Effect of MINERAL ADSORBENTS
in POULTRY PRODUCTION

D. Karanovic¹, V. Djermanovic², S. Mitrovic², V. Radovi1, D. Okanovic³, S. Filipovic³ y V. Djekic^1
1Department of Animal Husbandry, Faculty of Agronomy, University of Kragujevac, Cacak, Serbia ²Institute of Zootechnic, Faculty of Agriculture, University of Belgrade, Belgrade (Serbia) ³Institute for food technology in Novi Sad (Serbia) ⁴Center of Small Grains, Kragujevac, (Serbia)

MINERAL ADSORBENTS

Mineral adsorbents are increasingly used in
poultry production, especially in the nutrition of various types and categories of
poultry, to control fungal contamination.
Using different mineral adsorbents in
poultry nutrition can prevent the losses due to mycotoxicosis. It can also prevent:

• Appearance of toxic residues in poultry products
• Improve production and
  reproductive ability of birds
• Contribute to improving the quality of poultry
  products

The use of mineral adsorbents in poultry feeds has application
in neutralising the harmful effects of mycotoxins in buildings where poultry is
reared.

Datas introduction

According to official data from global institutions such as the FAO, at least 99 countries in the world, which contain approximately 87% of the world population, have some kind of regulation for the content of mycotoxins in food for humans and/or animals.

Worldwide interest in these problems is reflected in the vast number of scientific and professional papers published on mycotoxins since the discovery of aflatoxin B1 in the early 1960’s.

Given the ubiquitous nature of moulds, as well as the general impossibility to prevent mycotoxin contamination in foods feed materials, this topic is an integral part of modern livestock production.
The increase in irregularity of meteorological conditions associated with global climate change has increased the problems of fungal contamination at harvest and the production of toxins.

Although it is almost impossible to examine and measure the true impact of moulds and mycotoxins, the risks associated with the presence of mycotoxins is well researched and proven.

Mycotoxins

Mycotoxins are toxic secondary metabolites of a large number of saprophytic organisms (moulds), which, proliferate in contaminated food infested with spores, conidia and/or fragments of mycelium.
Fungal toxins entering the body of animals and humans via the gut cause intoxication, generally called mycotoxicosis.

Damage to livestock due to mycotoxicosis may be significant, and is manifested in the form of direct losses due to mortality of animals or, more commonly, caused indirectly due to falling production and reproductive performance (Ožegović, 1983).

A specific problem is the mycotoxin residues found in different quantities in edible organs and animal products, which enter the foodchain and may cause adverse effects in humans.

Mycotoxins properties

In chemical terms, mycotoxins represent a wide range of complex compounds with different functional groups and therefore different properties:

• Mycotoxins do not have sufficiently large molecules, and human and animal organisms do not produce antibodies against them and so remain permanently unprotected from their action
• There is no simple method for their identification

Most frequent mycotoxins in food

Zeolites

Semmens (1983) state that zeolites, as mineral adsorbents, in accordance of their structure, are part of the alumina silicates group (SlO₄ and AlO₄), where the tetrahedral structure (TO₄) is the basic unit.

Zeolite structure

Tetrahedrons may contain various bonds, giving the zeolite structure many channels and cavities.
TThe channel system may be One-dimensional (unconnected parallel channels) Two-dimensional (channels connected in one plane) and Three-dimensional.
The diffusion rate of adsorption and ion exchange are functions of the spatial channels distribution.
Every mineral is characterised by the channel opening size, so zeolites selectively retain or lose molecules depending on their dimensions.

Negative charge

The negative charge of the threedimensional network, which is conditioned with tetrahedral coordination, is characteristic of all the zeolites, with respective isostructural substitution of Sl₄₊ ions with Al₃₊ ions.
The surplus negative charge is compensated for by univalent and/or divalent cations which are located in the channels and cavities.

The presented ions do not enter the zeolite tetrahedron network and, with the ion exchange reaction, they can be replaced by cations of other metals.
The cation exchange capacity of zeolites is a function of silicon substitution with aluminium in the tetrahedron network.
More alkali cations are required to compensate for the negative charge of elementary cells if the degree of substitution is higher.

Clinoptilolite supplementation in feed

Boyer (2000) states that clinoptilolite supplementation in animal feed leds to a significant increase in feed efficiency as well as reducing the potential of intestinal diseases (diarrhoea), and the toxic effects of surplus ammonium ions.

Some researchers explain this as the clinoptilolite preference for large ions, such as NH₄₊, so it serves as a reservoir for ammonia. Some natural zeolites adsorb mycotoxins from feedstuffs and offer some protection from their toxic affects during digestion.

Mixing process

The process of mixing is an important phase in the production of premixes and feeds, in order to attain uniformity in the basic matrix (carrier) distribution of the components so that each consumed amount of feed contains the required amount of nutrients (Filipović et al., 1993), including toxin binders.

Spoilage of animal feed means deviation from the normal quality in terms of changes of organoleptic characteristics, nutritional value and/ or hygiene of food stuffs (Šefer et al., 1997).

Feed contamination with fungi causes poorer productive performance, increased metabolic disorders and diseases, and can eventually cause death. As a result, the presence of moulds in animal feed is an important criterion in evaluation of the quality of an animal feed.

