Interactions between plant-derived oestrogenic substances and the mycoestrogen zearalenone in a bioassay with MCF-7 cells.

Human and animal diets may contain several non-steroidal oestrogenic compounds which originate either from plants (phytoestrogens) or from fungi that infect plants (mycoestrogens such as zearalenone (ZEN)). Phytoestrogens may compete with ZEN in binding to the oestrogen receptor ß and thereby may counteract the oestrogenic activity of ZEN. Using a modified version of the E-screen assay, plant-derived oestrogenic substances were tested for their proliferative or anti-proliferative effect on oestrogen-dependent MCF-7 cells. The samples were additionally tested for their ability to influence the oestrogenic activity of ZEN (1 µM). Among the individual substances tested, 8-prenylnaringenin had the strongest effect, as cell proliferation was increased by 78% at the lowest concentration (0.23 µM), and by 167% at the highest concentration (29.4 µM). Coumestrol (5.83 µM) increased cell proliferation by 39%, and genistein (370 µM) by 61%, respectively. Xanthohumol and enterolactone did not stimulate cell proliferation significantly. In the co-incubation experiments with ZEN, none of the single substances was able to decrease the oestrogenic activity of ZEN. Only for 8-prenylnaringenin (14.7 and 29.4 µM) was a trend towards an increase in the ZEN-induced cell proliferation up to 72% observed. In conclusion, with the exception of 8-prenylnaringenin, no substantial interaction between phytoestrogens and the mycotoxin ZEN could be detected using a bioassays with MCF-7 cells.

Enzymatic hydrolysis of fumonisins in the gastrointestinal tract of broiler chickens.

Fumonisins (FB) are among the most frequently detected mycotoxins in feedstuffs and finished feed, and recent data suggest that the functions of the gastrointestinal tract (GIT) in poultry species might be compromised at doses ranging from 10 to 20 mg/kg, close to field incidences and below the US and EU guidelines. Strategies are therefore necessary to reduce the exposure of poultry to FB. In the present study, we assessed the efficacy of fumonisin esterase FumD (EC 3.1.1.87, commercial name FUMzyme®) to cleave the tricarballylic acid side chains of FB, leading to the formation of non-toxic hydrolyzed fumonisins in the GIT of broiler chickens. Broiler chickens were fed for 14 d (7 to 21 d of age) 3 different diets (6 birds/cage, 6 cages/diet), i) control feed (negative control group), ii) feed contaminated with 10 mg FB/kg (FB group), and iii) feed contaminated with 10 mg FB/kg and supplemented with 100 units of FUMzyme®/kg (FB+FUMzyme® group). To determine the degree of reduction of FB in the GIT, 2 characteristics were analyzed. First, the sphinganine-to-sphingosine ratio in the serum and liver was determined as a biomarker of effect for exposure to FB. Second, the concentration of fumonisin B1 and its hydrolyzed forms was evaluated in the gizzard, the proximal and distal parts of the small intestine, and the excreta. Significantly reduced sphinganine-to-sphingosine ratios in the serum and liver of the FB+FUMzyme® group (serum: 0.15 ± 0.01; liver: 0.17 ± 0.01) compared to the FB group (serum: 0.20 ± 0.01; liver: 0.29 ± 0.03) proved that supplementation of broiler feed with FUMzyme® was effective in partially counteracting the toxic effect of dietary FB. Likewise, FB concentrations in digesta and excreta were significantly reduced in the FB+FUMzyme® group compared to the FB group (P < 0.05; up to 75%). FUMzyme® furthermore partially counteracted FB-induced up-regulation of cytokine gene expression (IL-8 and IL-10) in the jejunum. The FB group showed significantly higher gene expression of IL-8 and IL-10 compared to the negative control group (IL-8: fold change = 2.9 ± 1.1, P < 0.05; IL-10: fold change = 3.6 ± 1.4, P < 0.05), whereas IL-8 and IL-10 mRNA levels were not significantly different in the FB+FUMzyme®® group compared to the other 2 groups. In conclusion, FUMzyme® is suitable to detoxify FB in chickens and maintain gut functions.

