Digestibilidade e efeitos hematológicos da aflatoxina B1 em equinos / Effect of aflatoxin B1 on digestibility and blood parameters in horses

Objetivou-se com esta pesquisa avaliar o efeito da Aflatoxina B1 (AFB1) na digestibilidade dos nutrientes e no perfil hematológico de equinos. O ensaio durou 40 dias, sendo 12 dias para adaptação e 28 dias para experimentação. No período experimental, os cavalos foram distribuídos em delineamento inteiramente casualizado, com três tratamentos, com quatro animais cada. Os tratamentos utilizados foram 0 µg/kg (controle), 50 µg/kg e 100 µg/kg de AFB1 adicionados ao concentrado da dieta basal. A dieta basal continha alimentos naturalmente contaminados com micotoxinas. Um ensaio de digestibilidade foi realizado no final do período experimental, pelo método de coleta parcial de fezes utilizando o LIPE® como indicador. Amostras de sangue foram coletadas uma vez por semana, durante o ensaio para avaliações hematológicas e bioquímicas. Os resultados dos parâmetros hematológicos, bioquímicos e do ensaio de digestibilidade foram submetidos à análise de variância (ANOVA) e comparados pelo teste de Tukey a 5% de significância. As aflatoxinas da dieta aumentaram a contagem de leucócitos, principalmente os neutrófilos maduros. A creatina quinase e a fosfatase alcalina (P0,05).

This study aimed to evaluate the effect of aflatoxin B1 (AFB1) on the digestibility of nutrients and the hematological profile of horses. The assay lasted 40 days, with 12 days for adaptation and 28 days for experimentation. In the experimental stage, the horses were distributed in a completely randomized design, including three treatment groups with four animals in each group. The treatments used included 0 µg/kg (control), 50 µg/kg, and 100 µg/kg of AFB1 added to a concentrate in the basal diet. The basal diet contained mycotoxins from naturally contaminated feed. A digestibility essay was carried out at the end of the experimental period through partial feces collection, with LIPE® as an indicator. Blood samples were collected once a week during the assay for hematological and biochemical evaluations. The results of the hematological and biochemical parameters were submitted to analysis of variance (ANOVA) and compared by the Tukey test at 5% significance. The aflatoxins in the diet increased the leukocyte count, especially that of mature neutrophils. Creatine kinase and alkaline phosphatase (P 0.05).

Effects on meat quality and black bone incidence of elevated dietary vitamin levels in broiler diets challenged with aflatoxin.

Vitamins play an essential role in broiler nutrition. They are fundamental for normal metabolic and physiological process, and their requirements for poultry are not fixed and can be affected by multiple factors. In contrast, mycotoxins are a challenging issue because they hinder performance and the immune system. Vitamin supplementation above minimum requirements would permit improvement in productive potential, health, bone and meat quality in a situation of mycotoxin challenge. The objective of this study was to determine the influence of optimum vitamin nutrition in diets contaminated with aflatoxin in broilers from 1 to 44 days of age. A total of 1800 Cobb 500 male chicks were randomized to 15 sets of eight treatment groups, each containing 15 birds using a 2 × 2 × 2 factorial design (commercial vitamin levels and high vitamin levels, two levels of aflatoxin - 0 and 0.5 ppm with binder levels of 0 and 10 000 mg/kg). The mash diets were corn and soybean meal based, formulated according to commercial practices. Feed intake, weight gain and feed conversion were analyzed for birds from 1 to 44 days of age. To determine carcass characteristics (carcass yield, breast yield and leg yield) and black bone syndrome, two birds were slaughtered from each group at 45 days. Other analyses included breast tenderness, water loss by dripping and malonaldehyde concentrations. The results demonstrated that broilers that were fed high levels of vitamins showed better weight gain, feed conversion, carcass yield and breast yield than broilers that were fed diets with commercial vitamin levels (P < 0.05); also, broilers that were fed diets containing 0.5 ppm aflatoxin had lower weight gain, carcass yield and breast yield (P < 0.05). The use of 10 000 mg/kg of binder improved (P < 0.05) feed conversion throughout the rearing period. We conclude that aflatoxin negatively affects performance and carcass yield; however, feeding optimum vitamin nutrition improved these performance traits.

