The quest for financial discipline at local government level: The regulation of municipal borrowing and financial emergencies

No Abstrac

Editorial

No Abstrac

The value of supplementary feeding to pre-weaned and weaned lambs grazing Italian ryegrass

The variation in, and often the disappointingly poor weight gains and the inability of lambs to achieve desirable carcass grades on ryegrass pastures have long been a concern to researchers, extension officers, advisors and farmers. The objectives of this study were to investigate whether concentrate supplementation to lambs on Italian ryegrass (Lolium multiflorum cv Midmar) pastures would improve the performance of lambs, and what the optimum level of supplementation is to lambs on the pasture. The investigation extended over the pre- and post-weaning growth phases of lambs and was conducted during two consecutive seasons at the Cedara Research Station in the KwaZulu-Natal Mistbelt. The pre-weaning stocking rate applied, was 20 South African Mutton Merino ewes with lambs/ha and the following treatments were applied: Control: continuous grazing - no creep feed; forward creep grazing by the lambs in a rotational grazing system where the lambs were allowed to graze paddocks allocated to the ewes, plus the next paddock in their series of grazing paddocks; 100 g creep feed/lamb/day; 250 g creep feed/lamb/day and creep feed ad libitum. The post-weaning stocking rate applied, was 50 lambs/ha and treatments were: Control - no supplement; 250 g of supplement/lamb/day (only the second season); 500 g of supplement/lamb/day and supplement ad libitum. From 42 days of age to weaning, supplementation significantly improved the live weight gain of suckling lambs. Creep feed intake varied between 300 and 350 g/lamb/day. The average daily gain of the weaned lambs improved significantly with supplementation. No significant advantage in terms of growth was gained by supplementing the weaned lambs at levels of higher than 500 g/day. South African Journal of Animal Science Vol.32(1) 2002: 30-3

Do mutualists matter? The role of pollinators, seed dispersers and belowground symbionts in the invasion success of Acacia

Plant species introduced to new locations may lose their natural enemies but can also leave behind important mutualists. Here, I take a novel comparative approach to identify the potential role of mutualistic interactions in determining invasion outcomes. I examine the strength of pollination, seed dispersal and belowground symbioses with nitrogen-fixing bacteria (rhizobia) across three species that vary in invasion success in both their introduced and native range. I used species of Australian Acacia introduced to New Zealand. I hypothesised that if interactions with mutualists are important for plant invasion then species would vary in the strength of interactions with one or more of the groups of mutualists I examined, and that the pattern of variation would correlate with the degree to which they have established and spread in New Zealand. At each stage I also consider the potentially mediating influence of natural enemies. For A. dealbata, a highly invasive species, and A. baileyana, a species that is widely naturalised in New Zealand, I found no differences in any of the variables I examined in relation to pollination and predispersal seed predation. However, for A. pravissima, currently considered a casual species in New Zealand, pre-dispersal seed predation was lower in New Zealand and overall seed production was much higher relative to conspecifics in Australia, and relative to the other two species. In relation to seed dispersal I found that the three species, which are all adapted for dispersal by ants (myrmecochory), were able to form dispersal mutualisms in New Zealand, potentially to the same degree as in Australia. Seed predation following seed fall was also lower for species in New Zealand than in Australia. There was no variation between the three species in seed removal associated with either dispersal or predation. By examining species’ growth and nodulation with rhizobia in both Australia and New Zealand I found that their ability to spread away from introduction sites could be limited by the availability of rhizobia in New Zealand, relative to Australia. However, there were again no differences between species. This is the first study to have directly measured mutualistic interactions across species that vary in invasive success in both their native and introduced range. I demonstrated that species introduced to new locations are able to establish mutualistic interactions with pollinators and dispersers to the same degree as in their native range. I also found the first direct evidence that the availability of rhizobia could limit species’ abilities to colonise new sites in the introduced range. However, mutualistic associations could not explain the variable invasive success of each species. Overall, these findings suggest that mutualistic interactions may be important for alien plant establishment, but alone cannot explain invasion outcomes. Instead, it is likely that invasive success is determined by a combination of biotic, abiotic and human factors, with the ability to establish mutualistic interactions just one component necessary for successful establishment and spread. These findings underline the importance of such broad geographical and comparative studies in attempts to elucidate drivers of invasion

