Short‐term effects of T‐2 toxin exposure on some lipid peroxide and glutathione redox parameters of broiler chickens

The purpose of this study was to investigate the short‐term effects of T‐2 toxin exposure (3.09 mg/kg feed) on lipid peroxidation and glutathione redox system of broiler chicken. A total of 54 Cobb 500 cockerels were randomly distributed to two experimental groups at 21 days of age. Samples (blood plasma, red blood cell, liver, kidney and spleen) were collected every 12 h during a 48‐h period. The results showed that the initial phase of lipid peroxidation, as measured by conjugated dienes and trienes in the liver, was continuously, but not significantly higher in T‐2 toxin‐dosed birds than in control birds. The termination phase of lipid peroxidation, as measured by malondialdehyde, was significantly higher in liver and kidney as a result of T‐2 toxin exposure at the end of the experimental period (48th hour). The glutathione redox system activated shortly after starting the T‐2 toxin exposure, which is supported by the significantly higher concentration of reduced glutathione and glutathione peroxidase activity in blood plasma at 24 and 48 h, in liver at 12, 24 and 36 h, and in kidney and spleen at 24 h. These results suggest that T‐2 toxin, or its metabolites, may be involved in the generation of reactive oxygen substances which causes an increase in lipid peroxidation, and consequently activates the glutathione redox system, namely synthesis of reduced glutathione and glutathione peroxidase.     

Effect of diets with different inclusion levels of distillers dried grain with solubles combined with lysine and methionine supplementation on the lipid peroxidation and glutathione status of chickens

To study the possible effects of different inclusion levels of distillers dried grain with solubles (DDGS) on the lipid peroxidation and glutathione redox status of chickens, 200 three-week-old Ross 308 cockerels were assigned to four treatment groups of 50 birds each. The groups were fed a control and three experimental, isocaloric and isonitrogenous grower diets containing 15, 20 and 25% DDGS, respectively, combined with lysine (Lys) and methionine (Met) supplementation until 6 weeks of age. It was found that DDGS inclusion increased the ether extract content of the diets which resulted in higher reduced glutathione (GSH) content and elevated glutathione peroxidase activity (GSHPx) in the liver. However, DDGS addition with Lys and Met supplementation did not influence the malondialdehyde content of the blood and the liver. The oleic acid proportion of the diet showed a close positive correlation with GSH content of the liver. A smaller ratio of methionine and cysteine in the diet with DDGS resulted in significantly higher liver GSH content. GSHPx activity increased parallel with the elevated GSH content of the liver homogenate, suggesting that the enzyme is activated by the actual supply of its co-substrate. In conclusion, the results show that DDGS, even at a high inclusion level combined with Lys and Met supplementation, has no initiative effect on lipid peroxidation in the blood and liver of broiler chickens.     

Changes in the regulation and activity of glutathione redox system,and lipid peroxidation processes in short‐term aflatoxin B1 exposure in liver of laying hens

The purpose of this study was to investigate the short‐term (48 hr) effects of feeding aflatoxin contaminated diet (170.3 μg/kg AFB1) in 49‐week‐old laying hens. Liver samples were taken at 12‐hr intervals. Feed intake, body weight, absolute and relative liver weight were the same in groups. However, there was no feed intake during both dark periods (between 12nd to 24th and 36th to 48th hours of the experiment); therefore, aflatoxin intake was also negligible. Markers of initial phase of lipid peroxidation, conjugated dienes and trienes did not change as effect of aflatoxin, but terminal marker, malondialdehyde content was significantly higher at 12 hr as effect of aflatoxin. No significant difference was found in reduced glutathione concentration and glutathione peroxidase activity between the groups. Expression of glutathione peroxidase 4 gene (GPX4) was significantly reduced due to aflatoxin treatment at 12 and 24 hr, but induced later, while glutathione reductase gene (GSR) expression was significantly lower at 24 hr and glutathione synthetase gene (GSS) in aflatoxin‐treated group at 12 hr. The results suggest that aflatoxin induced oxygen‐free radical formation, but it did not reach critical level during this short period of time to cause activation of the expression of glutathione system.     

