Influence of diets with cereal grains contaminated by graded levels of two Fusarium toxins on selected enzymatic and histological parameters of liver in gilts

Short-term consumption of the mycotoxin zearalenone by pubertal gilts causes persistent changes in the histoarchitecture of reproductive tissues

Consumption of zearalenone (ZEN) detrimentally affects tissues and systems throughout the body, and these deleterious effects are especially pronounced in swine. The objectives of this project were to determine the effects of short-term consumption of ZEN (at concentrations that could be found on-farm) on growth, carcass weight, liver weight, and reproductive tissues of pubertal gilts, and to determine if the effects are transient or persistent. Cross-bred gilts (107.25 ± 2.69 kg) were randomly assigned to one of three feed treatments: 1) solvent only for 21 d (CON; n = 10), 2) ZEN for 7 d followed by 14 d of solvent (ZEN-7; 6 mg/d; n = 10), and 3) ZEN for 21 d (ZEN-21; 6 mg/d; n = 10). Body weights were collected at the beginning and end of the experiment (189.1 ± 0.8 and 211.1 ± 0.8 d of age, respectively). Carcass weights and tissues were collected at harvest. There were no treatment-based differences in growth, carcass, liver, or reproductive tissue weights. Histological analyses revealed differences based on treatment and the interaction between treatment and luteal status. The thickness of the ampullary muscularis declined with ZEN exposure (P < 0.05), while the isthmic epithelial cell height (P < 0.01) and uterine endometrial thickness (P < 0.02) increased. Interestingly, the thickness of the isthmic muscularis, uterine myometrium, and epithelial cell height only differed in the presence of a corpus luteum. Uterine epithelial cell height in the luteal phase was lowest in ZEN-7 pigs (P < 0.01). The isthmic muscularis in the luteal phase was thinner in pigs from both ZEN treatments (P < 0.01). Conversely, the luteal-stage myometrium was thicker in pigs from both ZEN treatments (P < 0.01). The discovery of these tissue-based differences during the luteal phase is particularly concerning since this corresponds with the time when embryos would be affected by the functional competency of the oviduct and uterus. The results of this work demonstrate that short-term consumption of ZEN produces microscopic, but not macroscopic alterations in reproductive organs which are likely to have negative effects on their subsequent function and that these differences persist even after ZEN consumption ceases. Taken together, these results indicate that it is insufficient to rely solely on outwardly visible symptoms as indicators of zearalenone exposure, as detrimental effects on reproductive tissues were found in the absence of phenotypic and morphologic changes.

Time- and Dose-Dependent Effects of Dietary Deoxynivalenol (DON) in Rainbow Trout (Oncorhynchus mykiss) at Organism and Tissue Level

This study with juvenile rainbow trout evaluated the effects of dietary exposure to deoxynivalenol (DON) at industrially relevant doses (up to 1.6 mg/kg) on growth performance, the liver, and the gastrointestinal tract. Fifteen groups of 30 fish each were given one of five dietary treatments in triplicate: (1) control diet (CON; DON < 100 µg/kg feed), (2) naturally DON-contaminated diet (ND1) with a DON content of 700 µg/kg in the feed, (3) ND2 with a DON content of 1200 µg/kg feed, (4) a pure DON-contaminated diet (PD1) with 800 µg/kg of DON in the feed, and (5) PD2 with DON at a concentration of 1600 µg/kg in the feed. The feeding trial lasted eight weeks: six weeks of restrictive feeding followed by two weeks of ad libitum feeding. Exposure to DON during restrictive feeding for six weeks did not affect the growth performance of trout but did lead to a reduction in retained protein in fish fed with higher doses of DON in the ND2 and PD2 groups. During the two following weeks of ad libitum feeding, feed intake was similar among all groups, but body weight gain was lower in the ND2 and PD2 groups and feed efficiency was higher in PD2 (week 8). Histopathological assessment revealed liver damage, including altered nuclear characteristics and haemorrhages, in groups fed higher doses of natural DON (ND2) after just one week of restrictive feeding. Liver damage (necrosis and haemorrhage presence in ND2) was alleviated over time (week 6) but was again aggravated after ad libitum exposure (week 8). In contrast, gastrointestinal tract damage was generally mild with only a few histopathological alterations, and the absence of an inflammatory cytokine response was demonstrated by PCR at week 8. In conclusion, ad libitum dietary exposure of rainbow trout to either natural or pure DON resulted in reduced growth (dose-dependent), while restrictive exposure revealed time-dependent effects of natural DON in terms of liver damage.

Ruscogenin protects against deoxynivalenol-Induced hepatic injury by inhibiting oxidative stress, inflammation, and apoptosis through the Nrf2 signaling pathway: An In vitro study

Background

Deoxynivalenol (DON) is a trichothecene mycotoxin with demonstrated cytotoxicity in several cell lines and animals, primarily owing to inflammation and reactive oxygen species accumulation. Ruscogenin (RGN), a steroidal sapogenin of Radix Ophiopogon japonicus, has significant anti-thrombotic/anti-inflammatory effects.

Objective:

The aim of this study was to assess the protective role of RGN against DON-induced oxidative stress, which occurs through the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway and is regulated by phosphoinositide 3-kinases/protein kinase B (PI3K/AKT).

Methods:

The effects were examined using the HepG2 cell line. RGN and DON were suspended in serum-free medium. Cells were seeded onto plates, and then RGN, DON, or both were added over 24 h in triplicates for each group.

Results:

RGN conferred protection against DON-exhibited cytotoxicity against HepG2 cells. RGN pretreatment downregulated the expression of DON-induced TNF-α and COX-2 and the formation of reactive oxygen species in a dose-dependent manner. RGN upregulated the expression of Nrf2 and its antioxidant proteins as well as mRNA levels of HO-1/NQO-1/HO-1/Nrf2. Similarly, treatment with DON + RGN resulted in upregulation of the pI3K/pAKT signaling pathway in a dose-dependent manner. Finally, RGN was also found to inhibit the DON-induced apoptosis by upregulating the levels of cleaved proteins and downregulating the expression of Bcl2.

Conclusion:

The study demonstrates that RGN suppresses hepatic cell injury induced by oxidative stress through Nrf2 via activation of the pI3K/AKT signaling pathway.

Deoxynivalenol: Mechanisms of action and its effects on various terrestrial and aquatic species

Deoxynivalenol, a type B trichothecene mycotoxin produced by Fusarium species of fungi, is a ubiquitious contaminant of cereal grains worldwide. Chronic, low dose consumption of feeds contaminated with DON is associated with a wide range of symptoms in terrestrial and aquatic species including decreased feed intake and feed refusal, reduced weight gain, and altered nutritional efficiency. Acute, high dose exposure to DON may be associated with more severe symptoms such as vomiting, diarrhea, intestinal inflammation and gastrointestinal hemorrhage. The toxicity of DON is partly related to its ability to disrupt eukaryotic protein synthesis via binding to the peptidyl transferase site of the ribosome. Moreover, DON exerts its effects at the cellular level by activating mitogen activated protein kinases (MAPK) through a process known as the ribotoxic stress response (RSR). The outcome of DON-associated MAPK activation is dose and duration dependent; acute low dose exposure results in immunostimulation characterized by the upregulation of cytokines, chemokines and other proinflammatory-related proteins, whereas longer term exposure to higher doses generally results in apoptosis, cell cycle arrest, and immunosuppression. The order of decreasing sensitivity to DON is considered to be: swine > rats > mice > poultry ≈ ruminants. However, studies conducted within the past 10 years have demonstrated that some species of fish, such as rainbow trout, are highly sensitive to DON. The aims of this review are to explore the effects of DON on terrestrial and aquatic species as well as its mechanisms of action, metabolism, and interaction with other Fusarium mycotoxins. Notably, a considerable emphasis is placed on reviewing the effects of DON on different species of fish.