Creatine kinase and ATPase activities in piglets fed a fungal mycotoxin co-contaminated diet: Consequences in the pathogenesis of subclinical intoxication.

Creatine kinase (CK) activity, through the creatine-kinase-phosphocreatine (CK/PCr) system, provides a temporal and spatial energy buffer to maintain cellular energetic homeostasis, being responsible to provide adenosine triphosphate (ATP) to the proper function of ATPases enzymes, such as the sodium-potassium (Na+, K+-ATPase) and hydrogen (H+-ATPase) pumps. Thus, the aim of this study was to evaluate the involvement of CK/PCr system in the impairment of energetic homeostasis in piglets fed with a diet co-contaminated with mycotoxins, as well as the effects on ATPases enzymes. Animals were randomly divided in two groups (eight repetitions with two animals each): CON (basal diet) and MYC (mycotoxin diet; 9300 µg/kg of aflatoxins and 8000 µg/kg of fumonisins) which were feed during 15 days. Piglets that received a diet containing 300 µg/kg of aflatoxins and 8000 µg/kg of fumonisins (MYC group) presented lower body weight on days 10 and 15 of experiment when compared to control (CON group). Serum CK activity was lower on days 5, 10 and 15 of experiment in the MYC group. The same occurred for serum Na+, K+-ATPase and H+-ATPase activities on days 10 and 15 when compared to CON group. Moreover, serum calcium levels were superior on day 15 of experiment in the MYC group, while serum potassium and sodium levels were lower in comparison to CON group. Based on these evidences, a diet co-contaminated by aflatoxins and fumonisins inhibits serum CK activity, impairing the energetic homeostasis. This inhibition alters the activities of ATPases (Na+, K+-ATPase and H+-ATPase), contributing to the imbalance of Na+, K+ and Ca+ ionic levels. In summary, the cascade of alterations contributes directly to disease pathogenesis of piglets intoxicated by mycotoxins.

Lipid metabolism of commercial layers fed diets containing aflatoxin, fumonisin, and a binder.

Aflatoxins (AF) and fumonisins (FU) are a major problem faced by poultry farmers, leading to huge economic losses. This experiment was conducted to determine the effects of AF (1 mg/kg of feed) and FU (25 mg/kg of feed), singly or in combination, on the lipid metabolism in commercial layers and investigate the efficacy of a commercial binder (2 kg/t of feed) on reducing the toxic effects of these mycotoxins. A total of 168 Hisex Brown layer hens, 37 wk of age, were randomized into a 3 × 2 + 1 factorial arrangement (3 diets with no binder containing AF, FU, and AF+FU; 3 diets with binder containing AF, FU, and AF+FU; and a control diet with no mycotoxins and binders), totaling 7 treatments. The hens contaminated with AF showed the characteristic effects of aflatoxicosis, such as a yellow liver, resulting from the accumulation of liver fat, lower values of plasma very low-density lipoprotein and triglycerides, and higher relative weight of the kidneys and liver. Hepatotoxic and nephrotoxic effects of FU were not observed in this study. On the other hand, the FU caused a reduction in small intestine length and an increase in abdominal fat deposition. The glucan-based binder prevented some of the deleterious effects of these mycotoxins, particularly the effects of AF on hepatic lipid metabolism, kidney relative weight, and FU in the small intestine.

