scholarly journals Some fungi, zearalenone and other mycotoxins in chicken rations, stock feedstuffs, lucerne and pasture grasses in the communal farming area of Rhenosterkop in South Africa

2007 ◽  
Vol 78 (2) ◽  
Author(s):  
D. Naicker ◽  
G.J. Marais ◽  
H. Van den Berg ◽  
M.G. Masango
Keyword(s):  
South Africa ◽  
Detection Limits ◽  
Cattle Feed ◽  
Pasture Grasses ◽  
Commercial Chicken ◽  
Low Levels ◽  
Maize Kernels ◽  
Communal Farming ◽  
Feed Samples ◽  
Mould Contamination

Mycotoxins may be present in feeds without any visible signs of mould contamination. There is a need for rapid and accurate measurement of mycotoxins for purposes of continual monitoring and identification of high risk commodities. Samples from commercial chicken feed (maize kernels), cattle feed (lucerne, grass and hay) and milk were analysed for the presence of certain mycotoxins and cultured for fungi. Results of fungal profiles showed that most samples were contaminated by moulds belonging to the genera, Alternaria, Aspergillus, Fusarium, Penicillium, Mucor, Phoma and Rhizopus. All the chicken feed samples tested contained mycotoxins either below the recommended safe levels for poultry or below the detection limits of the ELISA tests. However, samples of grass contained levels of zearalenone greater than the allowable concentration for dairy and beef cattle (250 ppm), which may be linked to the presence of Fusarium scirpi identified in the fungal profiles. The levels of AFM1 were below the detection limits of the ELISA tests, which may be attributed to the low levels of aflatoxins found in the feed (grass) samples. The presence of the fungus in samples analysed is not evidence for the presence of mycotoxins.

Determination of Ochratoxin A in Feed by Immunoaffinity Cleanup and Liquid Chromatography

2013 ◽  
Vol 96 (3) ◽  
pp. 599-602 ◽  
Author(s):  
Ping Ding ◽  
Ziyou Mi ◽  
Yali Hou ◽  
Yigang He ◽  
Jianhua Xie
Keyword(s):  
Liquid Chromatography ◽  
Detection Limit ◽  
Ochratoxin A ◽  
Cyanogen Bromide ◽  
Polyclonal Antibodies ◽  
Immunoaffinity Column ◽  
Low Levels ◽  
Sepharose 4B ◽  
Feed Samples

Abstract A method using LC was developed for determination of ochratoxin A (OTA) in feeds. The extracted samples were cleaned up by an immunoaffinity column prepared by covalently coupling polyclonal antibodies against OTA to cyanogen bromide-activated Sepharose 4B. The eluates were determined by LC with fluorescence detection. Recoveries of OTA from fortified samples of 1–10 μg/kg levels ranged from 84.3 to 90.0%, with CVs of 3.3–7.8%. The detection limit was 0.045 μg/kg based on an S/N of 3:1. A total of 65 feed samples were screened for OTA with the proposed method. The results showed that only nine samples were contaminated with OTAs at low levels. The presented method was successfully applied to quantify OTAs in real feed samples.

scholarly journals Can South Africa sustain and diversify its exports?

2016 ◽  
Vol 19 (2) ◽  
pp. 249-263 ◽  
Author(s):  
Marianne Matthee ◽  
Ernst Idsardi ◽  
Waldo Krugell
Keyword(s):  
South Africa ◽  
Human Capital ◽  
Comparative Advantage ◽  
Export Growth ◽  
Intensive Margin ◽  
Manufactured Products ◽  
Low Levels

The aim of this paper is to examine the diversification of South Africa’s exports over the period 1994 to 2012. A decomposition of export growth shows that exports of non-fuel primary commodities as well as medium-skill and technology-intensive manufactured products increased. The largest decrease was in the export of resource-intensive manufactures. These changes reflect South Africa’s endowment of relatively low levels of physical and human capital. The analysis shows that export products that are further from the country’s comparative advantage, make smaller contributions to growth in the intensive margin. It clearly shows the challenge of sustainably diversifying the export basket.

scholarly journals An Alderfer perspective of the higher education restructuring in South Africa

