Review: Near infrared spectroscopy of faeces to evaluate the nutrition and physiology of herbivores

Near infrared (NIR) spectroscopy, usually in reflectance mode, has been applied to the analysis of faeces to measure the concentrations of constituents such as total N, fibre, tannins and delta C-13. In addition, an unusual and exciting application of faecal NIR [F.NIR] analyses is to directly predict attributes of the diet of herbivores such as crude protein and fibre contents, proportions of plant species and morphological components, diet digestibility and voluntary DM intake. This is an unusual application of NIR spectroscopy insofar as the spectral measurements are made, not on the material of interest [i.e. the diet), but on a derived material (i.e. faeces). Predictions of diet attributes from faecal spectra clearly depend on there being sufficient NIR spectral information in the diet residues present in faeces to describe the diet, although endogenous components of faeces such as undigested debris of micro-organisms from the rumen and Large intestine and secretions into the gastrointestinal tract wilt also contribute spectral information. Spectra of forage and of faeces derived from the forage are generally similar and the observed differences are principally in the spectral regions associated with constituents of forages known to be of low, or of high, digestibility. Some diet components (for example, ureal which are likely to be entirely digested apparently cannot be predicted from faecal NIR spectra because they cannot contribute to faecal spectra except through modifying the microbial and endogenous components. The errors and robustness of F.NIR calibrations to predict the crude protein concentration and digestibility of the diet of herbivores are generally comparable with those to directly predict the same attributes in forage from NIR spectra of the forage. Some attributes of the animal, such as species, gender, pregnancy status and parasite burden have been successfully discriminated into classes based on their faecal NIR spectra. Such discrimination was likely associated with differences in the diet selected and/or differences in the metabolites excreted in the faeces. NIR spectroscopy of faeces has usually involved scanning dried and ground samples in monochromators in the 400-2500nm or 1100-2500nm ranges. Results satisfactory for the purpose have also been reported for dried and ground faeces scanned using a diode array instrument in the 800-1700nm range and for wet faeces and slurries of excreta scanned with monochromators. Chemometric analysis of faecal spectra has generally used the approaches established for forage analysis. The capacity to predict many attributes of the diet, and some aspects of animal physiology, from NIR spectra of faeces is particularly useful to study the quality and quantity of the diet selected by both domestic and feral grazing herbivores and to enhance production and management of both herbivores and their grazing environment.

Development of an immunomagnetic capture-reverse transcriptase-PCR assay for three pineapple ampeloviruses

A semi-automated, immunomagneticcapture-reverse transcription PCR(IMC-RT-PCR) assay for the detection of three pineapple-infecting ampeloviruses, Pineapple mealybug wilt-associated virus-1, -2 and -3, is described. The assay was equivalent in sensitivity but more rapid than conventional immunocapture RT-PCR. The assay can be used either as a one- or two-step RT-PCR and allows detection of the viruses separately or together in a triplex assay from fresh, frozen or freeze-dried pineapple leaf tissue. This IMC-RT-PCR assay could be used for high throughput screening of pineapple planting propagules and could easily be modified for the detection of other RNA viruses in a range of plant species, provided suitable antibodies are available.

Defining and predicting the 'break of the season' for north-east Queensland grazing areas

For pasture growth in the semi-arid tropics of north-east Australia, where up to 80% of annual rainfall occurs between December and March, the timing and distribution of rainfall events is often more important than the total amount. In particular, the timing of the 'green break of the season' (GBOS) at the end of the dry season, when new pasture growth becomes available as forage and a live-weight gain is measured in cattle, affects several important management decisions that prevent overgrazing and pasture degradation. Currently, beef producers in the region use a GBOS rule based on rainfall (e. g. 40mm of rain over three days by 1 December) to define the event and make their management decisions. A survey of 16 beef producers in north-east Queensland shows three quarters of respondents use a rainfall amount that occurs in only half or less than half of all years at their location. In addition, only half the producers expect the GBOS to occur within two weeks of the median date calculated by the CSIRO plant growth days model GRIM. This result suggests that in the producer rules, either the rainfall quantity or the period of time over which the rain is expected, is unrealistic. Despite only 37% of beef producers indicating that they use a southern oscillation index (SOI) forecast in their decisions, cross validated LEPS (linear error in probability space) analyses showed both the average 3 month July-September SOI and the 2 month August-September SOI have significant forecast skill in predicting the probability of both the amount of wet season rainfall and the timing of the GBOS. The communication and implementation of a rigorous and realistic definition of the GBOS, and the likely impacts of anthropogenic climate change on the region are discussed in the context of the sustainable management of northern Australian rangelands.

