玉米赤霉烯酮、呕吐毒素及黄曲霉毒素B1联合染毒对小鼠睾丸的影响

试验旨在探究玉米赤霉烯酮(ZEN)、呕吐毒素(DON)和黄曲霉毒素B1(AFB₁)联合染毒对小鼠睾丸的毒性作用。选用60只8周龄SPF ICR小鼠，适应性饲养10 d后，将体重相近(38.88±0.29)g的48只小鼠随机分为4组，每组12只，低剂量霉菌毒素联合染毒组(LD组)腹腔注射10mg/kgBWZEN+1 mg/kg BW DON+0.5 mg/kg BW AFB₁，中剂量霉菌毒素联合染毒组(MD组)腹腔注射20 mg/kg BW ZEN+1.5 mg/kg BW DON+1 mg/kg BW AFB₁，高剂量霉菌毒素联合染毒组(HD组)腹腔注射30 mg/kg BW ZEN+2 mg/kg BW DON+2 mg/kg BW AFB₁，对照组(CON组)腹腔注射等量玉米油。腹腔注射24 h后处死小鼠，采集附睾精子及睾丸组织样本。结果表明：与CON组相比，LD组(P<0.05)、MD组(P<0.001)、HD组(P<0.001)精子活性均降低；与CON组相比，霉菌毒素联合染...     

免疫组织化学法定位肝脏中脱氧雪腐镰刀菌烯醇的初步研究

本研究旨在探索定位肝脏中脱氧雪腐镰刀菌烯醇（deoxynival,DON）的方法,为以后定位全身组织中的DON提供方法依据。选用刚断奶的二元白猪,保定后,耳缘静脉滴注葡萄糖盐水,外科手术法暴露其肝脏,采用微量进样器缓缓注入DON,采用免疫组织化学染色结合显微镜观察,对肝脏中的DON进行定位研究,可以在注射针眼附近定位到DON。免疫组织化学法可以作为一种定位组织中DON的方法。     

怀孕后期和哺乳期呕吐毒素通过胎盘和母乳传递给仔猪

呕吐毒素污染的饲料会引起猪的生长性能下降、拒食、免疫抑制和其他诸多健康问题。仔猪在出生前和哺乳期可分别经过胎盘和母乳接触和摄入呕吐毒素(Deoxynivalenol,DON)。然而,人们对仔猪早期接触呕吐毒素的情况并未完全了解。本文旨在调查研究呕吐毒素在怀孕后期如何通过胎盘和哺乳(初乳与常乳)传递给仔猪。试验选取44头怀孕后期(93 d±1 d)的母猪,饲喂由天然污染呕吐毒素的燕麦制成的饲料,直到仔猪断奶结束。试验日粮中的呕吐毒素含量分为三个水平:(1)对照组(DON 0.2 mg/kg);(2)DON-L1组(DON1.4mg/kg);(3)DON-L2组(DON2.17mg/kg)。选取15头母猪,每窝选取5头仔猪,重复采集母猪的母乳与血液以及仔猪血液进行检测;计算仔猪/母猪血液DON浓度比和母乳/母猪血液DON浓度比(M/P)以评估呕吐毒素的转移状况。仔猪血液/母猪血液DON浓度比在仔猪出生时为2.14,分娩后12 h～36 h为1.21,分娩后7 d为0.08,分娩后21 d为0.16,断奶时为0.20;母猪母乳与母猪血液中DON浓度比则分别为0.92、1.11、0.94、1.21和0.90。研究结果表明,DON能够通过胎盘和母乳高效传递给仔猪。尽管母乳/母猪血液中呕吐毒素浓度比较高且能够有效分泌DON到母乳中,但研究表明,仔猪/母猪血液DON浓度比较低时,哺乳仔猪在生长早期具有足够抵抗呕吐毒素的能力。     

一株毕赤酵母菌MC-1降解呕吐毒素、生物学特性及初步应用

呕吐毒素（DON）是危害动物健康的霉菌毒素之一，本研究旨在分离出能够降解DON的益生菌，以期应用于动物饲料中降解DON。本研究从普洱茶叶中分离出一株益生菌，经16S rDNA基因序列比对确定该菌株为毕赤酵母菌MC-1菌株；其在含有DON(1 mg/L)发酵液中DON降解率为59.21%。此外研究了毕赤酵母菌MC-1生物学特性，活性成分定位和应用试验。结果表明：毕赤酵母菌MC-1具有耐盐、耐酸、耐胆盐及在模拟消化液中存活的特性；其发酵上清液（DON 1 mg/L） DON降解率为54.76%，该菌株与（DON 1 mg/kg）豆粕共同发酵48 h后DON降解率为46.79%。综上，毕赤酵母菌MC-1能够用于动物发酵饲料中降解DON。     