铁过量或缺乏对新生仔猪血清生化指标及肝脏hepcidin mRNA表达量的影响

本试验旨在研究铁过量或缺乏对新生仔猪血清生化指标及肝脏hepcidin mRNA表达量的影响.挑选新出生的“杜长大”三元杂交仔猪15头[平均体重为(1.22±0.13)kg],随机分为3组,即缺铁组、正常组和铁过量组,每组5个重复,每个重复1头猪.3和7日龄时,缺铁组分别注射1 mL生理盐水,正常组分别注射1 mL右旋糖酐铁(含铁150 mg),铁过量组分别注射3 mL右旋糖酐铁(含铁450 mg).7日龄时,将所有仔猪全部处死,采集血清,并分离肝脏和脾脏,以测定血清生化指标、机体铁含量和肝脏hepcidin mRNA表达量.结果表明:肝脏、脾脏和血清中铁的含量均随着注射铁量的增加而显著或极显著增加(P ＜0.05或P＜0.01).与正常组相比,铁过量组血清中血红蛋白、球蛋白、总蛋白、丙二醛含量以及谷胱甘肽过氧化物酶、过氧化物酶活性显著或极显著升高(P＜0.05或P＜0.01),超氧化物歧化酶活性显著降低(P＜0.05);而缺铁组血清中血红蛋白、球蛋白、总蛋白、丙二醛含量以及谷胱甘肽过氧化物酶、过氧化氢酶、过氧化物酶活性则显著或极显著降低(P＜0.05或P＜0.01),超氧化物歧化酶活性显著升高(P＜0.05).与正常组相比,铁过量组仔猪肝脏中hepcidin mRNA表达量极显著升高(P＜0.01),而缺铁组则极显著降低(P＜0.01).由此得出,铁过量或缺乏均会影响新生仔猪机体的免疫功能和抗氧化功能;铁过量可提高新生仔猪机体铁含量和肝脏中hepcidin mRNA表达量,铁缺乏则会降低新生仔猪机体铁含量和肝脏中hepcidin mRNA表达量.     

Effect of supplementation with methionine and different fat sources on the glutathione redox system of growing chickens

The effect of supplementary methionine and fats of different saturation levels on the glutathione redox system of growing broiler cockerels was studied. The diet of three groups of chicks was supplemented with corn germ oil, beef tallow and fish oil at the levels of 30 g/kg and 50 g/kg of feed, respectively. The diet of further three groups was supplemented with methionine (5 g/kg of feed) in addition to the different fat sources. Control chicks were fed with a compound feed without methionine and fat supplementation. Reduced glutathione (GSH) and glutathione disulphide (GSSG) content as well as glutathione peroxidase activity in the liver were determined and GSH/GSSG ratio was calculated at day old and then at one and three weeks of age. Our results indicate that supplementary methionine stimulates both the synthesis of the glutathione redox system and glutathione peroxidase activity in growing chickens in the first period of postnatal life, when the risk of lipid peroxidation is high due to feeding unsaturated fats in the diet.     

Comparative investigation on the effect of T-2 mycotoxin on lipid peroxidation and antioxidant status in different poultry species

The effect of low dose T-2 toxin was investigated in chicken, duck and goose. The purpose of the present study was to investigate the effect of T-2 toxin on the lipid peroxidation and on the activity of glutathione redox system (amount of reduced and oxidised glutathione and the activity of glutathione peroxidase) in blood and liver. The treatment lasted days and two samples were taken, first at the time of lowest feed intake and second when the intake was the same as the control. It was found, that lipid per oxidation as detected by the amount of malondialdehyde increased in all of the species and tissues but the changes varied by species. The most sensitive species was goose followed by duck and chicken, and the most sensitive tissue was the liver followed by blood plasma and red blood cells.     

