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1.
Phytopathology ; 94(1): 88-93, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18943824

RESUMO

ABSTRACT Fusarium ear rot and fumonisin contamination are serious problems for maize growers, particularly in the southeastern United States. The lack of maize genotypes highly resistant to infection by Fusarium verticillioides or to fumonisin contamination emphasizes the need for management strategies to prevent contamination by this mycotoxin. Information on the initial appearance of infection and fumonisin contamination of kernels and their increase over time is needed to determine if early harvest may be an appropriate control strategy. Maize ears from replicated studies at two locations in eastern North Carolina were harvested weekly, starting 2 weeks after pollination and continuing for 14 weeks. The percentage of kernels infected with F. verticillioides and the fumonisin contamination in the harvested samples were determined. Kernel infection by F. verticillioides and fumonisin contamination appeared as kernels neared physiological maturity and increased up to the average harvest date for maize in North Carolina. Beyond this date, the concentrations of fumonisin fluctuated. Under years conducive for fumonisin contamination, early harvest (greater than 25% grain moisture) may help reduce the level of contamination.

2.
Avian Dis ; 33(4): 804-8, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-2533495

RESUMO

In an experiment to determine the effect of corn vs. grain sorghum on performance of laying hens, egg production decreased significantly in the grain sorghum-fed hens in each of two trials starting 24 weeks after the trials began. Necropsy of chickens fed both diets revealed buccal ulceration at the ventral aspect of the oral cavity and squamous metaplasia of the esophageal glands and submaxillary salivary glands. Lesions were much more severe in the sorghum-fed birds than in the corn-fed birds. Analysis of the grain sorghum and corn revealed the presence of mycotoxins. Zearalenone and deoxynivalenol were present in the grain sorghum, and a lower amount of deoxynivalenol and a trace of aflatoxin B1 were found in the corn. Although mycotoxin levels were low, interaction between these mycotoxins and others may have decreased egg production.


Assuntos
Ração Animal , Galinhas/fisiologia , Grão Comestível , Ovos , Resorcinóis/toxicidade , Sesquiterpenos/toxicidade , Tricotecenos/toxicidade , Zearalenona/toxicidade , Animais , Ingestão de Alimentos , Feminino , Contaminação de Alimentos , Metaplasia/patologia , Metaplasia/veterinária , Glândula Submandibular/patologia , Zea mays
3.
Res Vet Sci ; 31(2): 131-5, 1981 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7323458

RESUMO

Purified diacetoxyscirpenol (DAS) mycotoxin fed to growing pigs at 0, 2, 4, 8, and 9 ppm for as long as nine weeks caused several lesions at all levels. The pigs developed multifocal, proliferative, gingival, buccal and lingual lesions. The small intestine had both glandular and mucosal cell hyperplasia. No other lesions were seen at necropsy or in any of the 19 tissues examined microscopically using haematoxylin and eosin stain. A one-way analysis of variance revealed statistically significant (P less than 0.05) decreased ration consumption and weight gain at all levels of DAS. Total ration refusal occurred at 10 ppm of DAS. There was no effect on the packed cell volume, haemoglobin concentration, total red blood cell count, total white blood cell count, 300 cell differential, terminal bone marrow smears or on the serum levels of aspartate transaminase, serum glutamic pyruvic transaminase and lactic dehydrogenase at any level of DAS. Based on the gross and microscopic lesions, decreased ration consumption and decreased weight gain the no-effect level was less than 2 ppm of DAS in the ration.


Assuntos
Micotoxinas/toxicidade , Sesquiterpenos/toxicidade , Doenças dos Suínos/induzido quimicamente , Tricotecenos/toxicidade , Administração Oral , Ração Animal , Animais , Gengiva/patologia , Intestino Delgado/patologia , Masculino , Micotoxinas/administração & dosagem , Suínos , Doenças dos Suínos/patologia , Língua/patologia , Tricotecenos/administração & dosagem
4.
J Anim Sci ; 67(2): 465-72, 1989 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2495262