The climate change risk management matrix for the grazing industry of northern Australia

The complexity, variability and vastness of the northern Australian rangelands make it difficult to assess the risks associated with climate change. In this paper we present a methodology to help industry and primary producers assess risks associated with climate change and to assess the effectiveness of adaptation options in managing those risks. Our assessment involved three steps. Initially, the impacts and adaptation responses were documented in matrices by ‘experts’ (rangeland and climate scientists). Then, a modified risk management framework was used to develop risk management matrices that identified important impacts, areas of greatest vulnerability (combination of potential impact and adaptive capacity) and priority areas for action at the industry level. The process was easy to implement and useful for arranging and analysing large amounts of information (both complex and interacting). Lastly, regional extension officers (after minimal ‘climate literacy’ training) could build on existing knowledge provided here and implement the risk management process in workshops with rangeland land managers. Their participation is likely to identify relevant and robust adaptive responses that are most likely to be included in regional and property management decisions. The process developed here for the grazing industry could be modified and used in other industries and sectors. By 2030, some areas of northern Australia will experience more droughts and lower summer rainfall. This poses a serious threat to the rangelands. Although the impacts and adaptive responses will vary between ecological and geographic systems, climate change is expected to have noticeable detrimental effects: reduced pasture growth and surface water availability; increased competition from woody vegetation; decreased production per head (beef and wool) and gross margin; and adverse impacts on biodiversity. Further research and development is needed to identify the most vulnerable regions, and to inform policy in time to facilitate transitional change and enable land managers to implement those changes.

Inland Salt

This work, a small single room installation, was my contribution to the 2015 Palimpsest Biennale in Mildura, and was shown at the ADFA building in the town's centre. On an initial research trip in July, 2015, I stopped at a dried out salt lake near Wentworth. Beach-like, the lake left a tidal line along a curving shore. The vegetation looked like ocean flora; there was the glimmering saltiness of everything, and saltbush everywhere. It brought to mind Sturt's hankering for an inland sea, and his wishful voyage along the Murray, that led him out, not in. This work puts these observations together: a drawing, made from the sanded emboss of saltbush leaves, runs, riverlike, across the space. A looped film of clouds reflected in a shallow saltlake, recalls the dream of an inland sea, supported by the sound of ocean.

Seasonal changes in pasture quality and diet selection and their relationship with liveweight gain of steers grazing tropical grass and grass-legume pastures in northern Australia.

The variation in liveweight gain in grazing beef cattle as influenced by pasture type, season and year effects has important economic implications for mixed crop-livestock systems and the ability to better predict such variation would benefit beef producers by providing a guide for decision making. To identify key determinants of liveweight change of Brahman-cross steers grazing subtropical pastures, measurements of pasture quality and quantity, and diet quality in parallel with liveweight were made over two consecutive grazing seasons (48 and 46 weeks, respectively), on mixed Clitoria ternatea/grass, Stylosanthes seabrana/grass and grass swards (grass being a mixture of Bothriochloa insculpta cv. Bisset, Dichanthium sericeum and Panicum maximum var. trichoglume cv. Petrie). Steers grazing the legume-based pastures had the highest growth rate and gained between 64 and 142 kg more than those grazing the grass pastures in under 12 months. Using an exponential model, green leaf mass, green leaf %, adjusted green leaf % (adjusted for inedible woody legume stems), faecal near infrared reflectance spectroscopy predictions of diet crude protein and diet dry matter digestibility, accounted for 77, 74, 80, 63 and 60%, respectively, of the variation in daily weight gain when data were pooled across pasture types and grazing seasons. The standard error of the regressions indicated that 95% prediction intervals were large (+/- 0.42-0.64 kg/head.day) suggesting that derived regression relationships have limited practical application for accurately estimating growth rate. In this study, animal factors, especially compensatory growth effects, appeared to have a major influence on growth rate in relation to pasture and diet attributes. It was concluded that predictions of growth rate based only on pasture or diet attributes are unlikely to be accurate or reliable. Nevertheless, key pasture attributes such as green leaf mass and green leaf% provide a robust indication of what proportion of the potential growth rate of the grazing animals can be achieved.

Activation of several key components of the epidermal differentiation pathway in cattle following infestation with the cattle tick, Rhipicephalus (Boophilus) microplus.