The Protective Effect of Heme Oxygenase-1 on Liver Injury Caused by DON-Induced Oxidative Stress and Cytotoxicity

Deoxynivalenol (DON) is a kind of Fusarium toxin that can cause a variety of toxic effects. Oxidative stress and DNA damage play a critical role in the toxicity of DON. However, previous studies focused more on acute toxicity in vivo/vitro models and lacked subchronic toxicity study in vivo. The potentially harmful effect of DON given at doses comparable to the daily human consumption in target organs, especially the liver, which is the main detoxification organ of DON, is also still not fully understood. Otherwise, Heme Oxygenase-1 (HO-1) has also reduced cell damage under the DON condition according to our previous study. Therefore, we used a rodent model that mimicked daily human exposure to DON and further explored its mechanism of toxic effects on liver tissue and Hepa 1-6 cell line. We also used adeno-associated virus (AAV)-modified HO-1 expressing by tail vein injection and constructed lentivirus-Hepa 1-6 cell line for mimicking HO-1 protective ability under the DON condition. The main results showed that both 30 d and 90 d exposures of DON could cause low-grade inflammatory infiltration around hepatic centrilobular veins. The reactive oxygen species (ROS) and 8-hydroxy-2 deoxyguanosine (8-OHdG) increased during DON exposure, indicating oxidation stress and DNA damage. Significantly, AAV-mediated liver-specific overexpression of HO-1 reduced DON-induced liver damage and indirectly protected the abilities of antioxidant enzyme/DNA damage repair system, while AAV-mediated silence of HO-1 produced the opposite effect. In addition, we found that overexpression of HO-1 could enhance autophagy and combined it with an antioxidant enzyme/DNA damage repair system to inhibit DON-induced hepatocyte damage. Altogether, these data suggest that HO-1 reduces the oxidative stress and DNA damage caused by DON sub-chronic exposure through maintaining DNA repair, antioxidant activity, as well as autophagy.

The Influence of Fusarium Mycotoxins on the Liver of Gilts and Their Suckling Piglets

Simple Summary

Mycotoxins are toxic secondary metabolites of fungi that frequently contaminate animal feed and human food in different combinations; therefore, it is of great importance to determine the effects of mycotoxin co-contamination. Pigs are one of the most sensitive animal species to Fusarium mycotoxins, and the liver is an important site of mycotoxin metabolism. The objective of the present research was to determine histopathological changes, apoptosis, and proliferation in the liver of gilts fed with Fusarium mycotoxin-contaminated feed for a prolonged time at the end of their pregnancy and until weaning of their piglets. Additionally, the same parameters were evaluated in the liver of their piglets to determine whether Fusarium mycotoxins would affect the offspring. The results revealed increased hepatocellular necrosis and apoptosis as well as sinusoidal leukocytosis with inflammatory infiltrates of hepatic lobules in experimental gilts, but no significant changes were observed in the piglet livers, implying that the utilized concentrations and duration of exposure did not cause detrimental effects on them. Interestingly, the amount of interlobular connective tissue in the liver of experimental gilts was significantly decreased. The obtained results emphasized the need to evaluate Fusarium mycotoxin concentrations in feed because even at low concentrations, they can cause adverse effects, but there is less concern for severe detrimental effects on the offspring.

Abstract

Mycotoxins are common fungal secondary metabolites in both animal feed and human food, representing widespread toxic contaminants that cause various adverse effects. Co-contamination with different mycotoxins is frequent; therefore, this study focused on feed contaminated with Fusarium mycotoxins, namely, deoxynivalenol (5.08 mg/kg), zearalenone (0.09 mg/kg), and fusaric acid (21.6 mg/kg). Their effects on the liver of gilts and their piglets were chosen as the research subject as pigs are one of the most sensitive animal species that are also physiologically very similar to humans. The gilts were fed the experimental diet for 54 ± 1 day, starting late in their pregnancy and continuing until roughly a week after weaning of their piglets. Livers of gilts and their piglets were assessed for different histopathological changes, apoptosis, and proliferation activity of hepatocytes. On histopathology, gilts fed the experimental diet had a statistically significant increase in hepatocellular necrosis and apoptosis (p = 0.0318) as well as sinusoidal leukocytosis with inflammatory infiltrates of hepatic lobules (p = 0.0004). The amount of interlobular connective tissue in the liver of experimental gilts was also significantly decreased (p = 0.0232), implying a disruption in the formation of fibrous connective tissue. Apoptosis of hepatocytes and of cells in hepatic sinusoids, further assessed by the terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL) assay, showed a statistically significant increase (p = 0.0224 and p = 0.0007, respectively). No differences were observed in piglet livers. These results indicated that Fusarium mycotoxins elicited increased apoptosis, necrosis, and inflammation in the liver of gilts, but caused no effects on the liver of piglets at these concentrations.

Mycotoxin Production in Fusarium According to Contemporary Species Concepts

Fusarium is one of the most important genera of plant-pathogenic fungi in the world and arguably the world's most important mycotoxin-producing genus. Fusarium species produce a staggering array of toxic metabolites that contribute to plant disease and mycotoxicoses in humans and other animals. A thorough understanding of the mycotoxin potential of individual species is crucial for assessing the toxicological risks associated with Fusarium diseases. There are thousands of reports of mycotoxin production by various species, and there have been numerous attempts to summarize them. These efforts have been complicated by competing classification systems based on morphology, sexual compatibility, and phylogenetic relationships. The current depth of knowledge of Fusarium genomes and mycotoxin biosynthetic pathways provides insights into how mycotoxin production is distributedamong species and multispecies lineages (species complexes) in the genus as well as opportunities to clarify and predict mycotoxin risks connected with known and newly described species. Here, we summarize mycotoxin production in the genus Fusarium and how mycotoxin risk aligns with current phylogenetic species concepts.

The Occurrence of Mycotoxins in Raw Materials and Fish Feeds in Europe and the Potential Effects of Deoxynivalenol (DON) on the Health and Growth of Farmed Fish Species-A Review

The first part of this study evaluates the occurrence of mycotoxin patterns in feedstuffs and fish feeds. Results were extrapolated from a large data pool derived from wheat (n = 857), corn (n = 725), soybean meal (n = 139) and fish feed (n = 44) samples in European countries and based on sample analyses by liquid chromatography/tandem mass spectrometry (LC-MS/MS) in the period between 2012-2019. Deoxynivalenol (DON) was readily present in corn (in 47% of the samples) > wheat (41%) > soybean meal (11%), and in aquafeeds (48%). Co-occurrence of mycotoxins was frequently observed in feedstuffs and aquafeed samples. For example, in corn, multi-mycotoxin occurrence was investigated by Spearman's correlations and odd ratios, and both showed co-occurrence of DON with its acetylated forms (3-AcDON, 15-AcDON) as well as with zearalenone (ZEN). The second part of this study summarizes the existing knowledge on the effects of DON on farmed fish species and evaluates the risk of DON exposure in fish, based on data from in vivo studies. A meta-analytical approach aimed to estimate to which extent DON affects feed intake and growth performance in fish. Corn was identified as the ingredient with the highest risk of contamination with DON and its acetylated forms, which often cannot be detected by commonly used rapid detection methods in feed mills. Periodical state-of-the-art mycotoxin analyses are essential to detect the full spectrum of mycotoxins in fish feeds aimed to prevent detrimental effects on farmed fish and subsequent economic losses for fish farmers. Because levels below the stated regulatory limits can reduce feed intake and growth performance, our results show that the risk of DON contamination is underestimated in the aquaculture industry.

