Tissue Residue Depletion Research Articles

Tissue Deposition and Residue Depletion of Cyadox and Its Three Major Metabolites in Pigs after Oral Administration

Tissue deposition and residue depletion profiles of cyadox (Cyx) and its three major metabolites, including 1,4-bisdesoxycyadox (Cy1), 4-desoxycyadox (Cy2), and quinoxaline-2-carboxylic acid (QCA), in pigs after multiple oral administrations were determined. Thirty-five healthy adult pigs were randomly divided into seven groups and orally treated with Cyx at a dosage of 20 mg/kg of body weight for five consecutive days. Each group of five pigs was randomly slaughtered 12, 24, 72, 120, 168, 216, and 264 h after the last dosing, and tissue samples, including muscle, liver, kidney, and fat, were collected and analyzed via the liquid chromatography-tandem mass spectrometry method. The concentration-time data of Cyx and its three metabolites (Cy1, Cy2, and QCA) were analyzed with WinNonlin. Results showed that metabolites of Cyx were quickly generated in swine tissues and the concentrations of QCA in kidney were higher than those of Cyx and other metabolites in all edible tissues. These results provide further insight into the metabolism of Cyx and confirmation of the residue marker and target tissue of Cyx in pigs.

DEPLETION OF CARBADOX AND ITS METABOLITE (QUINOXALINE-2-CARBOXYLIC ACID) IN PIGS FOLLOWING A SINGLE DOSE AND MULTIPLE IN-FEED DOSING

The tissue distribution and residue depletion of carbadox and its metabolites (QCA) were investigated in swine after a single oral dose of 3.5 mg/kg of body weight of carbadox and multiple dose (2 weeks) in-feed (50 ppm) administration. Plasma, muscle, liver, and kidney were sampled pre- and post-treatment and, subsequently, analyzed for carbadox and QCA concentrations using liquid chromatography with tandem mass spectrometry (LC-MS-MS). Carbadox concentration in plasma peaked 2 hr after a single oral dose administration, while QCA concentration was still detectable in liver tissue (2 ng/g) at the fifth week and in kidney tissue (0.9 ng/g) at the sixth week after withdrawal. The volume of distribution (V) of carbadox is 4700 + /−2200 mL/kg and areas under the concentration curves (2.36 + /−0.86 hr µg/mL) indicated that the drug was adequately distributed throughout the body from the blood of pigs. The slow elimination of the carbadox metabolites suggests a need for long withdrawal periods prior to the use of dosed swine for human consumption.

Tissue Deposition and Residue Depletion in Broiler Exposed to Melamine-Contaminated Diets

To investigate the tissue deposition and elimination of melamine (MEL) in broilers, a total of 1 920 commercial 1-d-old male Cobb broilers were randomly allotted to 6 treatments with diets contaminated by MEL at 0, 2, 10, 30, 50, 100 mg kg−1 of diet for 42 d, and followed MEL withdrawal from diet at 50 or 100 mg kg−1 of diet for 96 h. The MEL was found in residue of plasma, liver, kidney, breast, and leg muscle with the highest level in kidney and in dose response manner (except in kidney), but no time response (except in plasma). The MEL residue in organ tissue was below the safe level of 50 μg mL−1 in blood or 50 μg kg−1 in tissues proposed by the US FSIS when MEL in diet was lower (2 mg kg−1). The MEL in tissues was eliminated by withdrawal MEL from diets. The elimination half-life of MEL was from 3.2 to 6.6 h, and the clearance time, when MEL residue concentration under limit detection, was from 18.0 to 31.4 h.

Tissue Deposition and Residue Depletion in Laying Hens Exposed to Melamine-Contaminated Diets

To investigate the deposition and elimination of melamine in hen eggs and tissues, 72 Roman laying hens were administrated with melamine at 8.6-140.9 mg per kilogram of body weight per day for 34 days. The crystals were found in one of three kidneys of hens treated with melamine at either 62.6 or 140.9 mg/kg. Furthermore, the melamine concentrations in egg, muscle, liver, kidney, stomach, duodenum, uterus, ovary, and blood plasma were determined by high-performance liquid chromatography-ultraviolet (HPLC-UV) methods. A higher dosage of melamine in the diet corresponded to higher concentrations in tissues and eggs. The concentrations of melamine in tissues were in the following ranges (microg/g): egg, 1.1-28.7; muscle, 0.4-9.3; liver, 0.5-6.9; kidney, 1.3-21.7; stomach, 0.4-7.3; duodenum, 0.3-2.8; uterus, 0.5-6.9; ovary, 0.5-9.1; and blood plasma, 0.8-7.6. When melamine was withdrawn from the diet of hens, the melamine concentration in hen tissues fell to below 2.5 microg/g by day 10 and no residues were detected in eggs or tissues at days 7 and 20, respectively.