The relationship between nutritional and inflammatory changes during critical illness

Muscle mass loss in the critically ill is substantial, between 1-2% per day. Muscle wasting and weakness delays patient recovery and rehabilitation. Understanding the relationship between nutritional and inflammatory markers will help to identify a notional “nutritional tipping point”, where anabolism exceeds catabolism, which will allow us to target nutritional therapy more successfully. Muscle depth on ultrasound, inflammatory markers, cytokines, urinary markers of protein breakdown and nitrogen balance data were collected in 78 critically ill patients. Patients lost a significant amount of muscle depth during their intensive care unit (ICU) stay. Results indicate that a nutritional tipping point is unlikely to exist during an ICU admission. Data suggests that nitrogen balance remains negative over 20 days, indicating that whilst patients should continue to receive standard nutrition support during their ICU stay, any additional nutritional strategy should be targeted outside of the ICU environment. Multilevel modelling indicated that each additional day spent on ICU was significantly associated with decreased C-reactive protein, muscle depth and interleukin-10 levels. With every year increase in a patient’s age muscle depth and 3-methylhistidine levels were significantly reduced and interleukin-10 levels were significantly increased. Sample size estimates from current data provide some guidance for future studies, however estimates should be viewed with caution. The feasibility of providing a leucine-enriched essential amino acid supplement to trauma ICU patients was furthermore assessed. Inflammatory and nutritional makers were assessed along with protein turnover. Although it was feasible to use the supplement in the trauma population, studying this patient group was more complicated than anticipated. Whole body protein turnover was enhanced in trauma patients with breakdown far exceeding synthesis. These studies suggest that although it may be feasible to provide amino acid supplementation to critically ill patients, this type of intervention should be targeted outside of the ICU environment.Open Acces

The value of Kikuyu foggage for overwintering dry ewes

Kikuyu (Pennisetum clandestinum) is a summer growing tropical pasture species well adapted to the Midlands of KwaZulu-Natal. Kikuyu foggage (standing hay) could play an important role in a fodder flow programme to sustain dry ewes during late winter after their lambs have been weaned in mid-winter. The potential of kikuyu foggage to supply in the feed requirements of dry ewes was evaluated over four winter periods. The foggage was obtained by closing off the kikuyu to grazing during either late January or late February. The foggage was grazed for eight weeks, from mid-July to mid-September, using either strip or continuous grazing systems. Closing off date did not significantly influence the chemical composition of the material on offer. The ewes in the different treatments lost between 4.7 and 10.3% of their initial body weight over the grazing period. In vitro digestible organic matter (IVDOM) of the foggage declined as winter progressed and was positively correlated with the body weight loss of the ewes. Foggage utilization varied between 36.7 and 43.5%, indicating a high proportion of fodder wastage. The body weight loss of the dry ewes during the grazing period suggested that kikuyu foggage in the KwaZulu-Natal Midlands was unable to sustain the body weight of the dry ewe. South African Journal of Animal Science Vol.32(1) 2002: 7-1

Coinfeccio´n entre el gyrovirus aviar 2 y el virus de la enfermedad de Newcastle avirulento en una parvada de pollo de engorde con signos neurolo´gicos y alta mortalidad

