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Biomedical subjects

R B Harvey

Publications and source records attributed to R B Harvey.

At least 55 records · Page 3Linked to original sources

Effects of long-term feeding of diets containing moniliformin, supplied by Fusarium fujikuroi culture material, and fumonisin, supplied by Fusarium moniliforme culture material, to laying hens.

Beginning at 24 wk of age, control diets or diets containing 50 or 100 mg/kg moniliformin (M), 100 or 200 mg/kg fumonisin B1 (FB1), or a combination of 50 mg M and 100 mg FB1/kg of diet were fed to White Leghorn laying hens for 420 d. The hens were then fed the control diet for an additional 60 d. At the beginning of the experiment, each treatment consisted of four replicates of six hens. Egg production was reduced by approximately 50% by the end of the second 28-d laying period and remained at approximately this level for the 420 d in only the hens fed the diet containing 100 mg M/kg feed. Production returned to control levels or above within 60 d after hens were fed the control diet. Egg weights were reduced by the 100-mg M diet during the first three 28-d laying periods before returning to weights comparable with controls. The hens in this group also had significantly lower body weights than the other treatments. Mortality was minimal except in hens fed the 100 mg M/kg diet and the 100 mg FB1/kg diet, on which approximately 20% of the hens died. The hens were artificially inseminated with semen from males fed control diets, and fertility was not affected by the dietary treatments. Importantly, toxic synergy between M and FB1 was not observed for any of the parameters measured. Results indicate that laying hens may be able to tolerate relatively high concentrations of M and FB1 for long periods of time without adversely affecting health and performance. Interestingly, hens fed the 100-mg M/kg diet were able to recover when returned to control diets. The likelihood of encountering M or FB1 at these concentrations in finished feed is small.

Animal Feed↗

Effects of a hydrated sodium calcium aluminosilicate (T-Bind) on mycotoxicosis in young broiler chickens.

Experiments were conducted to determine the ability of a hydrated sodium calcium aluminosilicate (T-Bind) sorbent to reduce the toxicity of aflatoxins (AF) or T-2 toxin in male broiler chickens from day of hatch to 21 d of age. In Experiment 1, the sorbent was added at 0.250 or 0.375% to diets containing AF at 5 or T-2 toxin at 8 mg/kg of diet. When compared with controls, AF reduced BW gain by 27% and T-2 toxin reduced BW gain by 17%. The addition of the sorbent at 0.250 or 0.375%, in the absence of added mycotoxins, did not alter the performance of the chicks. The sorbent reduced the toxic effects of 5 mg AF/kg of diet on BW gain by 43% but did not significantly diminish the toxic effects of 8 mg T-2 toxin/kg of diet. The decreased efficiency of feed utilization and the increased relative organ weights caused by AF were significantly diminished to differing degrees by the sorbent. Oral lesions caused by T-2 toxin were not affected by the sorbent. In Experiment 2, the sorbent was added at 0.80% to a diet containing 8 mg T-2 toxin/kg of diet. The sorbent did not diminish the toxic effects of T-2 toxin when added at 0.80% of the diet. These data demonstrate that this specific sorbent can provide protection against the toxicity of AF, but not T-2 toxin, in young broiler chicks.

Aflatoxins↗

Efficacy of various inorganic sorbents to reduce the toxicity of aflatoxin and T-2 toxin in broiler chickens.

Experiments were conducted to determine the efficacy of three inorganic sorbents, S1, S2, and S3, to reduce the toxicity of aflatoxins (AF) and T-2 toxin in male broiler chickens from day of hatch to 21 d of age. The compounds had been reported to bind to AF and T-2 toxin in vitro. S1 and S2 were the same basic compound that had been stored for different lengths of time following activation. In Experiments 1, 2, and 3, the appropriate diets were produced to contain no mycotoxins, the specific adsorbent at 0.5% of diet, AF alone at 5 mg/kg of diet, T-2 alone at 8 mg/kg of diet, AF at 5 mg/kg of diet plus the specific sorbent at 0.5% of diet, or T-2 at 8 mg/kg of diet plus the specific sorbent at 0.5% of diet. The specific sorbents used were: 1) Experiment 1, S1; 2) Experiment 2, S1 and S2; and 3) Experiment 3, S3. In Experiments 1 and 3, S1 and S3, respectively, showed no protection against AF or T-2 toxin as measured by BW gain, when compared to AF alone group. In Experiment 2, S1 showed no protection; however S2 reduced the effects of AF on BW gain by 25% as compared to AF alone diet. The data demonstrate that under the conditions of our experiment: 1) one of the sorbents provided some protection against aflatoxicosis; 2) there was variability in protection against aflatoxicosis between two different samples of the same sorbent that had been stored for different lengths of time following activation; 3) protection by the sorbents against the effects of T-2 toxin was not observed.

