in chicks fed AFB1 compared with the positive control (P < 0.05). Severe liver damage was observed in chicks fed 2 mg/kg of AFB1 with lesions consistent with aflatoxicosis, including fatty liver and vacuolar degeneration. Serum glucose, albumin, total protein, Ca, P, and alkaline phosphatase concentrations were reduced by AFB1 (P < 0.05). The addition of either SO or MTB ameliorated the negative effects of 1 mg/kg of AFB1 on growth performance and liver damage (P < 0.05). However, supplemental MTB failed to diminish the negative effects of 2 mg/kg of AFB1, whereas SO was more effective compared with MTB at 2 mg/kg of AFB1 (P < 0.05). These data indicate that the HSCAS product effectively ameliorated the negative effect of AFB1 on growth performance and liver damage, whereas the yeast cell wall product was less effective especially at the higher AFB1 concentration.
Key words: adsorbent, aflatoxin, broiler, hydrated sodium calcium aluminosilicate 2010 Poultry Science 89:2147–2156 doi:10.3382/ps.2009-00608
INTRODUCTION Aflatoxins, a class of mycotoxins produced by fungal species of the genus Aspergillus (flavus and parasiticus), are sometimes found in feed ingredients used for poultry rations. Major forms of aflatoxins include B1, B2, G1, and G2, with aflatoxin B1 (AFB1) being the most common and biologically active component (Busby and Wogan, 1981). Economic losses associated with aflatoxin exposure in broilers include poor growth and feed conversion, increased mortality, leg problems, and carcass condemnations. Aflatoxin causes a wide range of metabolic changes in poultry and is associated with liver damage, reduced digestive enzyme activities, and ©2010 Poultry Science Association Inc. Received December 13, 2009. Accepted June 16, 2010. 1 Corresponding author: [email protected]
2 Current address: Ajinomoto Heartland LLC, Chicago, IL 60631. 3 Current address: Dow Agro-Sciences LLC, Indianapolis, IN 46268.
immunosuppression (Edds and Bortell, 1983). Recent studies indicated that aflatoxin affects hepatic gene expression (Yarru et al., 2009) and impairs gut morphology and function (Applegate et al., 2009) With the global shortage of grains and increase in international agricultural trade, mycotoxin contamination has become more of a reality for animal producers worldwide. A survey conducted by Biomin suggested that more than one-third of grains are contaminated with mycotoxin in the Asia-Pacific region (Binder et al., 2007). Hydrated sodium calcium aluminosilicates (HSCAS) have been shown to be effective in preventing aflatoxicosis (Araba and Wyatt, 1991; Scheideler, 1993; Ledoux et al., 1999). The β-carbonyl portion of the aflatoxin molecule binds to the uncoordinated edge site of aluminum ions of the HSCAS, making the aflatoxin molecule unavailable for adsorption (Phillips et al., 1990ab). Modified yeast cell wall has also been used to sequester aflatoxin and its effectiveness has been variable in ruminants (Diaz et al., 2004; Kutz et al., 2009). Yiannikouris et al. (2003, 2004) proposed that
2147 Downloaded from https://academic.oup.com/ps/article-abstract/89/10/2147/1499818 by guest on 06 February 2018
Zhao et al.
Table 1. Analyzed dietary aflatoxin B1
Treatment 1 2 3 4 5 6 7 8 9 10 11
Designed aflatoxin level, mg/kg
Analyzed aflatoxin level, mg/kg
0 1 2 1 1 1 1 2 2 2 2
0 0.955 2.135 0.990 1.175 0.950 0.960 2.290 1.930 2.050 2.255
1Diets were analyzed in triplicate for aflatoxin by HPLC following Gowda et al. (2009).
the glucan portion of the yeast cell wall interacts with the mycotoxin molecule and is the active component. The authors hypothesized that different types of adsorbents would differ in their effectiveness to sequester AFB1 in feed and consequently in reducing aflatoxicosis in chickens. The objective of this study was to determine the efficacy of 2 types of adsorbents, one containing a mixture of HSCAS [SO, Solis, Novus International Inc., St. Charles, MO] and the other a combination of clay and yeast cell wall [MTB, MTB-100, Alltech Inc., Nicholasville, KY] in preventing aflatoxicosis in young broilers.