Intoxicação experimental por aflatoxina em bezerros / Experimental aflatoxin poisoning in calves

Foram realizados dois experimentos para determinar os efeitos tóxicos de diferentes doses de aflatoxinas em bezerros, considerando-se aspectos clínicos, produtivos e patológicos. ... No primeiro experimento, o ganho de peso dos bezerros recebendo AFB1 foi equivalente ao do grupo controle durante todo período experimental. ...Durante o período experimental, e três semanas após o término desse período, não foram observados sinais clínicos e alterações histopatológicas associadas ao consumo de aflatoxinas, em qualquer dos bezerros do grupo tratamento do primeiro experimento.... Níveis alterados da atividade sérica de FA e GGT foram observados em todos os bezerros do grupo tratamento durante grande parte do período experimental. Queda acentuada do nível da AS sérica foi observada na coleta do 49º dia do experimento no bezerro que recebia a maior dose de aflatoxina. Não foram observadas variações no hematócrito e na atividade sérica da AST, nem nos níveis séricos de proteína total, bilirrubina total e bilirrubina direta em qualquer dos bezerros desse experimento. Alterações histopatológicas nos bezerros intoxicados incluíram proliferação de ductos biliares, degeneração citoplasmática vacuolar consistente com acumulação hepatocelular de lipídios, fibrose periportal, ou em ponte, megalocitose, fibrose subendotelial das veias hepáticas terminais e edema. Achados de necropsia do bezerro recebendo a maior dose de AFB1 incluíram fígado levemente aumentado de tamanho, difusamente amarelo-claro e firme, discreta ascite, edema de mesentério e submucosa do abomaso. Os dados obtidos nesses experimentos permitem afirmar que doses de 500±100 ppb de AFB1 não causam alterações patológicas e produtivas em bezerros em condições experimentais, mas podem estar associadas à mínimas alterações bioquímicas, enquanto doses de 1.250, 2.500 e 5.000 ppb de aflatoxina B1 causam doença hepática crônica em bezerros em condições experimentais.

Two experiments were performed in order to determine the toxic effects of varying doses of aflatoxins in calves. Clinical, productive and pathologic aspects of affected calves were considered….During all the experimental period of the first experiment, the weight gain of the calves receiving AFB1 was equivalent to that of the control group.…During the whole experimental period and up to three weeks after the final of the experiment, no clinical signs or histopathological changes associated with the consumption of aflatoxins were observed in any of the calves of the first experiment….Increased activity of AF and GGT were observed in all the calves of the treated group during most part of the experimental period. A marked drop in the serum levels of SA was observed in the serum sampled on the 49º day of the experiment in the calf receiving. the largest dose of aflatoxin. No changes were observed regarding PCV, TP, total bilirubin, direct bilirubin and in the serum activity of AST in any of the calves of the second experiment. Histopathological changes in intoxicated calves included bile duct proliferation, cytoplasmic vacuolar hepatocelular degeneration consistent with hepatocelular deposit of lipids, periportal to bridging fibrosis, megalocytosis, subendothelial edema and fibrosis in terminal hepatic veins. Necropsy findings in the euthanatized calf which receive de largest doses of AFB1 included slight enlargement of the liver which was firm and diffusely light-yellow, mild ascites, and edema of the mesentery and of abomasal folds. Data stemmed from these two experiments allow to conclude that AFB1 doses of 500±100 in the ration do not cause pathologic changes or decrease in productivity in calves kept in experimental conditions, but can be associated to minimal serum biochemistry; while AFB1 doses of 1.250, 2.500 e 5.000 ppb in the ration cause chronic hepatic disease in calves in kept in experimental conditions.

Intoxicação experimental por aflatoxina em bezerros / Experimental aflatoxin poisoning in calves

