Are the Australian poultry industries vulnerable to large outbreaks of highly pathogenic avian influenza?

Objective   To describe the structure of the Australian poultry industry and discuss the potential for highly pathogenic avian influenza (HPAI) to spread between Australian poultry farms.
Procedure   High densities of poultry farms, frequent contacts between farms by service providers, the supply of live poultry markets (LPM) and the presence of free-range duck flocks in affected regions have been identified as risk factors for the spread of HPAI between flocks in outbreaks causing the death or destruction of over 1 million poultry overseas. Data on 1,594 commercial Australian chicken meat, chicken egg, duck and turkey farms were collected by a telephone questionnaire of farm managers to assess the risk of a HPAI outbreak in Australia.
Results and Discussion   Five regions of Australia had farm densities comparable to overseas regions that experienced widespread HPAI. Common service providers routinely contacted different classes and types of farms over wide geographic areas. However, no responding farms supplied LPM and the majority of duck farms did not produce free-range ducks.
Conclusion   Outbreaks of HPAI have the potential to cause serious impacts on the Australian poultry industry. The risk posted by LPM and free-range ducks is limited, but the movement of genetic stock and common service providers could spread infection between companies, industries or geographical regions. Biosecurity measures are therefore considered critical to limit the secondary spread of infection should an outbreak occur.     

Métabolisme glucidique de la racine de carotte cultivée (variété Nantaise demi-longue) au cours du cycle végétatif de la plante

Tuberisation of the carrot root is accompanied by a regular accumulation of soluble carbohydrates, greater in the case of saccharose than for glucose and fructose, so that very soon the reserve is principally disaccharide in nature. At first there is also slight formation of starch but it generally disappears by the end of autumn.The role of the tissues of the carrot root does not seem to be merely that of accumulating sugars provided by the leaves, but also of taking part to a certain degree in the synthesis of the saccharose that they contain. The formation of starch appears to be related to the osmotic pressure of the cells which rises with the increase of sugars.The ripening of carrots is not a well-defined physiological phenomenon. It may be regarded as corresponding to the time when the level of soluble sugars attains a constant value, even if the root continues to grow and consequently accumulate a further quantity of sugar.Development of the tuberous root and accumulation of sugars do not cease under the influence of climatic conditions, but depend on the date of sowing, as if they were limited by an ageing of the cells.Winter normally brings about a break in the development of the roots and a beginning of the utilisation of sugars. However, in plants sown late, the roots continue to grow and accumulate soluble sugars until mid-winter. A part of these sugars results from the hydrolysis of starch, but some are assimilated by the few green leaves that persist.In spring, vegetation is resumed after rehydration of tissues that were partly dehydrated during the accumulation of sugars. Formation of the flowering stalk is accompanied by the progressive disappearance of all sugars, which does not permit the attribution to any particular sugar of a specific biological role either in the formation of cell constituents or in the release of energy.It also appears that saccharose is not a merely passive form of reserve sugar, but that it is probably involved in certain reactions as a metabolite independent of the two reducing sugars.The period of flowering is independent of the time of sowing.In the tuberous root of the carrot, as in that of the sugar-beet and the rhizome of Jerusalem artichoke, the levels of ash and sugar vary inversely. The phenomenon has no biological significance, as claimed by certain authors, since the high rate of sugar accumulation affects the ratio only in a mathematical sense by reducing the relative percentage of ash.