Decrease in immune function and the role of mitogen-activated protein kinase (MAPK) overactivation in apoptosis during T lymphocytes activation induced by zearalenone, deoxynivalenol, and their combinations

Currently there are few reports on the combined immunotoxicity of zearaleone (ZEA) and deoxynivalenol (DON). Since the two coexist naturally, it is necessary to understand the immunotoxicity caused by the two mycotoxins alone and in combination. To examine T lymphocytes activation and immune effect during activation, we used mouse primary spleen T lymphocytes as the experimental material and concanavalin (Con A) as the stimulator. The effects of ZEA, DON, and their combined exposure on T lymphocytes immune related function and the relationship between the activation of the mitogen-activated protein kinase (MAPK) signaling pathway and mycotoxin induced T lymphocytes apoptosis were studied in vitro. Specifically, T lymphocytes were isolated from primary mouse splenic lymphocytes, activated by Con A and then exposed to different concentrations of ZEA, DON, and their combinations. Our results showed that ZEA and DON alone and their combinations (20:1) can decrease the cell viability of T lymphocytes activated by Con A. The inhibitory effect of the combined groups was greater than that of the single mycotoxins, showing a synergistic effect. In addition, single or combined mycotoxins can lead to intracellular and surface ultrastructure damage of T lymphocytes, inhibit the expression of CD25 and CD278 and inhibit the synthesis of effect molecules poreforming protein (PFP), granzyme A (GZMA), and tumor necrosis factor-α (TNF-α). Meanwhile, the single mycotoxin or combined mycotoxins can promote the apoptosis of T lymphocytes which was accompanied by the overactivation of MAPK. After using the inhibitors of extracellular regulated protein kinases (ERK) and c-Jun N-terminal kinase (JNK) in the MAPK pathway, we found that the apoptosis of the cells induced by the ZEA was significantly decreased, and the apoptosis of the cells induced by DON had no significant changes. This suggests that the activation of MAPK induced by ZEA can promote the apoptosis of T lymphocytes, but the activation of MAPK induced by DON is not directly related to T cell apoptosis.

Low doses of individual and combined deoxynivalenol and zearalenone in naturally moldy diets impair intestinal functions via inducing inflammation and disrupting epithelial barrier in the intestine of piglets

The intestinal epithelium is the first barrier against food contaminants and is highly sensitive to Fusarium toxins, especially deoxynivalenol (DON) and zearalenone (ZEA). Here, we explored the effects of low doses of DON and/or ZEA in naturally moldy diets on intestinal functions in piglets, including inflammatory responses, epithelial barrier, and microbial composition. Piglets were treated with a control diet (CON), DON diet (1000.6 μg/kg), ZEA diet (269.1 μg/kg), and DON + ZEA diet (1007.5 + 265.4 μg/kg), respectively, for 3 weeks and then switched to the same CON diet for another 2 weeks. In the first period, even the selected low doses of DON or ZEA in the diet resulted in intestinal inflammation, diminish protein expression (claudin-4) and altered gut microbiota populations. Whereas upon switching to the CON diet for another 2 weeks, the deleterious effect of ZEA and DON on IL-1β and Bifidobacterium population could not be recovered. Additionally, combined DON and ZEA negatively affected body weight gain and feed consumption of piglets, as well as shown synergistic effects on evoking pro-inflammatory cytokines contents (TNF-α, IL-1β, and IL-6) and perturbing the cecum microbiota profile (E. coli, Lactobacillus, and Bifidobacterium). Collectively, chronic consumption of DON and ZEA contaminated feed or food, even at low doses, can induce intestinal damage and may have consequences for animal and human health.

Bacillus subtilis ANSB01G culture alleviates oxidative stress and cell apoptosis induced by dietary zearalenone in first-parity gestation sows

This study was conducted to evaluate the alleviation of Bacillus subtilis ANSB01G culture as zearalenone (ZEA) biodegradation agent on oxidative stress, cell apoptosis and fecal ZEA residue in the first parity gestation sows during the gestation. A total of 80 first-parity gilts (Yorkshire × Landrace) were randomly allocated to 4 dietary treatments with 20 replications per treatment and one gilt per replicate. The dietary treatments were as follows: CO (positive control); MO (negative control, ZEA level at 246 μg/kg diet); COA (CO + B. subtilis ANSB01G culture with 2 × 10⁹ CFU/kg diet); MOA (MO + ZEA level at 260 μg/kg diet + B. subtilis ANSB01G culture with 2 × 10⁹ CFU/kg diet). The experiment lasted for the whole gestation period of sows. Results showed that feeding the diet naturally contaminated with low-dose ZEA caused an increase of cell apoptosis in organ and the residual ZEA in feces as well as a decrease of antioxidant function in serum. The addition of B. subtilis ANSB01G culture in the diets can effectively alleviate the status of oxidative stress and cell apoptosis induced by ZEA in diets of gestation sows, as well as decrease the content of residual ZEA in feces.

Effects of mycotoxin-contaminated feed on farm animals

Mycotoxins are secondary products produced by fungi in cereals and are frequently found in the livestock industry as contaminants of farm animal feed. Studies analyzing feed mycotoxins have been conducted worldwide and have confirmed the presence of mycotoxins with biological activity, including aflatoxin, ochratoxin A, fumonisin, zearalenone, and deoxynivalenol, in a large proportion of feed samples. Exposure to mycotoxins can cause immunotoxicity and impair reproductive function in farm animals. In addition, exposure of tissues, such as the kidneys, liver, and intestines, to mycotoxins can exert histopathological changes that can interfere with animal growth and survival. This review describes previous studies regarding the presence of major mycotoxins in the feed of farm animals, especially pigs and poultry. Moreover, it describes the adverse effects of mycotoxins in farm animals following exposure, as well as the biological activity of mycotoxins in animal-derived cells. Mycotoxins have been shown to regulate signaling pathways, oxidative stress, endoplasmic reticulum stress, apoptosis, and proliferation in porcine and bovine cells. A clear understanding of the effects of mycotoxins on farm animals will help reduce farm household economic loss and address the health concerns of people who consume these meat and dairy products.

