populations ranged from 2.8% ± 1.8 to 16.5% ± 3.2. Using the small populations, we tested for correlations between various fragmentation variables and mating system and pollen dispersal parameters. We found significant negative linear relationships between population isolation and outcrossing rate; population shape and neighbourhood size; and conspecific density and mean pollen dispersal distance. There were significant positive linear relationships between population shape and pollen pool differentiation and between population size and number of different fathers per seed crop. Our results suggest that birds may use a series of fragmented populations as a vegetation corridor while foraging across the landscape and that population connectivity is a critical determinant of pollinator visitation. Our results also suggest that the effect of a linear population shape on the mating system and pollen dispersal is routinely underestimated.

Mixed Mating With Preferential Outcrossing in Acacia saligna (Labill.) H. Wendl. (Leguminosae: Mimosoideae)

Abstract Acacia saligna is being developed as an agroforestry crop for the southern agricultural regions of Australia. This study investigated the breeding system of A. saligna to generate basic knowledge for breeding and utilization of the species. Allozyme markers were used to investigate the mating system of four populations of the species. All the populations had high outcrossing rates, with a mean multilocus outcrossing rate of 0.91. The implications of a highly outcrossed mating system to the utilization of A. saligna are discussed.

Vitamin E and selenium status of sheep during autumn in Western Australia and its relationship to the incidence of apparent white muscle disease

This paper reports on the status of vitamin E and selenium in weaner and adult sheep in Western Australia (WA) during autumn, and its relationship to the incidence of apparent white muscle disease (WMD). A survey was conducted in which blood samples were taken from 10 weaner sheep (8–12 months of age) and 10 adult ewes (3 years of age) from flocks on 38 properties within the main southern agricultural region of WA, an area carrying ~10 million sheep. Deficiency of vitamin E was defined as a plasma α-tocopherol concentration less than 0.7 mg/L. Selenium deficiency was defined as whole blood glutathione peroxidase (GPx) activity less than 50 U/L. Incidence and severity of apparent WMD were defined in terms of elevated plasma activities of creatine kinase (CK) or aspartate aminotransaminase (AST). Of the weaner flocks, 58% (22/38) had mean plasma vitamin E concentrations in the deficient range (<0.7 mg/L) and 50% (19/38) had mean CK activities above 400 U/L (mild WMD); four of these flocks had mean CK activities over 1200 U/L (severe WMD). Of all the individual weaner sheep sampled, 6% had plasma CK activities >1200 U/L. It is likely that the incidence of vitamin E deficiency would have been higher had it not been for unseasonal summer rain germinating pasture on eight of the survey farms in the northern wheat belt. Flocks from farms with an evident green flush to their pastures had higher vitamin E levels than flocks grazing dry pasture. Vitamin E deficiency was less common in adult sheep than weaner sheep, with only 16% of flocks (6/38) having mean plasma concentrations below 0.7 mg/L and 11% (4/38) with CK values above 400 U/L. Selenium deficiency was less common than vitamin E deficiency and was mostly confined to adult flocks, with only 5% (2/38) of these having mean GPx values below the critical value of 50 U/g haemoglobin. For both weaner and adult sheep classed as vitamin E deficient, CK and AST activity in plasma was best described by a combination of plasma vitamin E concentration and whole blood activity of GPx (significant linear step wise regression, P < 0.001). The present study shows that subclinical vitamin E deficiency (<0.7 mg/L) was widespread in weaner flocks in WA during autumn and that, based on the biochemical data, deficiency was associated with apparent severe muscle damage in 6% of weaner sheep sampled. Recommended strategies to treat weaner sheep showing signs of WMD include dosing with 2000–4000 mg vitamin E either by injection, oral drench or by spraying it onto supplementary grain. The level and frequency of dosing depends upon the severity of the WMD symptoms. Less is known about preventative treatment, but recent evidence suggests that providing weaner sheep with access to saltbush during autumn may prove to be a practically useful strategy. Selenium supplements should also be supplied to weaner and adult sheep in areas known to be selenium deficient.