Adsorption↗

Aflatoxicosis in turkey poults is prevented by treatment of naturally contaminated corn with ozone generated by electrolysis.

Previous studies have demonstrated that a novel source of ozone gas (O3) maybe used to chemically degrade numerous mycotoxins, including aflatoxin (AF) B1. Subsequent in vitro analyses demonstrated detoxification of AFB1, suggesting a potential method of remediate AF-contaminated grain. The objective of this study was to evaluate the capability of electrochemically produced ozone to degrade AFB1 in naturally contaminated whole kernel corn and confirm detoxification in turkey poults. Corn was procured from the southern coastal areas of Texas and HPLC revealed 1,220 +/- 73.3 ppb AFB1. Control and contaminated corn were treated for 92 h with O3 at 200 mg/min in 30 kg batches; greater than 95% reduction of AFB1 in contaminated corn was achieved. One-day-old female turkey poults were fed 1) control corn, 2) control corn + O3, 3) AFB1 corn, or 4) AFB1 corn + O3 mixed in rations (46% by wt.) and consumed ad libitum for 3 wk. When compared with controls, turkeys fed AFB1 corn had reduced body weight gain and relative liver weight, whereas turkeys fed control corn + O3 or AFB1 corn + O3 did not differ from controls. Furthermore, alterations in the majority of relative organ weight, liver discoloration, serum enzyme activity, hematological parameters, and blood chemistry caused by AFB1 were eliminated (no difference from controls) by treatment with O3. These data demonstrate that treatment of contaminated corn with electrochemically produced O3 provided protection against AFB1 in young turkey poults. It is important to note that treatment of control corn with O3 did not alter the performance of the turkey poults.

Animal Feed↗

Individual and combined effects of fumonisin B1 present in Fusarium moniliforme culture material and diacetoxyscirpenol or ochratoxin A in turkey poults.

The individual and combined effects of feeding diets containing 300 mg fumonisin B1 (FB1), and 4 mg diacetoxyscirpenol (DAS) or 3 mg ochratoxin A (OA) were evaluated in two experiments using female turkey poults (Nicholas Large Whites) from day of hatch to 3 wk of age. When compared with controls, body weight gains were reduced 30% (Study 1) and 24% (Study 2) by FB1, 30% by DAS, 8% by OA, 46% by the FB1 and DAS combination, and 37% by the FB1 and OA combination. The efficiency of feed utilization was adversely affected by all treatments except FB1 in Experiment 2. Relative weights of the liver were significantly increased by all treatments except the DAS treatment. Serum concentrations of cholesterol were decreased and activities of aspartate aminotransferase and lactate dehydrogenase were increased and several hematological values were altered in poults fed FB1 alone and in combination with either DAS or OA. Results indicate additive or less than additive toxicity, but not toxic synergy, when poults are fed diets containing 300 mg FB1, and 4 mg DAS or 3 mg OA/kg of diet. The likelihood of encountering FB1, DAS, or OA at these concentrations in finished feed is small. However, under field conditions, other stress factors could alter the impact of these mycotoxins on the health and performance of poultry.

Animal Feed↗

Individual and combined effects of moniliformin present in Fusarium fujikuroi culture material and aflatoxin in broiler chicks.