Equol: A Microbiota Metabolite Able to Alleviate the Negative Effects of Zearalenone during In Vitro Culture of Ovine Preantral Follicles

The impact of zearalenone (ZEN) on female reproduction remains an issue, since its effects may differ among exposed cell types. Besides the use of decontaminants in animal diet, other approaches should be considered to minimise ZEN effects after exposure. Since the first organ in contact with ZEN is the gastrointestinal tract, we hypothesise that products of microbiota metabolism may play a role in ZEN detoxification. We aimed to evaluate the effect of 1 µmol/L ZEN and 1 µmol/L equol (a microbial metabolite), alone or in combination, on the survival and morphology of in vitro cultured ovarian preantral follicles. Ovaries from 12 sheep were collected at a local abattoir and fragmented, and the ovarian pieces were submitted to in vitro culture for three days in the presence or absence of the test compounds. The follicular morphology was impaired by ZEN, but equol could alleviate the observed degeneration rates. While ZEN decreased cell proliferation in primary and secondary follicles, as well as induced DNA double-strand breaks in primordial follicles, all these observations disappeared when equol was added to a culture medium containing ZEN. In the present culture conditions, equol was able to counteract the negative effects of ZEN on ovarian preantral follicles.

Effects of maize naturally contaminated with aflatoxin B1 on growth performance, intestinal morphology, and digestive physiology in ducks

This study was conducted to determine the effects of maize naturally contaminated with aflatoxin B1 (AFB1) on growth performance, intestinal morphology, relative digestive organs weight, digestive enzymes activities, and biochemical index of intestinal development in ducks. A total of 640 ducks was blocked on the basis of sex and body weight, and then allocated randomly to 2 treatments with 20 pens per treatment and 16 ducks per pen. The experiment lasted for 5 wk, and dietary treatments included basal diet (CON) and diets with 100% of normal maize replaced by AFB1 contaminated maize. Detectable levels of other toxins were present but only AFB1 exceeded limits and the level of AFB1 was 195.4 ug/kg in the contaminated maize, and ranged from 2.91 to 120.02 ug/kg in the starter diet and 2.03 to 153.12 ug/kg in the grower diet. Feeding AFB1 contaminated diets decreased (P < 0.05) ADG and ADFI during the whole experiment, whereas F/G during d 15 to 35 and d zero to 35 was reduced (P < 0.05). The mortality of ducks fed AFB1 contaminated diets increased (P < 0.05). Ducks fed AFB1 contaminated diets had greater (P < 0.05) relative weights of proventriculus and gizzard on d 14 as well as the duodenum, jejunum, and ileum on d 14 and 35. Feeding AFB1 contaminated diets increased (P < 0.05) crypt depth, villus width, and surface area in the duodenum on d 35 and villus height, villus width, and surface area in the jejunum on d 14. The activities of alkaline phosphatase and leucine aminopeptidase in the jejunum brush border together with chymotrypsin and trypsin in the pancreas increased (P < 0.05) on d 14 with the inclusion of AFB1 contaminated maize. The jejunum villus became long and wide in ducks fed AFB1 contaminated diets. Taken together, the feeding of maize naturally contaminated with AFB1 caused adverse effects on growth performance and intestinal morphology, and altered digestive physiology and development.

Fusarium Molds and Mycotoxins: Potential Species-Specific Effects

This review summarizes the information on biochemical and biological activity of the main Fusarium mycotoxins, focusing on toxicological aspects in terms of species-specific effects. Both in vitro and in vivo studies have centered on the peculiarity of the responses to mycotoxins, demonstrating that toxicokinetics, bioavailability and the mechanisms of action of these substances vary depending on the species involved, but additional studies are needed to better understand the specific responses. The aim of this review is to summarize the toxicological responses of the main species affected by Fusarium mycotoxins.

Effects of High Levels of Deoxynivalenol and Zearalenone on Growth Performance, and Hematological and Immunological Parameters in Pigs

Background: Deoxynivalenol (DON) and zearalenone (ZEN) are common food contaminants produced by Fusarium sp. Mycotoxins are a potential health hazard because of their toxicological effects on both humans and farmed animals. Methods: We analyzed three groups of pigs: a control group (fed a standard diet), and the DON and ZEN groups, fed a diet containing 8 mg/kg DON and 0.8 mg/kg ZEN respectively, for four weeks. Results: DON and ZEN exposure decreased body weight (BW), average daily feed intake (ADFI), food conversion rate (FCR), and the serum levels of immunoglobulin (Ig)G and IgM. The total antioxidant levels significantly decreased in serum and increased in urine samples of both treatment groups. Additionally, DON and ZEN exposure increased serotonin levels in urine. Hematological parameters were not affected by the investigated toxins. Microscopic lesions were evident in sections of kidneys from either treatment group: we found sporadic interstitial nephritis in the DON group and renal glomerulus atrophy in the ZEN group. The expression levels of inflammatory cytokines and chemokine marker genes were reduced in tissues from DON- and ZEN-exposed pigs. Conclusions: chronic ingestion of high doses of DON and ZEN alters the immune response and causes organs damage, and might be associated with various diseases in pigs.

Hepatic Lipodystrophy in Galloway Calves

Hepatic lipodystrophy in Galloway calves is a fatal liver disease affecting a small proportion of the Galloway breed described in different parts of Europe and North America during the past decades. The clinical findings include a diversity of neurological signs. Clinical pathology findings frequently indicate hepatobiliary disease. Postmortem examination reveals an enlarged, pale yellow, and firm liver. Histologic lesions include hepatic fibrosis, hepatic lipidosis, and bile duct hyperplasia. To date, the etiopathogenesis remains obscure. Infectious causes, intoxications, and a hereditary origin have been considered. We describe hepatic lipodystrophy in Galloway calves from an extensively farmed cow-calf operation in southern Germany. Main clinical findings in 6 calves were consistent with hepatic encephalopathy. Clinical pathology findings in 5 of 6 tested animals revealed increased concentration of total bilirubin (maximum value [MV], 54 μmol/l; reference range [RR], <8.5 μmol/l), direct bilirubin (MV, 20 μmol/l; RR, <3.4 μmol/l), increased activity of gamma glutamyl transferase (MV, 162 U/l; RR, <36 U/l) and glutamate dehydrogenase (MV, 420 U/l; RR, <16 U/l). In addition, activity of glutathione peroxidase was decreased in all tested ( n = 5) animals (MV, 61 U/g hemoglobin [Hb]; RR, >250 U/g Hb). Postmortem examination in 6 calves revealed a firm, diffusely enlarged yellow liver with a finely nodular surface. Histologic lesions included hepatic fibrosis, hepatic lipidosis, and bile duct hyperplasia. Our findings add to the existing data on hepatic lipodystrophy in the Galloway breed and outline a protocol to aid in the diagnosis of this disorder.

Activity of Zearalenone in the Porcine Intestinal Tract

This study demonstrates that low doses (somewhat above the No Observed Adverse Effect Level, NOAEL) of the mycoestrogen zearalenone (ZEN) and its metabolites display multispecificity towards various biological targets in gilts. The observed responses in gilts were surprising. The presence of ZEN and zearalenols (ZELs) did not evoke a response in the porcine gastrointestinal tract, which was attributed to dietary tolerance. Lymphocyte proliferation was intensified in jejunal mesenteric lymph nodes, and lymphocyte counts increased in the jejunal epithelium with time of exposure. In the distal digestive tract, fecal bacterial counts decreased, the activity of fecal bacterial enzymes and lactic acid bacteria increased, and cecal water was characterized by higher genotoxicity. The accompanying hyperestrogenism led to changes in mRNA activity of selected enzymes (cytochrome P450, hydroxysteroid dehydrogenases, nitric oxide synthases) and receptors (estrogen and progesterone receptors), and it stimulated post-translational modifications which play an important role in non-genomic mechanisms of signal transmission. Hyperestrogenism influences the regulation of the host's steroid hormones (estron, estradiol and progesteron), it affects the virulence of bacterial genes encoding bacterial hydroxysteroid dehydrogenases (HSDs), and it participates in detoxification processes by slowing down intestinal activity, provoking energy deficits and promoting antiporter activity at the level of enterocytes. In most cases, hyperestrogenism fulfils all of the above roles. The results of this study indicate that low doses of ZEN alleviate inflammatory processes in the digestive system, in particular in the proximal and distal intestinal tract, and increase body weight gains in gilts.