Foram realizados dois experimentos para determinar os efeitos tóxicos de diferentes doses de aflatoxinas em bezerros, considerando-se aspectos clínicos, produtivos e patológicos. ... No primeiro experimento, o ganho de peso dos bezerros recebendo AFB1 foi equivalente ao do grupo controle durante todo período experimental. ...Durante o período experimental, e três semanas após o término desse período, não foram observados sinais clínicos e alterações histopatológicas associadas ao consumo de aflatoxinas, em qualquer dos bezerros do grupo tratamento do primeiro experimento.... Níveis alterados da atividade sérica de FA e GGT foram observados em todos os bezerros do grupo tratamento durante grande parte do período experimental. Queda acentuada do nível da AS sérica foi observada na coleta do 49º dia do experimento no bezerro que recebia a maior dose de aflatoxina. Não foram observadas variações no hematócrito e na atividade sérica da AST, nem nos níveis séricos de proteína total, bilirrubina total e bilirrubina direta em qualquer dos bezerros desse experimento. Alterações histopatológicas nos bezerros intoxicados incluíram proliferação de ductos biliares, degeneração citoplasmática vacuolar consistente com acumulação hepatocelular de lipídios, fibrose periportal, ou em ponte, megalocitose, fibrose subendotelial das veias hepáticas terminais e edema. Achados de necropsia do bezerro recebendo a maior dose de AFB1 incluíram fígado levemente aumentado de tamanho, difusamente amarelo-claro e firme, discreta ascite, edema de mesentério e submucosa do abomaso. Os dados obtidos nesses experimentos permitem afirmar que doses de 500±100 ppb de AFB1 não causam alterações patológicas e produtivas em bezerros em condições experimentais, mas podem estar associadas à mínimas alterações bioquímicas, enquanto doses de 1.250, 2.500 e 5.000 ppb de aflatoxina B1 causam doença hepática crônica em bezerros em condições experimentais.(AU)

Two experiments were performed in order to determine the toxic effects of varying doses of aflatoxins in calves. Clinical, productive and pathologic aspects of affected calves were considered….During all the experimental period of the first experiment, the weight gain of the calves receiving AFB1 was equivalent to that of the control group.…During the whole experimental period and up to three weeks after the final of the experiment, no clinical signs or histopathological changes associated with the consumption of aflatoxins were observed in any of the calves of the first experiment….Increased activity of AF and GGT were observed in all the calves of the treated group during most part of the experimental period. A marked drop in the serum levels of SA was observed in the serum sampled on the 49º day of the experiment in the calf receiving. the largest dose of aflatoxin. No changes were observed regarding PCV, TP, total bilirubin, direct bilirubin and in the serum activity of AST in any of the calves of the second experiment. Histopathological changes in intoxicated calves included bile duct proliferation, cytoplasmic vacuolar hepatocelular degeneration consistent with hepatocelular deposit of lipids, periportal to bridging fibrosis, megalocytosis, subendothelial edema and fibrosis in terminal hepatic veins. Necropsy findings in the euthanatized calf which receive de largest doses of AFB1 included slight enlargement of the liver which was firm and diffusely light-yellow, mild ascites, and edema of the mesentery and of abomasal folds. Data stemmed from these two experiments allow to conclude that AFB1 doses of 500±100 in the ration do not cause pathologic changes or decrease in productivity in calves kept in experimental conditions, but can be associated to minimal serum biochemistry; while AFB1 doses of 1.250, 2.500 e 5.000 ppb in the ration cause chronic hepatic disease in calves in kept in experimental conditions.(AU)

Evaluation of the ability of a feed additive to ameliorate the adverse effects of aflatoxins in turkey poults.

1. A study was conducted to evaluate the possible protective effect of a feed additive containing aluminosilicate and phytogenic substances against the adverse effects of aflatoxins in turkey poults. 2. Dietary treatments (6) were given to turkey poults from d 1 to d 42 of age. From d 1 to 21 the dietary treatments were as follows: 1, negative control, no aflatoxins or feed additive added; 2, feed additive control, 1 kg/t feed additive, no aflatoxins; 3, 250 ppb (microg/kg) aflatoxins, no feed additive; 4, 250 ppb aflatoxins + 1 kg/t feed additive; 5, 500 ppb aflatoxins, no feed additive; and 6, 500 ppb aflatoxins + 1 kg/t feed additive. From d 22 to 42, the dietary concentration of the feed additive was increased from 1 to 2 kg/t in all treatment groups receiving the feed additive (2, 4 and 6), while keeping constant the dietary concentrations of aflatoxins. 3. Aflatoxins at 250 ppb did not cause adverse effects on performance but affected certain toxicopathological parameters. At 500 ppb, adverse effects on performance and several toxicological parameters were observed. 4. Some of the adverse affects were partially or completely overcome by supplementation with the feed additive, including amelioration of the performance parameters, suppression of mortality and correction of the immunological alterations induced by the exposure to the aflatoxins.

