Fish oil replacement in starter, grow-out, and finishing feeds for farmed aquatic animals

As aquaculture production continues to grow, there will be an increased use of lipid resources (oils and fats) alternative to fish oil for feed production. The potential for the use of these alternatives varies depending on the feeds in which they are included according to the production phase of the animals to which they are being fed. In starter feeds, where rapid growth, high survival, and normal development are critical priorities, there will remain a need for the use of lipid resources high in omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA). Fish in this starter phase have a critical requirement for the n-3 LC-PUFA docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), and fish oils remain the only cost-effective source of these nutrients in the volumes required. However, the greatest demand for lipids is in those diets for the grow-out phase. Most studies on alternative lipid use with animals in this part of the production phase show positive outcomes, in that there are few studies where all the added fish oil cannot be replaced. There are some species, however, where potential replacement levels are suggested to be more conservative, and a general substitution level in this production phase of 75% has been suggested. One of the key effects noted across the grow-out phase is that all alternatives affect the flesh fatty acid characteristics by reducing the level of n-3 LC-PUFA. This issue has provoked the concept of finisher diets, whereby a high n-3 LC-PUFA content diet is fed in order to restore the desired meat fatty acid profiles. Studies examining this concept have found that the tissue triacylglycerol fatty acids were greatly modified and responded in a simple dilution process to the added oil fatty acid composition, whereas the fatty acids of tissue phospholipids were less influenced by dietary fatty acid makeup.<br /

Response to nitrogen fertilisers of wheat, oats, and barley in Western Australia

Trials were mainly sited in areas normally receiving more than 450 mm average annual rainfall. Response curves were fitted to each set of data and then averaged to give overall response curves for each crop. There was little difference between the crops in absolute or percentage response to nitrogen fertiliser but the nitrogen fertiliser rate required for maximum yield was highest for wheat and lowest for oats

Soil acidity and liming in the Lower Great Southern

In the 375 to 750 millimetre rainfall area of the Lower Great Southern, reports of loss of subterranean clover from established pastures, reduced carrying capacity for sheep and increasing soil acidity lead to the establishment in 1981 of a research programme into the effects of soil acidity on pasture productivity in that region

Privacy-certification standards for extended-reality devices and services

In this position paper, we discuss the need for, and potential requirements for privacy certification standards for extended-reality devices and related services. We begin by presenting motivations, before discussing related efforts. We then review the issue of certification as a research problem and identify key requirements. Finally, we out-line key recommendations for how these might feed into a grander roadmap for privacy and security research

A review of carotenoid utilisation and function in crustacean aquaculture

Crustaceans are cultured extensively around the world in intensive farming systems. High-performance formulated feeds have been developed for crustacean aquaculture, which are often supplemented with a number of natural and synthetic carotenoid sources. Studies over a number of years have consistently shown that dietary carotenoid supplementation is beneficial for crustacean aquaculture across a range of commercially relevant parameters. Most obvious is the effect on pigmentation, where carotenoid inclusion levels in feeds and duration of feeding diets with carotenoids have been optimised across many species to improve product colour, and subsequently quality and price. However, beneficial effects of carotenoid inclusion have increasingly been demonstrated on other parameters. This review updates the recent progress in our understanding of dietary carotenoid utilisation and storage, and the combined effects of diet, genetics and environment on crustacean pigmentation. In addition, the range of other physiological benefits this class of molecules brings to these animals is summarised. These include improvements in survival, growth, reproductive capacity, disease resistance and stress resistance. &copy; 2015 Wiley Publishing Asia Pty Ltd

Effect of dietary saturated and monounsaturated fatty acids in juvenile barramundi Lates calcarifer

Barramundi (Lates calcarifer), a catadromous teleost of commercial interest, perform well when fed a wide range of dietary oils. However, the range of alternative oils now being explored is typically rich in saturated and monounsaturated fatty acids (SFA and MUFA). In this study, the response of juvenile barramundi (47.0 g per fish initial weight) fed isolipidic and isoenergetic diets with 82 g kg-1 added oil was tested. The experimental test diets had a 2 : 1 or 1 : 2 ratio of SFA to MUFA (SFA-D and MUFA-D, respectively) compared to a control diet (CTRL-D) fed for 8 weeks. The diets containing mostly olive oil (dietary MUFA-D) and mostly refined palm oil (dietary SFA-D) did not impact the growth performance or feed utilization parameters of the barramundi. The in vivo beta-oxidation activity was consistent with the dietary fatty acid composition, with the most dominant FA being heavily beta-oxidized. Together, the in vivo whole-body mass balance of fatty acids showed that n-3 long-chain polyunsaturated fatty acids (LC-PUFA) were most efficiently utilized in the SFA-D- and MUFA-D-fed fish. This study provides evidence that additional dietary MUFA and SFA are suitable lipid classes for juvenile barramundi and they are both equally efficient at sparing LC-PUFA from an oxidative fate.