In vitro inhibition of Eimeria tenella sporozoite invasion into host cells by probiotics.

The aim was to study the effects of probiotics isolated from the intestinal tract of livestock animals on Eimeria tenella invasion into Madin-Darby bovine kidney (MDBK) cells in vitro. E. tenella sporozoites were purified and labeled with 5(6)-carboxyfluorescein diacetate N-succinimidyl ester before seeding on cell cultures, and invasion was evaluated by fluorescence microscopy. Two protocols (A and B) were used. In protocol A, Enterococcus faecium # 589 or Lactobacillus salivarius subsp. salivarius # 505 were added together with sporozoites to MDBK cell cultures and invasion was evaluated after incubation for approximately 20h. Viable, dead, or spent culture supernatants of probiotics were tested. In protocol B, viable probiotics were incubated with MDBK cells for one hour before sporozoites were added and invasion was evaluated after two more hours of incubation. Parasite invasion of viable, dead, or spent culture supernatant of E. faecium # 589 was assessed. Using protocol A, it was shown that parasite invasion was inhibited by viable (80%) or dead (75%) E. faecium # 589. While inhibition by viable L. salivarius subsp. salivarius # 505 was not valid at the highest concentration and not significant at the other test concentrations, dead cells inhibited parasite invasion up to 45%. Spent culture supernatants of both probiotics had no influence on parasite invasion. Using protocol B, it was shown that viable Bifidobacterium animalis subsp. animalis # 503, E. faecium # 497, E. faecium # 589, L. reuteri # 514, L. salivarius subsp. salivarius # 505, and Bacillus subtilis # 588 inhibited parasite invasion into MDBK cells up to 80%. Anticoccidial activity was strain-specific for E. faecium strains, and the strongest effect was shown by E. faecium # 589. Anticoccidial effects of some of the tested probiotics have already been shown in vivo, which makes them candidates to prevent coccidiosis. These findings have now been confirmed in vitro. The used parasite invasion assay is a fast and inexpensive tool to screen probiotics for prevention of coccidiosis.

Probiotic form effects on growth performance, digestive function, and immune related biomarkers in broilers.

The aim of this work was to assess the effect of dietary viable or heat inactivated probiotic forms (PF) combined or not with avilamycin (AV) used as a growth promoter, on broiler growth performance, nutrient digestibility, digestive enzyme activities, and expression of immune response related genes.Depending on the type of PF (i.e., no addition, viable, inactivated) and AV addition (no/yes), 450 one-day-old Cobb male broilers were allocated in the following 6 treatments according to a 3 × 2 factorial arrangement with 5 replicates of 15 broilers each for 6 wk: CoN: diet without any addition; CoN+A: combination of CoN with AV; ViP: viable PF - no AV; ViP+A: combination of ViP with AV; InP: inactivated PF - no AV; InP+A: combination of InP with AV.There were no interactions (P > 0.05) for overall performance parameters. In contrast, PF or AV addition improved BW gain (PPF= 0.015; PAV < 0.001), FCR (PPF < 0.001; PAV < 0.001) and production efficiency factor (PPF= 0.001; PAV= 0.001).Significant (PPF×AV ≤ 0.05) interaction effects regarding ileal digestibility (IAD) of DM and total tract apparent digestibility (TTAD) of DM and ether extracts (EE) were noted. In addition, PF affected IAD and TTAD of CP (PPF < 0.001, PPF= 0.004, respectively). Inactivated PF increased (PPR= 0.024) lipase activity in jejunal digesta.At spleen level InP and ViP+A down-regulated TGF-ß4 (PPF × AV = 0.035) compared to CoN and ViP, whereas ViP+A up-regulated iNOS (PPF × AV = 0.022). An anti-inflammatory effect of live and inactive PF and/or AV addition at cecal tonsils was shown by iNOS down-regulation (PPF × AV= 0.015) compared to CoN. Furthermore, AV down-regulated IFN-γ (PAV= 0.002).In conclusion, viable probiotic, as well as inactivated probiotic alone or in combination with avilamycin, improved nutrient digestibility. All dietary additives affected growth performance positively and induced an anti-inflammatory response at cecal level.

