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Previous issue date: 2007-03-27 / The commercial feed constitutes an important element in the pet industry in Brazil. Its
composition includes cereal mixtures produced in farms such as sorghum, maize and
some oily seeds. All feed destined to pets are supplemented with fats, vitamins,
minerals, antirust and flours of diverse origins incorporated in some cases as pellets.
When conditions of nutrients and moisture are adequate, fungal contamination could be
present during pre and post harvest, storage, manufacture and processing of these
ingredients. The filamentous stored grain fungi more commonly found include the
species belonging to Aspergillus, Penicillium and Fusarium genera. They are able to
produce different mycotoxins. Species of Aspergillus such as Aspergillus flavus,
Aspergillus parasiticus and Aspergillus nomius are able to produce aflatoxins,
considered as carcinogen type 1A. The pet foods have important amounts of cereals and
therefore, they can concentrate important amounts of toxins. In dogs and cats the effects
of mycotoxins are severe and can produce death, besides the loss of nutrients, to alter
the organoleptic properties and to diminish the average life of the product in the market.
On the other hand, the presence of toxicogenic species could indicate the contamination
with several mycotoxins and this situation represents a potential risk for the animal
health. On the basis of these antecedents the objectives of this work were 1) to
characterize the mycoflora, 2) to detect the natural incidence of mycotoxins from raw
materials and compound feed for dogs and 3) to establish parameters to prevent and/or
to control micotoxicoses. A total of 230 samples (117 suspected foods to produce
natural poisoning (AIN), 43 commercial foods (AC) of 3 different qualities, 70
ingredients of the production line (ALP)) of ingredients and rations destined to the
feeding of dogs were analyzed. The fungal isolation was made by the surface spread
method. The culture media were dicloran-rose-bengal-chloranphenicol agar (DRBC),
dicloran-chloranphenicol 18% glicerol agar (DG18) and Nash-Snyder agar. The average
of the number of colonies by triplicate was determined and it was expressed as colony
forming units/gram of feed (UFC/g). AIN and some ALP (maize, ground maize, flour of
sorghum, maize flour and gluten) obtained fungal counts over than 104 UFC/g. The AC
samples were not over this value. Each strain was isolated and identified at the species
level. The species belonging to the Aspergillus genera were predominant in all of the
analyzed samples, having aflatoxicogenic species A. flavus/A. parasiticus those of
greater frequency. These strains were evaluated in their ability to produce aflatoxins by
the TLC method. The 100% of isolated strains of AIN, 80% of AC and 70% of ALP
were able to produce aflatoxins at levels that varied from 2 and 66.25 ng/g. The natural
incidence of aflatoxins in all feed samples was determined by high performance liquid
chromatography (HPLC). AIN and some samples of ALP ingredients, mainly those
containing maize, obtained aflatoxins levels over than 20 ppb. The hystopatological and
biochemical studies of the affected animals organs demonstrated the death cause
(aflatoxicosis), and were confirmed by the mycological studies: the fungal counts and
aflatoxins levels were over the allowed ones by national and international regulations in
use. The commercial feed of different qualities are feeds in conditions to be consumed,
but have a potential risk if they are in inadequate storage conditions due to the aflatoxicogenic ability of the studied strains. As far as the ingredients and finished feed
of the production line, those made up of maize did not fulfill the values of fungi and
aflatoxins allowed by the legislation. Although the finished ration adjusts to the required
regulation, probably by the processing, it presents a potential risk since more of 80% of
the species of A. flavus, were able to produce aflatoxins B1 and B2. It is important then
to emphasize the need to a suitable control of the used ingredients in the compound feed
elaboration and the adequate environmental conditions to preserve the pet food of
undesired fungal contamination and the consequent production of their mycotoxinas. / Os alimentos balanceados comerciais constituem um elemento importante na ind?stria
de c?es no Brasil. Sua composi??o inclui misturas de cereais produzidos nas granjas,
tais como sorgo, milho e algumas oleaginosas. Todos os alimentos destinados a c?es
est?o suplementados com gorduras, vitaminas, minerais, antioxidantes e farinhas de
diversas origens incorporados, em alguns casos como pellets. Ao possuir suficientes
nutrientes e condi??es de umidade adequadas s?o suscet?veis a contamina??o por fungos
durante a pr? e p?s-colheita, no armazenamento, na manufatura e no processamento
destes ingredientes. Os fungos filamentosos mais comumente encontrados em gr?os
armazenados incluem as esp?cies dos g?neros Aspergillus, Penicillium e Fusarium,
capazes de produzir deteriora e diferentes micotoxinas. Esp?cies de Aspergillus como
Aspergillus flavus, Aspergillus parasiticus e Aspergillus nomius s?o as mais toxic?genas
podendo produzir aflatoxinas, consideradas como carcin?genos tipo 1A. Os alimentos
destinados a c?es possuem quantidades importantes de cereais e, portanto podem
concentrar quantidades importantes de toxinas. Em c?es e gatos os efeitos das
micotoxinas s?o severos e podem produzir a morte, al?m de levar a perda de nutrientes,
alterar as propriedades organol?pticas e diminuir a vida m?dia do produto no mercado.
