The combination of different mycotoxins produces a greater negative effect on health and productivity of animals than they do individually, because of their synergistic, additive or antagonistic characteristics. Recent trials were set up to investigate the efficacy of inactivators (based on botanicals, yeast and clay-minerals) on animal performance.
By Koen Schwarzer and Monique Baecke, Nutri-Ad, Belgium
Possible measures taken by the livestock industry to protect animals from the toxic effects of mycotoxins include the use of microbial inactivation, mould inhibition, fermentation, physical separation, thermal inactivation, irradiation, ammonification, ozone degradation and adsorptions.
Unfortunately, most of these methods are costly, time-consuming, and only partially effective. The most promising and practical approach has been the addition of mycotoxic inactivators with multi-functional activity to contaminated feed in order to selectively bind, fixate or transform mycotoxins during the digestive process and to protect or regenerate vital organs, avoiding mycotoxins to become harmful to the animal.
The natural contamination of feed with several mycotoxins at relative low concentrations can disturb the digestibility of nutrients in the animal by reducing feed intake and growth which, subsequently, increases the feed conversion ratio weakening the liver functionalities and causing organ injury and stress.
Declined animal performance
The presence of different mycotoxins at relative low concentrations in broilers diets had affected the nutrient digestibility of the birds and as a consequence the zoo technical performance.
This was demonstrated in a broiler trial at the All-Russian Scientific Research and Technological Institute of Poultry Breeding (GNU-VNITIP), Russia (2008) (Table 1), a completely randomised experimental design with three mycotoxins types (Ochratoxin A at 0.41 ppm, T2-toxin at 0.16 ppm and fumonisin B1 at 12.7 ppm), natural contaminants in feed and two levels of UNIKESRTm(hereafter called inactivator) resp. 0 and 1kg/tonne. The effect on digestibility in broilers receiving diets free of mycotoxins (neg control) or containing mycotoxins (pos control) treated with 1.0 kg/tonne inactivator is shown inFigure 1 and 2. Further analysis demonstrated that a large part of the mycotoxins were available for absorption into the gastro intestinal tract (GIT) (up to 91.1% of T2-toxin, up to 54.4% of fumonisin B1 and up to 52.0% of ochratoxin A).
Mycotoxins hepatic concentrations (Figure 3 and 4) were high, the liver being the basic organ responsible for detoxification. Supplementation of the inactivator to the mycotoxins contaminated feed led to a significant raise of mycotoxins excretion from the gastro-intestinal tract. As a result, the absolute content of toxic agents in the liver decreased by 22-42% (p<0.05-0.02).
A trial (LAMIC, Federal University of Santa Maria, department of preventive veterinarian medication, Brazil) was set up to investigate the efficacy of inactivator (based on botanicals, yeast and clay-minerals) in counteracting the toxic effects of aflatoxins and fumonisins in broilers. A randomised experimental design with two mycotoxins types (aflatoxins and fumonisins) and four levels of the mycotoxin in-activator were used. Three hundred day-old male Cobb broilers were distributed into 5 treatments with 6 replicates of 10 birds. The inactivator was included at 0, 1.5, 2.5 and 5.0 kg/tonne of feed, contaminated with aflatoxins (1.4 mg/kg) and fumonisins (25 mg/kg). The weight loss at 21 days of age was significantly lower in birds fed with the diet containing the mycotoxin inactivator (resp. 5.1%, 7.4% and 7.9%) than in birds receiving the mycotoxin contaminated control diet. Birds receiving treated feed at 0.25% and 0.50% in the contaminated diets showed significant lower liver weight against those receiving the control diet (Figure 5).
Trial with mycotoxin inactivator
An experiment was conducted to investigate the efficacy of the inactivator (based on botanicals, yeast and clay-minerals) in broilers (Cobb) challenged withE.colilipopolysaccharide (LPS) raised from 0 to 21 days of age to counteract the toxic effects of T-2 toxin (T-2). (University of Missouri, Columbia, USA, 2007). A 2 x 2 x 2 factorial arrangement of dietary treatments was used with 5 pens of 7 chicks (first 12 days) or 5 birds (12-21 days) assigned to each of the dietary treatments. Treatments included a basal diet supplemented with two levels of the inactivator (0 or 0.3%), two levels of T-2 (0 or 2.5 ppm) or two levels of LPS (0 or 150 mg/bird). The birds received a first LPS challenge at day 9 and a second at day 19. Creatine phosphokinase (CPK), an indicator for organ injury and stress, showed increased levels in the blood plasma of birds receiving T2-toxin and LPS, whereas these blood plasma levels were reduced in birds receiving the diet addition of the inactivator at 3 kg/tonne (Figure 6).
The diet addition of T-2 decreased (p<0.05) feed intake and body weight gain (BWG) after the first and second challenge measured at 21 days.
There was an additive T-2 + LPS interaction on BWG (P< 0.05). The T-2 diet addition increased (p< 0.05) the numbers of oral lesions, while the addition of the inactivator decreased the severity of them by 39%.
Trial in pigs
A trial with 20 weaned pigs (female) was set up in Spain, Zaragoza, to evaluate the zootechnical performance and health condition when offering diets without mycotoxins and with mycotoxins (596 ppb ofZearalenone, 1.56 ppm Vomitoxin (DON), 1 ppb Aflatoxin B1, 1.8 ppm of Fumonisin B1, 22.2 ppb of T2-toxin and the presence of Ochratoxin) where inactivator had been included at 0 and 1.5 kg/tonne. The pigs’ body weight was reduced in the group receiving contaminated feed with 39.7% against those receiving the control diet. The inclusion of the inactivator in the contaminated diet diminished the negative impact on body weight and feed efficiency significantly.
The alanine amino transferase (ALT) liver enzyme is an indication of hepato-cellular damage.
The presence of mycotoxins in the diet has clearly an impact on the pigs (Figure 7). The diet inclusion of the inactivator in contaminated feed prevented the liver cells from being damaged.
Feeds are obviously contaminated with different types of mycotoxins, which have an impact on nutrient digestion, animal performance and health, even at low concentrations.
A multi-functional approach such as using the inactivator is essential to counteract the negative influence of these so dissimilar noxious molecules and to reduce the interaction among themselves and with other molecules such as lipopolysaccharides.
Not only the discussed experiments, but also many years of practical experience indicate the necessity of specific concepts to neutralise the toxic effect of mycotoxins for preserving animal health and performance in today’s economically challenged environment.
Source: Feed Tech Volume 13. No. 7
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