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Biomedical subjects

J P Minyard

Publications and source records attributed to J P Minyard.

12 recordsLinked to original sources
PubMed1982

Jimson weed seed toxicity in cattle.

A subacute experiment was undertaken for 14 days. The results obtained from these studies suggest that: 1) unless a highly Jimson weed seed contaminated feed is ingested (greater than 0.09% of body weight) or force fed, death should be a rare consequence of Jimson weed seed contamination; 2) Jimson weed seed toxicity in cattle as a result of feed contamination appears a self-limiting problem (rumen atony and anorexia prevent further intoxication until the blood levels of alkaloids are reduced to allow normal ruminant intestinal function); 3) cattle may exhibit signs of atropine toxicity at contamination levels of 881 seed/kg of feed or higher; 4) rumen fluid from heifers fed diet containing 4,408 Jimson weed seed had the greatest VFA concentration change from day 0 to 7; 5) in vitro fermentation of diets resulted in no difference in IVDMD values, but VFA concentration values tended to increase with increased concentrations of Jimson weed seed in the diet.

Alkaloids↗
PubMed1981

Minicolumn detection methods for aflatoxin in raw peanuts: collaborative study.

The Holaday-Velasco method and a modified Holaday method have been compared. The former method combines the speed and simplicity of the Holaday extraction and cleanup with the sensitivity of the minicolumn originally described by Velasco. The combination method has been approved by the AOAC and the AACC for determining aflatoxin in corn. The Holaday method was modified by substituting toluene for benzene in the solvent partition, and methylene chloride for chloroform in the minicolumn development to eliminate use of hazardous solvents. The neutral alumina in the Holaday minicolumn was changed from activity V to activity III to provide a more stable column. At aflatoxin levels in raw peanuts of 13-20 ng/g, the presence of aflatoxin was missed by the modified Holaday method in 4 analyses (3 laboratories) of 42 reported. There were no misses in this contamination range by the Holaday-Velasco method. There were no misses by either method with samples containing greater than 20 ng total aflatoxins/g. Analysis of uncontaminated raw peanuts by the modified Holaday method resulted in 2 false positives of 14 reports; the Holaday-Velasco method produced no false positive reports from 15 analyses of uncontaminated peanuts. The Holaday-Velasco method was adopted official first action for peanuts.

Aflatoxins↗
PubMed1977

Aluminum oxide cleanup of feed grade fats for residues of dieldrin.

A method is described for the analysis of dieldrin in feed grade fats. Fat samples in petroleum ether are cleaned up by column chromatography on 10% deactivated aluminum oxide followed by Florisil and analyzed by electron capture gas chromatography. Fourteen laboratories tested the method for determining dieldrin in naturally contaminated feed grade fats. Recoveries averaged greater than 90% with a coefficient of variation of 13% (0.54 ppm +/- 0.07), indicating that the method is sufficiently reproducible to be used by different laboratories for detecting dieldrin in feed grade fats.

Aluminum↗
PubMedDate not supplied

State findings on pesticide residues in food--1988 and 1989.

Findings of pesticide and related chemical residues are presented for 27,065 samples of foods collected and analyzed in 10 state food laboratories over 1988 and 1989 (fiscal years (FY) 88 and 89). These laboratories conduct food regulatory programs compatible with national programs of the U.S. Food and Drug Administration. Of the findings, 6325 samples contained detectable levels of 1 or more pesticide analytes and 418 (or 1.5%) of the total number of samples were deemed to be of regulatory significance.

Food Analysis↗
PubMedDate not supplied

State programs for pesticide residues in foods.

Two U.S. data collection and dissemination programs, FEEDCON and FOODCONTAM, are described. FEEDCON provides information on contamination levels in animal feeds of toxic chemical residues (pesticides, industrial chemicals, heavy metals, mycotoxins, natural plant toxins, salmonella, and therapeutic drug cross-contaminations). FEEDCON data are collected from approximately 40 state feed regulatory agencies, feed manufacturers, and related groups who subscribe ($100-$200 per year) to the program, which is sponsored by the Association of American Feed Control Officials. FOODCONTAM provides similar information, but is limited to pesticides, heavy metals and industrial chemicals (polychlorinated and polybrominated biphenyls, etc.) in human foods. Both programs have been developed and initiated under U.S. Food and Drug Administration contracts with the Mississippi State Chemical Laboratory. Program structures of both are outlined conceptually, and FOODCONTAM is described in detail. FOODCONTAM data-sharing program development is essentially complete, but expansion by incorporating FDA data with State Laboratory data is nearing reality.

Food Contamination↗