On the specific and unspecific effects of a polymeric glucomannan mycotoxin adsorbent on piglets when fed with uncontaminated or with Fusarium toxins contaminated diets

Abstract

A 35-day feeding experiment was performed with weaned piglets (initial live weight of 7.7±1 kg) to test the effects of a Fusarium toxin contamination of the diet (4.44 mg deoxynivalenol [DON] per kg diet) compared to an uncontaminated control diet. Both diet types were fed either unsupplemented or supplemented with a polymeric glucomannan mycotoxin adsorbent (GMA) to examine the claimed efficacy of detoxification of this feed additive through unspecific performance parameters and the specific proof of the prevention of DON absorption. Feeding of the mycotoxin-contaminated diets resulted in a decrease in feed intake and live weight gain by 28% and 14% when compared to the control group. These effects were independent of GMA addition. Based on the lack of significant interactions between diet mycotoxin-contamination and GMA supplementation for the performance data, and because of the inefficiency of GMA in decreasing DON absorption, it was concluded that the supplementation of DON-contaminated piglet diets with GMA cannot be recommended as an effective tool for alleviation of adverse DON effects.     

Humic substances failed to prevent the systemic absorption of deoxynivalenol (DON) and its adverse effects on piglets

The aim of this study was to examine the effects of a control diet (CON, 0.25?mg DON/kg diet) or a Fusarium toxin-contaminated diet (FUS, 4.49?mg DON/kg diet) without and with humic substances (HS) (CON-HS and FUS-HS, 0.23 and 4.56?mg DON/kg diet, respectively) on piglets during a 5-week growth trial starting after weaning (6.7?±?0.9?kg live weight, n?=?20/group). Feed intake was significantly reduced by feeding the FUS containing diets by approximately 21% compared with the CON diet irrespective of HS supplementation. The decrease in live weight gain paralleled the feed intake depression and amounted to approximately 26%. Feeding the FUS diet was clearly reflected by the DON levels in blood. While only traces of DON with median concentrations of 3?ng/ml (2?C5?ng/ml) and 2?ng/ml (0?C3?ng/ml) were detected in piglets fed the CON and CON-HS diets, respectively, significantly higher levels of 22.5?ng/ml (7?C30?ng/ml) and 23.5?ng/ml (15?C32?ng/ml) were found in piglets fed the FUS and FUS-HS diet, respectively. The urinary excretion of DON and its metabolite de-epoxy-DON as percentage of DON intake was not significantly influenced by HS supplementation and amounted to 24.1 and 20.2% for groups FUS and FUS-HS, respectively. In conclusion, the tested HS preparation cannot be recommended as a DON inactivating feed supplement for pigs.     

Effects of deoxynivalenol (DON) on growth performance, nutrient digestibility and DON metabolism in pigs

Wheat infected naturally withFusarium, contaminated mainly with 18.53 mg DON per kg, was added to a total constant wheat proportion of 400g/kg diet. Control and DON contaminated feed was fed for 11 weeks underad libitum and restrictive feeding conditions to 48 pigs of both sexes, which were randomly divided into 4 groups. Effects on performance (live weight range between 26 and 100kg), duration of feed intake and blood parameters were investigated. Parallel to this study, a balance study was carried out to examine the effects on nutrient digestibility and DON metabolism. The group fed the DON contaminated rationad libitum consumed 15% less feed and gained 14% less live weight compared to thead libitum control group, while the feed to gain ratio was unaffected. Under restrictive feeding conditions (DON and control) pigs exhibited 33%, 25% and 10% lower feed consumption, live weight gain and feed to gain ratio, respectively, than the control group fedad libitum. Metabolizability of energy, digestibility of organic matter, crude protein, crude fat and N-retention were significantly increased by 4, 3, 6, 11 and 10%, respectively, in the DON group of the restrictively fed pigs. In average up to 43.2% of the ingested DON, as the parent toxin in both groups, was eliminated with the urine and up to 3.0% with faeces. DON fed animals needed more time to consume the restrictive ration than the control group. Presented at the 26^th Mykotoxin-Workshop in Herrsching, Germany, May 17–19, 2004. Financial support Deutsone Forschungsgemeingschaft     