Effect of lignin on oxidative stress in chickens fed a diet contaminated with zearalenone

The effect of lignin supplementation to a diet contaminated with zearalenone (ZEA) on antioxidant status was studied in female chickens of the ISA BROWN laying strain. From the day of hatching to 2 weeks of age, four groups of chickens were fed the same uncontaminated control diet. After 14 days, Group 1 (control) continued to receive the uncontaminated diet, while Group 2 was fed an identical diet enriched with 0.5% chemically modified lignin. Simultaneously, chickens of Group 3 were switched to a diet contaminated with 7.9 mg/kg ZEA and those of Group 4 to an identical contaminated diet supplemented with 0.5% lignin. At 6 weeks of age blood and tissue samples were collected. Feeding of a diet contaminated with a high level of ZEA resulted in elevated glutathione peroxidase (GPx) activity in the duodenal mucosa and kidney tissues, and an increased γ-glutamyltransferase (GGT) activity in the plasma, indicative of oxidative stress. In the liver tissue, no mycotoxin-induced response in GPx and thioredoxin reductase (TrxR) activities occurred, and the malondialdehyde (MDA) level was even reduced. Neither the plasma levels of retinol and α-tocopherol nor the activities of superoxide dismutase in erythrocytes and GPx in blood were affected in birds fed the contaminated diet. The only effect of lignin supplemented to the contaminated feed was that it prevented the increase of GPx activity in the duodenal mucosa as an indicator of oxidative stress.     

Effect of excess selenium supplementation on the glutathione redox system in broiler chicken

Selenium, as part of selenocysteine, is the active centre of selenoenzymes. Excess amount of selenium generates oxygen free radicals and reacts with thiol compounds such as reduced glutathione, composing seleno-diglutathione. These reactions impair the amount and/or activity of the biological antioxidant defence system. In the present experiment the effects of two inorganic selenium sources (Na2SeO3, Na2SeO4) on lipid peroxidation and on the content and activity of some components of the antioxidant defence mechanism were studied in Ross 308 hybrid cockerels. In the tissues examined, the glutathione redox system was altered in different ways as an effect of excess selenium. The amount of glutathione and, consequently, glutathione peroxidase activity declined in the blood plasma and in the red blood cell haemolysate, while in the liver malondialdehyde concentration increased only at the end of the experimental period as a result of the boosted enzyme activity. The authors suppose that the cause of increased lipid peroxidation was the potential toxic effect of selenium accumulation above the actual demand.     

苜蓿皂甙对断奶仔猪生长性能和抗氧化性能的影响

为探讨苜蓿(Medicago sativa)皂甙对断奶仔猪生长性能和抗氧化性能的影响,选用72头体重7.5 kg左右的"杜×长×大"三元杂交断奶仔猪进行研究。试验随机分为4组:基础日粮组(C)、基础日粮添加0.5%苜蓿皂甙组(T1)、基础日粮添加1%苜蓿皂甙组(T2)和基础日粮添加2%苜蓿皂甙组(T3),每组3个重复,每个重复6头猪(公母各3头)。结果表明:苜蓿皂甙可以显著提高断奶仔猪的日增重(P<0.05),降低料重比,以T2组(1%苜蓿皂甙)效果最好;苜蓿皂甙可以显著提高断奶仔猪血清和组织中谷胱甘肽过氧化物酶(GSH-PX)和超氧化物歧化酶(SOD)的活性(P<0.05),降低丙二醛(MDA)的含量(P<0.05),而且随着苜蓿皂甙水平的增加,仔猪血清和组织中GSH-PX,SOD的活性呈升高趋势,MDA的含量呈下降趋势。因此,在断奶仔猪日粮中添加苜蓿皂甙可以提高其抗氧化能力,促进其生长。     

Experimental coccidiosis provoked by Eimeria acervulina in chicks simultaneously fed on ochratoxin A contaminated diet