Tissue Deposition and Residue Depletion in Lambs Exposed to Melamine and Cyanuric Acid-Contaminated Diets

Many countries have introduced maximum residue limits for melamine in foods since its adulteration in infant formula in China. However, more animal feeding studies are needed to understand the fate of melamine-contaminated animal feed. In this study, the melamine contents in tissues and serum were tested using LC-MS/MS for up to 60 days for lambs fed with diets containing 2-100 mg of melamine per kg of diet. A higher dose of melamine in the diet resulted in a higher concentration in tissues and serum, with the maximum melamine content in the kidney. When cyanuric acid was coadministered at an equal concentration to that of melamine, the deposition of melamine in lambs was similar to the treatment with melamine only and was much higher than the deposition of cyanuric acid. When melamine was withdrawn from the diet, melamine concentrations decreased below 20 microg/kg in all tissues after 4 days. The present study may provide available information for future work about the risk assessment of melamine to human health.

Tissue residue depletion of oxytetracycline after repeated intramuscular administration of Oxysentin 100 in sheep

The depletion profile of oxytetracycline was studied in healthy sheep after intramuscular administration of Oxysentin 100, given at a dose of 10 mg oxytetracycline per kg body weight once daily for 5 consecutive days. Five medicated sheep were slaughtered at 0, 2, 4, 6, 9 and 12 days postmedication, and injection site, muscle, fat, liver and kidney tissues were sampled and analysed using a liquid chromatographic method, which was fully validated for oxytetracycline and 4-epi-oxytetracycline. At day 0 postmedication, the concentrations of oxytetracycline marker residue (sum of oxytetracycline and 4-epi-oxytetracycline) in all tissues examined were at the mg/kg level. At day 2 postmedication, the concentrations of oxytetracycline marker residue in all injection site and kidney samples examined were higher than the corresponding maximum residue limits (MRLs) established by the European Union, while the concentrations in muscle and liver tissues of two and three out of five animals examined, respectively, were below the corresponding MRLs. At days 4 and 6 postmedication, concentrations of oxytetracycline marker residue above the MRLs were found only in the injection site, whereas at day 9 postmedication, all observations were below the corresponding MRLs.

Patterns of doramectin tissue residue depletion in parasitized vs nonparasitized lambs

The effect of gastrointestinal parasitism on patterns of edible tissue depletion of doramectin was studied in greyface Suffolk lambs. Twelve weight-matched pairs of lambs were allocated into group I (nonparasitized, pretreated with three administrations of 5 mg/kg fenbendazole) and group II (parasitized, did not receive anthelmintic treatment). Both groups were maintained together under similar conditions for 70 days, when they were treated with a subcutaneous dose of 0.2 mg/kg bw doramectin. At 7, 14, 21, and 28 days after doramectin administration, three lambs from each group were slaughtered and samples of liver, kidney, muscle, and fat were obtained. Pre-treatment with fenbendazole significantly reduced the nematode fecal egg count and significantly increased lamb body weight compared to the parasitized group. Doramectin was detected in all of the tissues up to 28 days post-treatment. Significantly higher and more persistent doramectin concentrations were found in the nonparasitized lambs compared to the parasitized animals. Considering the EMEA maximum residue limits for doramectin in fat, the calculated withdrawal period for the healthy lambs (43 days) was significantly higher than that for the parasitized animals (26 days).

Residue Depletion of Tilmicosin in Cattle after Subcutaneous Administration

A study of tissue residue depletion of tilmicosin in cattle was conducted after a single subcutaneous injection at the therapeutic level of 10 mg per kg body weight. Eighteen cross cattle were treated with the tilmicosin oil formulation (30%). Three treated animals (two males and one female) were selected randomly to be scarified at 1, 7, 14, 28, and 35 days withdrawal after injection. Samples of the injection site and of muscle, liver, kidney, and fat were collected. Tilmicosin residue concentrations were determined using a high-performance liquid chromatography (HPLC) method with a UV detector at 290 nm. Using a statistical method recommended by the Committee for Veterinary Medical Products of European Medical Evaluation Agency, the withdrawal time of 34 days was established when all tissue residues except samples in the injection site were below the accepted maximum residue limits.