Piloting a national laboratory electronic programme status reporting system in Ekurhuleni health district, South Africa

Background. The National Health Laboratory Service (NHLS) performs ~4 million CD4 tests per annum for the public health sector at 61 CD4 testing laboratories across South Africa. Currently, CD4 laboratory data captured do not differentiate between antiretroviral treatment (ART) and pre-ART care.Methods. A cross-sectional study was undertaken to evaluate a redesigned Comprehensive Care, Management and Treatment of HIV and AIDS (CCMT) request form, incorporating a two-tick collection procedure linking the CD4 test request to patient CCMT programme status. Field testing was undertaken at three health facilities, where healthcare personnel were required to capture whether the CD4 count requested was a ‘first-ever CD4’, ‘CD4 taken previously, not yet in ART care’ or ‘in ART care’. All data were extracted from the NHLS Corporate Data Warehouse and analysed using Microsoft Excel and Stata-12.Results. A substantial increase in the number of request forms with a CCMT programme status (28.1% v. 84.4%) was reported pre- and post-implementation. Post-implementation data (N=1 004) revealed that 30.8% patients were ART naive (‘first-ever CD4’), with 7.4% ‘not yet on ART’ (median CD4 counts of 150 and 328 cells/μL, respectively). Patients on ART comprised 61.9% of the study group (median CD4 count ~346 cells/μL). Sixty percent of patients were aged between 30 and 44 years, and females predominated (male/ female ratio 0.7:1).Conclusions. A simple modification to the CCMT request form can successfully facilitate collection of programme status. For national implementation, it would be advantageous to have a unique patient identifier to further enhance laboratory-based programmatic monitoring and evaluation

Documented higher burden of advanced and very advanced HIV disease among patients, especially men, accessing healthcare in a rapidly growing economic and industrial hub in South Africa: A call to action

Background. Lephalale Municipality in Limpopo Province, South Africa, has seen significant economic and industrial development owing to expansion of the coal mining and power generation sectors. This development has coincided with substantial population growth of 65% between 2001 and 2016, attributable to largely (migrant) males living in the area who, overall, outnumbered females by ~121:100. The local HIV prevalence is reported to be higher than national rates.Objectives. Anonymised National Health Laboratory Service CD4+ data were used to document increasing laboratory services workload and to establish the burden of advanced (CD4+ count &lt;200 cells/µL) and very advanced (&lt;100 cells/µL) HIV disease among adult patients accessing public healthcare in Lephalale between 2006 and 2015.Methods. A cross-sectional design was used to analyse CD4+ laboratory data. CD4+ outcomes were categorised by volumes of tests, year, health facility type, age categories (15 - 19, 20 - 24, 25 - 29, 30 - 34, 35 - 39, 40 - 44, 45 - 49 and &gt;49 years), CD4+ test range (≤50, 51 - 100, 101 - 200, 201 - 350, 351 - 500 and ≥501 cells/µL) and gender. Median CD4+ counts were calculated.Results. Extracted Lephalale data comprised 57 490 CD4+ results, with a mean patient age of 34 years. Considerably fewer male than female patients had CD4+ counts reported (male/female ratio 0.45:1). CD4+ test volumes showed a five-fold escalation over the study period, increasing from 1 458 tests in 2006 to 8 239 in 2015. A considerable burden of advanced and very advanced HIV disease (exceeding 50% of all cases) was noted in 2006/2007; by 2015 the proportion had fallen, but was still high at 27%. The overall median CD4+ count in 2006 (192 cells/µL) confirmed a high burden of advanced disease, with modest improvement to 289 cells/µL by 2015. Between 2006 and 2015, the median CD4+ count for females increased from 204 to 405 cells/µL, while that for males increased from 126 to 285 cells/µL. Age analysis further revealed that men aged &lt;20 years or &gt;25 years, and specifically those aged 30 - 45 years, had up to 44% more advanced HIV disease.Conclusions. Lower median CD4+ counts and a dramatic increase in volumes of CD4+ tests performed from 2007 onwards revealed a high burden of advanced and very advanced HIV disease in patients accessing care in Lephalale. Viewed together with Statistics South Africa census documentation of a disproportionately high number of males compared with females living in the area, these figures suggest that improved systems are urgently needed to encourage and accommodate access to HIV care for male (migrant worker) patients living and working in emerging industrial centres