The progression of coccidiosis provoked by Eimeria acervulina was followed in chicks fed on OTA-contaminated as well as on OTA-free diets. More heavy progress of duodenal coccidiosis, including mortality, occurred in OTA-treated chicks as can be seen from the higher value of lesion (3.50) and oocyst (31.65) indices. A stronger decrease of serum total protein was found in OTA-treated chicks (22.80 g/l) than in chicks infected with E. acervulina(24.20 g/l), but that decrease was strongest in chicks treated with OTA and simultaneously infected with E. acervulina (19.71 g/l). The serum concentration of uric acid was significantly increased in all chicks exposed to OTA, most notably in those additionally infected with E. acervulina (1020.6 (micro mol/L), whereas the serum enzyme activity of AST was increased only in chicks infected with E. acervulina and highest in those fed OTA contaminated diet (122.2 U/L). OTA induced degenerative changes in kidneys, liver and heart as well as a depletion of lymphoid tissue in the lymphoid organs and a decrease of body weight. Coccidiosis induced only a slight growth depression and duodenal hemorrhages in addition to characteristic duodenal damages. The impairment of kidney function, histopathological changes and general growth depression were stronger when chicks infected with E. acervulina were also given OTA.     

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

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

Changes in the lipid peroxide status of broiler chickens in acute monensin poisoning

The effect exerted by overdosage of monensin, an ionophore antibiotic, on the lipid peroxide status of broiler chickens was studied. Three-week-old broiler cockerels were given 150 mg monensin/kg body mass through a tube, and the malondialdehyde (MDA) concentration, glutathione peroxidase (GSH-Px) and catalase activity of the liver and breast muscle, and MDA concentration and GSH-Px activity of the blood plasma were determined. Liver MDA and catalase values rose rapidly and significantly during the experimental period. GSH-Px activity initially decreased, then tended to rise. Blood plasma and breast muscle variables did not change during the experiment. Acute monensin poisoning induced substantial enhancement of lipid peroxidation processes in the liver, while it did not appreciably affect the lipid peroxide status of the blood plasma and breast muscle. The role of the observed phenomenon in the rather complex pathogenesis of monensin poisoning is not known sufficiently. Further studies are needed to elucidate the problem.     

Clinicomorphological Studies in Chicks Fed Ochratoxin A While Simultaneously Developing Coccidiosis

The progression of coccidiosis and the resultant mortality were followed in chicks fed a OTA-contaminated diet. More complex and rapid progress of coccidiosis occurred in OTA-treated chicks than in chicks fed a OTA-free diet. The concentration of total protein in the serum was significantly decreased in the chicks in the OTA-treated group, whereas this was significantly increased in chicks infected with Eimeria tenella, irrespective of additional treatment with OTA. The serum glucose concentration was significantly increased in all the chicks exposed to OTA and/or suffering from coccidiosis, as was serum retention of uric acid in all groups, most notably in those consuming OTA. OTA induced degenerative changes in, and an increase in the weight of the kidneys, liver, heart and ventriculum; there was depletion of lymphoid tissue and a decrease in the lymphoid organs' weight and body weight. Coccidiosis induced only a slight growth depression and a slight increase in the relative weight of the kidneys and liver. The intensity of the clinical signs, the impairment of kidney function, macroscopic and histopathological changes, deviations in the weight of some organs and general depression in growth were greater when chicks infected with E. tenella were also given OTA.     

Vitamin E supplementation does not mitigate the acute morbidity effects of porcine reproductive and respiratory syndrome virus in nursery pigs