Effects of a Fusarium toxin-contaminated triticale, either untreated or treated with sodium metabisulphite (Na2S2O5, SBS), on weaned piglets with a special focus on liver function as determined by the 13C-methacetin breath test

The aim of the present experiment was to test the effects of a wet preservation of triticale contaminated mainly with deoxynivalenol (DON) with sodium metabisulphite (Na2S2O5, SBS) on growth performance, liver function, clinical-chemical plasma parameters and organ histopathology of piglets. For this purpose both the uncontaminated control triticale and the DON contaminated triticale were included in the piglet diet either untreated (CON, FUS) or SBS-treated (CON-SBS, FUS-SBS) and fed for 28 d starting from weaning. The dietary concentrations of DON and DON sulfonate (DONS), the DON derivative resulting from the SBS treatment, amounted to 0.156, 0.084, 2.312 and 0.275 mg DON per kg CON, CON-SBS, FUS and FUS-SBS diet, and to <0.05, <0.05, <0.05 and 1.841 mg/kg diet, respectively. Feeding the FUS diet significantly reduced the feed intake compared to the other three groups as indicated by the significant interactions between triticale source and SBS treatment when the whole experimental period of 28 d was considered (p = 0.014) while live weight gain and feed to gain ratio remained unaffected. The total plasma protein concentration was significantly depressed due to feeding the contaminated diets whereas SBS treatment exerted an increasing effect at the same time (45.4, 49.5, 40.7 and 46.5 g/l for piglets fed the CON, CON-SBS, FUS and FUS-SBS diet, respectively). The liver function was tested by the 13C-methacetin breath test (MBT) allowing evaluation of the cytochrome P4501A2 activity. MBT results, expressed as cumulative percentage dose recovery after 360 min (cPDR360) revealed a slight stimulation of liver function due to SBS treatment (p = 0.052) (37.5, 39.4, 37.4 and 55.1% for piglets fed the CON, CON-SBS, FUS and FUS-SBS diet, respectively). Liver weight and histopathological scoring were only weakly related to the MBT results. Further histopathological examinations of kidneys, pancreas and heart revealed no treatment effects. It was concluded that the SBS treatment of the contaminated triticale restored the performance of piglets to the level of the piglets fed the control diet while the effects on liver function, clinical-chemical plasma parameters - excepting the protein concentration - and organ histopathology were only marginal.     

Effect of herbal supplementation on growth,immunity, rumen histology,serum antioxidants and meat quality of sheep

There is a wide range of feed additives deliberately designed to be used in sheep diets that can improve production performance. Whereas herbal supplementation is gaining popularity not only for improving sheep productivity and mutton quality but also for safe application without any harmful residual effects. The present study was designed to investigate the effect of plantain (Plantago lanceolata L.) and/or garlic leaf (Allium sativum) dietary supplementation on growth performance, immunity, rumen histology, serum antioxidants and meat quality of sheep. The experiment consisted of a completely randomized design with 32 one-year-old sheep (initial mean live weight 9 ± 0.2 kg) allocated to four groups (8 sheep per group). Rice straw and concentrates-based total mixed ration pellets (2390 kcal/kg DM, CP = 15.1%) were offered as a control diet (CL diet). Herbal treatment diets included (i) CL diet + 10 g DM of plantain herb (PL diet), (ii) CL diet + 10 g DM of garlic leaf (GL diet) and (iii) CL diet + 5 g DM of PL and 5 g DM of GL (PG diet). Compared with the CL diet group, the live weight gain and feed conversion ratio were 18% to 26% and 13% to 20% higher in herbal-supplemented groups, respectively. Moreover, the herbal-supplemented groups, especially the PL diet group had higher serum immunoglobulin concentration, antioxidant capacity and rumen papillae size compared to the control. Besides, the lowest caul fat and pelvic fat levels were observed in the PL diet group followed by PG, GL and CL diet groups. In addition, lower mutton ether extract and saturated fatty acid along with higher polyunsaturated fatty acid levels were found in all herbal-supplemented groups. In conclusion, dietary supplementation with PL and/or GL might be used as an alternative in sheep to promote growth, health status and lean mutton production.     