Prevalence and effects of mycotoxins on poultry health and performance, and recent development in mycotoxin counteracting strategies.

Extensive research over the last couple of decades has made it obvious that mycotoxins are commonly prevalent in majority of feed ingredients. A worldwide mycotoxin survey in 2013 revealed 81% of around 3,000 grain and feed samples analyzed had at least 1 mycotoxin, which was higher than the 10-year average (from 2004 to 2013) of 76% in a total of 25,944 samples. The considerable increase in the number of positive samples in 2013 may be due to the improvements in detection methods and their sensitivity. The recently developed liquid chromatography coupled to (tandem) mass spectrometry allows the inclusion of a high number of analytes and is the most selective, sensitive, and accurate of all the mycotoxin analytical methods. Mycotoxins can affect the animals either individually or additively in the presence of more than 1 mycotoxin, and may affect various organs such as gastrointestinal tract, liver, and immune system, essentially resulting in reduced productivity of the birds and mortality in extreme cases. While the use of mycotoxin binding agents has been a commonly used counteracting strategy, considering the great diversity in the chemical structures of mycotoxins, it is very obvious that there is no single method that can be used to deactivate mycotoxins in feed. Therefore, different strategies have to be combined in order to specifically target individual mycotoxins without impacting the quality of feed. Enzymatic or microbial detoxification, referred to as "biotransformation" or "biodetoxification," utilizes microorganisms or purified enzymes thereof to catabolize the entire mycotoxin or transform or cleave it to less or non-toxic compounds. However, the awareness on the prevalence of mycotoxins, available modern techniques to analyze them, the effects of mycotoxicoses, and the recent developments in the ways to safely eliminate the mycotoxins from the feed are very minimal among the producers. This symposium review paper comprehensively discusses the above mentioned aspects.

Impact of a probiotic, inulin, or their combination on the piglets' microbiota at different intestinal locations.

Natural feed additives are used to maintain health and to promote performance of pigs without antibiotics. Effects of a probiotic, inulin, and their combination (synbiotic), on the microbial diversity and composition at different intestinal locations were analysed using denaturing gradient gel electrophoresis (DGGE), real-time PCR, and 16S rRNA gene pyrosequencing. Bacterial diversity assessed by DGGE and/or pyrosequencing was increased by inulin in all three gut locations and by the synbiotic in the caecum and colon. In contrast, the probiotic did only affect the microbiota diversity in the ileum. Shifts in the DGGE microbiota profiles of the caecum and colon were detected for the pro- and synbiotic fed animals, whereas inulin profiles were more similar to the ones of the control. 16S rRNA gene pyrosequencing revealed that all three additives could reduce Escherichia species in each gut location, indicating a potential beneficial effect on the gut microbiota. An increase of relative abundance of Clostridiaceae in the large intestine was found in the inulin group and of Enterococcaceae in the ileum of probiotic fed pigs. Furthermore, real-time PCR results showed that the probiotic and synbiotic increased bifidobacterial numbers in the ileum, which was supported by sequencing results. The probiotic and inulin, to different extents, changed the diversity, relative abundance of phylotypes, and community profiles of the porcine microbiota. However, alterations of the bacterial community were not uniformly between gut locations, demonstrating that functionality of feed additives is site specific. Therefore, gut sampling from various locations is crucial when investigations aim to identify the composition of a healthy gut microbiota after its manipulation through feed additives.

Mycotoxin-contaminated diets and deactivating compound in laying hens: 1. effects on performance characteristics and relative organ weight.