The objective of this study was to determine whether feeding a vitamin E-rich diet would benefit nursery pigs infected with porcine reproductive and respiratory syndrome virus (PRRSV). Sixty-four pigs were subjected to one of four treatment combinations (2 x 2 factorial) of dietary vitamin E (adequate or excess) and PRRSV (medium or inoculation with VR-2385 isolate P-129). Pigs were fed experimental diets during a 3-wk period before inoculation as well as during a 12-d period after inoculation. Growth performance was determined throughout the study, and lipid peroxidation in liver, glutathione peroxidase (GPX) activity in serum, circulating white blood cells, and serum interleukin-1beta (IL-1beta) and interferon-gamma (IFN-gamma) were determined in samples collected from pigs killed 4 or 12 d after inoculation. Infection by PRRSV (P < 0.001) induced a marked decrease in both ADFI and ADG, but neither the main effect of diet nor the diet x PRRSV interaction was significant. Neither diet nor PRRSV affected feed efficiency. At 12 d after inoculation, lipid peroxidation in liver and GPX activity in serum were lower in pigs fed excess vitamin E than in those fed adequate vitamin E (P < 0.01), suggesting that the diet high in vitamin E bolstered the antioxidant status of the pigs. However, PRRSV did not affect lipid peroxidation in liver or serum GPX activity, and the diet x PRRSV interaction was not significant. White blood cell counts were decreased and IFN-gamma, and IL-1beta were increased (P < 0.05) 4 and 12 d after inoculation in PRRSV-infected pigs, but neither diet nor the diet x PRRSV interaction was significant. Collectively, these results indicate that increasing antioxidant defenses by feeding high levels of vitamin E did not ameliorate the effects of PRRSV on decreased growth, leukopenia, and increased serum IL-1beta and IFN-gamma. Thus, feeding nursery pigs a diet high in vitamin E may not be useful for mitigating the acute morbidity effects of PRRSV infection.     

Effect on hepatonephric organs, serum metabolites and oxidative stress in post-weaning piglets fed purified zearalenone-contaminated diets with or without Calibrin-Z

The objectives of this study were to investigate the toxicity of zearalenone (ZEA) on hepatonephric organs, serum metabolites and oxidative stress of piglets and to evaluate the efficacy of Calibrin‐Z (CAZ) in preventing ZEA‐induced adverse effects. The experiment was conducted for 22 days using 36 piglets weaned at 21 days of age (Landrace × Yorkshire × Duroc, 18 females and 18 males; 8.84 ± 0.21 kg average body weight). Piglets of each gender were randomly allocated to the following six dietary treatments: (i) Control (basal diet only); (ii) Control + 1 g/kg CAZ; (iii) Control + 1 mg/kg ZEA; (iv) Control + 1 mg/kg ZEA + 1 g/kg CAZ; (v) Control + 1 mg/kg ZEA + 2 g/kg CAZ; (vi) Control + 1 mg/kg ZEA + 4 g/kg CAZ. Piglets were housed and fed individually for the entire experimental period. Blood samples were taken, and piglets were killed at the end of the experiment to obtain organs for physiological assessment. Results showed that piglets fed the ZEA‐contaminated diet had increased (p < 0.05) activities of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma‐glutamyltransferase (GGT), creatine kinase and cholinesterase, concentrations of urea, and creatinine in serum, and malondialdehyde (MDA) in serum and liver. Pigs fed the ZEA‐only diet also showed reductions in serum (p < 0.05) globulin, triglycerides and high‐density lipoproteins (HDL), and reductions in total superoxide dismutase (TSOD) and glutathione peroxidase (GSHPx) activity in both serum and liver. Supplementation of CAZ at the dosages of 1–4 g/kg to the diet containing 1.05 mg/kg ZEA linearly increased (p < 0.05) concentrations of triglycerides and HDL in serum, activity of TSOD and GSHPx in serum and liver, but linearly reduced (p < 0.05) all tested serum enzymes and lowered (p < 0.05) the elevated concentrations of urea, and creatinine in serum, and MDA in serum and liver caused by dietary ZEA. Piglets fed the ZEA‐contaminated diet showed increased (p < 0.05) relative weight of liver and kidney compared with the control, whereas only numerical improvement on relative weight of liver and kidney was observed with simultaneous addition of CAZ at 4 g/kg diet and ZEA. However, feeding the diet with CAZ alone at 1 g/kg had no impact on any of the measured parameters when compared to the control. It is suggested that feeding ZEA at 1.05 mg/kg exerted a deleterious effect on piglets, which was totally or partly ameliorated by dietary supplementation of CAZ at concentrations between 1 and 4 g/kg diet.     