Changes in the metabolic profile and body weight of pre-pubertal gilts during prolonged monotonic exposure to low doses of zearalenone and deoxynivalenol

The aim of this study was to determine whether exposure to low doses of ZEN + DON induces changes in serum biochemical and hematological parameters in pre-pubertal gilts. In the evaluated groups, minor but statistically significant changes were noted in selected serum biochemical parameters, including glucose, total cholesterol, ALT, AST, AP, total bilirubin, P_in, Fe, K and Cl, and in hematological parameters, including WBC, eosinophils, basophils, monocytes, Ht, Hb, MCHC, HDW and PLT. A statistical analysis of the results revealed significant differences between groups in the values of WBC, eosinophils, basophils, Hb, Ht, PLT, glucose, ALT, AP, total bilirubin, Fe and K. Change trends were noted mainly in weeks II and V-VI. An analysis of the metabolic profile of pre-pubertal gilts exposed to ZEN + DON indicates that homeostasis and biotransformation of ZEN + DON can be toned down at the expense of the animals' energy reserves. Body weight gains were lower in group E, and BW gains were not observed in weeks II and VI. The activity levels of gilts decreased in the first weeks of exposure (I and II), but the drop was minimized by a compensatory effect, or in the last two weeks of exposure due to nutrient deficiency or insufficient supply of protein and energy with feed and feed additives, which decreased BW gains. Low doses of mycotoxins induce completely different changes in the metabolic test than higher doses. The above can probably be attributed to: (i) a negative compensatory effect, (ii) initiation of adaptive mechanisms and stimulation of the immune system, probably due to the allergizing properties of mycotoxins, (iii) excessive loss of energy and protein due to more effective feed utilization, or (iv) involvement in detoxification processes which leads to fatigue. Depending on the body's energy stores, the above processes tend to tone down the biotransformation of low doses of the examined mycotoxins but in the present study, the BW of gilts did not increase under exposure to a combination of ZEN + DON.

Risk assessment for changes in the metabolic profile and body weights of pre-pubertal gilts during long-term monotonic exposure to low doses of zearalenone (ZEN)

The aim of the study was to examine whether the process of exposure to low doses of ZEN generates changes in the hematological and biochemical image of blood serum. During the experiment, pre-pubertal gilts (up to 25kg) were administered per os ZEN at a dose of 40μg/kg BW (Group E, n=18) or placebo (Group C, n=21) on a daily basis for 42days. Blood samples for investigation were collected seven times at intervals of one week. In the experimental groups, slight but statistically significant changes in the values of selected biochemical blood indices such as glucose, ALT, P_in, total protein and Fe, or in hematological indices such as RBC, MCV, PLT, WBC, basophils, eosinophils and monocytes were observed. Based on statistical analysis between the groups, differences in the values of WBC, basophils, peroxidase negative cells, Hb, Ht, MCV, HDW, glucose, ALT, AP, total protein, iron or potassium were found. In Group E, decreasing trends in the values of PLT and glucose, and increasing trends in the values of total protein, P_in, Na and Cl were found. The described situations occurred during the last three weeks of exposure. Low levels of exposure to ZEN lead to completely different changes in the metabolic profile than those resulting from higher doses of the toxin. The stimulatory effect of mycotoxins, observed in initial stages of exposure, is eliminated when the compensatory response and adaptive mechanisms are triggered, and due to excessive loss of energy, which may point to more efficient feed utilization and/or detoxification processes. The values of body weight gain obtained in Group E were monotonically higher in four out of the six investigated weeks of exposure. The above changes were accompanied by a decrease in glucose concentrations and higher total protein levels (a rising tendency), which could have affected the rate of body weight gain.

The potential effects of antioxidant feed additives in mitigating the adverse effects of corn naturally contaminated with Fusarium mycotoxins on antioxidant systems in the intestinal mucosa, plasma, and liver in weaned pigs

Seventy-two piglets (6.0 kg BW) were randomly distributed within six different dietary treatments to evaluate the effect of deoxynivalenol (DON) and the potential of four antioxidant feed additives in mitigating the adverse effects of DON on growth performances and oxidative status. Dietary treatments were as follows: control diet 0.8 mg/kg DON; contaminated diet (DON-contaminated diet) 3.1 mg/kg DON; and four contaminated diets, each supplemented with a different antioxidant feed additive, DON + vitamins, DON + organic selenium (Se)/glutathione (GSH), DON + quercetin, and DON + COMB (vitamins + Se/GSH + quercetin from the other treatments). Although DON was the main mycotoxin in the contaminated diet, this diet also contained 1.8 mg/kg of zearalenone (ZEN). The "mycotoxin" effects therefore included the combined effect of these two mycotoxins, DON, and ZEN. The DON-ZEN ingestion did not affect growth performances, average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (G:F ratio), but partially induced oxidative stress in weaned pigs as shown by increased malondialdehyde (MDA) content in the plasma and superoxide dismutase (SOD) activity in liver (P < 0.05). However, no change in the activity of other antioxidant enzymes or GSH concentrations was observed in plasma and liver of piglets fed the DON-contaminated diet (P > 0.05). Supplementation with individual antioxidant feed additive had a limited effect in weaned pigs fed DON-ZEN-contaminated diets. Combination of antioxidants (vitamins A, C, and E, quercetin, and organic Se/GSH) reduced plasma and liver MDA content and SOD activity in liver (P < 0.05) of piglets fed DON-ZEN-contaminated diets. Furthermore, this combination also reduced MDA content in the ileum (P < 0.05), although activity of glutathione peroxidases (GPx), SOD or catalase (CAT) in the ileum was not affected by DON-ZEN contamination or antioxidant supplements. In conclusion, DON-ZEN contamination induced oxidative stress in weaned pigs and combination of antioxidant feed additives restored partially the oxidative status. Further studies will be necessary to assess whether the effects of antioxidant feed additives on oxidative status are specific when feed is contaminated with DON-ZEN.

Effects of Wheat Naturally Contaminated with Fusarium Mycotoxins on Growth Performance and Selected Health Indices of Red Tilapia (Oreochromis niloticus × O. mossambicus)

An 8-week feeding trial was conducted to examine effects of wheat naturally contaminated with Fusarium mycotoxins (deoxynivalenol, DON 41 mg·kg⁻¹) on growth performance and selected health indices of red tilapia (Oreochromis niloticus × O. mossambicus; initial weight = 4.3 g/fish). Five experimental diets were formulated by replacement of clean wheat with naturally contaminated wheat resulting in graded levels of DON and zearalenone (ZEN) (Diet 1 0.07/0.01, Diet 2 0.31/0.09, Diet 3 0.50/0.21, Diet 4 0.92/0.37 and Diet 5 1.15/0.98 mg·kg⁻¹). Groups of 50 fish were randomly allocated into each of 20 aquaria and fed to near-satiety for eight weeks. Growth rate, feed intake and feed efficiency of fish fed the experimental diets decreased linearly with increasing levels of Fusarium mycotoxins (p < 0.05). Although growth depression was associated with feeding diets naturally contaminated with Fusarium mycotoxins, especially DON, no biochemical and histopathological parameters measured in blood and liver appeared affected by Fusarium mycotoxin concentrations of diets (p > 0.05). Though there was no clear evidence of overt DON toxicity to red tilapia, it is recommended that feed ingredients should be screened for Fusarium mycotoxin contamination to ensure optimal growth performance.