A common corn-soybean meal basal diet was used and was formulated to meet or exceed the nutritional requirements of growing chicks as recommended by the NRC (1994, Table 2). Each dietary treatment was then made by adding AFB1 and adsorbents in the common basal. Aflatoxin was supplied by Aspergillus parasiticus (NRRL-2999) culture material (815 mg/kg of AFB1, University of Missouri, Columbia). Dietary concentrations of aflatoxin were confirmed by analysis (Gowda et al., 2009). In brief, feed samples were extracted with acetonitrile and water (86:14) and an aliquot of the extract was passed through a puriTox TC-M160 cleanup column (Trilogy Analytical Laboratory Inc., Washington, MO) and suitably diluted with water before analysis using HPLC with cobra cell postcolumn derivatization with fluorescence detection at 365 nm excitation and 440 nm emission. All diets were screened by the methods of Rottinghaus et al. (1992) for the presence of citrinin, T-2 toxin, vomitoxin, zearalenone, fumonisins, and ochratoxin A.
Sample Collection On d 21, birds were weighed by pen and total feed consumption was recorded for each pen. Average feed intake and weight gain were corrected for mortality when calculating feed conversion for each pen. Fifteen Table 2. Basal diet composition and nutrient profile
MATERIALS AND METHODS Birds, Diets, and Aflatoxin Quantification The study was conducted in an environmentally controlled battery room at the Animal Science Research Center, University of Missouri, Columbia. The animal care and use protocol was reviewed and approved by the University of Missouri, Columbia Animal Care and Use Committee. A total of 275 one-day-old-broilers were weighed, wing-banded, and randomly assigned to 11 dietary treatments, with 5 replicate pens per treatment and 5 birds per pen. Chicks were maintained on a 24-h constant-light schedule and were allowed access to feed and water ad libitum. The 11 treatments included 3 diets without any adsorbent containing either 0, 1, or 2 mg/kg of AFB1 plus 8 additional treatments employing 2 dietary levels of AFB1 (1 or 2 mg/kg), 2 different adsorbents (SO and MTB), and 2 different levels of each absorbent (0.1 and 0.2%) in a 2 × 2 × 2 factorial arrangement (Table 1). The adsorbent doses used in this trial are within the commercial recommendation for both SO and MTB. The SO product is a combination of different HSCAS (Solis, Novus International Inc.) and MTB is a commercial product containing modified yeast cell walls based on the Saccharomyces cerevisiae strain 1026 with HSCAS stated as one of the ingredients on the label (MTB-100, Alltech Inc.).
Downloaded from https://academic.oup.com/ps/article-abstract/89/10/2147/1499818 by guest on 06 February 2018
Ingredient (%) Corn Soybean meal Calcium carbonate Dicalcium phosphorus Soybean oil Sodium chloride l-Lysine, 78% HMTBA1 Antioxidant (ethoxyquin) Sodium bicarbonate Cellulose Vitamin-mineral premix2 Silica or adsorbents to 100 Nutrient3 ME, kcal/kg CP, % Ca, % Available P, % Available amino acids Lysine, % Methionine + cystine, % Threonine, %
54.80 36.91 1.14 2.03 3.49 0.27 0.01 0.21 0.01 0.28 0.30 0.35 — 3,070 22.73 1.00 0.50 1.15 0.82 0.77
1HMTBA = 2-hydroxy-4-methylthiobutanoic acid, provides 88% methionine activity; product of Novus International Inc. (St. Charles, MO). 2Vitamin-mineral premix provided (per kg of feed): Mn, 110 mg/kg; Fe, 60 mg/kg; Zn, 110 mg/kg; I, 2 mg/kg; Se, 0.2 mg/kg; vitamin A, 8,800 IU/kg; cholecalciferol, 3,855 ICU/kg; vitamin E, 14 IU/kg; niacin, 55 mg/kg; calcium pantothenate, 17 mg/kg; riboflavin, 6.6 mg/kg; folic acid, 1.4 mg/kg; thiamin mononitrate, 1.1 mg/kg; biotin, 0.2 mg/kg; and cyanocobalamin, 11 μg/kg. 3Calculated value based on NRC (1994).