The cattle tick, Rhipicephalus (Boophilus) microplus, and the diseases it transmits pose a persistent threat to tropical beef production. Genetic selection of host resistance has become the method of choice for non-chemical control of cattle tick. Previous studies have suggested that larval stages are most susceptible to host resistance mechanisms. To gain insights into the molecular basis of host resistance that occurs during R. microplus attachment, we assessed the abundance of proteins (by isobaric tag for relative and absolute quantitation (iTRAQ) and Western blot analyses) and mRNAs (by quantitative reverse transcription PCR (qRT-PCR)) in skin adjacent to tick bite sites from high tick-resistant (HR) and low tick-resistant (LR) Belmont Red cattle following challenge with cattle tick. We showed substantially higher expression of the basal epidermal keratins KRT5 and KRT14, the lipid processing protein, lipocalin 9 (LCN9), the epidermal barrier catalysing enzyme transglutaminase 1 (TGM1), and the transcriptional regulator B lymphocyte-induced maturation protein 1 (Blimp1) in HR skin. Our data reveals the essential role of the epidermal permeability barrier in conferring greater resistance of cattle to tick infestation, and suggest that the physical structure of the epidermal layers of the skin may represent the first line of defence against ectoparasite invasion. Crown Copyright. © Australian Society for Parasitology Inc.

Anthraquinones from the Fungus Dermocybe sanguinea as Textile Dyes

This study is based on the multidiciplinary approach of using natural colorants as textile dyes. The author was interested in both the historical and traditional aspects of natural dyeing as well as the modern industrial applications of the pure natural compounds. In the study, the anthraquinone compounds were isolated as aglycones from the ectomycorrhizal fungus Dermocybe sanguinea. The endogenous beta-glucosidase of the fungus was used to catalyse the hydrolysis of the O-glycosyl linkage in emodin- and dermocybin-1-beta-D-glucopyranosides. The method, in which 10.45 kg of fresh fungi was starting material, yielded two fractions: 56.0 g of Fraction 1 (94% of the total amount of pigment,) consisting almost exclusively of the main pigments emodin and dermocybin, and 3.3 g of Fraction 2 (6%) consisting mainly of the anthraquinone carboxylic acids. The anthraquinone compounds in Fractions 1 and 2 were separated by one- and two-dimensional thin-layer-chromatography (TLC) using silica plates. 1D TLC showed that neither an acidic nor a basic solvent system alone separated completely all the anthraquinones isolated from D. sanguinea, in spite of the variation of the rations of the solvent components in the systems. Thus, a new 2D TLC technique was developed, applying n-pentanol-pyridine-methanol (6:4:3, v/v/v) and toluene-ethyl acetate-ethanol-formic acid (10:8:1:2, v/v/v/v) as eluents. Fifteen different anthraquinone derivatives were completely separated from one another. Emodin, physcion, endocrocin, dermolutein, dermorubin, 5-chlorodermorubin, emodin-1-beta-D-glucopyranoside, dermocybin-1-beta-D-glucopyranoside and dermocybin, and five new compounds, not earlier identified in D. sanguinea, 7-chloroemodin, 5,7-dichloroemodin, 5,7-dichloroendocrocin, 4-hydroxyaustrocorticone and austrocorticone, were separated and identified on the basis of their Rf-values, UV/Vis spectra and mass spectra. One substance remained unidentified, because of its very low concentration. The anthraquinones in Fractions 1 and 2 were preparatively separeted by liquid-liquid partition, with isopropylmethyl ketone and aqueous phosphate buffer as the solvent system. Advantage was taken of the principle of stepwise pH-gradient elution. The multiple liquid-liquid partition (MLLP) offered an excellent method for the preparative separation of compounds, which contain acidic groups such as the phenolic OH and COOH groups. Due to their strong aggregation properties, these compounds are, without derivatization, very difficult to separate on a preparative scale by chromatographic methods. By the MLLP method remarkable separations were achieved for the components in each mixture. Emodin and dermocybin were both obtained from Fraction 1 in a purity of at least 99%. Pure emodin and dermocybin were applied as mordant dyes to wool and polyamide and as disperse dyes to polyester and polyamide, using the high temperature (HT) technique. A mixture of dermorubin and 5-chlorodermorubin was applied as an acid dye to wool. In these experiments, synthetic dyes were used as references. Experiments were also performed using water extract of the air-dried fungi as dye liquor for wool and silk. The main colouring compounds in the crude water extract were emodin and dermocybin, which indicated that the O-glycosyl linkages in emodin- and dermocybin-1-beta-D-glucopyranosides were broken by the beta-glucosidase enzyme. Apparently, the hydrolysis occurred during the drying of the fungi and during the soaking of the dried fruit bodies overnight when preparing the dyebath. The colour of each dyed material was investigated in terms of the CIELAB L*, a* and b* values, and the colour fastness to light, washing and rubbing was tested according to the ISO standards. In the mordant dyeing experiments, emodin dyed wool and polyamide yellow and red, depending on the pH of the dyebath. Dermocybin gave purple and violet colours. The colour fastness of the mordant-dyed fabrics varied from good to moderate. The fastness properties of the natural anthraquinone carboxylic acids on wool were good, indicating the strength of the ionic bonds between the COO- groups of the dyes and the NH3+ groups of the fibres. In the disperse dyeing experiments, emodin dyed polyester bright yellow and dermocybin bright reddish-orange, and the fabrics showed excellent colour fastness. In contrast, emodin and dermocybin successfully dyed polyamide brownish-orange and wine-red, respectively, but with only moderate fastness. In industrial dyeing processes, natural anthraquinone aglycone mixtures dyed wool and silk well even at low concentrations of mordants, i.e. with 10% of the weight of the fibre (owf) of KAl(SO4)2 and 1 or 0.5% owf of other mordants. This study showed that purified natural anthraquinone compounds can produce bright hues with good colour-fastness properties in different textile materials. Natural anthraquinones have a significant potential for new dyeing techniques and will provide useful alternatives to synthetic dyes.