The individual and combined effects of feeding diets containing 100 mg moniliformin (M) and 3.5 mg aflatoxins (AF)/kg of diet were evaluated in male broiler chicks from day of hatch to 3 wk of age. When compared with controls, BW gains were reduced 29% by M, 13% by AF, and 33% by the M and AF combination. The efficiency of feed utilization was adversely affected by M independent of AF. Feeding M resulted in decreased relative weights of the bursa of Fabricius and increased relative weights of the heart, increased serum concentrations of creatinine and calcium, increased activities of alkaline phosphatase and alanine aminotransferase, and changes in hematological values. Feeding AF resulted in increased relative weights of the kidney and heart, decreased serum concentrations of total protein, albumin, cholesterol, and calcium, and decreased mean corpuscular volume. Feeding the combination of M and AF resulted in increased relative weights of the heart, decreased serum concentrations of total protein, albumin, and inorganic phosphorus, increased concentrations of creatinine and activity of alanine aminotransferase, and changes in hematological values. Results indicate additive or less than additive toxicity, but not toxic synergy, for most parameters when chicks are fed diets containing the combination of 100 mg M and 3.5 mg AF/kg of diet. The likelihood of encountering these high concentrations of these mycotoxins in finished feed is small; however, additional data on the naturally occurring concentrations of M are necessary before the importance of this mycotoxin to the poultry industry can be assessed.

Aflatoxins↗

Effects of inorganic adsorbents and cyclopiazonic acid in broiler chickens.

Previous studies with cyclopiazonic acid (CPA) have indicated that this mycotoxin strongly adsorbs onto the surface of a naturally acidic phyllosilicate clay (AC). The objective of this study was to determine whether AC (and similar adsorbents) could protect against the toxicity of CPA in vivo. Acidic phyllosilicate clay, neutral phyllosilicate clay (NC, or hydrated sodium calcium aluminosilicate), and a common zeolite (CZ, or clinoptilolite) were evaluated. One-day-old broiler chicks consumed diets containing 0 or 45 mg/kg CPA alone or in combination with 1% AC, NC, or CZ ad libitum from Day 1 to 21. Body weight, feed consumption, feed:gain, hematology, serum biochemical values, and enzyme activities were evaluated. Compared to controls, CPA alone reduced body weight at Day 21 by a total of 26% and resulted in a significantly higher feed:gain ratio. Toxicity of CPA was also expressed through increased relative weights of kidney, proventriculus, and gizzard. Also, there were some alterations in hematology, serum biochemical values, and enzyme activities. Treatment with inorganic adsorbents did not effectively diminish the growth-inhibitory effects of CPA or the increased weights of organs, although there was some protection from hematological, serum biochemical, and enzymatic changes produced by CPA. The results of this study suggest that in vitro binding of CPA to clay does not accurately forecast its efficacy in vivo; the reasons for this discrepancy are not clear, but they may be related to differences in clay binding capacity and ligand selectivity for CPA in vitro vs in vivo. Predictions about the ability of inorganic adsorbents to protect chickens from the adverse effects of mycotoxins should be approached with caution and should be confirmed in vivo, paying particular attention to the potential for nutrient interactions.

Adsorption↗

Influence of a superactivated charcoal on the toxic effects of aflatoxin or T-2 toxin in growing broilers.

To evaluate the effectiveness of a superactivated charcoal (SAC) in alleviating mycotoxicosis, two experiments were conducted in which 432 male broiler chicks (216 per experiment) were fed diets containing 4 mg aflatoxin (AF) or 6 mg T-2 toxin/kg of diet, with and without 0.5% SAC, from 1 to 21 d of age. Feeding AF and T-2 toxin significantly decreased BW gain over the 21-d experimental period. Inclusion of SAC in the diet containing AF resulted in BW gains that were intermediate between gains of chicks fed AF and those of controls. No benefits were seen in BW gain when SAC + T-2 toxin was fed. Feeding AF increased relative weights of liver, spleen, and kidney; however, only liver weight in Experiment 1 was similar to controls when SAC was included. Of the blood parameters altered by AF (decreased cholesterol, inorganic phosphorus, total protein, and urea nitrogen, and increased mean corpuscular volume and hematocrit in Experiment 1; decreased albumin and total protein, and increased creatine kinase in Experiment 2) only urea nitrogen, hematocrit, and inorganic phosphorus (Experiment 1) and hematocrit (Experiment 2) were comparable to controls when SAC was included in the diet. Feeding T-2 toxin decreased serum cholesterol, total protein, urea nitrogen, and mean corpuscular volume; however, only cholesterol and mean corpuscular volume were improved with the addition of SAC (Experiment 1). Oral lesions were observed in birds fed T-2 toxin with no difference in severity when SAC was added in Experiment 1, however in Experiment 2, birds fed SAC + T-2 had a significantly lower lesion scores than those fed T-2 alone. Mortality was noted in both experiments but was not influenced by SAC treatment. These findings suggest that the addition of dietary SAC is marginally effective in alleviating some of the toxic affects associated with AF, but was of little benefit when T-2 toxin was fed to growing broiler chicks.