EFFICACY OF AFLATOXIN ADSORBENTS IN BROILERS
chicks (5 pens per diet, 3 birds/pen) from each treatment were selected randomly, anesthetized with carbon dioxide, bled, and then killed for tissue collection. About 5 mL of blood samples was collected via cardiac puncture using a 5-mL syringe with a needle that was 0.91 mm in diameter and 3.81 cm long for serum chemistry analysis. The liver weight of each bird was recorded and liver tissue samples from each of the 15 birds from each treatment were fixed in 10% neutralbuffered formalin and saved for histopathologic evaluation. Mean average of the 3 birds within a pen was used for statistical analyses.
Blood sat at room temperature at least 1 h before being centrifuged at 1,400 × g at 8°C for 30 min (Sorvall, RC 3 B plus) and serum was separated and preserved at −20°C until submitted for biochemical analysis. Serum samples were analyzed for urea N, Na, K, Cl, Ca, P, total protein (TP), albumin, globulin, uric acid, gamma glutamyltransferase, aspartate aminotransferase, and creatinine phosphokinase (CPK) using an autoanalyzer (Kodak Ektachem Analyzer, Eastman Kodak Co., Rochester, NY).
Table 3. Efficacy of adsorbents to ameliorate the toxin effects of aflatoxin on performance and mortality in broiler chicks
Treatment 1 2 3 4 5 6 7 8 9 10 11 SEM P-value Main effect means AFB,3 mg/kg 1 2 Adsorbents SO4 MTB5 Adsorbent level, % 0.1 0.2 2-way means AFB 1 mg/kg + MTB (0.1 + 0.2%) AFB 1 mg/kg + SO (0.1 + 0.2%) AFB 2 mg/kg + MTB (0.1 + 0.2%) AFB 2 mg/kg + SO (0.1 + 0.2%) AFB 1 mg/kg + 0.1% (MTB + SO) AFB 1 mg/kg + 0.2% (MTB + SO) AFB 2 mg/kg + 0.1% (MTB + SO) AFB 2 mg/kg + 0.2% (MTB + SO) AFB (1 + 2 mg/kg) + MTB at 0.1% AFB (1 + 2 mg/kg) + MTB at 0.2% AFB (1 + 2 mg/kg) + SO at 0.1% AFB (1 + 2 mg/kg) + SO at 0.2% Source A (aflatoxin) B (adsorbent) L (level) AB AL BL ABL
Aflatoxin, mg/kg 0 1 2 1 1 1 1 2 2 2 2
Adsorbent level, %
Feed intake,1 g
0 0 0 SO SO MTB MTB SO SO MTB MTB
0 0 0 0.1 0.2 0.1 0.2 0.1 0.2 0.1 0.2
1,046a 919b 753d 973ab 993ab 962ab 933b 810cd 945ab 703d 739d 38
METABOLISM AND NUTRITION Comparison of hydrated sodium calcium aluminosilicate and yeast cell wall on counteracting aflatoxicosis in broiler chicks J. Zhao,1 R. B. Shirley,2 J. D. Dibner, F. Uraizee,3 M. Officer, M. Kitchell, M. Vazquez-Anon, and C. D. Knight Novus International Inc., St. Charles, MO 63304 ABSTRACT The objective of this research was to determine the efficacy of 2 types of adsorbents [hydrated sodium calcium aluminosilicates (HSCAS) vs. a combination of clay and yeast cell wall] in preventing aflatoxicosis in broilers. A total of 275 one-day-old birds were randomly divided into 11 treatments, with 5 replicate pens per treatment and 5 chicks per pen. The 11 treatments included 3 diets without any adsorbent containing either 0, 1, or 2 mg/kg of aflatoxin B1 (AFB1) plus 8 additional treatments employing 2 dietary levels of AFB1 (1 or 2 mg/kg), 2 different adsorbents [Solis (SO) and MTB-100 (MTB)], and 2 different levels of each absorbent (0.1 and 0.2%) in a 2 × 2 × 2 factorial arrangement. Solis is a mixture of different HSCAS and MTB is a combination of clay and yeast cell wall. Feed and water were provided ad libitum throughout the 21-d study period. Body weight gain and feed intake were depressed and relative liver weight was increased