Feed samples

In Serbian conditions, feed samples commonly contain zearalenone, ochratoxin A,
trichothecenes (T-2, DAS) and aflatoxins.
Research by Bočarov-Stančić et al. (2000)
and Jajić et al. (2010) showed that in years with good climatic conditions, between 20
and 25% of cereals were contaminated with mould and mycotoxins. Rajić and Ožegović
(1990) suggested a set of measures for the prevention and control of moulds in corn,
namely:

• The selection of corn resistant to mould
• Seeding early varieties
• Prevention of
  grain breakage
• Artificial grain drying
• Hygienic cleaning of the grain hoppers
• Grain
  aeration
• Tighter control measures for moisture
• Treating grain with propionic acid
  or a mixture of organic acids

Adsorbent in Poultry production

In intensive poultry production adsorbents most often used to neutralise the harmful
effects of mycotoxins achieve this by bonding.
Adsorption is one of the most
important and common methods in preventing mycotoxicosis.
Some of the adsorbents used include:

• Activated charcoal
• Hydrated sodium-aluminosilicates calcium (HSCAS)
• Bentonite
• Clay
  soil
• Various aluminosilicates or zeolites (Adamović et al., 2003; Resanović et al.,
  2004)

Zeolites are classified as safe or GRAS (Generally Regarded As Safe) compounds
as per EU 21 CFR Part 582.2729.

Supplementing zeolites

Supplementing zeolites at a rate of 0.5% in poultry feed under field conditions has
achieved good results in the prevention of mycotoxins.

Further research on the different
categories of poultry showed that zeolites can be used in amounts of 0.2% of the feed to
effectively prevent the harmful effects of mycotoxicosis (Radović et al., 2000), which
confirmed the previous results obtained in vitro.

Studies

The effects of different types and levels of mineral adsorbents (MINAZEL and ‘Min-a-Zel
Plus’ (MZ+)) on production and slaughter characteristics of broilers at 42 days were
studied by Karović (2009), Karović et al. (2010) and Radovic et al. (2010a; 2010c).

During the fattening stage, different zeolites at different levels were used and compared
to a negative control; MINAZEL at 0.5%; MINAZEL PLUS at 0.2% and MINAZEL PLUS at 0.3% inclusion.

Radović et al. (2010^a) examined the
impact of different levels of mineral adsorbents (MINAZEL and MINAZEL’) added to broiler feed on
production.

Similar studies were conducted by Radović et al. (2009; 2010^b) who explored the
influence of the addition of the mineral adsorbents MINAZEL and MINAZEL PLUS to feed on the yield of
broiler chickens separated by gender.

The research was conducted on 400 Cobb 500
broilers, divided into four treatment groups, until they were 42 days of age.

Dietary
treatments included a control (0%), 0.5% MINAZEL, 0.2% MINAZEL PLUS and 0.3% MINAZEL PLUS.

• The highest
  mortality was seen in the control group
• The lowest mortality: in the experimental group with
  the addition of 0.3% ‘ MINAZEL PLUS.

One experimental group received T-2 toxin at a level of 1 mg/kg
body weight directly into the crop.
The other groups received the same treatment, but
with the addition of 0.2% MINAZEL into the feed.

The group that received the MINAZEL achieved the
highest average body weight (899 g) compared to the chicks that did not receive the
mycotoxin adsorbent (805 g).

It was determined that 0.2% MINAZEL gave the best results, showing
the lowest mortality, highest weight and lowest average feed consumption per kg gain.

In a study with 100 broilers divided into four groups of 25 animals, a complete diet
either without zeolite (control) or with the addition of 0.2%, 0.5% and 1% zeolite.

Rajić
et al. (1992) found that:

• The average weight of the experimental groups, compared to the
  control, on the 35th and 40th day of age were significantly higher (P< 0.001).
• FCR,
  relative to the control group, was 3.4% lower for the 0.2% group, 3.66% for the 0.5%
  group and 3.70% for the 0.1% group.

Based on these results, the authors concluded that
the addition of zeolite to feed for chickens had a positive impact on body weight and feed
conversion.

• On
  the 50th day of feeding, the body weight was 1803 g and 1819 g (with 1% or 2% of
  zeolite respectively).
  The body weight of chickens fed the negative control was 1873 g.

• Feed conversion in which the zeolite was added was 2.36 and 2.184, and without zeolite
  it was 2.00.

Lon-Wo et al. (1987) fattened chickens with feed containing 5% of zeolite
for a period of eight weeks.

Application of zeolite in feed to prevent poultry mycotoxicosis has been shown to be
effective (Sinovec et al., 2002; Radović and Bogosavljević-Bosković, 2006) both in
experimental (Resanović et al., 2004), and practical conditions (Palić et al., 1991).

• Adding zeolite in feed contaminated with different mycotoxins reduces pathomorphological
  alterations in target organs (Nedeljković-Trailović et al., 2001; 2004).
• In addition, significant reductions in the presence of residues in edible tissues of broilers
  have been noted (Sinovec et al., 2002).
• But it should be stated that the efficiency of
  zeolite depends on the application and form in which it is used (Radović et al., 2000;
  Resanović et al., 2004).

Conclusions