RESUMO

Two experiments were conducted using corn from clean or aflatoxin B1 (AFB1)-contaminated (182 ppb) sources. Weanling pigs (28 d) were fed one of eight dietary treatments arranged in a 2 x 2 x 2 factorial design. In Exp. 1 (192 pigs), treatments varied in corn source (clean or AFB1-contaminated), CP level (18 or 20%) and added fat (0 or 5%). At the end of the 28-d growth trials, plasma samples were obtained. An AFB1 x CP level interaction was detected (P less than .05) for growth rate (ADG), feed intake (FI) and feed/gain ratio (F/G). Feeding AFB1 reduced (P less than .05) ADG (.30 vs .37 kg/d) and FI (.57 vs .66 kg/d) and increased F/G (1.88 vs 1.78) of pigs fed 18% CP diets. Performance of pigs fed 20% CP diets was not altered by AFB1. Adding 5% fat to diets improved (P less than .05) F/G but did not improve ADG of pigs fed AFB1. There was an AFB1 x CP x fat interaction (P less than .05) for plasma cholesterol. Adding fat or increasing the CP level prevented the depression of plasma cholesterol in pigs fed AFB1. In Exp. 2 (96 pigs), all diets contained 18% CP and the treatments varied in corn source (clean or AFB1-contaminated), added L-lysine HCl (0 or .25%) and added DL-methionine (0 or .15%). Feeding AFB1 reduced (P less than .05) ADG of pigs fed the 18% CP diet (.44 vs .50 kg/d) but not of pigs fed diets supplemented with .25% lysine.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Aflatoxinas/farmacologia , Aminoácidos/farmacologia , Gorduras na Dieta/farmacologia , Proteínas Alimentares/farmacologia , Suínos/fisiologia , Aumento de Peso/efeitos dos fármacos , Aflatoxina B1 , Ração Animal , Animais , Contaminação de Alimentos
5.
J Anim Sci ; 68(9): 3023-32, 1990 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-2291758

RESUMO

Exocrine secretions in the digestive tract of domestic livestock are controlled by a combination of neural and endocrine inputs. The parasympathetic domain of the autonomic nervous system is responsible for efferent signals that regulate most exocrine secretory processes. Exocrine tissues possess cholinergic muscarinic receptor subtypes that are different from those found in brain, heart and muscle tissues. Cholinergic stimulation of specific muscarinic receptor subtypes has enhanced secretions of the salivary glands and pancreas. These changes in output of exocrine glands can alter digestive function that may benefit production of cattle and swine.


Assuntos
Animais Domésticos/metabolismo , Digestão/fisiologia , Sistema Digestório/inervação , Sistema Nervoso Parassimpático/fisiologia , Ruminantes/fisiologia , Animais , Sistema Digestório/efeitos dos fármacos , Glândulas Exócrinas/inervação , Glândulas Exócrinas/metabolismo , Parassimpatomiméticos/farmacologia , Receptores Muscarínicos/fisiologia
6.
J Anim Sci ; 63(5): 1502-8, 1986 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-3793651

RESUMO

Effect of purified slaframine (SF; 1-acetoxy-6-aminooctahydroindolizine), a parasympathomimetic secretagogue isolated from Rhizoctonia leguminicola, on ruminal motility was investigated in cattle and sheep. In trial 1, four ruminal cannulated wethers, fed a pelleted concentrate and hay diet, were injected intramuscularly with 0, 12, 24 and 48 micrograms SF/kg body weight (BW) in a 4 X 4 Latin-square design. Ruminal motility was recorded 1 h before and 1 to 2 h and 3 to 4 h after SF administration by measuring pressure changes exerted upon a fluid-filled, open-tipped catheter inserted into the dorsal sac of the rumen. The frequencies of both primary and secondary ruminal contractions were decreased as much as 20 to 78% with SF (P less than .05) depending upon the dosage level and time after administration. In trial 2, three ruminal-cannulated steers fed a concentrated diet were injected intramuscularly with 0, 12 and 24 micrograms SF/kg BW in a 3 X 3 Latin-square design. A water-filled balloon inserted into the cranial sac of the rumen was used to measure ruminal pressure changes 1 h before and 1 to 2 h, 3 to 4 h and 7 to 8 after SE administration. Frequency of primary and secondary ruminal contractions decreased with SF as much as 27 to 64% depending on the dosage level and time after administration. The frequency of secondary contractions increased 28% (P less than .05) as compared with control during the 7 to 8 h after administration.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Alcaloides/farmacologia , Bovinos/fisiologia , Motilidade Gastrointestinal/efeitos dos fármacos , Micotoxinas/farmacologia , Parassimpatomiméticos/farmacologia , Rúmen/efeitos dos fármacos , Ovinos/fisiologia , Animais , Masculino
7.
J Anim Sci ; 62(5): 1404-11, 1986 May.
Artigo em Inglês | MEDLINE | ID: mdl-3722025