Administration, Oral↗

Individual and combined effects of fumonisin B1 present in Fusarium moniliforme culture material and T-2 toxin or deoxynivalenol in broiler chicks.

The individual and combined effects of feeding diets containing 300 mg fumonisin B1 (FB1), and 5 mg T-2 toxin (T-2)/kg of diet, or 15 mg/kg deoxynivalenol (DON, vomitoxin) from naturally contaminated wheat were evaluated in two studies in male broiler chicks from day of hatch to 19 or 21 d of age in Experiments 1 and 2, respectively. When compared with controls, body weight gains were reduced 18 to 20% by FB1, 18% by T-2, 2% by DON, 32% by the FB1 and T-2 combination, and 19% by the FB1 and DON combination. The efficiency of feed utilization was adversely affected by FB1 with or without T-2 or DON. Mortality ranged from none for the controls to 15% for the FB1 and T-2 combination. Relative weights of the liver and kidney were significantly increased by FB1 with or without T-2 or DON. Serum concentrations of cholesterol were increased in chicks fed FB1 with or without T-2 or DON. Activities of aspartate aminotransferase, lactate dehydrogenase, and gamma glutamyltransferase were increased in chicks fed FB1 at 300 mg/kg alone and in combination with T-2 or DON, indicating possible tissue damage and leakage of the enzymes into the blood. Results indicate additive toxicity when chicks were fed diets containing 300 mg FB1 and 5 mg T-2/kg of diet and less than additive toxicity when chicks were fed 300 mg FB1 and 15 mg DON/kg of diet. Of importance to the poultry industry is the fact that toxic synergy was not observed for either of these toxin combinations and the likelihood of encountering FB1 at this concentration in finished feed is small. However, under field conditions with additional stress factors, the toxicity of these mycotoxins could be altered to adversely affect the health and performance of poultry.

Animals↗

Hydrated sodium calcium aluminosilicate (HSCAS), acidic HSCAS, and activated charcoal reduce urinary excretion of aflatoxin M1 in turkey poults. Lack of effect by activated charcoal on aflatoxicosis.

In one experiment, the effect of inorganic sorbents on the metabolic fate of aflatoxin B1 (AFB1) was studied in turkey poults. At 5 weeks of age, female poults were surgically colostomized and 9 days later orally dosed with 0.75 mg AFB1/kg BW. Hydrated sodium calcium aluminosilicate (HSCAS), acidic HSCAS, and activated charcoal (AC) were tested, by concomitant administration with AFB1. Urine was collected up to 48 h post-dosing and analyzed for aflatoxin M1 (AFM1) which was the major metabolite found in all treatment groups. Hydrated sodium calcium aluminosilicate, previously proven beneficial in alleviating aflatoxicosis in farm animals, reduced urinary AFM1 output when orally dosed simultaneous with AFB1. Also, acidic HSCAS and AC significantly decreased AFM1 excretion when administered concomitantly with AFB1. A second experiment was conducted to evaluate the ability of two types of AC to modify aflatoxicosis when added to aflatoxin (AF)-contaminated (from culture material) diets of turkey poults. Although AC was able to decrease AFM1 excretion in the first experiment, no protective effects from AF toxicity were observed in the feeding study.

Aflatoxin M1↗

Effects of dietary fumonisin B1-containing culture material, deoxynivalenol-contaminated wheat, or their combination on growing barrows.