Effects of graded levels of Fusarium toxin contaminated wheat in diets for fattening pigs on growth performance, nutrient digestibility, deoxynivalenol balance and clinical serum characteristics

A dose response study was carried out with pigs in order to examine the effects of increasing dietary deoxynivalenol (DON)-concentrations on performance, clinical serum characteristics, nutrient digestibility and DON-metabolism. For this purpose, wheat contaminated naturally with Fusarium toxins was incorporated into pig diets at increasing proportions to give calculated dietary DON-concentrations of 0, 2.3 and 4.6 mg/kg during the starter period of phase 1 (14 d) of the experiment, and 0/0, 1.2/1.4, 2.3/3.7 mg/kg starter/grower diet during phase 3 (56 d) of the experiment. Each diet was tested on 16 pigs of both sexes with an initial average live weight of approximately 28 kg. A recovery phase (phase 2, 21 d) was intercalated between phase 1 and 3 of the growth experiment where all groups were fed with the uncontaminated control diet since some pigs exposed to the highest dietary DON-concentration during phase 1 nearly completely refused the offered feed. Affected pigs completely recovered during this phase. In phase 3, when diets with lower DON-concentrations were fed, no differences in performance could be detected. Serum clinical characteristics (enzymes indicating liver damage, total protein, immunoglobulins) did not respond to increasing DON-concentration in the diets. DON-concentration in serum increased in a dose-response-related manner as dietary DON-concentration increased. However, this parameter was not or only weakly correlated to any of the examined performance parameters or serum characteristics. Also, nutrient digestibility of the diets and N-retention were not affected by treatments with the exception of crude fat digestibility which was not consistently influenced. Concentration of DON and its metabolite de-epoxy-DON increased in urine with increasing dietary DON-concentration in a strongly linearly related fashion. The proportion of the excretion of de-epoxy-DON of the total urinary excretion of DON plus de-epoxy-DON rose linearly up to approximately 4%. Total recovery of DON plus de-epoxy-DON as percentage of DON-intake varied between 45 and 57% and was not influenced by dietary DON-concentration. Only a very small fraction of approximately 0.1% of ingested DON was recovered in faeces.     

Use of red pepper oil in quail diets and its effect on performance,carcass measurements,intestinal microbiota,antioxidant indices,immunity and blood constituents

Plant-derived additives are used to maintain the health and growth performance of livestock. The use of red pepper oil (RPO) has recently attracted considerable scientific interest mainly due to its potential benefits for animals and humans. The present study was conducted to evaluate the effect of dietary supplementation with RPO on growth performance, carcass measurements, antioxidant status and immunity of growing quails between 1 and 5 weeks of age. A total of 240 growing quails (1-week old) were distributed into 5 equal groups consisting of 48 birds (4 replicates of 12 birds each). The first group was fed a basal diet without RPO (0 g/kg diet), and the second, third, fourth and fifth groups received diets containing RPO (0.4, 0.8, 1.2, 1.6 g/kg diet, respectively). The experiment lasted for 5 weeks. At age of 5 weeks, quails were slaughtered for carcass examinations, microbiological analysis of intestine and to determine blood constituents. Data were statistically analyzed by one-way ANOVA. Quails fed with 0.8 g RPO/kg diet showed 12.14%, 14.4% and 15% improvement in live BW, body weight gain and feed conversion ratio, respectively, compared with the control group. Quails that received diets with 1.2 g RPO consumed more feed than the others during the total period (1 to 5 weeks). Plasma globulin levels were significantly decreased (P = 0.0102), but albumin/globulin ratio was significantly increased (P = 0.0009) in birds fed diets containing RPO (0.4 and 1.2 g/kg) compared with those in the control group. Activity of liver enzymes in the plasma was nonsignificantly decreased in quails supplemented with 0.8 g RPO/kg diet compared with those in the control group. Activities of antioxidant enzymes (glutathione and catalase) in the group fed on diets supplemented with RPO (0.8 g/kg) were significantly higher than those in the control group. The inclusion of RPO (0.8 g/kg diet) in quail diets improved (P < 0.05) plasma lipid profile and also decreased pH of the caecal content (P = 0.0280) compared with those in the control group. The caecal bacterial population, Salmonella spp., coliform and Escherichia coli, were lowered (P < 0.05) in the groups treated with RPO (0.8, 1.2 and 1.6 g/kg) compared with those in the control group. In conclusion, dietary supplementation of RPO (0.8 g/kg) can enhance the performance and antioxidant indices and decrease intestinal pathogens and thus improve the health status of Japanese quail.     

