Preliminary studies and previous work by other investigators have shown that jimsonweed and sicklepod seeds are very toxic. Such seeds and others are co-harvested and are often found mingling with commercial grain destined for human consumption. Low levels of these seeds were studied here to determine whether such levels would show signs of intoxication in rats by modulating growth, liver weight and relative size, cytochrome P-450 levels and function, and other relevant parameters proven to be sensitive to low levels of toxicants. Assessment of these factors showed that jimson weed does give indications of intoxication at low levels, whereas the highly toxic sicklepod does not give discernible indications.
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.