2005 ◽  
Vol 31 (2) ◽  
Author(s):  
C. A. Arnolds
Keyword(s):  
Higher Education ◽  
South Africa ◽  
Job Performance ◽  
Peer Relations ◽  
Employee Motivation ◽  
Regression Analyses ◽  
Organisational Commitment ◽  
Low Levels ◽  
And Performance ◽  
The Impact

The consequences of the restructuring of higher education in South Africa have not yet been thoroughly investigated. This study investigates the impact of the abovementioned restructuring on employee motivation (as measured by Alderfer’s ERG theory), organisational commitment and job performance. The results show that the respondents exhibit low levels of organisational commitment and low satisfaction with monetary remuneration and fringe benefits. The results, however, show high levels of satisfaction with growth factors, peer relations and performance intentions. These results are interpreted in the light of the multiple regression analyses conducted of the interrelationships among the variables. Opsomming Die nagevolge van die herkonstruksie van hër-onderwys in Suid-Afrika is nog nie deeglik ondersoek nie. Hierdie studie ondersoek die invloed wat bogenoemde rekonstruksie op die motivering (soos gemeet deur Alderfer se teorie), organisatories toegewydheid en werksprestasie van werknemers het. Die resultate toon dat die respondente lae vlakke van organisatoriese toegewydheid en lae tevredenheid ten opsigte van monetêre beloning en byvoordele tentoonstel. Die resultate toon egter hoë vlakke van tevredenheid in soverre groeifaktore, kollegiale verhoudinge en werkprestasievoornemens betref. Hierdie resultate word vertolk teen die agtergrond van veelvoudige regressie-analises wat op die inderlinge verwantskappe tussen die veranderlikes uitgevoer is.

Spectrophotofluorometric Estimation of Low Levels of Diethylstilbestrol in Feedstuffs

1973 ◽  
Vol 56 (6) ◽  
pp. 1483-1488
Author(s):  
Marshall T Jeffus ◽  
Charles T Kenner
Keyword(s):  
Standard Deviation ◽  
Fluorescent Intensity ◽  
Low Levels ◽  
Feed Samples

Abstract A method for the determination of low levels of diethylstilbestrol in feedstuffs is described. Interfering feed extractives are removed by using a tripotassium phosphate-Celite column prior to irradiation. The dione produced by irradiation is oxidized to a phenanthrenediol and extracted into CH2CI2 for measurement of fluorescent intensity. The amount of diethylstilbestrol found in several feed samples ranged from 0 to 10 ng (0.0–0.5 ppb) with an average of 4 ng (0.2 ppb). Recoveries of 100 ng standards (equivalent to 5 ppb) added to the same samples averaged 91 ng with a standard deviation of 14 ng. Recoveries of 1000 ng standards (equivalent to 50 ppb) added to the same samples averaged 820 ng with a standard deviation of 14 ng. For 100 ng standards analyzed beginning with the irradiation procedure, the standard deviation was 5.6%, and for 1000 ng standards, the standard deviation was 2.8%.

Microbiological Turbidimetric Analysis of Low Chlortetracycline Concentrations in Feeds

1975 ◽  
Vol 58 (3) ◽  
pp. 602-608
Author(s):  
Hussein S Ragheb ◽  
Linda S Porubcan
Keyword(s):  
Bacterial Growth ◽  
Room Temperature ◽  
Cattle Feed ◽  
Standard Curve ◽  
Turbidimetric Method ◽  
Feed Supplements ◽  
Turbidimetric Assay ◽  
Swine Feed ◽  
Low Levels ◽  
Turbidimetric Analysis

Abstract Recovery studies in which chlortetracycline hydrochloride (CTC-HCl) standard was added to cattle and swine feed supplements at 4.09–9.99 g/ton showed lower antibiotic recovery turbidimetrically (80.6–98.7%) than by the AOAC modified standard as in 38.179(d) (91.2–98.7%) and the plain buffer as in 38.179(b) (93.8-133.0%) methods. Three feeds fortified with a commercial premix at the levels of 5.0 and 10.0 g CTC-HCl/ton showed an overall CTC-HCl recovery of 87.6–110.6% by manual turbidimetric assay. Results were 89.1–108.7% by the AOAC inactivated feed diluent standard and 95.4–125.4% by the plain buffer methods. For some sample extracts (as in cattle feed) the use of heat to stop bacterial growth in the turbidimetric method caused formation of a precipitate. Cooling of cultures to room temperature and rapid reading of sample turbidity followed by standard curve concentrations minimized this interference. The manual turbidimetric assay of low levels of CTC-HCl in feeds appears to offer advantages over other methods.

