Aflatoxin incidence in feeds, toxicology and possible residue hazards in foods.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to G T Edds.
Explore the source record for details and available documents.
Twelve clinically normal Shetland ponies were allocated to one of four treatment groups. Aflatoxin B1 was administered at the dosage level of 2 mg/kg of body weight to group A, 1 mg/kg to group B, and 0.5 mg/kg to group C; a placebo was given to group D (controls). Plasma samples were assayed at 4-hour intervals for iditol dehydrogenase (ID) (sorbitol dehydrogenase) concentrations as an indicator of hepatic damage. One of the ponies in group A died 68 hours after dosing; another pony in group A died 76 hours after dosing. All other animals survived the experiment. The means of peak ID values were as follows: group A, 1514.0 IU/l (P < 0.05); group B, 192.6 IU/L (P < 0.05); group C, 8.5 IU/L (P < 0.05); and group D (controls), 2.7 IU/L. A square root transformation analysis of the postdosing response of ID values in relation to time demonstrated that the mean of group A became significantly higher (P < 0.05) than did the mean of the control group at 5 to 6 hours. The mean of group B at 12 to 16 hours and the mean of group C at 20 to 24 hours also were significantly higher (P < 0.05) than was the mean of the control group.
The relationships of acetylhistamine and histamine to the clinical signs of carbohydrate-induced acidosis were investigated in beef steers. Blood pH and plasma L-lactic acid decreased and serum sodium, serum potassium, ruminal fluid L-lactic acid, ruminal fluid histamine, and ruminal fluid and blood acetylhistamine increased in carbohydrate-engorged steers as compared with the changes in the steers while feeding on pasture (forage-fed steers). Twelve to 14 hours after the steers had become engorged, clinical signs of laminitis ("feedlot founder") were observed in three of six steers. These signs appeared 4 to 6 hours after blood acetylhistamine attained maximal concentration (2.9997 +/- 1.7054 microgram of histamine base/ml of blood) and blood pH decreased to 7.260 +/- 0.026 at 8 hours after engorgement. Blood histamine value reached 0.1298 +/- 0.1095 microgram of histamine base/ml 4 hours after engorgement (8 to 10 hours before the appearance of clinical illness), but had reached maximal concentration 32 hours after engorgement (0.3300 +/- 0.028 microgram of histamine base/ml of blood).
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
This experiment was designed to compare 3 dose levels of aflatoxin B1 (0.0, 0.5, and 1.0 mg/kg of body weight) and 2 infection levels of Fasciola hepatica metacercariae (0 and 220) to determine whether an additive effect from aflatoxin B1 occurs when fascioliasis is present in dairy calves. Twenty-four male, Holstein calves, 4 weeks old, and averaging 45.8 kg each, were assigned at random to 6 treatment groups, 4 calves per group: group 1--negative control; group 2--0.5 mg of aflatoxin B1/kg; group 3--1.0 mg of aflatoxin B1/kg group 4--220 metacercariae; group 5--220 metacercariae plus 0.5 mg of aflatoxin B1/kg; and group 6-220 metacercariae plus 1.0 mg of aflatoxin B1/kg. The single oral dose of 220 metacercariae was given (groups 4, 5, and 6) at the start of the 10-week experiment, and 5 weeks later, the single oral dose of aflatoxin B1 was given (groups 2, 3, 5, 6). Results from the principals, as compared with that from the controls (group 1), included significant decreases of dry matter intake (P less than 0.006), body weight (P less than 0.024), and serum albumin (P less than 0.04), and in groups 4, 5, and 6 infected with 220 flukes, there were significantly increased values of prothrombin time (P less than 0.014), serum alkaline phosphatase (P less than 0.04), and serum sorbitol dehydrogenase (P less than 0.007). Significant differences in number of flukes recovered from liver were seen in groups 4 to 6 given 0, 0.5, and 1.0 mg of aflatoxin B1/kg (P less than 0.046). The single oral dose of 22* fluke metacercariae in groups 4, 5, and 6 resulted in significantly increased concentrations of serum total protein (P less than 0.003) and globulins (P less than 0.01). Results from the development of the flukes from metacercariae to the mature state with sizes, numbers, feeding habits, and pathologic lesions were described. Differences in numbers of flukes recovered from liver of groups 4 to 6 and the presence of pneumonia in calves of group 6 indicated aflatoxin B1 produced persisting, lowered resistance. In all animals necropsied, the liver was the organ most affected by aflatoxin B1 as well as with flukes. Periportal fibrosis, monocytic infiltration, fatty infiltration, and bile duct proliferation were the usual lesions induced by aflatoxin B1. Additive toxic effects were observed in the groups 5 and 6 dosed with flukes and aflatoxin B1, with significant variations of serum and plasma values, as well as increased severity of histopathologic changes.