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Zusammenfassung Die Wurzelbildung der Karotten wird begleitet von einer gleichmäßigen Zunahme löslicher Kohlenhydrate, wobei der Anteil der Saccharose stärker wächst als der der Glukose, so daß die Biose bald die Kohlenhydrat-Hauptreserve ist. Anfangs findet auch eine Bildung von Stärke statt, aber immer in sehr geringer Menge. Die Stärke verschwindet gegen Ende des Herbstes. Die Rolle des Karottengewebes scheint sich nicht nur auf die Anhäufung des durch die Blätter zugeführten Zuckers zu beschränken, sondern es nimmt auch in einem gewissen Maße Anteil an der Synthese der Saccharose, die im Gewebe enthalten ist. Die Bildung der Stärke scheint an die osmotische Spannung der Zelle, die sich immer durch den Beitrag des Zuckers erhöht, gebunden zu sein. Die Maturation der Karotte ist kein wohldefiniertes physiologisches Phänomen. Man kann sie als den Zeitpunkt beschreiben, in dem der Gehalt des löslichen Zuckers einen fast konstanten Wert erreicht, auch wenn die Speicherwurzel weiter wächst und dadurch neue Mengen an Kohlenhydraten anhäuft.Die Entwicklung der Wurzel und die Zunahme des Zuckers hört nicht unter dem Einfluß der klimatischen Bedingungen auf, sondern hängt ab vom Datum der Aussaat, als wäre sie begrenzt durch ein Älterwerden der Zellen.Im Winter stimmt normalerweise das Aufhören der Entwicklung der Wurzeln und der Beginn des Verbrauchs der Kohlenhydrate überein, während bei den Pflanzen, die später ausgesät werden, die Wurzeln noch wachsen und immer noch löslichen Zucker bis zur Mitte dieser Jahreszeit anhäufen. Ein Teil dieses Zuckers entstammt der Stärkehydrolyse, ein anderer bildet sich noch durch die chlorophyllische Assimilation, die in beschränktem Maße mittels einiger lebendig gebliebener Blätter fortdauert. Im Frühling beginnt die Wiederaufnahme des Wachstums mit einer Wiederhydratation der Wurzelgewebe, die während der Anhäufung der Kohlenhydrate teilweise ausgetrocknet waren. Die Bildung des blühenden Stengels wird begleitet von dem fortschreitenden Verschwinden sämtlicher Zucker, ohne daß man jedem eine biologische Rolle zuschreiben kann, sei es in der Bildung der Zellbestandteile oder in der Energieerzeugung. Es scheint auch, daß die Saccharose nicht nur als passive Reserve der reduzierenden Zucker angesehen werden darf, sondern daß sie wahrscheinlich wie ein Stoffwechselprodukt unabhängig von ihren beiden Bestandteilen in bestimmte Reaktionen eingreift.Die Blütezeit tritt unabhängig vom Zeitpunkt der Aussaat ein.In der Wurzel der Möhre sowie in der der roten Rübe und im Rhizom des Topinamburs verändern sich die Gehalte von Asche und Zucker umgekehrt. Dieses Phänomen hat keine biologische Bedeutung, wie bestimmte Autoren meinen, denn die starke Anhäufung der Zucker beeinflußt das Zucker-Asche-Verhältnis nur mathematisch gesehen infolge Herabdrücken des Prozentsatzes der Mineralstoffe.

     

Multifunctionalised benzoxazinones in the systems Oryza sativa–Echinochloa crus‐galli and Triticum aestivum–Avena fatua as natural‐product‐based herbicide leads

BACKGROUND: Fifteen novel derivatives of D‐DIBOA, including aromatic ring modifications and the addition of side chains in positions C‐2 and N‐4, had previously been synthesised and their phytotoxicity on standard target species (STS) evaluated. This strategy combined steric, electronic, solubility and lipophilicity requirements to achieve the maximum phytotoxic activity. An evaluation of the bioactivity of these compounds on the systems Oryza sativa–Echinochloa crus‐galli and Triticum aestivum–Avena fatua is reported here. RESULTS: All compounds showed inhibition profiles on the two species Echinochloa crus‐galli (L.) Beauv. and Avena fatua L. The most marked effects were caused by 6F‐4Pr‐D‐DIBOA, 6F‐4Val‐D‐DIBOA, 6Cl‐4Pr‐D‐DIBOA and 6Cl‐4Val‐D‐DIBOA. The IC₅₀ values for the systems Echinochloa crus‐galli–Oryza sativa and Avena fatua–Triticum aestivum for all compounds were compared. The compound that showed the greatest selectivity for the system Echinochloa crus‐galli–Oryza sativa was 8Cl‐4Pr‐D‐DIBOA, which was 15 times more selective than the commercial herbicide propanil (Cotanil‐35). With regard to the system Avena fatua–Triticum aestivum, the compounds that showed the highest selectivities were 8Cl‐4Val‐D‐DIBOA and 6F‐4Pr‐D‐DIBOA. The results obtained for 6F‐4Pr‐D‐DIBOA are of great interest because of the high phytotoxicity to Avena fatua (IC₅₀ = 6 µM , r² = 0.9616). CONCLUSION: The in vitro phytotoxicity profiles and selectivities shown by the compounds described here make them candidates for higher‐level studies. 8Cl‐4Pr‐D‐DIBOA for the system Echinochloa crus‐galli‐Oryza sativa and 6F‐4Pr‐D‐DIBOA for Avena fatua‐Triticum aestivum were the most interesting compounds. Copyright © 2010 Society of Chemical Industry     

Insect midgut structures and molecules as targets of plant‐derived protease inhibitors and lectins

The midgut of insects is involved in digestion, osmoregulation and immunity. Although several defensive strategies are present in this organ, its organization and function may be disturbed by some insecticidal agents, including bioactive proteins like lectins and protease inhibitors (PIs) from plants. PIs interfere with digestion, leading to poor nutrient absorption and decreasing amino acid bioavailability. Intake of PIs can delay development, cause deformities and reduce fertility. Ingestion of PIs may lead to changes in the set of proteases secreted in the insect gut, but this response is often insufficient and results in aggravation of the malnutrition status. Lectins are proteins that are able to interact with glycoconjugates, including those linked to cell surfaces. Their effects on the midgut include disruption of the peritrophic matrix, brush border and secretory cell layer; induction of apoptosis and oxidative stress; interference with nutrient absorption and transport proteins; and damaging effects on symbionts. In addition, lectins can cross the intestinal barrier and reach the hemolymph. The establishment of resistant insect populations due to selective pressure resulting from massive use of a bioactive protein is an actual possibility, but this can be minimized by the multiple mode‐of‐action of these proteins, mainly the lectins. © 2018 Society of Chemical Industry     