The current experiment was conducted to determine the effect of mycotoxin-contaminated diets with aflatoxin (AFLA) and deoxynivalenol (DON) and dietary inclusion of deactivation compound on layer hen performance during a 10-wk trial. The experimental design consisted of a 4 × 2 factorial with 4 toxin levels: control, low (0.5 mg/kg AFLA + 1.0 mg/kg DON), medium (1.5 mg/kg AFLA + 1.5 mg/kg DON), and high (2.0 mg/kg AFLA + 2.0 mg/kg DON) with or without the inclusion of deactivation compound. Three hundred eighty-four 25-wk-old laying hens were randomly assigned to 1 of the 8 treatment groups. Birds were fed contaminated diets for a 6-wk phase of toxin administration followed by a 4-wk recovery phase, when all birds were fed mycotoxin-free diets. Twelve hens from each treatment were subjected to necropsy following each phase. Relative liver and kidney weights were increased (P < 0.05) at the medium and high toxin levels following the toxin phase, but the deactivation compound reduced (P < 0.05) relative liver and kidney weights following the recovery period. The high toxin level decreased (P < 0.05) feed consumption and egg production during the toxin period, whereas the deactivation compound increased (P < 0.05) egg production during the first 2 wk of the toxin phase. Egg weights were reduced (P < 0.05) in hens fed medium and high levels of toxin. An interaction existed between toxin level and deactivation compound inclusion with regard to feed conversion (g of feed/g of egg). High inclusion level of toxins increased feed conversion compared with the control diet, whereas deactivation compound inclusion reduced feed conversion to a level comparable with the control. These data indicate that deactivation compound can reduce or eliminate adverse effects of mycotoxicoses in peak-performing laying hens.

Effects of mycotoxin-contaminated diets and deactivating compound in laying hens: 2. effects on white shell egg quality and characteristics.

An experiment was conducted to determine the effect of dietary inclusion of Mycofix Select (Biomin GmbH, Herzogenburg, Austria) on discrete egg parameters and quality characteristics of hens fed mycotoxin-contaminated diets (aflatoxin; AFLA) and deoxynivalenol (DON)) during a 10-wk trial. A 4 × 2 factorial design was used with 4 contamination levels: control, low (0.5 mg/kg of AFLA + 1.0 mg/kg of DON), medium (1.5 mg/kg of AFLA + 1.5 mg/kg of DON), and high (2.0 mg/kg of AFLA + 2.0 mg/kg of DON) with or without the inclusion of mycotoxin deactivating compound. Three hundred and eighty-four 25-wk-old laying hens were housed 3 per cage. Birds were fed contaminated diets for a 6-wk phase of toxin administration followed by a 4-wk recovery phase, when all birds were fed mycotoxin-free diets. Parameters evaluated included egg weight, Haugh unit value, specific gravity, eggshell thickness, egg shape index, and relative albumen and yolk weights. Albumen height and Haugh unit value were depressed (P < 0.05) at the high mycotoxin level 2 wk postinclusion. Egg weight was significantly reduced (P < 0.05) with the high toxins level by the third week of toxin administration and remained throughout the study during toxin administration. Egg shape index indicated a variation (P < 0.05) in shape with all toxin levels compared with the control. Relative yolk weight was decreased (P < 0.05) by the high toxin level. An interaction existed between the deactivating compound inclusion and toxins level with regard to specific gravity. Following the toxin phase, the deactivating compound inclusion increased (P < 0.05) egg specific gravity in the control and low toxin groups whereas a decrease (P < 0.05) was observed at the high toxin level. These data indicate that mycotoxins present in feed can reduce egg quality, size, yolk weight, and alter egg shape and that inclusion of a mycotoxin deactivating compound can ameliorate some of the negative effects of mycotoxin consumption.

Evaluating the efficacy of an avian-specific probiotic to reduce the colonization of Campylobacter jejuni in broiler chickens.

Campylobacteriosis is the most frequent zoonotic disease in humans worldwide, and the contaminated poultry meat by Campylobacter jejuni can be considered one of the important sources of enteric infections in humans. The use of probiotics, which can help to improve the natural defense of animals against pathogenic bacteria, is an alternative and effective approach to antibiotic administration for livestock to reduce bacterial contamination. In vitro experiments showed that Enterococcus faecium, Pediococcus acidilactici, Lactobacillus salivarius, and Lactobacillus reuteri isolated from healthy chicken gut inhibited the growth of C. jejuni. To demonstrate this effect in vivo, 1-d-old broiler chicks received 2 mg/bird per day of a multispecies probiotic product via the drinking water. Controls received no probiotic treatment, and all chicks were infected with C. jejuni orally. Results showed that the cecal colonization by C. jejuni was significantly reduced by probiotic treatment at both 8 and 15 d postchallenge. To confirm this effect, in a second in vivo experiment, 1-d-old broiler chicks received the same dose of the same probiotic via the drinking water and controls received no probiotic, and all chicks were infected with C. jejuni orally. Similarly, probiotic treatment reduced (P=0.001) cecal colonization by C. jejuni at both 8 and 15 d postchallenge. The results of our in vivo experiments conclude that probiotic administration reduced the colonization of C. jejuni in broiler chickens.

