Salmonella monitoring programs in Australian feed mills: a retrospective analysis

The availability of safe, commercially prepared stock feed for production animals is an important step in ensuring animal health and welfare and the safety of food animal products for human consumption. Animal feed quality assurance programs include microbiological monitoring of raw materials, mill equipment and finished feed. Over a period of 16 years, 23,963 samples for Salmonella culture and serotyping were collected from 22 stock feed mills. A multivariable generalized linear mixed model (GLMM) was used to identify mill and sample type factors that increase the odds of detecting Salmonella. The odds of detecting a Salmonella positive sample was greatest in samples from raw materials and in mills that processed restricted animal material (RAM). The percentage of positive samples ranged from 7.2% in 2003 to 2.8% in 2017. Of the 1,069 positive samples, 976 were serotyped with 61 different Salmonella serotypes isolated. The serotype most frequently isolated from raw materials was S. Agona, (n = 108) whilst S. Anatum was the serotype most frequently isolated from equipment and finished feed (n = 156). The diversity of Salmonella serotypes differed between mills and different stages of the production line. Microbiological monitoring in the commercial preparation of animal feed in Australian stock feed mills guides the implementation of quality control measures and risk mitigation strategies thereby reducing the prevalence and diversity of potentially zoonotic bacteria such as Salmonella, enhancing food safety for both animal and consumer.     

Phosphorus Sources and Rates Associated with Nitrogen Fertilization in Mombasa Grass Yield

Nitrogen (N) and phosphorus (P) deficiency is one of the important causes of degradation of cultivated pasture under tropical conditions. The aim of this study was to evaluate phosphate rates and sources, and N rates on the concentration and uptake of N and P, and shoot dry mass (SDM) yield of Megathyrsus maximum grass cv Mombasa in an Ultisol. The trial was carried out in a greenhouse in pots with 4.0 dm^?3 of soil. The experiment was arranged in a completely randomized design with four replicates. The 3 × 3 × 3 factorial treatments consisted of phosphorus sources [reactive rock phosphate from Morocco (RPM), reactive rock phosphate from Algeria (RPA) and triple superphosphate (TSP)], three phosphorus rates (0, 150, and 300 mg kg^?1), and three N rates (0, 250, and 500 mg kg^?1). The SDM and tillering of Mombasa grass were significantly influenced with the TSP, RPM, and RPA application associated with N fertilization. The RPM, RPA, and TSP met the nutritional demands of Mombasa grass. The three P sources showed the same effect on the total N uptake by Mombasa grass. The P use efficiency (PUE) when fertilizer-P sources were added alone by Mombasa grass was <12% of the added P, and PUE decreased as follows: TSP > RPA > RPM. When P and N-fertilizer were added together, the fertilizer-N use efficiency (NUE) was 62%. The reactive phosphate (RPM and RPA) is an efficient P sources for Mombasa grass, but requiring higher rate of application compared to TSP source.     

Effect of Glyphosate and Zinc Application on Yield,Soil Fertility,Yield Components,and Nutritional Status of Soybean

Glyphosate is a widely used nonselective herbicide for the control of agricultural weeds. It is being increasingly used in glyphosate resistant genetically modified plants. However, there are few studies on its effects on the nutritional status of soybean, particularly on the uptake of zinc (Zn). Two experiments were conducted under field conditions in a Typic Quartzipsamment and an Orthic Ferralsol to investigate the effect of glyphosate application × Zn interaction on soil fertility, yield components, seed yield (SY), shoot dry weight (SDW) yield, and nutritional status of soybean. The five Zn rates 0, 3, 6, 9, and 12 kg ha^?1 were used in two soybean varieties [BRS 133 (conventional—NGM) and its essentially derived transgenic line BRS 245RR (GM), which was divided into: with (+Gly) and without (–Gly) glyphosate application. Only the P (phosphorus) and Zn available concentrations in the soil were impacted by Zn rates. However, the available P concentration only decreased in the soil planted with GM soybean. Mehlich 1 and diethylenetriaminepenta acetic acid–triethanolamine (DTPA–TEA), 7.3 extractants were effective to determine the available Zn. In the two crop sites, the number of pods per plant (NPP) and the SDW yield were affected by the interaction varieties × Zn. SY was influenced by the application of the herbicide, reducing a potential phytotoxic effect with the use of high rates. Regarding the nutrients, only the foliar calcium (Ca), boron (B), iron (Fe), and manganese (Mn) concentrations were negatively affected by glyphosate, and in the case of Zn, the difference occurred only between the varieties BRS 133 and BRS 245RR.     

Collaborative study of a gas-liquid chromatographic method for the analysis of chlorobenzilate and chloropropylate.