RESUMO

Four esophageal- and ruminal-cannulated Angus steers (avg weight, 308 kg) were used to investigate how salivation is affected by the administration of purified slaframine (SF; 1-acetoxy-6-aminooctahydroindolizine), a cholinergic secretagogue isolated from Rhizoctonia leguminicola. Steers were fed a concentrate diet at twice the net energy requirement for maintenance in hourly increments. In trial 1, a single injection of SF was administered to four steers intramuscularly at 0, 6, 12 and 24-micrograms/kg body weight (BW) in a 4 X 4 Latin-square design. Saliva was collected via esophageal cannula at 15-min intervals 30 min after each feeding, weighted, sampled and reinfused via ruminal cannula over a 10-h period. At 12- and 24-micrograms SF/kg BW, salivary flow was 31 to 43% greater (P less than .01) than at 0- or 6-micrograms SF/kg. Response peaked within the first 3 h and returned to baseline levels at 8 h. Buffering capacity and pH of saliva were not different (P greater than .10); however, osmolality and Na concentration increased and K concentration decreased (P less than .10) as salivation rates increased. Feed intake of steers did not appear affected at any level of SF administration. In trial 2, 0-, 12- and 24-micrograms SF/kg BW were repeatedly administered intramuscularly to three steers in a 3 X 3 Latin-square design at 8-h intervals for 24 h. Salivary flow was measured and sampled over the entire 24-h period, as in trial 1. Flow rates were increased 50 to 70% (P less than .01) by SF treatment.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Alcaloides/farmacologia , Bovinos/fisiologia , Parassimpatomiméticos/farmacologia , Saliva/análise , Salivação/efeitos dos fármacos , Alcaloides/administração & dosagem , Animais , Concentração de Íons de Hidrogênio , Injeções Intramusculares , Masculino , Parassimpatomiméticos/administração & dosagem
8.
J Anim Sci ; 67(3): 827-34, 1989 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2722711

RESUMO

Slaframine (SF), a parasympathomimetic salivary stimulant, was administered i.m. (10, 15 or 20 micrograms SF/kg BW) to ruminally and abomasally fistulated steers at 12-h intervals for 18-d periods in a latin square-designed experiment. Steers were fed semicontinuously (12 times daily) a 40:60 roughage:concentrate diet at twice their net energy requirement for maintenance. Ruminal digestion coefficients for DM, ADF and starch were 10 to 16% lower and linearly related in an inverse manner to the level of SF administered (P less than .05). Postruminal digestion of DM, ADF and starch increased as much as 46.7, 9.5 and 44.0%, respectively, in a fashion linearly related (P less than .05) to the level of SF administered. Total tract digestion of DM and ADF were not affected by SF; however, total tract starch digestion was increased as much as 5% and was related linearly (P less than .05) to SF treatment. With SF administration, as much as 13% more bacterial protein exited the rumen, resulting in a 16.5% linear improvement (P less than .1) in the efficiency of ruminal bacterial protein production per 100 g of OM fermented. Ruminal concentrations of VFA, ammonia and pH were not affected by SF. These results demonstrate a positive relationship between salivation and ruminal bacterial protein synthesis and suggest that feed utilization by ruminants may be improved by pharmacological stimulation of salivary secretions.


Assuntos
Alcaloides/farmacologia , Bovinos/metabolismo , Parassimpatomiméticos/farmacologia , Rúmen/efeitos dos fármacos , Abomaso/efeitos dos fármacos , Abomaso/metabolismo , Ração Animal , Animais , Proteínas de Bactérias/biossíntese , Digestão/efeitos dos fármacos , Relação Dose-Resposta a Droga , Fezes/análise , Fermentação/efeitos dos fármacos , Masculino , Rúmen/metabolismo , Rúmen/microbiologia , Salivação/efeitos dos fármacos
9.
J Anim Sci ; 73(10): 3103-10, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8617683