The effects of dietary deoxynivalenol (DON) on selected blood biochemical and hematological parameters in pre-pubertal gilts

The aim of this study was to determine whether exposure to low doses of DON leads to changes in serum hematological and biochemical profiles. In the experiment, pre-pubertal gilts (with body weight of up to 25 kg) were administered DON per os at a daily dose of 12 μg/kg BW (group E, n=18) or a placebo (group C, n=21) over a period of 42 days. Blood for analysis was sampled seven times at weekly intervals. Minor, but statistically significant changes were observed in selected indicators, particularly in weeks 2 and 3 in values of biochemical parameters such AlAT, AspAT, Pin and Fe, and in values of hematological parameters such as RBC, MCV, MCHC, PLT, MPV, WBC, neutrophil, eosinophil, lymphocyte and monocyte counts. In group E, a decreasing trend of the values was observed in most cases, except for RBC, PLT, eosinophil, lymphocyte and monocyte counts. Similar results were obtained in the last two weeks of the experiment. Initially, exposure to DON has a stimulating effect, which is eliminated when adaptive mechanisms are triggered. The results of the study indicate that the intensity of biotransformation processes varies subjected to the body's energy resources.

Protective effect of two yeast based feed additives on pigs chronically exposed to deoxynivalenol and zearalenone

To evaluate the effects of the mycotoxins deoxynivalenol (DON) and zearalenone (ZEA) on pigs and the benefits of two mycotoxin mitigation strategies, gilts (n = 84, 9.1 ± 0.1 kg) were allotted to four treatments: CON (control); MT (4.8 mg/kg feed DON and 0.3 mg/kg feed ZEA); MT-YC (MT + 2 g/kg of yeast cell wall product); and MT-YF (MT + 2 g/kg of yeast fermentation product). After 42 days of feeding, pigs fed MT had reduced (p < 0.05) growth performance compared with pigs fed CON. Pigs fed MT-YF had greater (p < 0.05) average daily gain and tended to have greater (p = 0.080) average daily feed intake than MT, whereas pigs fed MT-YC did not differ from MT. Oxidative DNA damage increased (p < 0.05) in MT, whereas pigs fed MT-YF tended to have lower (p = 0.067) oxidative stress. Liver hydropic degeneration was increased (p < 0.05) in MT in contrast to CON and MT-YF, and tended to be greater (p = 0.079) than MT-YC. Collectively, feeding diets contaminated with mycotoxins significantly reduced growth performance and impacted pig health. The yeast additives had varied ability to reduce mycotoxin effects on pig growth and health, but may still play a beneficial role in reducing the overall impacts of a mycotoxin challenge on pigs.

Toxic effects of maternal zearalenone exposure on uterine capacity and fetal development in gestation rats

The objectives of this study were to determine the effects of high-dose and early gestational exposure to zearalenone (ZEN) in female Sprague-Dawley (SD) rats, to correlate the maternal uterus with the fetus, and to explore the development and malformation of fetuses. Pregnant female SD rats were fed diets containing 0.3, 48.5, 97.6, or 146.0 mg/kg ZEN on gestational days (GDs) 0 through 7. All the females survived until GD 20, at which point a cesarean section was performed to harvest the organs, blood, and fetuses. The results indicated that exposure to ZEN during early gestation can impact the maternal reproductive capability. Delayed fetal development was directly linked to maternal toxicity. The toxic effects of ZEN caused early deaths more frequently than late deaths, and the deleterious effects lasted through the end of pregnancy.

Deoxynivalenol induced oxidative stress and genotoxicity in human peripheral blood lymphocytes

Deoxynivalenol (DON) is one of the most common mycotoxins. The aim of this study consists in using diverse cellular and molecular assays to evaluate cytotoxicity, genotoxicity as well as oxidative damage and to investigate their mechanisms in human peripheral blood lymphocytes. The human lymphocytes were cultured in eight different doses of DON (0, 6.25, 12.5, 25, 50, 100, 250 and 500 ng/mL) during 6, 12 and 24 h. DON was able to decrease cell viability and cause damage to the membrane, the chromosomes or the DNA at all times of culture. It was also able to induce lipid peroxidation and raise the levels of 8-OHdG and ROS in 6, 12 and 24 h. The results of the RT-PCR and the Western Blot indicated that DON is able to enhance mRNA or protein expressions of DNA repair genes and HO-1 in 6 h and to inhibit these expressions in 24 h. DON potentially triggers genotoxicity in human lymphocytes. This mechanism is probably related to depletion of antioxidase and oxidative damage to the DNA that reduced expression of HO-1, thereby inhibiting the ability of DNA repair.

Effects of zearalenone on oxidative stress and inflammation in weanling piglets

Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by the fungi of Fusarium genera. Piglets were fed for 18 days with a control or a ZEN (316 ppb) contaminated diet. At the end of the experiment tissue samples were taken for assessment of: lymphocyte proliferation, monocytes and granulocytes respiratory burst, inflammatory cytokine synthesis in blood and liver, expression of genes involved in oxidative stress or in inflammation, plasma biochemical parameters, total antioxidant status and nitric oxide synthesis. In blood, ZEN increases the respiratory burst of monocytes and the inflammatory cytokine (TNF alpha, IL-1 beta, IFN gamma) synthesis, while in liver, ZEN decreases the synthesis of all inflammatory cytokines investigated. In liver and spleen, different effect on the expression of genes involved in oxidative stress and inflammation was observed. While in liver, ZEN decrease the expression of cyclooxigenase gene, but increase the expression of glutathione peroxydase and catalase genes; in spleen, ZEN induces a decrease of the superoxide dismutase gene expression together with an increase of the cyclooxigenase. In conclusion, our results showed that liver, spleen and blood may also be target tissues in weanling piglets fed ZEN contaminated diet, with different effects on oxidative stress and inflammation.

The Fusarium toxins deoxynivalenol (DON) and zearalenone (ZON) in animal feeding

The contamination of cereal grains with toxic secondary metabolites of fungi, mycotoxins, is a permanent challenge in animal nutrition as health and performance of the animals may be compromised as well as the quality of animal derived food. Therefore the present article reviews the issue of mycotoxins in animal nutrition. As the Fusarium toxins deoxynivalenol (DON) and zearalenone (ZON) are of particular importance under the production conditions in central Europe and Germany, with respect to their frequent occurrence in toxicologically relevant concentrations, special emphasis is layed on those mycotoxins. The effects of DON and ZON on susceptible animals as well as management strategies to cope with the contamination of grain with those toxins are reviewed.