A gas-liquid chromatographic method for the determination of chlorobenzilate and chloropropylate in liquid formulations containing about 46 and 26% active ingredient, respectively, was collaboratively studied, using a matched pair scheme. The samples were dissolved in acetone containing debenzyl succinate as an internal standard and chromatographed on Carbowax 20M, using a flame ionization detector. Analyses of 4 samples by 13 collaborators using peak height measurements showed the following results: chlorobenzilate-2.5% overall coefficient of variation, 1.0% coefficient of variation for the random error, and 0.7% systematic error; chloropropylate-2.0, 1.4, and 0.4%, respectively. The method has been adopted as official first action.     

A new ornithological record,Pechora Pipit Anthus gustavi Swinhoe,1863,from Xinjiang

On 15 September,2010,a Pechora Pipit Anthus gustavi Swinhoe was found in the Hami prefecture(41°13’N and 93°29’E,1,143 m a.s.l.),Xinjiang,during the period of a comprehensive scientific survey in Lop Nur region.The bird,which was photographed,is a new avian record for Xinjiang.The pipit reproduces in northern Eurasia,mainly in wide meadows and low hills,and can be found in open forests and nearby residential areas in the process of on migration.The species is an insectivore and is a rare migrant or vagrant in Xinjiang.The geographical distribution,character,habitat,ecological habit and subspecies of the Pechora Pipit were discussed in this paper.     

Biologische Bek?mpfung des R��benzystennematoden Heterodera schachtii

The beet cyst nematode Heterodera schachtii is widely spread among sugar beet habitats with narrow crop rotation (especially in the warmer region of the Rhine Gorge). Without a consistent control management the economic efficiency of sugar beet cultivation under the current framework requirements is threatened. This problem is solved by the biological control using nematode-resistant oil radish or mustard which has been established during the last 25 years. Population of nematodes can be reduced up to 70% while maintaining the sugar beet yield on a high level. Big plot studies achieved a yield increase of 10?C15% thereby confirming the economic efficiency of nematode control measures using resistant undersown crops. Another starting point for problem solving lies within the cultivation of nematode-resistant sugar beet varieties. Currently, the sugar content and sugar yield of these varieties lie below the level of the standard varieties. Without nematode infection reduction in grain yield of approximately 10% must be accepted. Thus, cultivation is only economically reasonable in the infection areas. Heterodera schachtii is decreased by 60?C70%. Breeding of nematode-resistant sugar beet varieties has been the last step up to now. Already with low latent nematode infection these varieties clearly outbalance previous grain yields. A study series in 2009 showed an increase in sugar yield by an average of 10?C18% compared to the normal variety by cultivation of tolerant beet with latent nematode infection. Despite further developments in control management of tolerant/resistant beet, the culturing of resistant undersown crops remains up to date as these varieties, although only to a small degree, suffer from Heterodera schachtii.     

Assessing source-sink stability in the context of management and land-use change

Context

Management actions and land-use change can disrupt interdependent population processes, re-define population networks, and change source-sink dynamics. Yet we know little about the types of changes that can de-stabilize source-sink dynamics and how such changes could affect management decisions.

Objectives

We examined the degree to which source-sink status and strength could change under a range of management actions and land-use change scenarios including different patterns and extents of habitat loss, restoration, demographic improvements from parasitism control, and increased frequencies inter-population movement.

Methods

We developed an empirically-rich, spatially explicit, individual-based model for the formerly endangered Black-capped vireo in Texas. We simulated the network-wide consequences of different kinds of changes and compared the resulting source-sink strength, status, and regional abundance across scenarios. We gauged source-sink stability by the degree to which system changes caused the reversal of source or sink status.

Results

The stability of source-sink characterizations differed with the type of change. Source-sink dynamics were less responsive to small changes to population structure and changes that minimally affected demographic conditions. Source-sink status was most responsive to changes that affected habitat patterns and quality.

Conclusions

Accurately classifying sources and sinks is challenging, particularly in variable and directionally changing systems. The stability of source-sink classifications depends on the type of management or land-use change. Management actions may need to weigh interventions that improve regional abundance against those that alter regional source-sink dynamics as abundance and source-sink states can be sensitive to different kinds of change.

     

Killer whale predation on sea otters linking oceanic and nearshore ecosystems

After nearly a century of recovery from overhunting, sea otter populations are in abrupt decline over large areas of western Alaska. Increased killer whale predation is the likely cause of these declines. Elevated sea urchin density and the consequent deforestation of kelp beds in the nearshore community demonstrate that the otter's keystone role has been reduced or eliminated. This chain of interactions was probably initiated by anthropogenic changes in the offshore oceanic ecosystem.     

Replacement nutrition management

The basic principles of dairy cow feeding apply equally to the dairy heifer. Ration balancing must be accomplished in order to formulate least-cost, nutrient-balanced rations for each age group of heifers. Forage testing enables rations to be developed that utilize the various quality forages that are available on a farm and allows optimum allocation of forages for maximum profitability of the farm feeding system. In addition to feeding management, housing, ventilation, health care, grouping, cleanliness, and many other management factors can complement a sound heifer nutrition program.     

Vulnerabilities and fisheries impacts: the uncertain future of manta and devil rays

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