Effect of lupin supplementation and phenotypic characteristics on the performance of pastoral cattle grazing tagasaste

Within the Western Australian beef industry there is a negative perception of the capabilities of pastoral cattle to be finished in agricultural regions, especially those that have dominant Bos indicus characteristics. In order to address this perception, the performance, temperament and muscle glycogen levels of pastoral cattle grown in the agricultural region were investigated. Sixty steers were divided into phenotypic groups types, as either B. indicus (n = 30) or B. taurus (n = 30), and were randomly allocated to 2 treatments, each with 2 replicates. They were grazed on tagasaste (Chamaecytisus proliferus) and supplemented for 8 months with lupin grain 3 times per week at an equivalent of 1.5 or 3 kg/animal.day. There was no significant (P>0.05) difference in weight gain between the B. indicus and B. taurus type steers on either supplement level with both gaining weight at an average of 0.6 kg/day. Muscle biopsies from the M. semimembranosus (SM, topside) and M. semitendinosis (ST, eye round) were analysed for glycogen concentration, as an indicator of potential meat quality. Muscle glycogen concentration was not significantly (P>0.05) different between nutritional treatments or type of cattle. All steers had sufficient glycogen in the sampled muscles (1.3% in the SM and 1.0% in the ST) to produce meat with a desirable pH (<5.7). Flight speed, as an indicator of temperament, was recorded to detect any differences between the 2 types of cattle. Flight time was not significantly (P>0.05) different between the B. indicus or B. taurus steers, suggesting that there was no difference in temperament. The results illustrate that selection of pastoral cattle based on phenotypic characteristics alone is not substantiated, and that decisions should be made on the basis of genetic and past management information. If proper management strategies are put in place, pastoral cattle can perform adequately in the agricultural regions, which presents an opportunity for further integration between northern pastoral regions and southern agricultural regions to enhance overall beef productivity of the state.

The epidemiology of rabbit haemorrhagic disease, and its impact on rabbit populations, in south-western Australia

The impact of rabbit haemorrhagic disease (RHD) on free-ranging rabbit populations, their immunological response, and the abundance of insect vectors, were monitored in detail in the southern agricultural region of Western Australia. Further, a broad-scale rabbit monitoring program was also established at nine locations across a rainfall gradient in the southern half of Western Australia to monitor the natural arrival, or controlled release, of rabbit haemorrhagic disease virus (RHDV). Changes in rabbit populations and the immune status of RHDV antibodies were monitored in these areas to enable further understanding of the epidemiology of RHD, and its impact on rabbit numbers.RHDV had the greatest impact on rabbit populations in the arid and semi-arid areas (<360 mm per annum), where rabbit numbers were reduced to, and maintained at, 10% of pre-RHD levels. Conversely, the effects of RHD on rabbit numbers in higher-rainfall areas (360–700 mm per annum) were highly variable and patchy, and in some instances RHD had little apparent impact. In higher-rainfall areas where RHD was effective, rabbit numbers were reduced by 50–78%. RHDV was first confirmed in the southern agricultural region of Western Australia in early September 1996, ~1 year after its escape from Wardang Island, South Australia. At the detailed monitoring site (485 mm rainfall per annum), rabbit numbers declined by 65% within 2 weeks of RHDV being detected. However, ~70% of the remaining rabbits had antibodies against RHDV, indicating that they had survived the disease. There was also a demographic shift towards young rabbits (<1 year old) at this time. Further, even though there was no clinical evidence of RHD recurring in this population during the 3-year study, the presence of IgM antibodies in some rabbits well after the initial epizootic suggests that low-level transient outbreaks of RHDV had occurred at this site. Although the impact of these low-level outbreaks on population dynamics were uncertain, rabbit numbers at this site had recovered to pre-RHD levels within two breeding seasons.The abundance of insect vectors on the detailed monitoring site was similar between years with and without RHD outbreaks. Thus, the failure of RHDV to develop clinical disease on this site after the initial epizootic was unlikely to have been caused by the lack of suitable transmission vectors. The apparent lack of disease recurrence at the detailed monitoring site may have been caused by the presence of a non-pathogenic form of RHDV, which seemed to impart at least some cross-immunity to RHDV in these rabbits. The presence of RHDV also caused a shift in the timing of natural epizootics of myxomatosis at this site.