Effects of Dietary Arginine and Glutamine on Alleviating the Impairment Induced by Deoxynivalenol Stress and Immune Relevant Cytokines in Growing Pigs

Deoxynivalenol (DON) is a mycotoxin that reduces feed intake and animal performance, especially in swine. Arginine and glutamine play important roles in swine nutrition. The objective of this study was to determine the effects of dietary supplementation with arginine and glutamine on both the impairment induced by DON stress and immune relevant cytokines in growing pigs. A total of forty 60-d-old healthy growing pigs with a mean body weight of 16.28±1.54 kg were randomly divided into 5 groups, and assigned to 3 amino acid treatments fed 1.0% arginine (Arg), 1.0% glutamine (Gln) and 0.5% Arg+0.5% Gln, respectively, plus a toxin control and a non-toxin control. Pigs in the 3 amino acid treatments were fed the corresponding amino acids, and those in non-toxin control and toxin control were fed commercial diet with 1.64% Alanine as isonitrogenous control for 7 days. The toxin control and amino acid treatments were then challenged by feeding DON-contaminated diet with a final DON concentration of 6 mg/kg of diet for 21 days. No significant differences were observed between toxin control and the amino acid groups with regard to the average daily gain (ADG), although the values for average daily feed intake (ADFI) in the amino acid groups were significantly higher than that in toxin control (P<0.01). The relative liver weight in toxin control was significantly greater than those in non-toxin control, arginine and Arg+Glu groups (P<0.01), but there were no significant differences in other organs. With regard to serum biochemistry, the values of BUN, ALP, ALT and AST in the amino acid groups were lower than those in toxin control. IGF1, GH and SOD in the amino acid groups were significantly higher than those in toxin control (P<0.01). The IL-2 and TNFα values in the amino acid groups were similar to those in non-toxin control, and significantly lower than those in toxin control (P<0.01). These results showed the effects of dietary supplementation with arginine and glutamine on alleviating the impairment induced by DON stress and immune relevant cytokines in growing pigs.     

The potential effects of antioxidant feed additives in mitigating the adverse effects of corn naturally contaminated with <Emphasis Type="Italic">Fusarium</Emphasis> 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.     

Meat meal in the diet of the early-weaned pig. II. Amino acid supplementation

One hundred and twenty pigs, initially 4–5 kg liveweight, were fed on wheat-based diets supplemented with meat meal and amino acids in two experiments, each of 4 weeks duration.In the first experiment, the supplementation of a normal meat meal diet with lysine and methionine increased the feed intake and weight gains of the pigs by 15 and 18%, respectively. Nitrogen retention was increased by 30%. Tryptophane gave a similar response to lysine and methionine.In the second experiment, a 21% crude protein basal diet was similar to the basal diet of the first experiment but it contained 1.02% lysine and 0.50% methionine plus cystine, compared to 0.90 and 0.51%, respectively, in the first experiment. Lysine and methionine supplementation of the diet did not significantly improve the performance of the pigs in the second experiment, but the supplementation of the diets with 0.08% tryptophane and lysine and methionine increased weight gains and feed intakes and decreased urea content of the blood plasma. The 21% crude protein diet contained 0.15% tryptophane.Increasing the crude protein content of diets from 18 to 24% by increasing their meat meal content increased the daily weight gains from 190 to 276 g.     