RESUMO

The effect of duodenal slaframine (SF) infusion on site and extent of digestion was determined using four steers equipped with ruminal, duodenal, and ileal cannulas in a 4 x 4 Latin square. A 77% dry-rolled corn diet was provided in 12 equal portions daily at a DMI of 2.26% BW. Slaframine in a .9% saline excipient was infused into the duodenum every 12 h with total daily dose of 0, 30, 60, or 90 micrograms /kg of BW. Slaframine infusion had no effect on ruminal pH, ruminal NH3 N, or solids and liquids passage rate. Slaframine increased (linear, P < .10) total tract OM and starch disappearance and digestibility and tended to increase (linear, P = .14) total tract N digestibility. Ruminal starch disappearance tended to be decreased (quadratic, P = .16) by SF. Small intestinal OM digestibility was increased (linear, P < .10) but starch digestibility in the small intestine was not affected by SF. Increased total tract starch digestibility was caused by increased (quadratic, P < .10) starch fermentation in the large intestine. Ruminal feed N digestibility decreased at the intermediate doses of SF (quadratic, P < .10). Total N digestibility in the small intestine tended to be increased (cubic, P = .13) with 30 and 90 micrograms of SF/kg of BW. Decreased ruminal feed N digestion was compensated for by increased (quadratic, P < .10) small intestinal feed N disappearance for steers treated with intermediate doses of SF. The potential of SF to increase starch digestion in the rumen and small intestine seems to be limited.


Assuntos
Alcaloides/farmacologia , Bovinos/fisiologia , Dieta/veterinária , Digestão/efeitos dos fármacos , Parassimpatomiméticos/farmacologia , Alcaloides/administração & dosagem , Amônia/análise , Animais , Cateterismo/métodos , Cateterismo/veterinária , Bovinos/metabolismo , Dieta/normas , Digestão/fisiologia , Duodeno/fisiologia , Fermentação , Concentração de Íons de Hidrogênio , Íleo/fisiologia , Masculino , Nitrogênio/análise , Parassimpatomiméticos/administração & dosagem , Distribuição Aleatória , Rúmen/química , Rúmen/fisiologia , Amido/metabolismo
10.
J Anim Sci ; 73(5): 1499-508, 1995 May.
Artigo em Inglês | MEDLINE | ID: mdl-7665382

RESUMO

The history of "slobbers syndrome," a mycotoxicosis associated with Rhizoctonia leguminicola infestation of pastures and stored forages, is discussed. The chemistry and physiological effects of the two known biologically active alkaloids of R. leguminicola, slaframine and swainsonine, are described. Slaframine administration is generally associated with increased exocrine function, especially salivation. Ingestion of swainsonine may be linked to serious and potentially lethal central nervous system defects similar to that described for locoism. However, the singular effects of these alkaloids do not completely account for the total clinical picture noted in the field during the occurrence of slobbers syndrome. It is possible that this phenomenon is the result of an interaction between both known and unidentified biologically active metabolites of R. leguminicola.


Assuntos
Alcaloides/farmacologia , Doenças dos Bovinos/etiologia , Micotoxicose/veterinária , Parassimpatomiméticos/farmacologia , Sialorreia/veterinária , Swainsonina/farmacologia , Alcaloides/química , Animais , Bovinos , Doenças dos Bovinos/fisiopatologia , Sistema Nervoso Central/fisiologia , Micotoxicose/etiologia , Micotoxicose/fisiopatologia , Parassimpatomiméticos/química , Poaceae/microbiologia , Rhizoctonia/isolamento & purificação , Salivação/fisiologia , Sialorreia/etiologia , Sialorreia/fisiopatologia , Swainsonina/química , Síndrome
11.
J Anim Sci ; 64(4): 1241-8, 1987 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3571029

RESUMO

Two trials were initiated to determine if slaframine (SF) can be used to alter fluid digesta flow and fermentation patterns in the rumen. In trial 1, a preliminary experiment, four Dorset X Barbados Black-belly ruminal-cannulated wethers (avg weight 41.6 8.7 kg) given ad libitum access to a pelleted concentrate/hay diet were injected intramuscularly with 0, 12, 24 or 48 micrograms SF/kg body weight (BW) in a 4 X 4 Latin-square design. Ruminal fluid dilution rate was determined using a single intraruminal infusion of polyethylene glycol (7 g), followed by seven hourly ruminal fluid samples. The administration of 48 micrograms SF/kg BW increased (P less than .10) ruminal volume and outflow by 27 and 25%, respectively, compared with controls. In trial 2, two Hereford and two Angus ruminal cannulated steers (avg weight 568 +/- 93 kg) were injected with 0, 6, 12 or 24 micrograms SF/kg BW at 8-h intervals over a 24-h period in a 4 X 4 Latin-square design. Steers were fed a concentrate diet at twice maintenance in 24 equal portions daily. Ruminal fluid dilution was measured using a single intraruminal infusion of cobalt-ethylenediamine tetraacetic acid (20 g) administered 9 h after the initial SF injection. Ruminal fluid was collected each hour during 8 to 24 h after the initial SF injection and analyzed for pH, osmolality and volatile fatty acids (VFA).(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Alcaloides/farmacologia , Bovinos/fisiologia , Digestão/efeitos dos fármacos , Fermentação/efeitos dos fármacos , Parassimpatomiméticos/farmacologia , Rúmen/efeitos dos fármacos , Ovinos/fisiologia , Animais , Masculino , Rúmen/fisiologia
12.
J Anim Sci ; 73(2): 516-25, 1995 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7601786