The adoption of sustainable grazing land management practices in the Burdekin Rangelands of northern Australia.

The Burdekin Rangelands is a diverse area of semi-arid eucalypt and acacia savannah covering six million hectares in north eastern Australia. The major land use is cattle grazing on 220 commercial cattle properties (average size 26,000 ha) each carrying on average 2600 adult equivalents. Production was the focus of the beef industry and support agencies prior to the mid 1980's. Widespread land degradation during the 1980's led to a grassroots realisation that environmental impacts, including water quality had to be addressed for the beef industry to attain sustainability. The formation of a series of producer based landcare gropus and the support of several Queensland and Australian government research and extension agencies led to a greater awareness and adoption of sound grazing land management practices (Shepherd 2005).

Calf wastage - how big an issue is it?

What is calf wastage. Breeding female cattle in north Australia contribute best to business success by producing a heavy weaner each year at the first weaning round. This maximises increase in value by the cow unit over the year, generally from mid-year to mid-year. The ability to cycle in both maiden heifers and lactating cows is the primary limitation to achieving this. Wastage of a calf at any stage between conception and weaning also substantially limits fertility and value increase at a herd level. Embryo loss may result in later calves as cows re-conceive; the calves produced are smaller at weaning and have to be weaned later into the dry season. Late calf wastage usually results in breeders missing a calf for the year. Late calving often also results in failure to cycle, thus cows rear a calf in the subsequent year.

Where to from Brahmans in the Northern Australian herd? Maintaining the economic benefit of earlier infusions of Bos indicus.

The economic performance of a terminal crossbreeding system based on Brahman cows and a tropically adapted composite herd were compared to a straightbred Brahman herd. All systems were targeted to meet specifications of the grass-finished Japanese market. The production system modelled represented a typical individual central Queensland integrated breeding/finishing enterprise or a northern Australian vertically integrated enterprise with separate breeding and finishing properties. Due mainly to a reduced age of turnoff of Crossbred and Composite sale animals and an improved weaning rate in the Composite herd, Crossbred and Composite herds returned a gross margin of $7 and $24 per Adult Equivalent (AE) respectively above that of the Brahman herd. The benefits of changing 25% of the existing 85% of Brahmans in the northern Australian herd to either Crossbreds or Composites over a 10-year period were also examined. With no premium for carcass quality in Crossbred and Composite sale animals, annual benefits were $16 M and $61 M for Crossbreds and Composites in 2013. The cumulative Present Value (PV) of this shift over the 10-year period was $88 M and $342 M respectively, discounted at 7%. When a 5c per kg premium for carcass quality was included, differences in annual benefits rose to $30 M and $75 M and cumulative PVs to $168 M and $421 M for Crossbreds and Composites respectively.

Selectivity of chlorantraniliprole to parasitoid wasps.

BACKGROUND: Chlorantraniliprole is a novel anthranilic diamide insecticide registered for use in vegetables, fruits, grains and turf against a variety of insect pests. The objective of this article is to summarize results of acute toxicity testing of chlorantraniliprole on seven species of parasitic wasps with wide geographic distribution and relevance to different crops and integrated pest management (IPM) programmes. RESULTS: Tier-1, worst-case laboratory studies evaluated wasp survival and reproduction following different exposure concentrations and scenarios to chlorantraniliprole (i.e. fresh-dried spray deposits on glass plates, direct contact, ingestion, egg card, dipped leaf residue bioassays, sprayed mummies). No statistically significant effects on adult survival, percentage parasitism or emergence were observed following exposures to chlorantraniliprole compared with controls. CONCLUSION: Chlorantraniliprole was harmless to the parasitoid wasp species tested according to IOBC classification criteria (<30% effects) and may be a useful tool in IPM programmes.