Evaluation of probiotic administration on the immune response of coccidiosis-vaccinated broilers.

Probiotics are nonpathogenic bacteria that can promote bird health by reducing pathogen colonization. Researchers have previously demonstrated that the avian immune response can be modulated with probiotics, which may provide a mechanism for the reported reductions in pathogens. We examined phagocyte oxidative burst and cell proliferation of vaccinated broilers administered probiotics. We hypothesized that the combination of probiotic bacteria and a vaccine would affect immune function. Two studies were conducted to evaluate this interaction in broilers. Treatments consisted of a negative control, probiotic, vaccine, or a probiotic + vaccine. Peripheral blood was collected on d 7, 14, and 21 of age. Heterophils and monocytes were evaluated for oxidative burst and lymphocytes were assayed for proliferation. In study 1, heterophil oxidative burst was higher (P ≤ 0.05) in each treatment that received probiotic on d 14 when compared with the negative control. On d 21, an enhanced (P ≤ 0.05) heterophil oxidative burst was observed in the probiotic treatment when compared with the other treatments. On d 14, monocyte oxidative burst was greater (P ≤ 0.05) in the probiotic + vaccine treatment when compared with all other treatments. An increase (P ≤ 0.05) in lymphocyte proliferation was observed among all treatments on d 7 when compared with the negative control. Both vaccine treatments had significant lymphocyte proliferation on d 14 when compared with the negative control. In study 2, the probiotic treatment was associated with greater levels in heterophil oxidative burst on d 7 when compared with all other treatments. On d 21, an increase (P ≤ 0.05) in heterophil oxidative burst was seen in the vaccine treatment when compared with the negative control. On d 7, increased (P ≤ 0.05) monocyte oxidative burst was observed in the vaccine treatment when compared with the negative control. No significant differences were observed in lymphocyte proliferation in any of the treatment groups. These data suggest that probiotics can modulate the immune response and may play a role in vaccination.

Identification and antimicrobial susceptibility of porcine bacteria that inhibit the growth of Brachyspira hyodysenteriae in vitro.

AIMS: To identify bacilli, lactic acid bacteria and bifidobacteria that inhibit the growth of Brachyspira hyodysenteriae. METHODS AND RESULTS: A total of 80 isolates were obtained from various porcine intestinal compartments using selective conditions and grouped into 15 similarity clusters based on whole-cell protein profiles. Random amplified polymorphic DNA PCR patterns identified 24 genotypes. 16S rDNA sequencing assigned all genotypes, except eight aerobes, to established species (Bacillus subtilis, Enterococcus faecium, Lactobacillus salivarius, Lactobacillus mucosae, Lactobacillus reuteri, Lactobacillus amylovorus, Bifidobacterium thermophilum). According to their minimum inhibitory concentrations, four strains (Ent. faecium, Lact. reuteri, Lact. amylovorus, Bif. thermophilum) were susceptible to all clinically relevant antibiotics. Two lactobacilli showing multiresistance harboured the erm(B) determinant. A cross-section of eight representative strains was examined for growth suppression of two strains of Brach. hyodysenteriae, the aetiological agent of swine dysentery, and compared with intestinal strains derived from other animal sources. The Brachyspira strains were inhibited by strains of Lact. salivarius, Bif. thermophilum, Ent. faecium and B. subtilis. CONCLUSIONS: Three porcine strains of Ent. faecium, Bif. thermophilum and B. subtilis were found to be suitable as probiotic candidates because of their well-established identity, antibiotic susceptibility and antagonistic activity. SIGNIFICANCE AND IMPACT OF THE STUDY: For the first time, antagonistic activity of well-characterized porcine strains against Brach. hyodysenteriae is presented. These findings suggest that certain intestinal strains might have a potential as probiotic feed additives for prevention of swine dysentery.