Explore the source record for details and available documents.
Young New Hampshire and broiler chickens were given feed containing 2 concentrations of aflatoxin B1 (0.2 or 2.0 ppm). The larger concentration caused severe toxicosis and death in the New Hampshire chicks, but did not cause gross signs in the broiler chicks. However, temporary stunting was seen on both New Hampshire and broiler chicks during periods of aflatoxin feeding, along with persisting decreased weight gains in the broiler chicks; the latter apparently recovered during the next 21 days of feeding the starter ration. New Hampshire and broiler chicks which were given feed containing aflatoxin B1 at concentrations of 0.2 and 2.0 ppm for 28 days followed by a 21-day "recovery period" and which were not given a coccidiostat were more susceptible to severe cecal coccidiosis and had more persisting hepatic and cecal lesions than did chicks not given aflatoxin. The coccidiostat was protective against both cecal damage and losses in checks challenge exposed at 49 days of age to 100,000 infective Eimeria tenella oocysts.
A natural occuring outbreak of aflatoxicosis was observed in Bobwhite quail chicks while on a brooding experiment. A slight reduction in effects was noted for birds which received Tylan in the water from 0-3 days and Terramycin from 0-35 days of age. No symptoms of aflatoxicosis were observed in birds which received a product (FloxAid) containing two antibiotics and eight vitamins from 0-14 days. It is postulated that the primary mode of protection was via the water soluble vitamin D content of the product with possibly some protection from vitamins A, E and K.
The effects of treating adult wethers with 2 or 4 mg of coumaphos/kg of body weight each day for 6 days were investigated. The smaller dose produced a gradual decrease of erythrocyte acetylcholinesterase (AChE) activity (to maximum average reduction of approximately 45%), but without the appearance of signs of toxicosis. The larger dose appeared to be toxic. Treatment with the drug did not seem to alter significantly the anticholinesterase effects of a 2nd treatment made 6 weeks later. Coumaphos did not significantly affect serum activities of aspartate aminotransferase (glutamic oxalacetic transaminase) or isocitrate dehydrogenase (ICD) and concentrations of serum sodium and plasma calcium. A marked decrease in blood serum potassium and an increase in plasma magnesium occurred in all wethers that died after treatment with coumaphos, whereas appreciable changes did not occur in the survivors of the treatment given 6 weeks earlier. Treatment of sheep with an intravenous injection of the organophosphorous compound trichlorfon, insufficient to produce a significant effect on erythrocyte cholinesterase activity, produced additive effects with those of coumaphos.
Interactions between treatments with coumaphos, bishydroxycoumarin (an anticoagulane), trichlorfon (an organophosphorous compound), and phenobarbital sodium (an inducer of microsomal enzymes) were investigated in sheep. A daily dose of 2 mg of coumaphos/kg of body weight for 6 days did not affect the plasma enzymes or the antiprothrombinemic effect of bishydroxy-coumarin in wethers. The treatment of ewes with an intravenous (IV) injection of trichlorfon, insufficient to produce significant inhibition of erythrocyte acetylcholinesterase (AChE) activity, appeared to produce additive effects with those produced by subsequent treatment with 4 mg of coumaphos/kg/day. In ewes given 40 mg of phenobarbital sodium/kg for 5 days intraperitoneally (IP), the anticholinesterase effect of 4 mg of coumaphos/kg was significantly reduced and signs of toxicity were not present. Treatment with daily doses of 2 mg of coumaphos/kg for 6 days did not modify the anticholinesterase effect of a 2nd series of treatments given 6 weeks later.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.