Lupin-seed meal (Lupinus albus cv. Hamburg) as a source of protein for growing pigs

Two experiments were performed to evaluate Lupinus albus cv. Hamburg as a source of protein for growing pigs. The first was in a factorial design, involving two levels of feeding (restricted and ad libitum) and five isocaloric, isonitrogenous diets (0, 10.3, 20.7 and 31% Hamburg, and 31% Hamburg supplemented with 0.20% synthetic L-lysine). The growth performance of pigs from 22 to 70 kg live weight was unaffected by 10.3% Hamburg replacing soya-bean meal and meat and bone meal, but at higher levels both growth rate and feed conversion efficiency were significantly depressed. Feed intake was not significantly affected by the level of Hamburg, but dressing percentage decreased significantly from 84.3 to 80.2% as the proportion of Hamburg was increased from 0 to 31%. The addition of synthetic lysine to the 31% Hamburg diet improved feed conversion efficiency, but not to the level of the diet containing no Hamburg.Hamburg contained 2100 mg/kg manganese and the effects of levels of manganese from 72 to 1330 mg/kg on pig performance between 20 and 55 kg live weight were studied in the second experiment. Up to 1330 mg/kg manganese in the diet did not affect the growth performance or carcass quality of pigs. In both experiments, the growth performance of pigs given 31 or 33% Hamburg diets, each supplemented with 0.20% synthetic L-lysine, was lower than that of pigs receiving diets without Hamburg.The digestible energy content and alkaloid content of Hamburg were 18.2 (SE ± 0.38) MJ/kg dry matter and 0.018%, respectively.     

Effects of graded levels of Fusarium toxin contaminated maize in diets for female weaned piglets

A dose response study was carried out with piglets to examine the effects of increasing amounts of Fusarium toxins in the diet on performance, clinical serum characteristics, organ weights and residues of zearalenone (ZON) and deoxynivalenol (DON) and their metabolites in body fluids and tissues. For this purpose, Fusarium toxin contaminated maize (1.2 mg ZON and 8.6 mg DON per kg maize) was incorporated into a maize based diet for piglets at 0, 6, 12.5, 25 and 50% at the expense of control maize. The experimental diets were tested on 100 female piglets allotted to 20 boxes (five animals per box) covering a body weight range of 12.4 ± 2.2 kg to 32.5 ± 5.6 kg. Voluntary feed intake and, consequently, body weight gain of the animals receiving the highest proportion of Fusarium toxin contaminated maize were significantly decreased while the feed conversion ratio was not affected by the treatment. The mean weight of the uterus related to the body weight of the animals of the same group was increased by almost 100% as compared to the control. For this group, significantly decreased values of total serum protein were determined, while the serum activity of the liver enzyme glutamate dehydrogenase and the serum concentration of the follicle stimulating hormone were decreased for all treatment groups receiving 6% contaminated maize or more in the diet. Serum concentrations of immune-globulins were not consistently altered by the treatment. Corresponding to the dietary exposure, increasing concentrations of ZON and α-zearalenol were detected in the bile fluid, liver and in pooled urine samples. The metabolite β-zearalenol was detected only in bile fluid. The total concentration of ZON plus its metabolites in bile fluid correlated well with the diet contamination (r = 0.844). DON was found in serum, bile fluid and pooled urine samples while de-epoxy-DON was detected only in urine. The serum concentration of DON correlated well with the respective toxin intake 3 - 4 h prior to slaughtering (r = 0.957). For all mentioned analyses of residues it has to be noted that toxin residues were detectable even if negligible concentrations were present in the diet.     