Recent advances in allelopathy for weed control: from knowledge to applications

Allelopathy is the biological phenomenon of chemical interactions between living organisms in the ecosystem, and must be taken into account in addressing pest and weed problems in future sustainable agriculture. Allelopathy is a multidisciplinary science, but in some cases, aspects of its chemistry are overlooked, despite the need for a deep knowledge of the chemical structural characteristics of allelochemicals to facilitate the design of new herbicides. This review is focused on the most important advances in allelopathy, paying particular attention to the design and development of phenolic compounds, terpenoids and alkaloids as herbicides. The isolation of allelochemicals is mainly addressed, but other aspects such as the analysis and activities of derivatives or analogs are also covered. Furthermore, the use of allelopathy in the fight against parasitic plants is included. The past 12 years have been a prolific period for publications on allelopathy. This critical review discusses future research areas in this field and the state of the art is analyzed from the chemist's perspective. © 2019 Society of Chemical Industry     

Screening of two probiotic products for use in fermented liquid feed

In this trial two commercial probiotic products (Bactocell® and Adjulact® Pro) were investigated in vitro for their use as microbial inoculum for the production of fermented liquid feed (FLF) for pigs. Bactocell® was applied at a dose of 9 and 10 log₁₀ CFU/kg and Adjulact® Pro at a level of 9 log₁₀ CFU/kg. The FLF (control and treatments) was prepared with a water to feed ratio of 4:1 and run in batch for 72 h at 30 °C. The microbial population was followed with plate countings and the lactic acid, acetic acid and ethanol concentration was determined at different time points in the FLF. After 24 h, significant differences (P < 0.05) were found between the control and the Adjulact® Pro FLF for pH (4.7 vs 4.3), lactic acid (57.9 vs 91.5 mmol/L), acetic acid (23.1 vs 6.8 mmol/L), ethanol (24.5 vs 1.1 mmol/L), coliforms (7.2 vs 4.3 log₁₀ CFU/mL) and E. coli (6.2 vs 4.4 log₁₀ CFU/mL). Bactocell® addition did not alter the fermentation characteristics compared to the control FLF. After 72 h no significant differences between treatments were noted, except for the yeast count which was higher in the FLF inoculated with Adjulact® Pro.     

Influence of the Freezing Technique (Nitrogen Liquid vs Ultrafreezer of −152°C) and Male-to-Male Variation Over the Semen Quality in Canarian Mastiff Breed Dogs

This study was carried out to assess the in vitro quality of canine semen frozen in an ultrafreezer at -152 degrees C and to evaluate the male-to-male variation of frozen semen in five male dogs of the Canarian Mastiff breed. Four ejaculates of each dog were processed individually (5% glycerol and 0.5% Equex) to reach a final concentration of 100 x 10(6) spermatozoa/ml. Then, two freezing techniques were tested to assess the seminal quality (sperm motility, live spermatozoa and abnormal sperm cell percentages) at 1, 30, 60, 120 and 360 days after freezing: (i) semen was frozen and stored in liquid nitrogen; (ii) semen was frozen and stored in the ultrafreezer at -152 degrees C. After freezing-thawing, both freezing protocols showed no significant differences in sperm motility and the percentages of live and abnormal spermatozoa. On the other hand, the microscopic characteristics of spermatozoa in fresh semen were practically similar among males; however, after the semen processing and freezing, significant differences were observed (p < 0.05) among males, especially as regards sperm motility. This inter-individual variability was detected in both freezing protocols, showing that the male-to-male variation in the seminal quality post-freezing was independent of the freezing technique used. The in vitro results obtained in the Canarian Mastiff breed confirmed that the use of ultra-freezers at -152 degrees C is a potential alternative to liquid nitrogen for storing canine semen for long periods of time.     

Luteal Characteristics and Progesterone Production on Day 5 of the Bovine Oestrous Cycle

In this study we have examined luteal function in non-lactating and late lactation dairy cows on day 5 of the cycle, during the period of the post-ovulatory progesterone rise. Comparison of luteal progesterone content and in vitro synthetic capacity with circulating plasma progesterone demonstrated that circulating progesterone concentration is a function of total luteal activity rather than the activity of individual units of tissue. Incubation of luteal tissue in vitro demonstrated stimulatory activity of LH and IGF-I, and to a greater degree IGF-II, on luteal progesterone synthesis. Finally the study showed no effect of double ovulation on luteal function. Occurrence of double ovulation in 35% of animals was not associated with any difference in luteal function or plasma progesterone concentrations.