Feces cattle

Different sample materials including urine, feces, cattle feed, tissues, hair, eyes, and bile are offered for monitoring tire illegal use of -agonists. In determining... 

Studies examining the effects of caffle diet on E. coli 0157 H7 have primarily focused on fhe gasfroinfesfinal tract and fecal incidence. As a result, the interaction of dief x environment on the levels and persistence of E. coli 0157 H7 in caffle producfion has not been fully appreciafed. In addition to influencing fhe numbers of fhis pathogen that are shed in the feces, cattle diets can impact the extent to which E. coli 0157 H7 can persist in manure or feedlot surface soils. Cattle diets that result in enhanced survival in manure and the production environment can further contribute to the scenarios depicted in Fig. 4.2, by (1) increasing the opportunities for fecal-oral exposures resulting in additional or repeated... 

One of the earliest cattle problems involved widespread poisoning of cattle by arsenic at the turn of the century. Abnormal intake of arsenic results in severe colic (salivation, thirst, vomiting), diarrhea, bloody feces, and a garliclike odor on the breath cirrhosis of the liver and spleen as well as reproductive effects may be noted. Arsenic trioxide in the feed must be approximately 10 mg/kg body weight for these effects to occur. 

At low doses, the metabolism of diisopropyl methylphosphonate to IMPA in the body is rapid and nearly complete. After oral exposure to diisopropyl methylphosphonate, the principal metabolite isolated from both urine (93-99%) and feces ( 97%) in mink, mice, rats, dogs, and cattle is IMPA (Bucci et al. 1992 Hart 1976 Ivie 1980). Less than 0.5% of the radiolabel was detected in the exhaled air of rats and mice as carbon dioxide after diisopropyl methylphosphonate ingestion (Hart 1976). Thus, complete metabolism of diisopropyl methylphosphonate occurs only to a minor extent. 

After exerting their action in the organism, natural and synthetic hormones are catabolized in the liver by conjugation to glucuronide and/or sulfate moieties, forming more polar conjugated forms which are excreted via urine. This is the main route of hormone excretion in humans and pigs. A fraction of hormones is also excreted in a free form via feces in animals such as sheep and cattle this is the main route for hormone excretion (Table 3) [66, 67],... 

Oral treatment of sheep and cattle (Bos spp.) with diflubenzuron is followed by absorption of the compound through the gastrointestinal tract, metabolism, and elimination of residues through the urine, feces, and, to a very limited extent, milk. Intact diflubenzuron is eliminated in the feces of orally dosed cattle and sheep (Ivie 1978). Major metabolites of diflubenzuron excreted by cattle and sheep result from hydroxylation on the difluorobenzoyl and chlorophenyl rings, and by cleavage between the carbonyl and amide groups to produce metabolites that are excreted free or as conjugates (Ivie 1978). Cattle dosed repeatedly with diflubenzuron had detectable residues only in liver... 

The effects of leucaena and mimosine on nonruminants can be reduced to some extent by diet supplementation with ferrous sulfates. Mimosine forms a complex with iron, which is excreted in the feces. Zinc supplementation has reduced the toxicity in cattle and it is believed that copper and zinc ions bind more strongly to mimosine than most other amino acids. 

The indirect source of PBBs in soil was the contaminated farms in Michigan. Approximately 650 pounds (290 kg) of PBBs were mixed in cattle feeds that were delivered to Michi n farms during 1973 1974 (Fries 1985b). About 50% of this amount was excreted in the feces of the exposed animals and remained on the famis in places of fecal deposition and manure disposal (Fries 1985b). Soil in fields that received contaminated manure contained as high as 300 g/kg PBBs, whereas soil in resurfaced cattle exercise lots contained as high as 1,000 2,000 g/kg of PBBs (Fries 1985b). 

Results of pharmacokinetic studies of streptomycin are in most cases also applicable to dihydrostreptomycin and vice versa. In animals, the absorption of both streptomycin and dihydrostreptomycin is poor via the oral route but rapid after intramuscular administration. In cattle, peak serum levels were obtained 1 h after intramuscular injection of either streptomycin or dihydrostreptomycin (18), whereas serum concentrations produced in sheep and horses paralleled those obtained in cattle (19). As a result, most of an oral dose is recovered in the feces whereas most of a parenteral dose is recovered in the urine. However, if kidney function is severely impaired, little of an intramuscularly administered dose is excreted in the urine. 

Ceftiofiir is absorbed poorly after oral administration but rapidly after intramuscular injection. In all species, ceftiofur was rapidly metabolized to desfuroyl-ceftioftir and fiiroic acid. Desfiiroylceftiofur occurred in the free form in the plasma of treated cattle but was covalently bound to plasma proteins in rats (82). Maximum blood concentrations of ceftiofiir-related residues were achieved within 0.5 and 2 h of dosing. Unmetabolized ceftiofur was generally undetectable in blood within 2-4 h of dosing (83). More than 90% of the administered dose was excreted within 24 h of administration, mostly in urine. Residues in urine and feces were composed primarily of desfiiroylceftiofur and desfiiroylceftiofur cysteine disulfide, with small amounts of unmetabolized ceftiofur. 

Upon intramammary administration to cattle, novobiocin is rapidly absorbed and excreted through milk, feces, and urine. Detectable residues are present in milk for a few days after intramammary infusion, the elimination being highly depended on dosage and formulation. One day after treatment, the concentrations of microbiologically active residues in the liver, kidney, and udder tissue were in the range 1-4 ppm, whereas concentrations in muscle and fat were below 0.1 ppm. 