RESUMO

Experiments were conducted to determine 1) the effect of injecting slaframine (SF) on salivary output in growing beef steers and 2) whether increased salivary output after SF injection would inhibit the decrease in ruminal pH that occurs after experimentally induced subacute and acute ruminal acidosis. In Exp. 1 and 2, we measured ruminal pH and salivary output in ruminally and esophageally cannulated beef steers fed an 88% concentrate diet. Injections of 66 or 100 micrograms of SF/kg BW increased salivary flow approximately 50% compared with controls. Those doses were tested in subacute and acute acidosis models using ruminally cannulated beef steers in Exp. 3 and 4, respectively. In these experiments, salivation was assessed indirectly using a visual scoring system. In the subacute acidosis model, SF reduced (P < .10) the decrease in ruminal pH (1.1, .7, and .6 pH units for control, 66, and 100 micrograms of SF/kg BW doses, respectively), and excessive salivation was observed in all SF-injected steers. In the acute acidosis model, there were no differences (P > .10) in ruminal pH at 12 h after injection between control and SF-treated steers. Mean ruminal lactate concentrations for all treatment groups were between 87 and 112 mM. Although treatment with 66 micrograms of SF/kg BW reduced (P < .10) ruminal lactate concentrations, all ruminal lactate concentrations were indicative of acute acidosis. These results indicate that SF will reduce the decrease in ruminal pH associated with subacute acidosis in growing beef steers, but SF does not attenuate acute ruminal acidosis.


Assuntos
Acidose/veterinária , Alcaloides/farmacologia , Doenças dos Bovinos/fisiopatologia , Bovinos/crescimento & desenvolvimento , Parassimpatomiméticos/farmacologia , Salivação/efeitos dos fármacos , Acidose/tratamento farmacológico , Acidose/fisiopatologia , Doença Aguda , Alcaloides/uso terapêutico , Animais , Bovinos/fisiologia , Doenças dos Bovinos/tratamento farmacológico , Relação Dose-Resposta a Droga , Concentração de Íons de Hidrogênio , Lactatos/análise , Masculino , Parassimpatomiméticos/uso terapêutico , Distribuição Aleatória , Rúmen/química , Rúmen/fisiologia , Glândulas Salivares/efeitos dos fármacos , Glândulas Salivares/fisiologia , Salivação/fisiologia
13.
J Anim Sci ; 71(6): 1634-40, 1993 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8392051

RESUMO

Sixteen mature, ruminally cannulated wethers (average BW = 41 +/- 1 kg) were fed a low-quality hay diet with or without a cottonseed meal (CSM) supplement and the parasympathomimetic agonist slaframine (SF). Treatments were basal diet (Mitchell grass hay, 4.8% CP, 46.8% ADF) available on an ad libitum basis, basal diet plus SF (8 micrograms/kg BW, 2 x daily i.m. injection), basal diet plus CSM (41.0% CP; 100 g/d), or basal diet plus SF and CSM. Treatments were arranged as a 2 x 2 factorial within a replicated 4 x 4 Latin square with 20-d periods followed by a 10-d adjustment during which only the basal diet was fed. All measurements were performed within the final 10 d of each period. Slaframine increased salivary flow by 10 to 35% (P < .07), ruminal fluid dilution rate by 8 to 11% (P < .10), and pH by 3 to 4% (P < .001). A twofold increase (P < .05) in ruminal cellulolytic bacteria numbers occurred in SF-treated wethers. Despite these SF-induced changes in the ruminal environment, whole-tract apparent nutrient digestibility, N and mineral balance, and ruminal VFA concentrations were not changed. Cottonseed meal increased forage intake by 34 to 54% (P < .001) and DM digestibility by 30% (P < .001). Cottonseed meal supplementation of a Mitchell grass hay diet improved nutritional status and attenuated live weight loss.