Water will drive California response to climate change

Water will drive California response to climate change

Evaluation of bait stations for broadacre control of rabbits

The efficacy of bait stations (200-L drum cut in half longitudinally) for the broadacre control of rabbits was compared with that obtained with standard trail-baiting procedures in the southern agricultural region of Western Australia. Bait stations were tested with and without the provision of pre-feed. The bait used was 1.0% 1080 One-shot oats, and corresponding experimental control sites were treated with unpoisoned oats. On the basis of spotlight counts before and after baiting, the reduction in rabbit numbers obtained with bait stations in the absence of pre-feed was poor, with a mean reduction of only 27% within 14 days. These reductions did not improve appreciably where sites were monitored for a further 28 days (i.e. 42 days in total). In contrast, the provision of pre-feed for 21 days prior to adding the 1080 bait resulted in a mean reduction in rabbit numbers of 57% within 14 days after the poisoned bait was added. However, the greatest reductions in rabbit numbers were achieved with trail baiting, where, relative to pre-treatment counts, rabbit numbers were reduced by 72% at Day 7 and by 84% at Day 14. The oats used to manufacture the 1080 One-shot product are subjected to gamma-sterilisation to prevent the germination of the oats, and any associated seeds of weed species. When offered a choice (matched sets), there was no difference in the amount of non-toxic gamma-sterilised oats and unsterilised oats consumed by free-ranging wild rabbits. On the basis of the costs incurred during the trials, trail baiting was by far the cheapest option for the broadacre control of rabbits. However, the cost of using bait stations would be discounted to some degree once these stations are able to be reused. The cost of trail baiting to protect a 15-ha 'border' of crop was $157 and $113 for three and two parallel trails (6 kg km–1 trail–1), respectively.

Serum mineral levels among Nepalese living in the southern agricultural Terai region

The physical status and serum mineral concentrations for people aged 10 to 68 years living in an agricultural southern region of Nepal were determined. Systolic (SBP) and diastolic blood pressure (DBP) for both sexes in the 10-14 year age group were low (p<0.05. vs the other age groups) and those for the over 50-year-olds tended to be higher than the other age groups. The mean values of total proteins (TP) (8.6 ± 0.5 g/dl for males and 8.7 ± 0.6 g/dl for females) were high due to an increase of globulin (3.9 ± 0.4 g/dl for males and 4.1 ± 0.5 g/dl for females). More than three-fourths of the subjects of both sexes showed calcium (Ca) levels of 9.0-11.2 mg/dl and about 65% of them showed potassium (K) levels of 4.8-5.4 mEq/1. A significant positive correlation between DBP and serum K was observed (p<0.05). Serum inorganic phosphorus (IP) correlated with age (p<0.001) and body mass index (BMI) (p<0.001). The serum Ca levels correlated with TP (r=0.31, p<0.001), albumin (Alb) (r=0.50, p<0.001), IP (r=0.31, p<0.001), K (r=0.32, p<0.001) and chlorine (Cl)(r=-0.37, p<0.001). Cl was associated with TP (r=-0.21, p<0.05), Alb (r=-0.36, p<0.001) and IP (r=-0.21, p<0.05). These results suggested that Ca intake for the subjects seemed to be insufficient although their serum Ca level was within normal.

Current elephant conservation problems in Borno State, Nigeria

Two elephant populations are known to exist in Borno State. One occupies the Bama area in southern agricultural region and migrates between Cameroon and Nigeria elephant range, while the other occupys the Lake Chad Basin and constitutes the migratory populations moving between Chad and Nigeria and Nigeria and the northern tip of Cameroon. In the early 1970s estimated elephant population was 8,060, at present it is estimated to be under 200. The decline is attributed to habitat fragmentation, poaching, and uncontrolled problem elephant control, coupled with a lack of political will and funds to manage the remnant populations. Demand for agricultural land has been largely responsible for habitat fragmentation, and resulting land use conflict has been exacerbated by drought and political instability. Since 1988 when 36 elephant carcasses, with all tusks removed, were found along the Lake Chad shoreline few animals have been seen in this area and the migration from Waza NP in Cameroon to Lake Chad has been intermittent. Human-elephant conflict is increasing, elephant are shot indiscriminately due to lack of both adequate funding for animal control and enforcement of conservation. (Map and text may not be in clear aggreement)

CHINESE MEAT GOAT BREEDS AND THEIR CROSSES

SUMMARYSelection of meat goat breeds and crossing for meat production provides food a nd is a source of self sufficiency for man. The following four goat breeds are examples of meat production of, Manjiang yellow, Matou, Longling and Hual goat breeds. Recently, it was reported that the quantity of meat output was increased and quality of meat was improved of the local goats in some areas by crossing with Nanjing, Matou and Longling. The Huai breed is a very important breed for producing high quality meat and hides' It is also -noted for its high prolificacy. The natural environments of China are well suited for goat production. Most of its harsher environments can be utilized efficiently only by goats. Especially southern agricultural region and northern agricultural regions develop and use the meat goat breeds as genetic resources for adaptation and production of unique and economically important meat products, and as a complement to cattle or sheep production.