Amino acids modulates the intestinal proteome associated with immune and stress response in weaning pig

The objective of this study was to investigate the effects of free amino acids supplementation to protein restricted diet on the intestinal morphology and proteome composition in weaning pigs. Weanling piglets were randomly fed one of the three diets including a corn-soybean based control diet and two lower protein diets with or without free amino acids supplementation for 2 weeks. The jejunum samples of piglets were collected for morphology and proteome analysis. Compared with the control diet, the protein restricted diet had a significant lower average daily gain and higher feed conversion rate. Free amino acids supplementation to the protein restricted diet significantly improved average daily gain and higher feed conversion rate, compared with the protein restricted diet. The villous height in pigs fed the protein restricted diet was lower than that of the control and free amino acids diet. Using two-dimensional gel electrophoresis and mass spectrometry, we identified 16 differentially expressed protein spots in the jejunum of the weaning piglet. These proteins were related to stress and immune response, the metabolism of carbohydrates and lipids, and tissue structure. Based on the proteome and ELISA analysis, free amino acids diet significantly down-regulated the jejunal expression of stress protein heat shock 60 kDa protein. Our results indicated that amino acids supplementation to the protein restricted diet could enhance weight gain and feed efficiency in weanling pigs through improving intestinal nutrient absorption and transportation, gut health, and mucosal immunity.     

Performance of rabbits and oxidative stability of muscle tissues as affected by dietary supplementation with oregano essential oil

The effect of dietary supplementation with oregano essential oil on the performance of rabbits, and the susceptibility of the produced raw and thermally treated muscle tissue to lipid oxidation during refrigerated storage, were investigated. A total of 96 weaned rabbits were separated into four equal groups with three subgroups each. One group was given the basal diet and served as control, two groups were administered diets supplemented with oregano essential oil at levels of 100 and 200 mg/kg diet, whereas the remaining group was given a diet supplemented with alpha-tocopheryl acetate at 200 mg/kg. During the 42-day experimental period, body weight and feed intake were recorded weekly and the feed conversion ratio was calculated. Feeding the experimental diets to rabbits, performance parameters were not affected. Therefore, dietary oregano essential oil exerted no growth-promoting effect on rabbits. With increased supplementation of oregano essential oil, malondialdehyde values decreased in both raw and thermally treated muscles during refrigerated storage. This finding suggests that dietary oregano essential oil exerted a significant antioxidant effect. Dietary supplementation of oregano essential oil at the level of 200 mg/kg was more effective in delaying lipid oxidation compared with the level of 100 mg/kg, but inferior to dietary supplementation of 200 mg alpha-tocopheryl acetate per kg. This study indirectly provides evidence that antioxidant compounds occurring in oregano essential oil were absorbed by the rabbit and increased the antioxidative capacity of tissues.     

Effects of replacing palm oil with maize oil and Curcuma longa supplementation on the performance, carcass characteristics, meat quality and fatty acid profile of the perirenal fat and muscle of growing rabbits