Assuntos
Alcaloides/farmacologia , Digestão , Parassimpatomiméticos/farmacologia , Rúmen/efeitos dos fármacos , Ovinos/fisiologia , Alcaloides/administração & dosagem , Amônia/análise , Ração Animal , Animais , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Óleo de Sementes de Algodão/administração & dosagem , Fibras na Dieta/metabolismo , Digestão/efeitos dos fármacos , Ingestão de Alimentos , Ácidos Graxos Voláteis/análise , Alimentos Fortificados , Trânsito Gastrointestinal/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Injeções Intramusculares/veterinária , Masculino , Micotoxinas/administração & dosagem , Micotoxinas/farmacologia , Parassimpatomiméticos/administração & dosagem , Poaceae , Rúmen/química , Rúmen/microbiologia , Salivação/efeitos dos fármacos
14.
J Anim Sci ; 73(12): 3673-80, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8655443

RESUMO

The influence of slaframine (SF), a parasympathomimetic compound isolated from the fungus Rizoctonia leguminicola, on circulating metabolic hormone concentrations was investigated in goats. In Exp. 1, SF was administered i.v. at 0 (CONT), 50 (LSF), 100 (MSF), or 150 (HSF) microgram/kg.75 BW in four mature Spanish-cross does (average BW 36 +/- 7 kg) fitted with indwelling jugular vein catheters in a 4 x 4 Latin square design. Plasma glucose peaked (P < .06) at 120 min with LSF and at 180 min with HSF and was higher (P <.06) than the CONT at these times. Glucose exhibited a quadratic response (P < .03) to SF. Area under the response curve for glucose differed (P < .02) in HSF from CONT and MSF. Insulin peaked (P < .01) at 240 min with MSF and at 180 min with HSF. Plasma triiodothyronine was maintained at a higher level (P < .03) with HSF. Thyroxine peaked (P < .06) at 120 min with MSF and 300 min with HSF. Plasma NEFA and somatotropin concentrations were not affected (P > .10) by SF. In Exp. 2, four mature Spanish-cross wethers (average BW 27 +/- 2 kg) fitted with jugular vein catheters were administered SF (0 and 114 micrograms/kg.75 BW) and 4-diphenylacetoxy-N-methylpiperidine methiodide (4DAMP; 0 and 258 micrograms/kg.75 BW), a M3-muscarinic receptor antagonist, i.v. in a 4 x 4 Latin square design with a 2 x 2 factorial arrangement of treatments. With SF, glucose peaked (P < .06) at 60 min and insulin peaked (P < .05) at 180 min. Plasma triiodothyronine levels were maintained (P < .05) with SF but declined with other treatments. Plasma NEFA and thyroxine concentrations remained unchanged regardless of treatment. Slaframine administration induced hyperglycemia and hyperinsulinemia in goats; however, these changes were blocked by preadministration of isomolar quantities of the M3-muscarinic receptor antagonist, 4DAMP.


Assuntos
Alcaloides/farmacologia , Glândulas Endócrinas/fisiologia , Cabras/fisiologia , Agonistas Muscarínicos/farmacologia , Antagonistas Muscarínicos/farmacologia , Piperidinas/farmacologia , Receptores Muscarínicos/fisiologia , Alcaloides/administração & dosagem , Animais , Glicemia/análise , Glândulas Endócrinas/efeitos dos fármacos , Ácidos Graxos não Esterificados/sangue , Feminino , Doenças das Cabras/sangue , Doenças das Cabras/induzido quimicamente , Cabras/sangue , Hormônio do Crescimento/sangue , Hiperglicemia/sangue , Hiperglicemia/induzido quimicamente , Hiperglicemia/veterinária , Hiperinsulinismo/sangue , Hiperinsulinismo/induzido quimicamente , Hiperinsulinismo/veterinária , Injeções Intravenosas/veterinária , Insulina/sangue , Masculino , Agonistas Muscarínicos/administração & dosagem , Antagonistas Muscarínicos/administração & dosagem , Parassimpatomiméticos/administração & dosagem , Parassimpatomiméticos/farmacologia , Piperidinas/administração & dosagem , Receptores Muscarínicos/efeitos dos fármacos , Tiroxina/sangue , Tri-Iodotironina/sangue
15.
J AOAC Int ; 82(2): 264-70, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10191533