Induction of apoptotic lesions in liver and lymphoid tissues and modulation of cytokine mRNA expression by acute exposure to deoxynivalenol in piglets

Six 1-month-old piglets were intravenously injected with deoxynivalenol (DON) at the concentration of 1 mg/kg body weight, with three pigs each necropsied at 6 and 24 h post-injection (PI) for investigation of hepatotoxicity and immunotoxicity with special attention to apoptotic changes and cytokine mRNA expression. Histopathological examination of the DON-injected pigs revealed systemic apoptosis of lymphocytes in lymphoid tissues and hepatocytes. Apoptosis of lymphocytes and hepatocytes was confirmed by the TdT-mediated dUTP-biotin nick end-labeling (TUNEL) method and immunohistochemical staining against single-stranded DNA and cleaved caspase-3. The number of TUNEL-positive cells in the thymus and Peyer's patches of the ileum was increased at 24 h PI compared to 6 h PI, but the peak was at 6 h PI in the liver. The mRNA expression of interleukin (IL)-1β, IL-6, IL-18, and tumor necrosis factor (TNF)-α in the spleen, thymus and mesenteric lymph nodes were determined by semi-quantitative RT-PCR, and elevated expression of IL-1β mRNA at 6 h PI and a decrease of IL-18 mRNA at 24 h PI were observed in the spleen. IL-1β and IL-6 mRNA expressions increased significantly at 6 h PI in the thymus, but TNF-α decreased at 6 h PI in the mesenteric lymph nodes. These results show the apoptosis of hepatocytes suggesting the hepatotoxic potential of DON, in addition to an immunotoxic effect on the modulation of proinflammatory cytokine genes in lymphoid organs with extensive apoptosis of lymphocytes induced by acute exposure to DON in pigs.

Glucose balance of porcine liver allograft is an important predictor of outcome

BACKGROUND

The role of glucose metabolism in predicting postoperative liver graft function after transplantation is unclear. We investigated the relation between intraoperative glucose balance of the liver allograft and the postoperative graft function and survival in a porcine partial liver transplant model.

MATERIALS AND METHODS

Experiments follow Guiding Principles in the Care and Use of Animals. Fourteen female pigs received liver allografts of 17%-39% recipient liver volume. Recipients were classified into two groups based on positive glucose balance: the mean intraoperative blood glucose of the graft outflow was greater than the blood glucose of inflow, negative glucose balance: the mean blood glucose of graft outflow was less than blood glucose of inflow. Perioperative data and survival were studied.

RESULTS

In the positive group (n=9) intraoperative hepatic artery flow was significantly higher (P=0.028), and oxygen consumption was lower (P=0.018) than the negative group (n=5). Postoperatively, maximal serum aspartate aminotransferase (AST) (P=0.028), alanine aminotransferase (ALT) (P=0.028), and total bilirubin (P=0.027) of the positive group were significantly lower than the negative group. In survival analysis, the positive group had significantly better survival rate than the negative group (P=0.034). Using Periodic acid-Schiff staining, glycogen content of the allograft in the positive group at 10 min post-reperfusion was significantly decreased in comparison with the baseline value in the normal liver (P=0.005), however not statistically different in the negative group (P=0.175).

CONCLUSION

Intraoperative glucose balance can be used as an early predictor of the graft function following transplantation of partial liver allografts.

Effects of feeding diets naturally contaminated with Fusarium mycotoxins on protein metabolism in late gestation and lactation of first-parity sows

A study was conducted to assess the effects of feeding a blend of grains naturally contaminated with Fusarium mycotoxins to sows on the capacity for protein synthesis in skeletal muscle, the protein content per cellular unit, and the efficacy of a polymeric glucomannan adsorbent (GMA) to prevent these effects in late gestation and in lactation. Thirty-two Yorkshire sows were assigned to 4 treatment groups (8 per treatment) from 91 +/- 3 d of gestation up to weaning on d 21 after farrowing. Diets included 1) control, 2) contaminated grains, and 3) contaminated grains + 0.2% GMA. A fourth treatment of feeding sows the control diet at a restricted feed allowance was also included. The variables measured include ADFI, average daily BW change, serum total protein, urea, and ammonia, and skeletal muscle DNA, RNA, and protein. To assess the capacity for protein synthesis, ratios of RNA:DNA, and RNA:protein were compared among dietary treatments. To assess the degree of muscle protein mobilization in gestation and lactation, ratios of protein:DNA were compared among dietary treatments. Muscle samples were obtained from the triceps brachii. Blood and muscle samples were obtained 3 times: the first was obtained 1 d before the sows began to receive the experimental diets (90 +/- 3 d of gestation), a second sample was obtained 14 d later (104 +/- 3 d of gestation), and the third sample was obtained 10 d after farrowing. Serum ammonia concentrations were similar in sows fed the contaminated feed and sows fed the restricted feed compared with controls, but serum ammonia concentrations were greater in sows fed contaminated feed (P = 0.02) and restricted-fed sows (P = 0.008) compared with sows fed the contaminated grains plus GMA on 104 +/- 3 d of gestation. There were no reductions in the capacity for protein synthesis caused by mycotoxins or restricted feeding compared with controls. A reduction in ADFI (P = 0.003) was observed in sows fed the 2 contaminated diets in lactation. Muscle protein mobilization was not affected by diet, but a reduction (P = 0.04) in the content of protein per cellular unit was observed in lactation compared with gestation. Reduction in protein:DNA could be caused by the catabolic state in lactation, which was augmented by a low ADFI. The rate of muscle mobilization could be the result of the indirect effect of the reduction in ADFI in lactation rather than a direct effect of Fusarium mycotoxins in the capacity for protein synthesis.

Potential of deoxynivalenol to induce transcription factors in human hepatoma cells

To assess the hepatotoxicity of deoxynivalenol (DON), human hepatoma cells (Hep-G2) were used as an in vitro model. After exposing Hep-G2 cells to low (1 mciroM) and high dose (10 mciroM), gene expression profiles were analysed by microarray. More than 5% of genes were up-regulated, most of them being involved in transcriptional regulation. By real-time RT-PCR, elevated expression of transcription factors, commonly induced by activation of MAPK-pathway, was demonstrated for Hep-G2 cells on mRNA and protein level. Further studies, involving U937 human monocytes, showed that effects of DON treatment on mRNA and protein level were concentration-dependent and cell-specific. An inverse relation was noticed for the level of DON induced expression of transcription factors (JUN, FOS, EGR1 and ATF3) and the susceptibility of the cell lines towards the mycotoxin. This is the first report giving evidence that on a molecular level the mild hepatotoxic effects of DON are probably caused by the induction of transcription factors which are known to be associated with injury-induced liver regeneration processes. With ATF3, a novel downstream target gene was identified in DON-related cell signalling suggesting a potential linkage between molecular action and biological effects like reduction of glycogen storage in liver tissue.