An experiment has been conducted to study the effects of the inclusion of plant oil in rabbit diets. This study was aimed at evaluating the beneficial effects of the inclusion of maize oil (MO), rich in unsaturated fatty acids (UFAs), compared to palm oil (PO) containing saturated fatty acids (SFAs), on the meat fatty acid (FA) profile. As UFAs are susceptible to rancidity, Curcuma longa (CL), which is known for its antioxidant properties, was also added (3 g/kg) to the diet with two plant oils. CL contains curcuminoids, volatile oils, sugars, proteins, resins and polyunsaturated fatty acids (PUFAs). We also evaluated the influence of CL inclusion in the diet on the FA profile of the meat. Furthermore, the possibility of using these oil-enriched diets and the ability to assimilate CL in rabbits was evaluated by analysing the performance, carcass characteristics and meat quality. At the end of the experiment, there were no significant differences between the groups concerning the live weight, live weight gain, feed consumption, feed efficiency, carcass yield or the percentages of edible organs. The hind legs, forelegs, loins and abdominal wall, breast and ribs, skin and limbs and head were not affected by the oil type or by the inclusion of CL. The chemical composition, pH and oxidative status of the Longissimus dorsi muscle of the rabbits fed the experimental diets were not affected by the oil source or by the CL supplementation. Conversely, it has been shown that it is possible to modify the FA profile of rabbit meat and fat by dietary means. The SFA/PUFA ratio significantly decreased from -18% to -16% in the meat and from -25% to -23% in the perirenal fat of the rabbits fed diets containing MO without or with CL supplementation, respectively, compared to same tissues of the rabbits fed diets containing PO without or with CL supplementation, respectively. Similar trends were found for the atherogenic index, which decreased from -20% to -17% in the meat and from -26% to -23% in the perirenal fat, respectively, and the thrombogenic index, which decreased from -19% to -24% in the meat and from -24% to -23% in the perirenal fat, respectively. CL increased the α-Linolenic acid and PUFA n-3 contents and reduced the vaccenic acid content and the n-6/n-3 ratio in the meat of the rabbits fed the PO or MO diets.     

Performance of rabbits and oxidative stability of muscle tissues as affected by dietary supplementation with Oregano essential oil

The effect of dietary supplementation with oregano essential oil on the performance of rabbits, and the susceptibility of the produced raw and thermally treated muscle tissue to lipid oxidation during refrigerated storage, were investigated. A total of 96 weaned rabbits were separated into four equal groups with three subgroups each. One group was given the basal diet and served as control, two groups were administered diets supplemented with oregano essential oil at levels of 100 and 200?mg/kg diet, whereas the remaining group was given a diet supplemented with α-tocopheryl acetate at 200?mg/kg. During the 42-day experimental period, body weight and feed intake were recorded weekly and the feed conversion ratio was calculated. Feeding the experimental diets to rabbits, performance parameters were not affected. Therefore, dietary oregano essential oil exerted no growth-promoting effect on rabbits. With increased supplementation of oregano essential oil, malondialdehyde values decreased in both raw and thermally treated muscles during refrigerated storage. This finding suggests that dietary oregano essential oil exerted a significant antioxidant effect. Dietary supplementation of oregano essential oil at the level of 200?mg/kg was more effective in delaying lipid oxidation compared with the level of 100?mg/kg, but inferior to dietary supplementation of 200?mg α-tocopheryl acetate per kg. This study indirectly provides evidence that antioxidant compounds occurring in oregano essential oil were absorbed by the rabbit and increased the antioxidative capacity of tissues.     

Effects of Feed Contaminant Deoxynivalenol on Plasma Cytokines and mRNA Expression of Immune Genes in the Intestine of Broiler Chickens

An experiment was conducted to investigate the individual and combined effects of dietary deoxynivalenol (DON) and a microbial feed additive on plasma cytokine level and on the expression of immune relevant genes in jejunal tissues of broilers. A total of 40 broiler chicks were obtained from a commercial hatchery and divided randomly into four groups (10 birds per group). Birds were reared in battery cages from one day old for 5 weeks. The dietary groups were 1) control birds fed basal diet; 2) DON group fed basal diet contaminated with 10 mg DON/ kg feed; 3) DON + Mycofix group fed basal diet contaminated with 10 mg DON/ kg feed and supplemented with a commercial feed additive, Mycofix® Select (MS) (2.5 kg/ton of feed); 4) Mycofix group fed basal diet supplemented with MS (2.5 kg/ton of feed). At 35 days, the plasma levels of tumor necrosis factor alpha (TNF-α) and interleukin 8 (IL-8) were quantified by ELISA test kits. Furthermore, the mRNA expression of TNF-α, IL-8, IL-1β, interferon gamma (IFNγ), transforming growth factor beta receptor I (TGFBR1) and nuclear factor kappa-light-chain-enhancer of activated B cells 1 (NF-κβ1) in jejunum were quantified by qRT-PCR. The results showed that the plasma TNF-α decreased in response to DON, while in combination with MS, the effect of DON was reduced. DON down-regulated the relative gene expression of IL-1β, TGFBR1 and IFN-γ, and addition of MS to the DON contaminated diet compensates these effects on IL-1β, TGFBR1 but not for IFN-γ. Furthermore, supplementation of MS to either DON contaminated or control diet up-regulated the mRNA expression of NF-κβ1. In conclusion, DON has the potential to provoke and modulate immunological reactions of broilers and subsequently could increase their susceptibility to disease. The additive seemed to have almost as much of an effect as DON, albeit on different genes.     