Tissue Distribution, Metabolism, and Residue Depletion Study in Atlantic Salmon Following Oral Administration of [3H]Emamectin Benzoate

Atlantic salmon (approximately 1.3 kg) maintained in tanks of seawater at 5 +/- 1 degrees C were dosed with [3H]emamectin B1 benzoate in feed at a nominal rate of 50 microg of emamectin benzoate/kg/day for 7 consecutive days. Tissues, blood, and bile were collected from 10 fish each at 3 and 12 h and at 1, 3, 7, 15, 30, 45, 60, and 90 days post final dose. Feces were collected daily from the tanks beginning just prior to dosing to 90 days post final dose. The total radioactive residues (TRR) of the daily feces samples during dosing were 0.25 ppm maximal, and >97% of the TRR in pooled feces covering the dosing period was emamectin B1a. Feces TRR then rapidly declined to approximately 0.05 ppm by 1 day post final dose. The ranges of mean TRR for tissues over the 90 days post dose period were as follows: kidney, 1.4-3 ppm; liver, 1.0-2.3 ppm; skin, 0.04-0.09 ppm; muscle, 0.02-0.06 ppm; and bone, <0.01 ppm. The residue components of liver, kidney, muscle, and skin samples pooled by post dose interval were emamectin B1a (81-100% TRR) and desmethylemamectin B1a (0-17% TRR) with N-formylemamectin B1a seen in trace amounts (<2%) in some muscle samples. The marker residue selected for regulatory surveillance of emamectin residues was emamectin B1a. The emamectin B1a level was quantified in individual samples of skin and muscle using HPLC-fluorometry and was below 85 ppb in all samples analyzed (3 h to 30 days post dose).

Tissue distribution and residue depletion of oxolinic acid in gilthead sea bream (Sparus aurata) and sharpsnout sea bream (Diplodus puntazzo) following multiple in-feed dosing

Abstract The tissue distribution and residue depletion of oxolinic acid (OA) were investigated in gilthead sea bream and sharpsnout sea bream after a multiple (10 days) in-feed administration (30 mg/kg fish) at 19 °C. Plasma, muscle, skin, liver and bile were sampled daily during treatment (1–10 days) and post-treatment (11,12, 14, 15 and 17 days) and subsequently analysed for OA concentrations using high-performance liquid chromatography and fluorescent detection (HPLC-SFD). Oxolinic acid displayed biphasic elimination in tissues of both species during treatment and reached “consumer safe levels” 24 h after treatment. OA concentration in gilthead sea bream peaked on day 4, with highest concentrations in liver (2660 ng/g), followed by bile (2370 ng/ml), skin (2350 ng/g), muscle (1330 ng/g) and plasma (880 ng/ml). In sharpsnout sea bream, peaked OA concentrations were observed in liver (2720 ng/g) on day 4, while highest concentrations were measured later on day 5 in plasma (910 ng/ml) and day 6 in bile (2360 ng/ml), skin (1960 ng/g) and muscle (1770 ng/g). The calculated areas under the concentration curves (AUC) also reflect a good tissue distribution of OA. Elimination half-lives (t1/2) were estimated to be 11–14 and 11–19 h in tissues of gilthead sea bream and sharpsnout sea bream, respectively. Multiple dosing of OA in sparids should be adequate to confront bacterial pathogens considering published minimum inhibitory concentrations of the drug.

In-Transit Oxytetracycline Marking, Nonlethal Mark Detection, and Tissue Residue Depletion in Yellow Perch