RESUMO

Five 2 kg test samples were taken from each of 120 farmers' stock peanut lots contaminated with aflatoxin. Kernels from each 2 kg sample were divided into the following U.S. Department of Agriculture grade components: sound mature kernels plus sound splits (SMKSS), other kernels (OK), loose shelled kernels (LSK), and damaged kernels (DAM). The kernel mass (g), aflatoxin mass (ng), and aflatoxin concentration (ng of aflatoxin/g of peanuts) were measured for each of the 2400 component samples. The variabilities associated with measuring aflatoxin mass (ng) in OK + LSK + DAM, or A(OLD)ng, and in LSK + DAM, or A(LD)ng, and aflatoxin concentration (ng/g) in OK + LSK + DAM, or A(OLD)ng/g, and in LSK + DAM, or A(LD)ng/g, were determined. The variance associated with measuring aflatoxin in each of the 4 combinations of components increased with aflatoxin, and functional relationships were developed from regression analysis. The variability associated with estimating the lot concentration from each of the 4 combinations of components was also determined. The coefficients of variation (CV) associated with estimating the aflatoxin for a lot with aflatoxin at 100 ng/g were 90, 86, 94 and 96% for aflatoxin masses A(OLD)ng and A(LD)ng and aflatoxin concentrations A(OLD)ng/g and A(LD)ng/g, respectively. The performance of aflatoxin sampling plans using the combination of aflatoxin masses in OK + LD + DAM and LD + DAM components was evaluated with a 2 kg test sample and a 50 ng/g accept/reject limit.


Assuntos
Aflatoxinas/análise , Arachis/química , Controle de Qualidade , Agricultura , Cromatografia Líquida de Alta Pressão , Contaminação de Alimentos , Análise de Regressão
16.
J AOAC Int ; 77(3): 659-66, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-8012216

RESUMO

Suitability of the negative binomial function for use in estimating the distribution of sample aflatoxin test results associated with testing farmers' stock peanuts for aflatoxin was studied. A 900 kg portion of peanut pods was removed from each of 40 contaminated farmers' stock lots. The lots averaged about 4100 kg. Each 900 kg portion was divided into fifty 2.26 kg samples, fifty 4.21 kg samples, and fifty 6.91 kg samples. The aflatoxin in each sample was quantified by liquid chromatography. An observed distribution of sample aflatoxin test results consisted of 50 aflatoxin test results for each lot and each sample size. The mean aflatoxin concentration, m; the variance, S2 mean among the 50 sample aflatoxin test results; and the shape parameter, k, for the negative binomial function were determined for each of the 120 observed distributions (40 lots times 3 sample sizes). Regression analysis indicated the functional relationship between k and m to be k = 0.000006425m0.8047. The 120 observed distributions of sample aflatoxin test results were compared to the negative binomial function by using the Kolmogorov-Smirnov (KS) test. The null hypothesis that the true unknown distribution function was negative binomial was not rejected at the 5% significance level for 114 of the 120 distributions. The negative binomial function failed the KS test at a sample concentration of 0 ng/g in all 6 of the distributions where the negative binomial function was rejected. The negative binomial function always predicted a smaller percentage of samples testing 0 ng/g than was actually observed.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Aflatoxinas/análise , Arachis/química , Contaminação de Alimentos , Agricultura , Matemática , Análise de Regressão
17.
J AOAC Int ; 83(5): 1270-8, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11048872

RESUMO

The suitability of several theoretical distributions to predict the observed distribution of aflatoxin test results in shelled corn was investigated. Fifteen positively skewed theoretical distributions were each fitted to 18 empirical distributions of aflatoxin test results for shelled corn. The compound gamma distribution was selected to model aflatoxin test results for shelled corn. The method of moments technique was chosen to estimate the parameters of the compound gamma distribution. Mathematical expressions were developed to calculate the parameters of the compound gamma distribution for any lot aflatoxin concentration and test procedure. Observed acceptance probabilities were compared to operating characteristic curves predicted from the compound gamma distribution, and all 18 observed acceptance probabilities were found to lie within a 95% confidence band. The parameters of compound gamma were used to calculate the fraction of aflatoxin-contaminated kernels in contaminated lots. At 20 ppb, it was estimated that about 6 in 10,000 kernels are contaminated.