Por outro lado a presen?a de esp?cies toxicog?nicas poderia indicar a contamina??o com
v?rias micotoxinas e, esta situa??o representa um risco potencial para a sa?de dos
animais. Baseado no exposto anteriormente, os objetivos deste trabalho foram
caracterizar morfologicamente a micobiota, detectar a incid?ncia natural de micotoxinas
em ingredientes e alimentos balanceados para c?es, isolar microrganismos com
potencialidades toxicog?nicas e estabelecer par?metros para prevenir e/ou controlar as
micotoxicoses em c?es. Um total de 230 amostras (117 alimentos suspeitos de produzir
intoxica??o natural (AIN), 43 de alimentos comerciais (AC) de tr?s qualidades
diferentes, 70 ingredientes da linha de produ??o (ALP) de ingredientes e ra??es
destinadas ? alimenta??o de c?es) foram analisadas. O isolamento de fungos se realizou
pelo m?todo de dissemina??o em superf?cie. Os meios de cultivo utilizados foram ?gar
Diclor?n-Rosa de Bengala Cloramfenicol (DRBC), ?gar Diclor?n Cloramfenicol 18%
Glicerol (DG18) e ?gar Nash-Snyder. Se determinou a m?dia do n?mero de col?nias
por triplicata e se expressou como unidades formadoras de col?nias por grama de
alimento (UFC/g). Os AIN e alguns ALP (milho, milho mo?do, farinha de sorgo, farinha
de milho e gl?ten) apresentaram contagens f?ngicas superiores a 104 UFC/g. As
amostras de AC n?o superaram este valor. Cada cepa foi isolada e identificada a n?vel
de g?nero. As esp?cies pertencentes ao g?nero Aspergillus prevaleceram em todas as
amostras analisadas, sendo as esp?cies aflatoxicog?nicas, A. flavus/A. parasiticus, as de
maior freq??ncia. Estas cepas foram avaliadas em sua habilidade de produzir
aflatoxinas. Dos 100% das cepas isoladas de AIN, 80% de AC e 70% de ALP, foram
capazes de produzir aflatoxinas em n?veis que variaram entre 2 e 66,25 ng/g. Se
determinou a incid?ncia natural de aflatoxinas em todas as amostras de alimentos por
cromatografia l?quida de alta efici?ncia. Os AIN e algumas amostras de ingredientes de
ALP, principalmente aquelas compostas por milho, apresentaram n?veis de aflatoxinas
superiores a 20 ppb. Os estudos histopatol?gicos e bioqu?micos dos ?rg?os dos animais afetados evidenciaram a causa morte (aflatoxicose), assim como tamb?m os estudos
micotoxicol?gicos realizados: a carga f?ngica e os n?veis de aflatoxinas encontrados,
foram superiores aos permitidos pelas regulamenta??es nacionais e internacionais em
vig?ncia. Os alimentos comerciais pertencentes a distintas qualidades s?o alimentos
aptos para o consumo mas, potencialmente perigosos em condi??es de armazenamento
inadequado devido ? capacidade aflatoxicog?ncia das cepas estudadas. Quanto aos
ingredientes e alimentos terminados da linha de produ??o, aqueles compostos por milho
n?o cumpriram com os valores de fungos e aflatoxinas permitidos pela legisla??o.
Embora a ra??o terminada se ajuste ao requerido pela regulamenta??o, provavelmente
pelo processamento recebido, apresenta um risco potencial j? que mais de 80% das
esp?cies de A. flavus foram capazes de produzir aflatoxinas B1 e B2. ? importante ent?o
destacar a necessidade de realizar um controle adequado dos ingredientes utilizados na
elabora??o de alimentos compostos, como tamb?m as condi??es ambientais onde se
armazenam as ra??es destinadas aos c?es, para preserv?- los da indesejada contamina??o
f?ngica e a conseq?ente produ??o de micotoxinas.
| Identifer | oai:union.ndltd.org:IBICT/oai:localhost:tede/809 |
| Date | 27 March 2007 |
| Creators | Campos, Sergio Gaspar de |
| Contributors | Rosa, Carlos Alberto Rocha |
| Publisher | Universidade Federal Rural do Rio de Janeiro, Curso de P?s-Gradua??o em Ci?ncias Veterin?rias, UFRRJ, Brasil, Parasitologia Veterin?ria |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da UFRRJ, instname:Universidade Federal Rural do Rio de Janeiro, instacron:UFRRJ |
| Rights | info:eu-repo/semantics/openAccess |
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