OBJECTIVE: To examine the toxic effects of fumonisin B1 (FB1)-containing culture material and deoxynivalenol (DON)-contaminated wheat diets on barrows. ANIMALS: 24, 7-week-old crossbred barrows allotted to 4 equal groups of 3 replicates of 2 barrows/replicate. PROCEDURE: Barrows were fed diets for 28 days that were formulated as follows: no additional FCM or DON/kg of feed (control); 100 mg FB1/kg of feed; 5 mg DON/kg of feed; or 100 mg FB1 plus 5 mg DON/kg of feed. Body weight and feed consumption were monitored weekly. On day 28, blood samples were obtained for serum biochemical, hematologic, and immunologic measurements. On day 29, barrows were euthanatized and necropsies were performed. RESULTS: Analyzed mycotoxin content of diets were: none detected (control); 47 mg of FB1/kg of feed (FB1 diet); 4.5 mg of DON/kg of feed (DON diet); and 56 mg of FB1 and 3.7 mg of DON/kg of feed (FB1 plus DON diet). Differences were detected among groups of barrows for clinical performance, serum biochemical analytes, immunologic response, and histopathologic lesions. CONCLUSIONS: Combining FB1-containing material and DON-contaminated wheat in the diets of growing barrows induces a more toxic response than that induced by either toxin singly. For many variables, the response could be described as additive; however, for some variables, responses were interactive in a greater-than-additive manner. CLINICAL RELEVANCE: Caution should be exercised when formulating swine diets that could contain FB1 and DON, because the condition induced by their combination is more severe than that predicted for each mycotoxin's toxicity.

Animal Feed↗

Effects of phyllosilicate clay on the metabolic profile of aflatoxin B1 in Fischer-344 rats.

The phyllosilicate clay, hydrated sodium calcium aluminosilicate (HSCAS), has been shown to prevent aflatoxicosis in farm animals by reducing the bioavailability of aflatoxin. The present study was designed to determine the effects of HSCAS on the metabolism of aflatoxin B1 (AFB1) in an aflatoxin-sensitive species. Male Fischer-344 rats were orally dosed with 1.0, 0.5, 0.25 and 0.125 mg AFB1/kg body weight alone and in combination with 0.5% HSCAS. Urine samples were collected after 6, 24, 36, and 48 h. Aflatoxin M1 (AFM1) and aflatoxin P1 (AFP1) were detected in most urine samples, with or without HSCAS. AFM1 was found to be the major metabolite. Metabolite concentrations were significantly decreased in the presence of HSCAS, and more importantly, no additional metabolites were detected. Our results suggest that the AFB1-HSCAS complex was not significantly dissociated in vivo, and support earlier findings that HSCAS tightly binds aflatoxin.

Aflatoxin B1↗

Influence of the antibiotics lincomycin and tylosin on aflatoxicosis when added to aflatoxin-contaminated diets of growing swine.

Effects of dietary aflatoxin (AF) and the antibiotics lincomycin (L) and tylosin (T) were evaluated in growing crossbred pigs. Six barrows (3 replicates of 2 each, mean body weight 14.0 kg) per group were assigned to 1 of 6 treatment groups (for a total of 36): 0 mg L, 0 mg T, and 0 mg AF/kg of feed (control); 220 mg L/kg of feed (200 g/ton); 110 mg T/kg of feed (100 g/ton); 2.5 mg AF/kg of feed; 2.5 mg AF plus 220 mg L/kg of feed; 2.5 mg AF plus 110 mg T/kg of feed. Barrows were administered their respective diets for 28 days. Body weight, body weight gain, and feed consumption were reduced by the AF alone, the AF plus L, and the AF plus T treatments, compared with control, L, and T treatments. Altered serum biochemical or hematologic measurements induced by AF treatments included increased serum activities of alkaline phosphatase and gamma-glutamyltransferase, increased hematocrit, hemoglobin, RBC count, WBC count, and mean cell hemoglobin, decreased serum concentrations of albumin, cholesterol, inorganic phosphorus, unsaturated iron binding capacity, total protein, and urea nitrogen, and decreased lymphoblastogenic response. Liver weight was increased, and microscopic lesions were consistent with those observed in cases of aflatoxicosis. With some other minor exceptions for hematologic and immunologic variables, these data indicate that the feed antibiotics lincomycin and tylosin, when added to aflatoxin-contaminated diets, do not have beneficial or detrimental effects on aflatoxicosis in growing swine.

Aflatoxins↗

Acute hepatic and renal toxicity in lambs dosed with fumonisin-containing culture material.