酯化葡甘露聚糖作为霉菌毒素吸附剂应用的研究

选择21 d健康的100只雄性昆明小鼠,随机分为5组,1组为空白对照组,饲喂基础日粮;2组为阳性对照组,在基础日粮中添加2 mg/kg呕吐毒素(DON);3～5组为试验组,每组在添加2 mg/kg DON的基础日粮中分别添加0.05 %、0.10 %和0.15 %的酯化葡甘露聚糖(EGM).研究DON染毒饲料中添加EGM对小鼠生理和免疫指标的影响,结果表明,试验至30 d,1组、4组和5组平均日增质量及脾和胸腺指数显著高于2组;血液红细胞数量、白细胞数量、血红蛋白含量和淋巴细胞转化率极显著高于2组;2组肝指数极显著高于1组、4组和5组;1组、4组和5组各项指标差异不显著.由此表明,EGM能很好地吸附DON,减轻DON对小鼠的毒性损伤作用,在饲料中的最适添加剂量为0.10 %.     

不同方法检测霉菌毒素的比较研究

本研究通过比较三种不同方法对霉菌毒素检测结果的差异,旨在为检测霉菌毒素提供科学依据。本实验采用酶联免疫(ELISA)试剂盒、超高效液相色谱(UHPLC)和液相质谱质谱联用(HPLC-MS/MS)三种检测方法,对仔猪配合饲料中黄曲霉毒素B1(AFB1)、玉米赤霉烯酮(ZEA)、呕吐毒素(DON)含量进行检测。ELISA法检测AFB1、ZEA和DON时,超标率与UHPLC法和HPLC-MS/MS法接近;但ELISA法检测AFB1结果为限量值为80%以上时,采用UHPLC法的检测结果显著高于HPLC-MS/MS法(P0.05),其他所有样品的AFB1、ZEA和DON两种仪器检测方法差异不显著(P0.05)。ELISA可作为霉菌毒素检测的快速初筛法;对ELISA结果进行确认时,低含量AFB1样品更宜采用HPLC-MS/MS法,其余样品采用UHPLC法检测更经济;对DON和ZEA的ELISA结果确认时,也可采用UHPLC法。     

呕吐毒素脱毒菌对生长猪小肠内Hsp70分布和表达的影响

根据生长性能指标及小肠内Hsp70的蛋白定位及表达量的变化,探讨DON对生长猪小肠的影响以及脱毒菌(sp.WJ106)对DON的脱毒效果,为脱毒菌在养猪生产中的应用提供理论依据。本试验选择4月龄24头体质量为(55.58±1.83) kg的健康PIC父母代生长猪为研究对象,随机分为3组(n=8)。对照组饲喂基础日粮,DON组饲喂基础日粮+5.0 mg/kg DON,DON+脱毒菌组饲喂DON组日粮+15 mL/kg脱毒菌,预试期7 d,正试期28 d,试验结束取十二指肠、空肠和回肠。结果表明:DON组的平均日增质量下降(P0.05),但平均日采食量的升高,生产性能下降,添加脱毒菌之后,平均日增质量增加(P0.05),生产性能提高。Hsp70表达量显示与对照组相比DON引起了小肠黏膜上皮细胞及小肠腺内Hsp70蛋白表达量的异常增多,其中十二指肠尤为显著(P0.05),脱毒菌的添加,十二指肠的绒毛上皮阳性反应较DON组减弱尤为明显,空肠及回肠的Hsp70的蛋白量也呈下降趋势。本试验条件下,脱毒菌可在一定程度上减少DON对肠道的刺激,从而正向调节了Hsp70蛋白的异常表达。     

怀孕后期和哺乳期呕吐毒素通过胎盘和母乳传递给仔猪(续1)

本文旨在调查研究呕吐毒素在怀孕后期如何通过胎盘和母乳(初乳与常乳)传递给仔猪。研究结果表明,呕吐毒素(Deoxynivalenol,DON)能够通过胎盘和母乳高效传递给仔猪。尽管母乳/母猪血浆中呕吐毒素浓度比较高且能够有效分泌DON到母乳中,但较低的仔猪/母猪血浆DON浓度比表明哺乳仔猪在生长早期具有足够抵抗呕吐毒素的能力。     

梭状芽孢杆菌对DON处理生长猪肠道屏障和菌群区系的影响

旨在研究添加梭状芽孢杆菌(Clostridium)对脱氧雪腐镰刀菌烯醇(deoxynivalenol,DON)处理生长猪肠道屏障和菌群区系的影响,为DON生物解霉的研究提供基础。选取了24头4月龄,平均体质量为(55.58±1.83)kg的健康PIC父母代生长猪,随机分为3组,每组8个重复,每个重复1头。分别饲喂基础日粮(对照组)、5 mg/kg DON污染日粮(DON组)、添加Clostridium菌液(15 mL·kg~(-1)·d~(-1))的污染日粮(DON+C组)。预饲期7 d,正试期28 d。电镜扫描结果显示,DON能引起生长猪肠道屏障,特别是回肠绒毛的严重损伤,添加Clostridium后,肠道损伤减弱;16S rRNA结果表明,DON能导致回肠菌群区系的显著变化,而添加Clostridium后,其能在猪后段肠段中定植,维持肠道菌群的相对稳定。结果表明,Clostridium能够保护DON处理猪的肠道屏障及菌群结构。     

