A Possible Enzymic Assay for Trichothecene Mycotoxins in Animal Feedstuffs

A total of 57 samples of feedstuffs commonly used for animal nutrition in Colombia (maize, soybean, sorghum, cottonseed meal, sunflower seed meal, wheat middlings and rice) were analysed for Aspergillus contamination. Aspergillus fungi were identified at species level and their ability to produce aflatoxins was determined by highperformance liquid chromatography. A total of 31 of the feedstuffs analysed (54.4%) were found to contain Aspergillus spp. The most contaminated substrate was maize (100%) followed by cottonseed meal (80%), sorghum (60%) and wheat middlings (60%). Soybean showed lower levels of contamination (10%). No Aspergillus spp. could be isolated from rice or sunflower seed meal. Total Aspergillus strains isolated were 50, with 28 belonging to section Flavi (56%), 17 to section Nigri (34%), 4 to section Circumdati (8%) and 1 to section Fumigati (2%). Among section Flavi, 17 isolates were identified as A. flavus, seven as A. parasiticus, two as A. oryzae and two as A. tamarii. Production of aflatoxins by Aspergillus section Flavi was screened by liquid chromatography. About three quarters of the A. flavus strains (76.5%) produced aflatoxin B1 (0.2 to 240.4 µg/g) and aflatoxin B2 (0.2 to 1.6 µg/g), while all A. parasiticus strains produced the four naturally occurring aflatoxins (aflatoxin B1 from 0.6 to 83.5 µg/g, aflatoxin B2 from 0.3 to 4.8 µg/g, aflatoxin G1 from 0.4 to 19.3 µg/g and aflatoxin G2 from 0.1 to 1.0 µg/g). This is the first study demonstrating the presence of highly toxigenic Aspergillus fungi in Colombian animal feedstuffs.

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Prediction of crude protein and neutral detergent fibre concentration in residues of in situ ruminal degradation of pasture samples by near-infrared spectroscopy (NIRS)

Animal Production Science ◽

10.1071/an14822 ◽

2016 ◽

Vol 56 (9) ◽

pp. 1504 ◽

Cited By ~ 1

Author(s):

J. P. Keim ◽

H. Charles ◽

D. Alomar

Keyword(s):

Infrared Spectroscopy ◽

Near Infrared Spectroscopy ◽

Crude Protein ◽

Near Infrared ◽

External Validation ◽

Neutral Detergent Fibre ◽

Insufficient Amount ◽

Ruminal Degradation ◽

Animal Feedstuffs

An important constraint of in situ degradability studies is the need to analyse a high number of samples and often with insufficient amount of residue, especially after the longer incubations of high-quality forages, that impede the study of more than one nutritional component. Near-infrared spectroscopy (NIRS) has been established as a reliable method for predicting composition of many entities, including forages and other animal feedstuffs. The objective of this work was to evaluate the potential of NIRS for predicting the crude protein (CP) and neutral detergent fibre (NDF) concentration in rumen incubation residues of permanent and sown temperate pastures in a vegetative stage. In situ residues (n = 236) from four swards were scanned for their visible-NIR spectra and analysed for CP and NDF. Selected equations developed by partial least-squares multivariate regression presented high coefficients of determination (CP = 0.99, NDF = 0.95) and low standard errors (CP = 4.17 g/kg, NDF = 7.91 g/kg) in cross-validation. These errors compare favourably to the average concentrations of CP and NDF (146.5 and 711.2 g/kg, respectively) and represent a low fraction of their standard deviation (CP = 38.2 g/kg, NDF = 34.4 g/kg). An external validation was not as successful, with R2 of 0.83 and 0.82 and a standard error of prediction of 14.8 and 15.2 g/kg, for CP and NDF, respectively. It is concluded that NIRS has the potential to predict CP and NDF of in situ incubation residues of leafy pastures typical of humid temperate zones, but more robust calibrations should be developed.

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ChemInform Abstract: Hydrolysis of Tannery Wastes to Protein Meal for Animal Feedstuffs: A Process and Product Evaluation.

ChemInform ◽

10.1002/chin.199434272 ◽

2010 ◽

Vol 25 (34) ◽

pp. no-no

Author(s):

E. MONTONERI ◽

G. RIZZI ◽

A. RIZZI ◽

A. MORDENTI ◽

A. BAULI ◽

...

Keyword(s):

Product Evaluation ◽

Protein Meal ◽

Tannery Wastes ◽

Animal Feedstuffs ◽

Hydrolysis Of

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An enzymic assay for ammonia in waste matter

Journal of Agricultural and Food Chemistry ◽

10.1021/jf60211a001 ◽

1977 ◽

Vol 25 (3) ◽

pp. 688-690 ◽

Cited By ~ 3

Author(s):

John E. Robbins ◽

Shane C. Weber

Keyword(s):

Enzymic Assay

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Inhibition of steroid 5α-reductase by specific aliphatic unsaturated fatty acids

Biochemical Journal ◽

10.1042/bj2850557 ◽

1992 ◽

Vol 285 (2) ◽

pp. 557-562 ◽

Cited By ~ 126

Author(s):

T Liang ◽

S Liao

Keyword(s):

Fatty Acids ◽

Oleic Acid ◽

Linoleic Acid ◽

Linolenic Acid ◽

Unsaturated Fatty Acids ◽

Binding Assay ◽

Reductase Activity ◽

Undecylenic Acid ◽

Gamma Linolenic Acid ◽

Enzymic Assay

Human or rat microsomal 5 alpha-reductase activity, as measured by enzymic conversion of testosterone into 5 alpha-dihydrotestosterone or by binding of a competitive inhibitor, [3H]17 beta-NN-diethulcarbamoyl-4-methyl-4-aza-5 alpha-androstan-3-one ([3H]4-MA) to the reductase, is inhibited by low concentrations (less than 10 microM) of certain polyunsaturated fatty acids. The relative inhibitory potencies of unsaturated fatty acids are, in decreasing order: gamma-linolenic acid greater than cis-4,7,10,13,16,19-docosahexaenoic acid = cis-6,9,12,15-octatetraenoic acid = arachidonic acid = alpha-linolenic acid greater than linoleic acid greater than palmitoleic acid greater than oleic acid greater than myristoleic acid. Other unsaturated fatty acids such as undecylenic acid, erucic acid and nervonic acid, are inactive. The methyl esters and alcohol analogues of these compounds, glycerols, phospholipids, saturated fatty acids, retinoids and carotenes were inactive even at 0.2 mM. The results of the binding assay and the enzymic assay correlated well except for elaidic acid and linolelaidic acid, the trans isomers of oleic acid and linoleic acid respectively, which were much less active than their cis isomers in the binding assay but were as potent in the enzymic assay. gamma-Linolenic acid had no effect on the activities of two other rat liver microsomal enzymes: NADH:menadione reductase and glucuronosyl transferase. gamma-Linolenic acid, the most potent inhibitor tested, decreased the Vmax. and increased Km values of substrates, NADPH and testosterone, and promoted dissociation of [3H]4-MA from the microsomal reductase. gamma-Linolenic acid, but not the corresponding saturated fatty acid (stearic acid), inhibited the 5 alpha-reductase activity, but not the 17 beta-dehydrogenase activity, of human prostate cancer cells in culture. These results suggest that unsaturated fatty acids may play an important role in regulating androgen action in target cells.

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