To examine the effects of acute exposure to fumonisin-containing culture material (FCCM), 15 crossbred wether lambs were dosed intraruminally with FCCM containing 0 (CONTROL, n = 3), 11.1 (LOW, n = 4), 22.2 (MED, n = 4), or 45.5 (HIGH, n = 4) mg of total fumonisins (B1, B2, and B3)/kg BW daily for 4 d. Blood samples were collected daily, and on d 11 lambs were killed and necropsied. Changes in serum constituents in fumonisin-treated lambs indicative of liver damage, included increased (P < .05) activities of alkaline phosphatase, gamma-glutamyl transferase, aspartate aminotransferase, and lactate dehydrogenase. Serum concentrations of cholesterol, triglycerides, urea nitrogen, and creatinine were also increased (P < .05) in lambs dosed with FCCM. Hemoglobin tended to increase (P = .07) and white blood cell count tended to decrease (P = .08) in HIGH lambs and activated partial thromboplastin time tended to decrease (P < .10) in lambs dosed with LOW and MED treatments. Mitogen-induced lymphocyte blastogenesis was not different (P = .14) among treatments. Feed intake markedly decreased (P < .01) following the first dosing of FCCM and continued to decline throughout the study. Ruminal VFA concentrations and pH tended to decrease (P < .10) at d 11 in treated lambs. Relative liver and kidney weights (g/100 g of BW) increased (P < .05) in fumonisin-treated lambs. Histiolgical examination revealved tubular nephrosis and mild hepatopathy in dosed lambs. Lambs receiving the HIGH treatment died on d 3, 4, 5, and 7 of the study and on d 9 one lamb on the MED treatment died.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗

Influence of fumonisin B1, present in Fusarium moniliforme culture material, and T-2 toxin on turkey poults.

Diets containing 300 mg fumonisin B1 (FB1)/kg of feed and 5 mg T-2 toxin/kg of feed singly or in combination were fed to female turkey poults (Nicholas Large White) from day of hatch to 21 d of age. When compared with controls, 21-d body weight gains were reduced 21% by FB1, 26% by T-2, and 47% by the combination. the efficiency of feed utilization was adversely affected by FB1 and the combination of FB1 and T-2. Relative weights (grams/100 g BW) of the liver and gizzard were increased in poults fed the FB1 and the combination diets; whereas, the relative weight of the pancreas was increased in all treated groups. All poults were scored for oral lesions using a scale of 1 to 4 (1 = no visible lesions, 4 = severe lesions). Oral lesions were present in all poults fed the T-2 diet (average score of 3.29) or the combination diet (average score of 3.54). Serum concentration of cholesterol was decreased and lactate dehydrogenase activity was increased in poults fed the FB1 and combination diets. The activity of aspartate aminotransferase and the values for red blood cells, hemoglobin, and hematocrit were increased only in poults fed the combination diet. Inorganic phosphorus concentration was decreased only in poults fed the combination diet. The increased toxicity in poults fed the combination diet for most variables can best be described as additive, although some variables not altered by FB1 or T-2 singly were significantly affected by the combination, indicating that the combination may pose a potentially greater problem to the turkey industry than either of the mycotoxins individually.

Animals↗

Influence of a hydrated sodium calcium aluminosilicate and virginiamycin on aflatoxicosis in broiler chicks.

Male broiler chicks were fed diets containing 0 or 3.5 mg aflatoxin (AF)/kg from 1 to 28 d of age. The diets were amended with either .5% hydrated sodium calcium aluminosilicate (HSCAS), 16.5 mg virginiamycin (VM)/kg of diet, or .5% HSCAS + 16.5 mg VM/kg of diet to determine the effects of these compounds during aflatoxicosis. When compared with controls (814 g), BW gains were significantly lower for broilers fed the AF (731 g) or AF+VM (716 g) diets. No differences were found between the BW gains of chicks fed diets without aflatoxin (814 g) and those of chicks fed AF+HSCAS (793 g) or AF+HSCAS+VM (803 g), indicating approximately 75% protection against decreased BW gain by HSCAS and 87% protection by the HSCAS+VM combination. Relative weights of the liver and kidney and creatine kinase activity were significantly increased and albumin, total protein, cholesterol, uric acid, and inorganic phosphorus concentrations were decreased in chicks fed the diet containing AF alone. With the exception of albumin, HSCAS was effective in restoring these values to control values. The findings of this research suggest that HSCAS and HSCAS+VM can counteract some of the toxic effects of AF in growing broiler chicks.

Aluminum Silicates↗