scholarly journals Analysis of Mycotoxins Contamination in Poultry Feeds Manufactured in Selected Provinces of South Africa Using UHPLC-MS/MS

Toxins ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 452 ◽  
Author(s):  
Sharon Maphala Mokubedi ◽  
Judith Zanele Phoku ◽  
Rumbidzai Naledi Changwa ◽  
Sefater Gbashi ◽  
Patrick Berka Njobeh
Keyword(s):  
South Africa ◽  
High Performance ◽  
Fumonisin B1 ◽  
Monomethyl Ether ◽  
Poultry Feed ◽  
Alternariol Monomethyl Ether ◽  
Triple Quadrupole Mass Spectrometer ◽  
Type A Trichothecenes ◽  
Contamination Levels ◽  
Feed Samples

A total of 105 different types of poultry feed samples from South Africa were simultaneously analysed for the presence of 16 mycotoxins using ultra-high-performance liquid chromatography coupled to a triple quadrupole mass spectrometer (UHPLC-MS/MS). The data revealed the presence of 16 mycotoxins in the various poultry feed samples. Fumonisin B1 (FB1) was the most dominant recovered from 100% of samples analysed at concentrations ranging between 38.7 and 7125.3 µg/kg. This was followed by zearalenone (ZEN) (range: 0.1–429 µg/kg) and deoxynivalenol (DON) (range: 2.5–154 µg/kg). Samples were also found to be contaminated with fumonisin B2 (FB2) (range: 0.7–125.1 µg/kg), fumonisin B3 (FB3) (range: 0.1–125.1 µg/kg), α-zearalenol (α-ZEL) (range: 0.6–20 µg/kg ), β-zearalenol (β-ZEL) (range: 0.2–22.1 µg/kg), 3-acetyldeoxynivalenol (3-ADON) (range: 0.1–12.9 µg/kg) and 15-acetyldeoxynivalenol (15-ADON) (range: 1.7–41.9 µg/kg). Alternaria mycotoxin, i.e., Alternariol monomethyl ether (AME) was recovered in 100% of samples at concentrations that ranged from 0.3–155.5 µg/kg. Aflatoxins (AFs) had an incidence rate of 92% with generally low concentration levels ranging from 0.1–3.7 µg/kg. Apart from these metabolites, 2 type A trichothecenes (THs), i.e., HT-2 toxin (HT-2) (range: 0.2–5.9 µg/kg) and T-2 toxin (T-2) (range: 0.1–15.3 µg/kg) were also detected. Mycotoxin contamination in South African poultry feed constitutes a concern as correspondingly high contamination levels, such as those observed herein are likely to affect birds, which can be accompanied by severe health implications, thus compromising animal productivity in the country. Such exposures, primarily to more than one mycotoxin concurrently, may elicit noticeable synergistic and or additive effects on poultry birds.

Organochlorine and Organophosphorus Insecticides and Industrial Pollutants in the Milk Supplies of Ontario – 1983

1985 ◽  
Vol 48 (6) ◽  
pp. 499-504 ◽  
Author(s):  
R. FRANK ◽  
H. E. BRAUN ◽  
G. H. SIRONS ◽  
J. RASPER ◽  
G. G. WARD
Keyword(s):  
Polychlorinated Biphenyls ◽  
Case History ◽  
Detection Limits ◽  
Dairy Herd ◽  
Heptachlor Epoxide ◽  
Organophosphorus Insecticides ◽  
Industrial Pollutants ◽  
Milk Samples ◽  
Maximum Residue Limits ◽  
Low Levels