Assuntos
Aflatoxinas/análise , Zea mays/química , Algoritmos , Interpretação Estatística de Dados , Modelos Teóricos , Projetos de Pesquisa , Medição de Risco , Estudos de Amostragem
18.
J AOAC Int ; 83(5): 1279-84, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11048873

RESUMO

The effects of changes in sample size and/or sample acceptance level on the performance of aflatoxin sampling plans for shelled corn were investigated. Six sampling plans were evaluated for a range of sample sizes and sample acceptance levels. For a given sample size, decreasing the sample acceptance level decreases the percentage of lots accepted while increasing the percentage of lots rejected at all aflatoxin concentrations, and decreases the average aflatoxin concentration in lots accepted and lots rejected. For a given sample size where the sample acceptance level decreases relative to a fixed regulatory guideline, the number of false positives increases and the number of false negatives decreases. For a given sample size where the sample acceptance level increases relative to a fixed regulatory guideline, the number of false positives decreases and the number of false negatives increases. For a given sample acceptance level, increasing the sample size increases the percentage of lots accepted at concentrations below the regulatory guideline while increasing the percentage of lots rejected at concentrations above the regulatory guideline, and decreases the average aflatoxin concentration in the lots accepted while increasing the average aflatoxin concentration in the rejected lots. For a given sample acceptance level that equals the regulatory guideline, increasing the sample size decreases misclassification of lots, both false positives and false negatives.


Assuntos
Aflatoxinas/análise , Zea mays/química , Algoritmos , Interpretação Estatística de Dados , Modelos Teóricos , Projetos de Pesquisa , Medição de Risco , Tamanho da Amostra , Estudos de Amostragem
19.
J AOAC Int ; 83(5): 1285-92, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11048874

RESUMO

The variability associated with testing wheat for deoxynivalenol (DON) was measured using a 0.454 kg sample, Romer mill, 25 g comminuted subsample, and the Romer Fluoroquant analytical method. The total variability was partitioned into sampling, sample preparation, and analytical variability components. Each variance component was a function of the DON concentration and equations were developed to predict each variance component using regression techniques. The effect of sample size, subsample size, and number of aliquots on reducing the variability of the DON test procedure was also determined. For the test procedure, the coefficient of variation (CV) associated with testing wheat at 5 ppm was 13.4%. The CVs associated with sampling, sample preparation, and analysis were 6.3, 10.0, and 6.3%, respectively. For the sample variation, a 0.454 kg sample was used; for the sample preparation variation, a Romer mill and a 25 g subsample were used; for the analytical variation, the Romer Fluoroquant method was used. The CVs associated with testing wheat are relatively small compared to the CV associated with testing other commodities for other mycotoxins, such as aflatoxin in peanuts. Even when the small sample size of 0.454 kg was used, the sampling variation was not the largest source of error as found in other mycotoxin test procedures.


Assuntos
Tricotecenos/análise , Triticum/química , Algoritmos , Interpretação Estatística de Dados , Projetos de Pesquisa , Estudos de Amostragem
20.
J AOAC Int ; 84(3): 770-6, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11417641

RESUMO

The statistical distribution known as the compound gamma function was studied for suitability in describing the distribution of sample test results associated with testing lots of shelled corn for fumonisin. Thirty-two 1.1 kg test samples were taken from each of 16 contaminated lots of shelled corn. An observed distribution consisted of 32 sample fumonisin test results for each lot. The mean fumonisin concentration, c, and the variance, s2, among the 32 sample fumonisin test results along with the parameters for the compound gamma function were determined for each of the 16 observed distributions. The 16 observed distributions of sample fumonisin test results were compared with the compound gamma function using the Power Divergence test. The null hypothesis that the observed distribution could have resulted from sampling a family of compound gamma distributions was not rejected at the 5% significance level for 15 of the 16 lots studied. Parameters of the compound gamma distribution were calculated from the 32-fumonisin sample test results using the method of moments. Using regression analysis, equations were developed that related the parameters of the compound gamma distribution to fumonisin concentration and the variance associated with a fumonisin test procedure. An operating characteristic curve was developed for a fumonisin sampling plan to demonstrate the use of the compound gamma function.


Assuntos
Ácidos Carboxílicos/análise , Contaminação de Alimentos , Fumonisinas , Micotoxinas/análise , Zea mays/química , Cromatografia Líquida , Contaminação de Alimentos/estatística & dados numéricos , Análise de Regressão , Estatística como Assunto
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