Net effect of an acute phase response--partial alleviation with probiotic supplementation.

The acute phase response (APR) is characterized by inflammation, fever, and altered organ metabolism resulting in muscle catabolism and anorexia. Lipopolysaccharide (LPS)-induced APR may reflect depressed growth and appetite loss. Therefore, a 1-wk growth experiment was conducted to examine whether dietary supplementation of a multispecies probiotic (PoultryStar) would alleviate growth suppression and anorexia caused by LPS-induced APR. The experiment was designed with 4 treatments (n = 8 cages/treatment; 6 birds/cage) starting at 14 d of age. Before (0 to 14 d of age) and for the experiment (14 to 21 d of age), male broiler chicks were fed diets devoid of probiotic or were supplemented with 1.7 x 10(8) cfu/kg of probiotic. At 14 d of age, birds fed the diet devoid of probiotic were further divided into 3 treatments: an unchallenged positive control, LPS-challenged negative control (LPS-NC), and a treatment that was pair-fed to LPS-NC. The probiotic-fed birds were also then challenged with LPS. The LPS (Escherichia coli 055:B5) was injected intraperitoneally 4 times at 48-h intervals at 1 mg/kg of BW. The LPS challenge dramatically depressed BW gain from 14 to 21 d of age by 22% (P < 0.001). However, 41% of growth depression was attributable to factors other than feed intake reduction when compared with the pair-fed treatment. Probiotic supplementation recovered 17% of depressed growth (vs. LPS-NC; P = 0.068), but this improved growth was not due to improvements in feed intake (P = 0.47). However, recovery of feed intake of the probiotic + LPS birds occurred 48-h earlier than the LPS-NC birds. Growth depression induced by LPS administration resulted in an overall relative feed intake (vs. positive control) of 0.83 and also decreased net energy and protein accretion. Probiotic supplementation did not alleviate the reduction in net energy or protein accretion induced by LPS. In conclusion, APR (induced by LPS administration) diverted a large portion of consumed nutrients from tissue accretion. Probiotic supplementation lessened the anorexic effects of LPS resulting in a trend toward BW gain improvement versus the LPS-NC.

Effects of probiotic inclusion levels in broiler nutrition on growth performance, nutrient digestibility, plasma immunoglobulins, and cecal microflora composition.

The aim of this work was to investigate the effect of inclusion levels of a 5-bacterial species probiotic in broiler nutrition. Five hundred twenty-five 1-d-old male Cobb broilers were allocated in 5 experimental treatments for 6 wk. The experimental treatments received a corn-soybean coccidiostat-free basal diet and depending on the addition were labeled as follows: no addition (C), 10(8) cfu probiotic/kg of diet (P1), 10(9) cfu probiotic/kg of diet (P2), 10(10) cfu probiotic/kg of diet (P3), and 2.5 mg of avilamycin/kg of diet (A). Each treatment had 3 replicates of 35 broilers each. Treatment effects on broiler growth performance and biomarkers such as ileal and total tract nutrient digestibility, plasma Ig concentration, and cecal microflora composition were determined. Differences among treatments were considered significant when P < or = 0.05. Overall BW gain was significantly higher in treatment P1 (2,293 g) compared with P2 (2,163 g), C (2,165 g), and P3 (2,167 g), with A (2,230 g) being intermediate and not different from P1. Overall feed conversion ratio values were similar and significantly better for P1 (1.80) and A (1.80) compared with P2 (1.87), C (1.89), and P3 (1.92). Ileal apparent digestibility coefficients (ADC) of CP and ether extract were higher in A. Generally, treatments A and P1 showed an improved total tract ADC for DM, organic matter, ash, ether extract, and AME(n) values. The total tract ADC of CP was higher in P1, C, and P2. There were no differences between treatments regarding plasma Ig in 14- and 42-d-old broilers. Treatments P2 and P3 were effective at beneficially modulating cecal microflora composition. In particular, the lower cecal coliform concentration (log cfu/g of wet digesta) was seen in P2 (6.12) and P3 (4.90) in 14- and 42-d-old broilers, respectively, whereas at 42 d, P3 and P2 had the highest Bifidobacterium (8.31; 8.08) and Lactobacillus concentrations (8.20; 7.86), respectively. It is concluded that probiotic inclusion level had a significant effect on broiler growth responses, nutrient ADC, AME(n), and cecal microflora composition.