During the spring of 1983, fluid milk samples were collected from 359 bulk transporters representing 16 counties, municipalities and districts of Ontario, and were analyzed for organochlorine and organophosphorus insecticides plus selected halogenated industrial pollutants. Dieldrin, p,p′-DDE, heptachlor epoxide, and α-BHC were found in over 90% of samples, but none exceeded the accepted maximum residue limits. Polychlorinated biphenyls (PCB), lindane and pentachlorophenol (PCP) were found in 83, 68 and 57% of samples, respectively, with four samples exceeding the permissable PCB limit and one sample exceeding the permissable PCP limit. Residues of chlordane, endosulfan, p,p′-TDE, and p,p′-DDT were identified in only 1.9 to 4.7% of samples, and were present at levels only slightly above the detection limits. Hexachlorobenzene (HCB) was found at low levels in 40% of samples. Mean residues of organochlorines found were as follows (μg/kg butterfat): ∑DDT - 12; α-BHC - 5.3; lindane - 4.0; heptachlor epoxide - 3.9; dieldrin - 6.2; HCB - 0.67; PCB - 24; and PCP - 29. No residues of six organophosphorus insecticides, endrin, methoxychlor or mirex were detected in any samples. This survey was the sixth in a series beginning in 1967. Half-residue disappearance rates were calculated at 3.5, 5.4, 5.6 and 3.0 years for ∑DDT, dieldrin, PCB and HCB, respectively. A case history is included involving the misapplication of fenthion to a dairy herd which revealed a half-residue elimination from milk in approximately 3 d.

Stem mortality of Acacia nigrescens induced by the synergistic effects of elephants and fire in Kruger National Park, South Africa

2008 ◽  
Vol 24 (6) ◽  
pp. 655-662 ◽  
Author(s):  
Glenn R. Moncrieff ◽  
Laurence M. Kruger ◽  
Jeremy J. Midgley
Keyword(s):  
South Africa ◽  
National Park ◽  
Synergistic Effects ◽  
Kruger National Park ◽  
Field Surveys ◽  
Natural Fires ◽  
Large Trees ◽  
Low Levels ◽  
Stem Mortality

Abstract:One manner in which elephants utilize trees is by removing their bark. This type of utilization is concentrated on the largest trees in the landscape. The role of bark removal in increasing the vulnerability of large trees to fire and the mechanism through which fire damage is mediated were investigated in Kruger National Park, South Africa, by experimentally removing bark and burning Acacia nigrescens stems with diameters ranging between 30 and 68 mm. Also, field surveys were conducted subsequent to natural fires in order to investigate mortality patterns of large trees with dbh greater than 15 cm with bark removed by elephants. An increasing probability of mortality was associated with increasing amounts of bark removal but only if trees were burned. When trees had bark removed but were not burnt, simulating damage only to cambium and phloem, none of the 12 treated stems died in the 4-mo period over which the experiment ran. Moreover, low levels of cambium damage were detected in large burned stems. This suggests that bark removal increases fire-induced xylem damage and that this damage contributes towards stem mortality. In a survey of 437 large trees, bark removal by elephants was frequent on large stems (44%) and larger trees have greater amounts of bark removed. Post-fire mortality of large trees was significantly associated with increasing bark removal and stem diameter. These results indicate that bark removal by elephants increases the vulnerability of stems to fire, resulting in mortality of large stems otherwise protected from fire.

A review of the efficacy of mycotoxin detoxifying agents used in feed in light of changing global environment and legislation

2016 ◽  
Vol 9 (3) ◽  
pp. 419-433 ◽  
Author(s):  
E. Wielogórska ◽  
S. MacDonald ◽  
C.T. Elliott
Keyword(s):  
Agricultural Production ◽  
Production Efficiency ◽  
Scientific Literature ◽  
Animal Feed ◽  
Animal Health ◽  
Global Environment ◽  
Low Levels ◽  
Feed Samples

In the recent years, mycotoxins have undoubtedly gained a keen interest of the scientific community studying food safety. The main reason is their profound impact on both human and animal health. International surveys reveal a low percentage of feed samples being contaminated above permitted/guideline levels, developed to protect consumers of animal derived products. However, the deleterious impact of feed co-contaminated at low levels with numerous both known and regulated as well as novel mycotoxins on producing animals has been described. Associated effects on agro-economics world-wide include substantial pecuniary losses which are borne by the society as a whole. Even though good agronomic practice is thought to be the most effective way of preventing animal feed contamination, the EC have recognised the need to introduce an additional means of management of feed already contaminated with low-levels of mycotoxins to alleviate detrimental effects on agricultural production efficiency. This review discusses types of feed detoxifying agents described in scientific literature, their reported efficacy in both in vitro and in vivo systems, and comparison with available commercial formulations in the light of increasing knowledge regarding mycotoxin prevalence in the changing global environment.

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