Wet-dry cycling extends seed persistence by re-instating antioxidant capacity

Seeds in the field experience wet-dry cycling that is akin to the well-studied commercial process of seed priming in which seeds are hydrated and then re-dried to standardise their germination characteristics. To investigate whether the persistence (defined as in situ longevity) and antioxidant capacity of seeds are influenced by wet-dry cycling, seeds of the global agronomic weed Avena sterilis ssp. ludoviciana were subjected to (1) controlled ageing at 60% relative humidity and 53.5°C for 31 days, (2) controlled ageing then priming, or (3) ageing in the field in three soils for 21 months. Changes in seed viability (total germination), mean germination time, seedling vigour (mean seedling length), and the concentrations of the glutathione (GSH) / glutathione disulphide (GSSG) redox couple were recorded over time. As controlled-aged seeds lost viability, GSH levels declined and the relative proportion of GSSG contributing to total glutathione increased, indicative of a failing antioxidant capacity. Subjecting seeds that were aged under controlled conditions to a wet-dry cycle (to −1 MPa) prevented viability loss and increased GSH levels. Field-aged seeds that underwent numerous wet-dry cycles due to natural rainfall maintained high viability and high GSH levels. Thus wet-dry cycles in the field may enhance seed longevity and persistence coincident with re-synthesis of protective compounds such as GSH.

The effect of initial spacing and thinning on wood quality and graded sawn recovery of mature Caribbean pine grown in Queensland.

A mature Caribbean pine (Pinus caribaea var. hondurensis) silviculture experiment provided initial square spacing treatments of 1.8 m2, 2.4 m2, 3.0 m2 and 3.6 m2 (equal to 3088, 1737, 1111 and 772 stems/ha) that were thinned at age 10 years to 600, 400 and 200 stems/ha, retaining an unthinned control for each initial spacing. The trial was destructively sampled at age of 28 years and discs taken along 8 various stem heights were analysed for variation in basic density and SilviScan wood properties. In addition, the logs from ten stocking × thinning treatments were processed in a sawing study. Results indicate thinning effects were generally more pronounced than initial spacing effects. Fast growing trees produced wood with significantly higher average wood densities and higher average stiffness values. Detailed SilviScan densitometry results obtained radially and at various stem heights enabled construction of tree maps for wood properties, providing insights into the variation in juvenile to mature wood proportion across the initial and post-thinning stocking treatments studied. Dried dressed recovery was strongly related to tree size, and log value decreased consistently from butt to top logs across all treatments. The estimated value per hectare was highest in unthinned plots due to values being multiplied by high stem numbers per hectare. However, a complete economic analysis considering all cost structures is required to investigate the optimal silviculture to maximise economic returns to growers and processors. Improved understanding of the relationship between initial spacing, post-thinning stocking and wood and end-product quality should help to customize future forest management strategies required to produce better quality wood and wood products.

Accelerated drying of plantation grown Eucalyptus cloeziana and Eucalyptus pellita sawn timber

The objective of this study was to gain an understanding for drying sawn timber produced from fast-grown, well-managed Queensland hardwood plantations using accelerated drying methods. Due to limited resources, this was a preliminary study and further work will be required to optimize schedules for industrial implementation. Three conventional kiln trials, including two for 38-mm-thick, 19-year-old plantation Gympie messmate (Eucalyptus cloeziana F. Muell.) and one for 25mm thick, 15-year-old plantation red mahogany (Eucalyptus pellita F. Muell.), and two vacuum kiln drying trials, one each for 38- and 25mm thick Gympie messmate, were conducted. Measurements of final cross-sectional moisture content, moisture content gradient, residual drying stress, and internal and surface checking were used to quantify dried quality. Drying schedules were chosen based on either existing published schedules or, in the case of the vacuum drying trials, existing schedules for species with similar wood density and dying degrade properties, or manipulated schedules based on the results of trials conducted during this study. The findings indicate that both species can be dried using conventional drying techniques with acceptable grade quality in approximately 75 percent of the drying time that industry is currently achieving when drying native forest timber of the same species. The vacuum drying time was 60 percent less than conventional drying for 38-mm-thick, 19-year-old Gympie messmate, although drying quality needs improving. The findings have shown that through careful schedule manipulation and adjustment, the grade quality can be optimized to suit the desired expectation. Additional research is required to further optimize the schedules to ensure acceptable grade qualities can be reliably achieved across all drying criteria and exploit opportunities to reduce drying times further.