Trapping and transfer of juvenile and adult yellow perch Perca flavescens is conducted to fulfill perch stocking needs in South Dakota. To determine the utility of oxytetracycline (OTC) hydrochloride marking as an assessment tool for yellow perch stockings, we investigated a transfer tank marking protocol, compared OTC mark detection in dorsal spines with that in sagittal otoliths, and assayed the depletion of OTC residues in adult yellow perch muscle tissue. Juvenile yellow perch were immersed for 4, 6, or 8 h in 500 or 700 mg OTC/L at 18°C in transfer tanks. Acute mortality was less than 1% at 8 h. At 3 months postimmersion, fluorescent marks were detected on all spine sections and otoliths from fish treated for 6 h or longer. Mark quality was observed to be slightly better in juvenile dorsal spines than in otoliths. Adult yellow perch were immersed for 6 h in 600 mg OTC/L at 19°C. Marks were initially detected at otolith margins at 9 d postimmersion but were best detected on all otoliths after 51 d postimmersion. High pressure liquid chromatography of adult yellow perch muscle tissue indicated that OTC was rapidly depleted; the acceptable tolerance level of 2 μg total OTC residue/g for human consumption was reached by about 2 h postimmersion. The nonlinear relation between total residue (OTC base and 4-epioxytetracycline) and time was defined by the equation loge total(OTC) = 0.960 − 0.389·loge(time) (r2 = 0.99).

Tissue distribution and residue depletion of thiamphenicol after multiple oral dosing in seabass (Dicentrarchus labrax L.) and seabream (Sparus aurata L.)

Tissue distribution and residue depletion of thiamphenicol after multiple oral dosing in seabass (Dicentrarchus labrax L.) and seabream (Sparus aurata L.)

Oxytetracycline and oxolinic acid residues in kuruma prawn (Penaeus japonicus) and the effect of cooking procedures on the residues

Tissue distribution and residue depletion of oxytetracycline (OTC) and oxolinic acid (OA) were studied in the kuruma prawn (Penaeus japonicus). The prawn were kept in tanks with recirculated artificial seawater at a salinity of 22-23@1000. The water temperature was maintained at 25 degrees C. The average body weight was 22.9 +/- 4.9 g for OTC and 22.5 +/- 3.6 g for OA. The drug was mixed with the diet and orally administered through a catheter to the prawn. The doses of OTC and OA, respectively, were 50 mg/kg body weight. At each sample time, four prawns were sacrificed and tissues were sampled. OTC and OA levels were determined by high-performance liquid chromatography. At the highest levels, the concentrations of OTC were in the other: shell (13.57 micrograms/g) > hemolymph (12.20 micrograms/mL) > muscle (8.30 micrograms/g). For OA, the order was: shell (20.74 micrograms/g) > hemolymph (7.06 micrograms/mL) > muscle (2.05 micrograms/g). The elimination half-lives of hemolymph and muscle were 44.7 and 46.8 hours for OTC and 55.0 and 107.9 hours for OA, respectively. Residual OTC could not be detected in hemolymph and muscle at 20 days after dosing. Residual OA disappeared from hemolymph and muscle at 25 days after dosing. A 25-day period for OTC and 30-day period for OA could be regarded as the proper withdrawal time established for kuruma prawn by the Pharmaceutical Law in Japan. However, the elimination half-lives of shell for OTC and OA could not be calculated because both drug residues persisted in shell tissues, and the elimination phase was not completed during the experimental period. Residual OTC (14.10 +/- 2.26 micrograms/g, n = 6) and OA (0.32 +/- 0.06 microgram/g, n = 7) were detected in exuviae at 3 days and 4 days after dosing, respectively. Residual OTC was reduced to 50-70% in muscle by the usual methods of cooking (boiling, baking at 200 degrees C and frying at 180 degrees C), whereas reduction levels in shell were only 20-30%. Residual OA was reduced to 20-30% in muscle and shell by the cooking. These results confirm that the cooking procedures could only reduce but not completely eliminate these drug residues in prawn.

Tissue distribution and residue depletion of oxytetracycline in sea bream ( Sparus aurata) and sea bass ( Dicentrarchus labrax) after oral administration

Tissue distribution and residue depletion of oxytetracycline (OTC) following oral administration were evaluated in sea bream and sea bass under field conditions. Fish were held in floating cages placed in sea water and fed a commercial medicated diet containing 7.5 g/kg of OTC once daily for 14 days at a rate of 1.0% (75 mg a.i./kg) biomass per day. Muscle, liver, vertebrae, and skin with scales were sampled from fishes netted at different intervals during (2 nd, 4 th, 6 th,10 th, and 14 th day) and after treatment (10 th, 20 th, 30 th, 40 th, 50 th, and 60 th day). OTC analyses were carried out by HPLC, after SPE extraction. In sea bream, a great variation in drug intake was evident from the inter-subject differences in OTC tissue concentrations. The highest recorded concentrations were in skin and pooled liver (7.70 ± 6.71 μg/g and 14.65 μg/g at the 6 th day, respectively). Vertebrae showed concentrations even six-fold higher than those in muscle, and reached steady state concentrations at the 40 th day after the end of treatment (1.73 ± 0.92 μg/g), lasting until the end of the study. OTC concentrations in muscle were lower than in all the other tissues throughout the entire experiment and declined under 0.1 μg/g 20 days after treatment ceased. In sea bass a high mortality not related to infectious diseases was observed and muscle samples had only traces or no detectable OTC levels even during medication.