Effect of aflatoxin culture on intestinal function and nutrient loss in laying hens.

The negative effects of aflatoxins (AFLA) on hepatic necrosis and total tract digestibility of energy, N, and amino acids have been well documented. However, the question remains if this is an effect on nutrient metabolizability alone or an effect on the intestine, or both, resulting in increased endogenous nutrient loss or reduced nutrient retention, or both. Therefore, a 2-wk feeding study with a crude AFLA culture was conducted with laying hens to measure endogenous losses and digestive functionality of the intestine. Hy-Line W36 hens were fed 1 of 4 experimental diets containing a crude AFLA culture from 20 to 22 wk of age. Diets were analyzed to contain 0, 0.6, 1.2, or 2.5 mg/kg of AFLA B(1). Dietary AFLA concentration had no effect on BW, egg production, or feed intake. Intestinal crypt depth (but not villus length) increased linearly with increasing AFLA concentration. Similarly, specific activity of the intestinal disaccharidase, maltase, increased quadratically by feeding up to 1.2 mg/kg of AFLA and declined at 2.5 mg/kg of AFLA (P 0.05), sialic acid excretion increased quadradically such that it was increased 12% when 0.6 and 1.2 mg/kg of AFLA was fed versus the control (P

Evaluation of the efficacy of a probiotic containing Lactobacillus, Bifidobacterium, Enterococcus, and Pediococcus strains in promoting broiler performance and modulating cecal microflora composition and metabolic activities.

The aim of this work was to investigate the efficacy of a new multibacterial species probiotic in broiler nutrition. The probiotic contained 2 Lactobacillus strains, 1 Bifidobacterium strain, 1 Enterococcus strain, and 1 Pediococcus strain. Four hundred 1-d-old male Cobb broilers were allocated in 4 experimental treatments for 6 wk. The experimental treatments received a corn-soybean basal diet and were as follows: "control," with no other additions; "probiotic in feed and water," (PFW) with probiotic administered at 1 g/kg of feed for the whole period and in water on scheduled intervals during the first 4 wk; "probiotic in feed," (PF) with probiotic in feed as in PFW; and "antibiotic," (AB) with addition of avilamycin at 2.5 mg/kg of feed. Salinomycin Na was used as a coccidiostat. Each treatment had 5 replicates of 20 broilers. Treatment effects on parameters of broiler performance and cecal microbial ecology were determined. Broiler BW, feed intake, and feed conversion ratio were determined on a weekly and overall basis. Cecal microflora composition, concentration of volatile fatty acids, and activities of 5 bacterial glycolytic enzymes (alpha-galactosidase, beta-galactosidase, alpha-glucosidase, beta-glucosidase, and beta-glucuronidase) were determined at the end of the experiment. Overall, treatment PFW displayed a growth-promoting effect that did not differ from AB. Overall, feed conversion ratio in treatment AB was significantly better (P < or = 0.01) than the control treatment, whereas treatments PFW and PF were intermediate and not different from AB. Concentrations of bacteria belonging to Bifidobacterium spp., Lactobacillus spp., and gram-positive cocci were significantly (P < or = 0.05) higher in treatments PFW and PF compared with the control and AB treatments. Treatments PFW and PF had significantly higher specific activities of alpha-galactosidase and beta-galactosidase compared with the control and AB treatments. In conclusion, probiotic treatment PFW displayed a growth-promoting effect that was comparable to avilamycin treatment. In addition, treatments PFW and PF modulated the composition and, to an extent, the activities of the cecal microflora, resulting in a significant probiotic effect.