Wirkung von Deoxynivalenol beim wachsenden Schwein in Abhängigkeit von der Darreichungsform

To evaluate the minimum effective dose of pure DON leading to measurable losses in weight gain and feed consumption a special feeding experiment was created to compare the effect of DON in natural contaminated wheat and — for the first time — a non-cereal diet (potato) spiked with pure DON. Examined parameters were weight gain, feed consumption and blood parameters.Three trials were conducted. In the first trial a concentration of 4000 µg DON/kg feed was used. In the second and third trial we used concentrations of 4000 and 6000 µg DON/kg feed. Severe effects on feed consumption and weight gain were found only in the second trial (naturally contaminated wheat ad lib.). By contrast, no differences in any parameter were found in the first (restricted feeding) and third trial (non-cereal diet spiked with pure DON ad lib.).     

<Emphasis Type="Italic">Fusarium</Emphasis> toxin-contaminated maize in diets of growing bulls: effects on performance,slaughtering characteristics,and transfer into physiological liquids

The present feeding study was carried out to examine the effects of Fusarium toxin-contaminated diets on performance and slaughtering characteristics and on the transfer of the Fusarium toxins zearalenone (ZEN), deoxynivalenol (DON) and their metabolites into physiological matrices. A total of 61 bulls (483?±?46 kg) were fed with graded proportions of Fusarium toxin-contaminated feed over a period of 10 weeks. The total mixed rations (TMR) consisted of 47 % grass silage, 20 % press pulp silage, and 33 % concentrate on dry matter (DM) basis. Increasing toxin concentrations were achieved by the exchange of control maize with Fusarium toxin-contaminated maize in the concentrates. Thus, dietary toxin concentrations between 0.08 and 0.69 mg ZEN and 0.36 and 8.31 mg DON per kg DM were covered by the four feeding groups. Based on increasing DM intake with increasing mycotoxin contaminations of the diet, the live weight gain and energy intake differed significantly between the groups. No effects were observed on slaughtering characteristics and organ weights. ZEN, α-zeralenol, β-zeralenol (β-ZEL), zeralanone, α-zearalanol, β-zearalanol, DON, and de-deepoxy-DON (de-DON) were simultaneously determined in urine, plasma, and liquor whereby quantifiable concentrations of ZEN, β-ZEL, DON, and de-DON were found in urine, of DON and de-DON in plasma, and solely of de-DON in liquor. Based on overall results it can be concluded that current EU-guidance values for critical concentrations of DON and ZEN can be regarded as safe levels also for growing bulls. Urine and blood toxin residue levels can be used to assess exposure of bulls.     

Fütterungseinfluss von Deoxynivalenol-belastetem Weizen bei Ferkeln

Effects of the mycotoxin deoxnivalenol (DON) on weaned piglets were investigated. Two feeding trials were conducted with naturally contaminated wheat in the ration. In the first trial as preliminary study weaned piglets were fed for one week with 7.7 mg DON per kg ration, intake of DON contaminated diets was not associated with any obvious negative health effects. Also in the main feeding trial with 3 mg DON per kg ration no vomiting and other negative clinical symptoms could be registered. The feed intake and the daily weight gains were significantly lower in the DON fed group when compared with control group, but the feed conversion rates were slightly improved in group fed DON.

Presented at the 25^th Mykotoxin Workshop in Giessen, Germany, May 19–21, 2003