A Pharmacokinetic and Tissue Residue Depletion Study after Intramuscular Injection of Leotrox (Sulfatroxazole (STX)/Trimethoprim (TMP)) Combination in Calves

The object of this study was to determine 1) lung and plasma pharmacokinetic profiles of STX and TMP, 2) tissue depletion and residues of STX and TMP.

The effects of experimentally induced bronchopneumonia on the pharmacokinetics and tissue depletion of gentamicin in healthy and pneumonic calves

The effects of a bovine bronchopneumonia model on the pharmacokinetics and tissue residue depletion profiles of gentamicin in calves weighing 90-140 kg was explored. Two groups of heifer calves were used. The first was a normal group, while the second group had bronchopneumonia induced. A scoring system was developed to evaluate the extent of disease in the groups. A bimodal distribution of the serum pharmacokinetic parameters in the pneumonic group was caused by the effects of dehydration. When the severely dehydrated calves were omitted from the analysis, serum clearance of gentamicin was significantly higher in the pneumonic group than in the normal group (P less than 0.05). The pharmacokinetic equations used to fit the tissue concentrations varied from tissue to tissue and between groups. Because the best equation of a particular tissue's concentrations varied between groups, withdrawal periods, which are normally determined in healthy animals, may be inappropriate in diseased animals. Addition of several parameters (serum creatinine, serum urea nitrogen, albumin, fibrinogen, and total protein concentrations, white blood cell counts, central fluid volume, volume of distribution at steady state, area under the serum concentration vs time curve, serum clearance, and elimination rate constant) to these tissue-depletion models using multiple regression improved the prediction of a concentration in a given tissue.

Toxicity and tissue residue depletion of levamisole hydrochloride in young goats

SUMMARY Toxicity and tissue residue depletion studies were conducted in young goats, using an oral drench formulation of levamisole hydrochloride. In the target animal toxicity study, 3 groups of 5 goats each were given levamisole orally to provide approximately 11.88, 23.76, or 35.64 mg of levamisole HCl/kg/d for 3 consecutive days; a fourth group of 5 goats served as untreated controls. Blood samples were taken for analysis of levamisole 1 day prior to dosing and 1, 2, 3, 4, and 7 days following the third dose. At the 35.64-mg/kg dose, 2 of 5 goats responded with typical cholinergic signs of toxicosis on each of the 3 days of dosing. The times for the onset of clinical signs of toxicosis ranged from 18 to 63 minutes, with an average duration of 32 minutes. Administration of 23.76 mg of levamisole HCl/kg resulted in hyperactive behavior in 1 of 5 goats only on the first day of dosing; no abnormal behavior was observed in any of the 5 goats following the second or third dose of levamisole HCl at 23.76 mg/kg. Untoward effects were not seen in the 5 goats dosed at 11.88 mg of levamisole HCl/kg or in the controls during the 3-day dosing period or in the following 7-day observation period. Overall, the observed signs of toxicosis did not become more severe, affect more goats, or persist for a longer period on subsequent dosing days. In the 35.64-mg/kg/d group of the toxicity study, parent drug was detected in the serum of all 4 goats for which assaying was done 1 day after dosing and in the serum of 1 of the 4 goats for which assay was done 2 days after dosing. Only 1 of the 3 goats given 23.67 mg of levamisole HCl/kg/d had a detectable serum concentration of levamisole 1 day after dosing, and none of the goats had detectable serum levamisole concentrations 2 days after the final dose was given. One of the 3 goats for which assaying followed dosing of 11.88 mg/kg/d had measurable levamisole serum concentrations that persisted for 4 days after dosing; the apparent serum half-life of elimination for levamisole in this goat was 19.4 hours. Serum concentrations of levamisole at 1 day after dosing did not correlate with signs of toxicosis in goats immediately following dosing. Liver, kidney, and muscle samples from 25 goats given a single oral dose of 11.88 mg levamisole HCl/kg were analyzed for drug residues 1, 2, 3, 4, and 7 days after dosing (5 goats/sampling time). Within goats, the highest concentrations of levamisole were found in the liver, followed by kidney and then muscle. Depletion of levamisole from the liver was modeled as a single exponential decay function; using means, or an estimate of the 95th percentile of the population, from days 1, 2, 3, and 4 after dosing resulted in values for apparent half-lives of elimination of 1.4 and 1.2 days, respectively. Adjusting the means and 95th percentile estimates by eliminating observations &gt; 3 sd from the mean had little effect on the apparent half-lives of elimination (1.3 and 1.6 days), although the degree of fit was improved 17 and 28%, respectively. Fitting of the outlier values of levamisole liver concentrations to a similar monoexponential equation resulted in an estimate of the apparent half-life of elimination of 2.4 days. Levamisole concentrations in kidney and muscle decreased too rapidly to model their elimination rates. On the basis of serum kinetics of levamisole in 1 goat (of 10) for which the serum was assayed and liver depletion rates of levamisole estimated from 8 (of 25) goats, we concluded that goats may possess a genetic polymorphism with respect to levamisole metabolism and could be considered either normal or slow eliminators. Regardless of levamisole phenotype, however, liver residues of levamisole were estimated to be &lt; 100 μg/kg for 9 days following a single, oral dose of 11.88 mg of levamisole HCl/kg.