Investigation of various adsorbents for their ability to bind aflatoxin B1.

The contamination of animal feed with mycotoxins represents a worldwide problem for the animal industry. The most applied method for protecting animals against aflatoxicosis is the utilization of clay minerals. In the course of a research project adsorption experiments were performed in buffer solutions in order to evaluate the ability to bind Aflatoxin B1 (AfB1) at various pH-values. In order to investigate the strength of binding, the chemisorption index was calculated. Isothermal analysis was used to determine the values for the maximum adsorption capacity. Adsorption experiments in simulated gastrointestinal fluid and real gastric juice were carried out. Furthermore binding capability of the materials regarding selected vitamins was examined. Special attention was paid to the formation of AfB2a during experimental conditions. Based on the obtainedin vitro results, highly promising sorbent materials were ranked for furtherin vivo studies. Some adsorbing bentonites were also analysed mineralogically, but the results did not indicate which smectite property influences the adsorption process for AfB1.

Use of Trichosporon mycotoxinivorans to suppress the effects of ochratoxicosis on the immune system of broiler chicks.

(1) The objective of this study was to determine whether the dietary inclusion of Trichosporon mycotoxinivorans (TRM) could suppress the detrimental effects of ochratoxin A (OTA) on the immune system of broiler chicks. (2) Six experimental treatments were tested in 300 1-d-old broiler chicks. Treatments included addition to a standard broiler ration of neither OTA nor TRM (Diet 1), OTA alone (500 microg/kg), OTA plus TRM at three inclusion rates (10(4) CFU/g of feed, 10(5) CFU/g, 10(6) CFU/g) and TRM alone at 10(5) CFU/g of feed. The ration was fed to chicks for 42 d. (3) Blood samples were collected at d 10, 20, 30 and 40 and macrophages and heterophils were isolated. The following variables were determined in macrophages and heterophils activated by phorbol myristate acetate (65 microM): cell viability, total cell-associated urokinase-plasminogen activator (u-PA), membrane-bound u-PA, free u-PA binding sites and superoxide production. (4) There was a decrease in the viability of macrophages and heterophils from chicks receiving OTA-contaminated feed compared to the viability of cells from control birds at d 40. Dietary TRM completely blocked the effect of OTA on cell viability; all three inclusion rates were equally effective. There was a decrease in total cell-associated and membrane-bound u-PA in macrophages and heterophils of chicks receiving OTA-contaminated feed compared to the corresponding values in control birds for heterophils at d 30 and 40 and for the macrophages at d 40. (5) Similarly, dietary TRM abolished the effect of OTA on total cell-associated and membrane-bound u-PA activity. All three inclusion rates of yeast were equally effective. Heterophils, but not macrophages, isolated from chicks receiving OTA-contaminated diet produced less superoxide anion compared to all other diet groups at d 30 and 40. (6) The immune system is a primary target of OTA toxicity in broilers: several functional properties of macrophages and heterophils were depressed in chicks fed OTA-contaminated feed. There was a delay of 30d before the immunosuppressive effect became apparent. The dietary inclusion of TRM completely blocked the detrimental effects of OTA on several immune properties in broilers.

Toxicity of ochratoxin A in aBrevibacillus brevis - Growth inhibition assay.

Ochratoxin A (OTA) is a nephrotoxic, carcinogenic and immunosuppressive mycotoxin. It can be detoxified by various microorganisms, e.g. different yeast strains, via metabolisation into ochratoxin α (OTα). Within this study a growth inhibition assay was developed to compare the toxicity of OTA and its degradation product OTα. As an indicator organismBrevibacillus brevis was used. The assay was performed in microtiterplates. Growth inhibition was determined by comparing the optical density values ofBrevibacillus brevis cultures grown in medium supplemented with OTA/OTα and OTA/OTα-free medium, respectively.It could be shown thatB. brevis is sensitive to OTA (EC100=0.5 mg/L±0.03 mg/L), which is not the case for its metabolite OTα. Therefore this bioassay is a useful tool to show the detoxification of OTA to OTα by microbial degradation.