镰刀菌毒素对断奶仔猪脾脏抗氧化能力和白细胞介素-1β、白细胞介素-6分布和表达的影响

本试验旨在研究自然霉变饲粮中镰刀菌毒素对断奶仔猪脾脏抗氧化能力和白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)分布和表达的影响。选择35日龄平均体重为(8.45±0.94)kg的健康三元杂交(杜×长×大)断奶仔猪母猪40头,随机分为2组,每组20头。对照组饲喂基础饲粮,镰刀菌毒素组饲喂含镰刀菌毒素[玉米赤霉烯酮(ZEN)0.90 mg/kg;呕吐毒素(DON)1.43mg/kg,烟曲霉毒素(FUM)5.85 mg/kg]的试验饲粮。预试期7d,正试期35d。结果表明:1)与对照组相比,镰刀菌毒素显著降低了断奶仔猪血清和脾脏谷胱甘肽过氧化物酶(GSH-Px)和总超氧化物歧化酶(T-SOD)活性(P0.05),显著升高了丙二醛(MDA)含量(P0.05)。2)镰刀菌毒素使断奶仔猪脾脏白髓区明显变小,红髓区扩张且出现近圆形小空洞,动脉周围淋巴鞘中淋巴细胞数量较少。3)镰刀菌毒素导致断奶仔猪脾脏IL-1β和IL-6阳性细胞主要集中于白髓边缘,且靠近血窦的地方阳性点更多。4)与对照组相比,镰刀菌毒素显著升高了断奶仔猪脾脏IL-1β和IL-6mRNA相对表达量(P0.05)。由此可见,饲粮中镰刀菌毒素显著影响断奶仔猪血清和脾脏抗氧化能力,并通过改变脾脏IL-1β和IL-6的分布和表达,降低脾脏的免疫功能。     

The efficacy of a modified aluminosilicate as a detoxifying agent in Fusarium toxin contaminated maize containing diets for piglets

Two feeding experiments with female weaned piglets were carried out applying a complete two by two factorial design to investigate the effects of the dietary inclusion of 500 g/kg Fusarium toxin contaminated maize (8.6 mg/kg deoxynivalenol (DON); 1.2 mg/kg zearalenone (ZON)) and of 4 g/kg aluminosilicate (AS) as a detoxifying agent. The resulting four diets were fed ad libitum to a total of 80 piglets (20 piglets per group, allotted to a total of 20 pens) covering a live weight range of 10.5 +/- 1.3 to 27.5 +/- 4.4 kg in experiment 1, and to a total of 48 piglets (12 piglets per group, allotted to 12 pens) covering a live weight range of 9.7 +/- 1.8 to 21.4 +/- 4.8 kg in experiment 2. The animals of experiment 1 were slaughtered on days 34-36 of feeding the experimental diets. The mycotoxin analyses revealed that the control maize also contained considerable concentrations of Fusarium toxins, but the differences in DON and ZON concentrations between control and contaminated diets were sufficiently high to demonstrate both dose-related toxin effects. Voluntary feed intake and live weight gain of the animals were significantly reduced by the inclusion of Fusarium toxin contaminated maize into the diets in both experiments, while a significantly decreased feed to gain ratio was found in experiment 1. Furthermore, the relative weight of the uterus, stomach and heart of the animals fed the contaminated maize containing diets were significantly increased. Serum albumin concentrations and the activity of GLDH were significantly reduced by the inclusion of the contaminated maize. The addition of AS to the Fusarium toxin contaminated diets did not prevent or alleviate any of the mentioned effects. Moreover, the feed intake tended to be decreased by this supplementation in both experiments, while a significantly decreased feed to gain ratio was indicated for this factor in experiment one as well. The serum concentration of albumin and the activities of ASAT and gammaGT were significantly increased if AS was present in the diets while serum concentration of cholesterol and alpha-tocopherol were decreased significantly or in tendency, respectively. The concentrations of retinol and retinyl esters in liver and serum were not altered by the treatments. The analysed concentrations of zearalenone (ZON) and its metabolites in the bile fluid clearly indicated the differences in dietary ZON concentrations and showed that AS was ineffective in preventing the absorption of the toxin from the gastrointestinal tract. Also, serum concentrations of DON reflected the DON intake prior to sampling. However, there were no differences between groups fed diets with or without AS which also suggests the inefficacy of the tested AS in preventing the DON absorption. The present investigations failed to demonstrate a detoxifying capacity of the tested additive and emphasize the general necessity for a critical verification of detoxifying agents in vivo.     