The combination of deoxynivalenol and zearalenone at permitted feed concentrations causes serious physiological effects in young pigs

This study was to investigate the effects of the combination of deoxynivalenol (DON) and zearalenone (ZON) on pigs. Twenty-four weaning piglets were divided into a control group fed a diet free of mycotoxins and a toxin group fed a diet containing 1 mg/kg DON and 250 µg/kg ZON. The results showed that supplementation of DON and ZON in diets had extensive effects on pigs. More specifically, DON and ZON caused levels of total protein, albumin, and globulin in sera to decrease (p < 0.05) by 14.5%, 6.5% and 11.3%, respectively, and at the same time increased (p < 0.05) the serum enzyme activities of γ-glutamyltransferase, aspartate aminotransferase and alanine aminotransferase by 72.0%, 32.6% and 36.6%, respectively. In addition, DON and ZON decreased (p < 0.05) the level of anti-classical swine fever antibody titers by 14.8%. Real-time PCR showed that DON and ZON caused the mRNA expression levels of IFN-γ, TNF-α, IL-2, to decrease (p < 0.05) by 36.0%, 29.0% and 35.4%, respectively. Histopathological studies demonstrated that DON and ZON caused abnormalities in the liver, spleen, lymph nodes, uterus, and kidney. The concentrations of DON and ZON used in this study are in line with the published critical values permitted by BML. Our study clearly put the standard and adequacy of safety measures for these toxins into question. The authors suggest that with the increasing availability of cellular and molecular technologies, it is time to revisit the safety standards for toxins in feeds so as to make feeds safer, providing consumers with safer products.

Changes in the spleen and liver of pregnant sows and full-term piglets after feeding diets naturally contaminated with deoxynivalenol and zearalenone

Wheat contaminated naturally with the Fusarium toxins deoxynivalenol (DON) and zearalenone (ZON) was fed to pregnant Landrace sows for 35days. On day 110, caesarean section was carried out, the offspring were killed immediately after birth, and their livers and spleens examined. At necropsy there were no macroscopic lesions observed in any organ of either sows or piglets. Histopathological evaluation of tissues from sows of the treated group revealed changes in liver and spleen tissues, whereas no significant changes were observed in these tissues in their piglets. Liver damage, as measured by prominent elevated transaminase activities, was not detected in the serum of the sows. In pregnant sows there were individual variations in sensitivity to the Fusarium toxins. In conclusion, it can be assumed that there are no adverse effects on the liver and spleen of full-term piglets when their mothers consumed diets containing up to 9570 and 358mug DON/ZON per kg diet.

The effects of feeding grains naturally contaminated with Fusarium mycotoxins with and without a polymeric glucomannan adsorbent on lactation, serum chemistry, and reproductive performance after weaning of first-parity lactating sows1

An experiment was conduced to investigate the effects of feeding grains naturally contaminated with Fusarium mycotoxins such as deoxynivalenol on lactation, metabolism, and reproductive performance after weaning of first parturition sows and to evaluate the efficacy of a polymeric glucomannan mycotoxin adsorbent (GMA). Thirty-six Yorkshire sows were fed 3 diets (n = 12 sows/diet) from 91 +/- 3 d of gestation up to weaning on d 21 after farrowing. Diets included 1) control, 2) contaminated grains, and 3) contaminated grains + 0.2% GMA. The variables measured include ADFI, average daily BW change, serum biochemistry, milk composition, BW of litters at weaning, and weaning to estrus interval. The feeding of contaminated grains and contaminated grains + GMA reduced ADFI (P < 0.001). The feeding of contaminated grains resulted in weight loss (P = 0.007), as did the feeding of contaminated grains + GMA (P = 0.028), compared with controls, which underwent a small weight gain. There were no differences between the sows fed contaminated grains and those fed contaminated grains + GMA in average daily BW change. On the day of farrowing, total serum protein concentrations were lower for sows fed contaminated grains compared with controls (P = 0.038) and for sows fed contaminated grains compared with sows fed contaminated grains + GMA (P = 0.019). Seven days after farrowing, serum urea concentrations were lower for sows fed contaminated grains (P = 0.049) and contaminated grains + GMA (P = 0.048) compared with controls. Milk composition was not affected by treatments. There were no effects of diet on BW of litters at weaning or mortality of piglets during lactation. There was a trend for increased weaning to estrus interval in sows fed contaminated grains (P = 0.09) or contaminated grains + GMA (P = 0.08) compared with controls. It was concluded that the feeding of diets naturally contaminated with Fusarium mycotoxins to lactating sows reduces feed intake and increases BW losses. The weaning to estrus interval also tends to be longer in sows fed contaminated diets. Supplementing contaminated feed with GMA could counteract the reduction in serum protein and serum urea observed in sows fed contaminated feed.

In vivoandin vitroeffects of the mycotoxins zearalenone and deoxynivalenol on different non-reproductive and reproductive organs in female pigs: A review

This review summarizes the toxicological data on the effects of the mycotoxins zearalenone (ZON), its metabolites, and deoxynivalenol (DON) on different parameters relating to reproductive and non-reproductive organs in female pigs. In vivo, 22 mg ZON kg(-1) in the diet cause alterations in the reproductive tract of swine such as in the uterus, and affects follicular and embryo development. ZON and its metabolites have been shown to bind competitively to oestrogen receptors in an in vitro system. The feeding of pigs with a 9 mg DON kg(-1)-contaminated diet can act on protein synthesis, humoral and cellular immune response depending on dose, exposure and timing of functional immune assay, and affect liver and spleen cell structures. Beside these effects, reproductive alterations were observed in pigs, too. Both in vivo and in vitro exposure to DON decreased oocyte and embryo development. In vitro application of DON to uterine cells inhibits their proliferation rate and modulates the process of translation at a different molecular level when compared with the in vivo application. The histopathological results provide evidence of spleen and liver dysfunction in the absence of clinical signs, especially in pigs fed higher concentrations of Fusarium toxin-contaminated wheat. Prepuberal gilts react more sensitively to DON > ZON feeding compared with pregnant sows. In the liver, histopathological changes such as glycogen decrease and interlobular collagen uptake were only observed in prepuberal gilts, whereas enhancement of haemosiderin was found in both perpuberal gilts and pregnant sows. This review presents some of the current knowledge on the biological activities of ZON and DON in pig. Altogether, ZON affects reproduction of pigs most seriously because it possesses oestrogenic activity. However, DON affects reproduction in pigs via indirect effects such as reduced feed intake, resulting in reduced growth or impairment of function in vital organs such as liver and spleen.

On the transfer of the Fusarium toxins deoxynivalenol (DON) and zearalenone (ZON) from the sow to the full-term piglet during the last third of gestation

Pregnant sows were fed either a control diet (CON, n=8, 0.21 mg DON and 0.004 mg ZON/kg diet) or a diet containing 40% of a Fusarium toxin contaminated wheat (MYCO, n=7, 9.57 mg DON and 0.358 mg ZON/kg diet) from day 75 to 110 of gestation. Piglets were delivered by Caesarean section at the end. Spleen weights of piglets from the MYCO group were significantly lower. Hemoglobin concentration and hematocrit were also significantly decreased in these piglets, although this effect was more obvious in female than in male piglets. The transfer of DON and ZON was evaluated by the diet ratio (sum of concentrations of all metabolites in the physiological specimen divided by the dietary toxin concentration) and the piglet ratio (sum of concentrations of all metabolites in the physiological specimen of the piglet divided by that of the sows). The diet ratio for the liver (sows only) amounted to 0.001 (DON+de-epoxy-DON) and 0.016 (ZON and metabolites). The diet ratios of DON in bile reached up to 0.041 and 0.003 for sows and piglets, respectively, and those for ZON up to 2.896 and 0.128. The piglet ratios in bile varied up to 0.309 and 0.518 for DON and ZON, respectively, whereas nearly similar DON concentrations were found in serum of piglets and sows (median piglet ratio of 0.750). The results of the study suggest that the developing fetus is exposed to DON, ZON and their metabolites when the sows are fed a Fusarium toxin contaminated diet.