Aflatoxicosis in chickens (Gallus gallus): an example of hormesis?

Poultry has commonly been considered highly susceptible to aflatoxins. However, among domestic fowl there is wide variability in specific species sensitivity to these mycotoxins. Comparative toxicological studies in avian species have shown that ducklings and turkey poults are the most sensitive species to aflatoxins, quails show intermediate sensitivity, whereas chickens are the most resistant. Hormesis is a dose-response phenomenon characterized by low-dose stimulation and high-dose inhibition. The low-dose stimulation is typically maximal at only about 30 to 60% greater than controls. Hormesis has been noted in regards to changes in body weight in numerous studies, including those performed for the US National Toxicology Program, with over 50 chemicals. The present paper assesses how relatively low levels of aflatoxin consumption in feed may affect the growth rate of chickens. In general, multiple independent investigations have shown that such aflatoxin consumption affects growth in a hormetic-like biphasic manner with a low dose stimulation and a high dose inhibition. Such observations were then generalized to other toxic agents and animal models, suggesting that low doses of stressor agents induce adaptive responses as reflected in accelerated growth rates. The implications of such hormetic dose responses are briefly discussed.

Performance of turkey poults fed different doses of aflatoxins in the diet.

This work was conduced to determine the performance parameters of initial-phase turkey poults fed 7 different doses of aflatoxins in the diet. Three hundred thirty-six 1-d-old male turkey poults were used in this research. Turkeys were divided into 7 treatments according to aflatoxin doses (T1 = control; T2 = 20 ppb aflatoxins; T3 = 50 ppb; T4 = 100 ppb; T5 = 200 ppb; T6 = 500 ppb; T7 = 1,000 ppb). Birds were killed in 2 periods: half of them after 21 d of experiment and the remaining birds after 42 d of experiment. In both periods, the evaluated parameters were as follows: feed consumption, BW, relative weights of organs (liver, gizzard, heart, and bursa of Fabricius) and meat (breast and thighs), and clinical biochemistry parameters (total plasmatic proteins, albumin, uric acid, cholesterol, alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase). At 21 d of experiment, both feed consumption and BW were significantly affected by the aflatoxins present in the diet. Nevertheless, gizzard relative weight, total plasmatic proteins, and cholesterol levels were also affected. At the 42-d evaluation, besides feed consumption and BW, gizzard and liver relative weights and cholesterol levels were also affected by the presence of aflatoxins in the diet. Turkey poults are very sensitive to aflatoxin poisoning, because they are at least 3 to 6 times more sensitive to these contaminants than broilers.

[Influence of aflatoxin B1 on growth of rats under various nutritional conditions]. / Influencia de aflatoxina B1 sobre o crescimento de ratos submetidos a diferentes condições nutricionais.

The effect of the addition of aflatoxin B1 was studied in 48 male, Sprague-Dawley rats weaned at 21 days of age. The animals of the experimental group received one of the following diets to which aflatoxin B1 was added (5 mg/kg ration), a protein-free diet, the regional basic diet of Northeast Brazil (RBD) containing 9.07% protein, and commercial casein diets (at 10 and 20%). The control groups were fed the same diets without aflatoxin B1. To detect possible body alterations, the body weight and food intake, as well as protein and aflatoxin B1 intakes were recorded. Significant alterations were detected in the experimental groups, especially in the protein-depleted animals, and in those fed the RBD and 10% commercial casein diets, when compared to their controls.

Pesquisa e dosagem de aflatoxina em amendoim e derivados e em outros cereais / Search and dosage of aflatoxin in peanuts and derivatives and other cereals

Descrevem-se técnicas de cromatografia em papel e em camada delgada para pesquisa e determinação de aflatoxina em alimentos para consumo humano e em rações para animais (AU).