A disease with severe neurologic symptoms caused 100% mortality in a small broiler operation in the Gauteng Province, South Africa in late March 2013. Routine diagnostic PCR testing failed to identify a possible cause of the outbreak; thus, samples were submitted for virus isolation, serology, and bacteriology. An avirulent Newcastle disease virus (NDV) strain isolated was identified as a V4-like genotype 1 strain, by DNA sequencing, with a cleavage site of 112GKQGRQL117. Real-time reverse transcription PCR identified NDV in the brain but not in cecal tonsils or pooled tracheas, spleens, lungs, and livers. A random amplification deep sequencing of a transcriptome library generated from pooled tissues produced 927,966 paired-end reads. A contig of 2,309 nucleotides was identified as a near-complete avian gyrovirus 2 (AGV2) genome. This is the first report on the African continent of AGV2, which has been reported in southern Brazil, the Netherlands, and Hong Kong thus far. A real-time PCR for AGV2 only detected the virus in the brain but not in cecal tonsils or pooled tracheas, spleens, lungs, and livers. Sequence reads also mapped to the genomes of mycoplasma, Escherichia coli, avian leukosis virus subtype J, and Marek’s disease virus but excluded influenza A virus, Ornithobacterium rhinotracheale, avian rhinotracheitis virus, avian encephalomyelitis virus, and West Nile virus. Air sac swabs were positive on bacterial culture for E. coli. The possibility of a synergistic pathogenic effect between avirulent NDV and AGV2 requires further investigation.Una enfermedad con signos neurolo´gicos graves causo´ una mortalidad del 100 % en una operacio´n pequen˜a de pollos de engorde en la provincia de Gauteng, en Suda´frica a finales de marzo del 2013. Las pruebas rutinarias de diagno´stico por PCR no lograron identificar una posible causa del brote, por lo que las muestras fueron sometidas al aislamiento viral, serologı´a y bacteriologı´a. Se aislo´ e identifico´ un virus de la enfermedad de Newcastle no virulento (NDV) como una cepa similar al genotipo 1 V4, por secuenciacio´n de ADN, en el sitio de disociacio´n 112GKQGR Q L117. Mediante un me´todo de transcripcio´n reversa y PCR en tiempo real se identifico´ la presencia del virus de Newcastle en el cerebro, pero no en las tonsilas cecales o en las muestras agrupadas de tra´quea, bazo, pulmones, e hı´gado. Una amplificacio´n con secuenciacio´n profunda y aleatoria de una biblioteca de transcriptoma generada a partir de muestras agrupadas de tejidos produjo 927,966 lecturas emparejadas. Se identifico´ un contig de 2309 nucleo´tidos como un genoma casi completo de un Gyrovirus aviar 2 (AGV2). Este es el primer informe en el continente africano de la presencia del AGV2, que se ha reportado hasta el momento en el sur de Brasil, los Paı´ses Bajos y Hong Kong. Un me´todo de PCR en tiempo real para AGV2 so´lo detecto´ al virus en el cerebro, pero no se detecto´ en las tonsilas cecales, o en las muestras agrupadas de tra´quea, bazos, pulmones e hı´gado. Las lecturas de las secuencias tambie´n se relacionaron con el genoma de mycoplasma, Escherichia coli, con el virus de la leucosis aviar subtipo J, y con el virus de la enfermedad de Marek, pero excluyo´ al virus de la influenza A, Ornithobacterium rhinotracheale, al virus de la rinotraqueı´tis aviar, al virus de la encefalomielitis aviar y al virus del Nilo Occidental. Los hisopos de sacos ae´reos fueron positivos para el cultivo bacteriano de E. coli. La posibilidad de un efecto patoge´nico sine´rgico entre el virus de Newcastle avirulento y el AGV2 requiere de ma´s investigacio´n.http://www.aaapjournals.info/loi/avdiam2014ab201

Availability of soil mutualists may not limit non‐native Acacia invasion but could increase their impact on native soil communities

The availability of compatible mutualistic soil microbes could influence the invasion success of non-native plant species. Specifically, there may be spatial variation in the distribution of compatible microbes, and species-specific variation in plant host ability to associate with available microbes. Although either or both factors could promote or limit invasion, the scale over which most studies are conducted makes it difficult to examine these two possibilities simultaneously. However, this is critical to identifying a role of soil microbes in invasion. A series of recent research projects focused on interactions between Australian Acacia and nitrogen-fixing bacteria (rhizobia) at multiple spatial scales, from the local to the inter-continental, has allowed us to evaluate this question. Collectively, this research reveals that nodulation, performance and rhizobial community composition are all broadly similar across spatial scales and differentially invasive species. Synthesis and applications. We argue that current research provides convincing evidence that interactions with rhizobia do not determine invasion success in Acacia, but instead highlights key knowledge gaps that remain unfilled. Importantly, the ease with which non-native Acacia species form mutualistic associations with rhizobia, regardless of invasive status, highlights the critical need to understand the impacts of all non-native Acacia on native soil communities