Following administration, the drug is rapidly metabolized into a large number of degradation products. Tire largest proportion of the drug and its metabolites is excreted in the feces, whereas the remainder (25%) is excreted in the urine (6). Less than 5% of the excreted drug is actually intact cambendazole. When radiolabeled cambendazole was administered to cattle, liver radioactivity was detectable for 30 days after administration, and a fraction of this was in the bound form (8). 

Excretion of orally administered netobimin takes place through urine and feces. In adult cattle and sheep, the percentage of administered dose excreted via urine was 45% in cattle and 48% in sheep, whereas that excreted via feces was 37% in cattle and 40% in sheep. In calves, however, the percentage of the administered dose excreted in the urine was less (31%) than that in feces (46%). 

In all species, morantel is mostly unabsorbed and excreted in the feces. Only a small proportion of the administered dose is rapidly absorbed, producing peak blood levels within 4-6 h. The drug is quickly metabolized, presumably in the liver, and 17% of the administered dose is excreted in the urine of sheep in the form of metabolites within 4 days after administration (1). In cattle, less than 20% of the administered dose is recovered in the urine over 4 days after administration, whereas in swine 45% of the administered dose is excreted in urine within 24 h. 

Following subcutaneous administration of 0.3 mg radiolabeled abamectin/ kg bw to cattle, a mean peak plasma radioactivity level of 0.09 ppm equivalents was detected. Depletion half-life rates for liver, kidney, muscle, fat, and plasma were estimated at 4.6, 5.7, 5.6, 8.1, and 4.7 days, respectively. About 70% of radioactivity was detected in feces, and 1-2% in the urine, within 7 days of treatment. 

Pharmacokinetic studies (59) in cattle treated with the recommended dosage showed that the drug was well dispersed from the injection site, with less than 1% of the dose remaining at 21 day withdrawal. By 14 days, 87% of the dose was excreted via the bile and feces whereas less than 1% was eliminated via urine. Mean plasma half-life was found to be 6.2 days for the parent compound and 5.9 days for total drug-related residues. 

Following topical application to cattle, only 29% of the dose was absorbed through the skin. Most of the absorption occurred within 7-10 days postdosing, after an initial time lag of about 24 h, and continued for 17-21 days postdosing, but to a minor extent. Metabolism studies (62) in calves treated with the recommended dosage showed that only 0.35% of the applied dose was present in urine over 28 days, while 17-19.8% was present in feces. In feces, the eprinomectin... 

In cattle and sheep, parent moxidectin represented 40% of the total radioactivity in liver, 50% in muscle, 60-75% in kidney, and 90% in fat. When moxidectin was given subcutaneously to steers, both the parent drug and at least seven metabolites could be detected in extracts of tissues, feces, and bile (65). The... 

In cattle, imidocarb is well absorbed and distributed tlrroughout the body. After subcutaneous administration to calves of 3 mg radiolabeled imidocarb/kg bw, absorption of the drug was rapid with mean peak plasma concentrations of 1316 ppb equivalents occurring 1 h after dosing. The level of radioactivity remained constant for up to 4 h after dosing but declined to 279 ppb equivalents 24 h after dosing. More than 70% of the radioactivity was found to be bound to plasma proteins. Most of the administered radioactivity was excreted in feces, with smaller amounts in the urine. The major component of both urine and feces was identified as the unchanged imidocarb. 

Following oral administration to cattle, it is absorbed from the gastrointestinal tract, rapidly distributed, metabolized, excreted in the bile, and eliminated in the feces. Residues in liver averaged 0.4 ppm at 12 h after the last dose, whereas residues detected in other tissues were negligible (21). When radiolabeled monensin was administered to steers, essentially all radioactivity was eventually excreted in the feces after conversion to many metabolites that accumulated in the liver (22). 

Pharmacokinetic studies (10) showed that virginiamycin is not significantly absorbed and is eliminated mostly in the feces. Following administration of radio-labeled virginiamycin to rats, turkeys, and cattle, metabolites of the drug appeared in liver of all animals. Most of these metabolites were covalently bound to tissues, whereas the extractable metabolites could not be identified. No residues of virginiamycin could be detected in edible tissues and consequently no withdrawal period has been set up. 

Metabolism leads to their rapid deactivation in tire body and, hence, these compounds exhibit little oral activity. Thus, they have to be given parenterally. Most of the catabolism of these compounds occurs in liver, and enterohepatic circulation may then occur, with the metabolites exerting little if any biological activity. In cattle, most of these compounds are eliminated in feces where 60-90% of the metabolites are found in the free form. In conttast, metabolites occurring in urine are predominantly in conjugated forms. 

Total tissue residues resulting from ear implantation of radiolabeled zeranol to cattle at the recommended dosage peaked from 5 days to 15 days, decreasing slowly thereafter as the implantation time increased (38). At 65 days, approximately 60% of the initial dose remained at the implant site, 12-18% was recovered in the urine, and 21-34% in the feces. Total residue levels in edible tissues at all times postimplantation were generally very low. Highest residue concentrations occurred in liver but never exceeded the level of 10 ppb. Residue concentrations in muscle, kidney, and fat were below 0.2, 2 and 0.3 ppb, respectively, at any time postimplantation. 

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