Tissue residue depletion of sulfaquinoxaline in turkey poults.

Sulfaquinoxaline was administered in the drink- incomplete between 0 and 3 days withdrawal in ing water to turkey poults, 11-12 weeks old, at a all tissues. The most rapid depletion occurred in prophylactic (0.0175%) or therapeutic (0.1%) muscle tissues; residues persisted longer in liver, dose for 7 days. Sulfonamide residues were deter- renal, and skin tissues. A withdrawal period in mined in breast muscle, liver, kidney, skin, and excess of 10 days is indicated for turkeys given blood serum at 0 (the morning following the last sulfaquinoxaline at these dosages under the conday of medication), 3, 5, 7, and 10 days post- ditionsof thisstudy. treatment. Residue depletion was rapid although Sulfaquinoxaline is useful for the treatment of coccidiosis in chickens and for the prevention and treatment of this disease in turkeys (Merck Veterinary Manual, 1967). Losses due to fowl typhoid in turkeys can often be reduced by giving sulfaquinoxaline in the drinking water. Administration of this drug at 0.1 or 0.05% in the feed was shown to offer possibilities in the prevention of enzootic Pasteurella infections in chickens, although no recognizable curative properties were indicated (Delaplane, 1945). Sulfaquinoxaline, sulfamethazine, and sulfamerazine were markedly effective in the prophylaxis of experimental fowl cholera in turkeys; sulfaquinoxaline was the most effective at low intake levels (0.01%) (Peterson, 1948). Administration of sulfaquinoxaline at 1.5 g/10 lb of feed or 1.5 oz/gal of water protected 12-week-old turkeys against heavy inoculation of Pasteurella multocida organisms when given at the time of or before infection (Richey and Morgan, 1957). Sulfaquinoxaline is preferred over the more common sulfonamides because of its greater accumulation and longer retention time in the blood (Schlenker and Simmons, 1950; Smith and Robinson, 1944). The high degree of binding to plasma proteins is believed to be related to the blood concentrations attained in chickens, as well as its ready penetration into the egg (Bankowski and Johnson, 1949). Sulfonamide residues in tissues and eggs of chickens administered sulfaquinoxaline at therapeutic and prophylactic doses have been determined (Righter et al., 1970). Residue depletion was most rapid in muscle and fat; residues persisted tor the longest time in renal tissues. Concentrations in egg yolks were high (greater than 0.1 ppm) at the tenth day after withdrawal. Tissue residue levels of sulfonamides in turkeys are either obscure or lacking. This study was undertaken in order to determine the amount and duration of tissue residues of sulfaquinoxaline in turkey poults.

Tissue residue depletion of sulfamerazine in sheep.

Tissue residue depletion of sulfamerazine in sheep.

Tissue-residue depletion of sulfathiazole in swine.

Tissue-residue depletion of sulfathiazole in swine.