饲粮添加吡咯喹啉醌对围产期母猪繁殖性能和抗氧化功能的影响

本试验旨在比较吡咯喹啉醌(PQQ)与维生素E和有机硒对围产期母猪繁殖性能和抗氧化功能的影响。选用40头体重和背膘厚接近且妊娠90 d的第3胎大约克母猪,随机分为2组,每组20头。对照组在基础饲粮中添加60 mg/kg维生素E和0.20 mg/kg有机硒,试验组在基础饲粮中添加1 mg/kg PQQ。试验期为妊娠第90天至分娩后第7天。结果表明:与对照组相比,饲粮添加PQQ对母猪产程、产仔数、产活仔数及仔猪初生窝重、仔猪平均初生重以及产后7 d仔猪平均日增重均无显著影响(P0.05),但数值上有所升高;饲粮添加PQQ显著提高了初生仔猪和母猪血清总超氧化物歧化酶、谷胱甘肽过氧化物酶活性及还原型谷胱甘肽含量(P0.05),显著降低了血清丙二醛含量(P0.05),对血清过氧化氢酶活性、总抗氧化能力及氧化型谷胱甘肽含量均无显著影响(P0.05)。综合得出,围产期饲粮中添加PQQ较维生素E和有机硒对母猪繁殖性能无显著影响,能显著增强围产期母猪及初生仔猪的血清抗氧化功能。     

微粒蒙脱石对猪组织铅水平、红细胞生成和肝脏ALA-D酶活性及铅诱导的脂质过氧化的影响

选60头体质量约33kg的“杜长大”杂交猪，随机分成2组，每组3个重复，一组饲以基础日粮＋10mg/kg铅＋0.5％微粒蒙脱石，另一组饲以基础日粮＋10mg／kg铅作为对照。研究结果表明：添加微粒蒙脱石组与对照组相比，明显降低了猪全血、脑、肝、肾、骨和毛等组织中铅含量：通过血细胞计数、血红素和血球容积测定表明，添加微粒蒙脱石组的红细胞生成显著增高，且肝脏中ALA—D酶活性显著提高。铅对肝脏的损伤作用明显。表现为丙二醛（MDA）含量显著升高（17．08％），过氧化氢酶（CAT）、超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GPx）含量分别降低85．73％、52．17％、47．56％，而在日粮中添加微粒蒙脱石可以显著改善铅诱导的上述损伤。结果提示，微粒蒙脱石对铅中毒有潜在的治疗作用。     

Piglet blood glutathione peroxidase levels and preweaning mortality.

The blood glutathione peroxidase levels of one day old piglets from 22 litters were examined. Body weight and piglet survival were monitored in order to assess the relationship between these two factors and blood glutathione peroxidase activity. The mean blood glutathione peroxidase level of one day old piglets (65 mu/gHb) was significantly lower (p0.001) than the mean level (85 mu/gHb) at weaning. The mean blood glutathione peroxidase activity of one day old piglets was not related to the size of the litter, but was related (p less than 0.1) to the mean litter blood glutathione peroxidase level at weaning time. Piglet blood glutathione peroxidase was not related to piglet body weight. The blood glutathione peroxidase level of the sows at one-day post-farrowing was not related to the mean blood glutathione peroxidase activity of their litters at one day of age but was correlated (p less than 0.1) with the mean blood glutathione peroxidase levels of their litters at weaning. Piglet viability was shown to be strongly correlated (p less than 0.001) with body weight at one day of age. The blood glutathione peroxidase level of one day old piglets was weakly associated (p less than 0.1) with piglet survival. Further work is required to clarify this latter observation, which suggests that selenium supplementation to newborn piglets may be beneficial regardless of the dams nutritional status.