Analysis of HIV disease burden by calculating the percentages of patients with CD4 counts

Background. South Africa (SA)’s Comprehensive HIV and AIDS Care, Management and Treatment (CCMT) programme has reduced new HIV infections and HIV-related deaths. In spite of progress made, 11.2% of South Africans (4.02 million) were living with HIV in 2015.Objective. The National Health Laboratory Service (NHLS) in SA performs CD4 testing in support of the CCMT programme and collates data through the NHLS Corporate Data Warehouse. The objective of this study was to assess the distribution of CD4 counts &lt;100 cells/μL (defining severely immunosuppressed HIV-positive patients) and &gt;500 cells/μL (as an HIV-positive ‘wellness’ indicator).Methods. CD4 data were extracted for the financial years 2010/11 and 2014/15, according to the district where the test was ordered, for predefined CD4 ranges. National and provincial averages of CD4 counts &lt;100 and &gt;500 cells/μL were calculated. Data were analysed using Stata 12 and mapping was done with ArcGIS software, reporting percentages of CD4 counts &lt;100 and &gt;500 cells/μL by district.Results. The national average percentage of patients with CD4 counts &lt;100 cells/μL showed a marked decrease (by 22%) over the 5-year study period, with a concurrent increase in CD4 counts &gt;500 cells/μL (by 57%). District-by-district analysis showed that in 2010/11, 44/52 districts had &gt;10% of CD4 samples with counts &lt;100 cells/μL, decreasing to only 17/52 districts by 2014/15. Overall, districts in the Western Cape and KwaZulu-Natal had the lowest percentages of CD4 counts &lt;100 cells/μL, as well as the highest percentages of counts &gt;500 cells/μL. In contrast, in 2014/15, the highest percentages of CD4 counts &lt;100 cells/μL were noted in the West Rand (Gauteng), Vhembe (Limpopo) and Nelson Mandela Bay (Eastern Cape) districts, where the lowest percentages of counts &gt;500 cells/μL were also noted.Conclusions. The percentages of CD4 counts &lt;100 cells/μL highlighted here reveal districts with positive change suggestive of programmatic improvements, and also highlight districts requiring local interventions to achieve the UNAIDS/SA National Department of Health 90-90-90 HIV treatment goals. The study further underscores the value of using NHLS laboratory data, an underutilised national resource, to leverage laboratory test data to enable a more comprehensive understanding of programme-specific health indicators

The combined effects of diet, environment and genetics on pigmentation in the Giant Tiger Prawn, Penaeus monodon

The colour of prawns, particularly the Giant Tiger Prawn Penaeus monodon, is highly desired and fetches premium market prices. Prawn pigmentation is influenced by the interaction of a range of factors, including the amount of dietary carotenoid, the distribution of hypodermal pigments, and genetics. These aspects have been studied in isolation, but there is limited knowledge on how these components interact to influence prawn pigmentation. This study tracked the colour of prawns that had been fed four different levels of dietary astaxanthin (Axn) over 6. weeks, and then transferred to either black or white coloured tanks. The dietary influence on colour was slow and had only developed after 6. weeks. Meanwhile the effect of background colour was rapid, within 15. min. Results showed that diet and background colour work in combination to affect prawn colour. The poorest colour was recorded in prawns fed without dietary Axn and transferred to white substrates, and this colour was improved by the addition of dietary Axn. Animals fed without dietary Axn and exposed to black substrates showed an intermediate colour, and this was further improved by the addition of dietary Axn. The best colour was recorded in prawns fed 100. mg/kg Axn and exposed to black substrates. The abundance of the epithelial pigment protein crustacyanin (CRCN) was not correlated with prawn colour, suggesting that this protein does not regulate the modifications in response to background colour. Finally, the effect of substrate exposure was assessed on farmed prawns, and indicated a small positive effect on colour during harvesting. These data demonstrate that while short term exposure to black substrates can have positive effects on prawn colour, dietary Axn supplementation can both improve pigmentation of animals exposed to black substrates, and prevent the negative effects of exposure to white substrates