脱氧雪腐镰刀菌烯醇诱导CTLL-2细胞凋亡的信号途径研究

为探讨脱氧雪腐镰刀菌烯醇(deoxynivalenol,DON)对动物免疫功能的影响及其机理,以细胞毒性T淋巴细胞株CTLL-2为材料,用不同浓度的DON(0、0.5、1、2μg/m L)处理CTLL-2细胞48h,流式细胞术检测细胞的凋亡率,免疫印记法检测细胞凋亡相关通路蛋白CleavedCaspase 9、Cleaved-Caspase 3、Fas L、Fas、Cleaved-Caspase8等表达情况;并用流式细胞术检测了DON(1μg/m L)与Fas L中和抗体(10μg/m L)共处理后细胞的凋亡率。结果表明,随着DON浓度的升高,CTLL-2细胞的凋亡率呈上升趋势,染毒组均较对照组有极显著差异(P0.01);Bax/Bcl-2的比值升高,呈剂量-效应关系;DON促进细胞色素c(Cyt-c)从线粒体中释放到胞浆中,能够上调Cleaved-Caspase 9、Cleaved-Caspase 3的表达,染毒组均较对照组有显著性或极显著差异(P0.05或P0.01);Fas L、Fas、Cleaved-Caspase 8蛋白表达量随着DON浓度的升高逐渐增加,染毒组均较对照组有显著性或极显著差异(P0.05或P0.01);随着DON浓度的升高,p38 MAPK、JNK、Erk的磷酸化水平也升高,呈剂量-效应关系;与DON处理组相比,Fas L中和抗体与DON共同处理组细胞凋亡率明显下降(P0.01)。结果表明,DON可以诱导CTLL-2细胞发生凋亡,激活CTLL-2细胞线粒体通路、MAPKs通路,DON通过死亡受体途径诱导CTLL-2细胞凋亡,影响动物的免疫机能。     

Effect of long-term feeding of graded levels of deoxynivalenol (DON) on growth performance,nutrient utilization,and organ health in finishing pigs and DON content in biological samples

The prevalence of deoxynivalenol (DON) is a concern for swine producers, and although there has been extensive research into the effects of DON in pigs, focus has been in young pigs and/or in short-term studies. The objective of the study was to determine the effect of long-term exposure to DON-contaminated diets in finisher pigs. A total of 200 pigs (76.6 ± 3.9 kg initial weight) were group housed (five pigs per pen; n = 10 pens/treatment) in a 6-wk trial. Pigs were fed a wheat-barley-soybean meal-based control (CONT) diet with no DON or the basal diet in which clean wheat was replaced by DON-contaminated wheat and wheat screenings to provide DON content of 1, 3, or 5 ppm (DON1, DON3, and DON5, respectively). Individual BW and pen feed intake were recorded weekly to calculate average daily gain (ADG), average daily feed intake (ADFI), and gain to feed ratio (G:F). Blood was collected on days 0, 14, and 43 and analyzed for indicators of liver and kidney health. Nitrogen (N)-balance was conducted immediately following the growth performance period to determine the effect of DON on nutrient utilization. Blood and urine samples collected during N balance were analyzed for DON content. Feeding DON reduced (P < 0.05) ADFI and ADG from days 0 to 28 compared with CONT, after which there was no effect of diet on ADFI and ADG. The G:F was lower (P < 0.05) in DON5 fed pigs compared with all treatments during days 0 to 7; however, no treatment effects on G:F was observed from days 8 to 42. Nitrogen retention was lower (P < 0.05) in DON3 and DON5 compared with DON1-fed pigs. Nitrogen retention efficiency was higher (P < 0.05) in DON1 compared with DON3 and DON5 and protein deposition for DON1 pigs was higher (P < 0.05) than all treatments. There were no treatment effects on indicators of liver and kidney health. As dietary DON intake increased, concentration of DON in blood and urine increased. Overall, although there was an initial decrease in ADG and ADFI in pigs receiving diets containing >1 ppm DON, pig performance recovered after a period of time, whereas nutrient utilization continued to be affected after recovery of performance. Moreover, the lack of DON on G:F indicates that the negative effects of DON on growth performance are largely due to reduced feed intake. Overall, although pigs maybe capable of adapting to intake of DON-contaminated diets, their final body weight will be reduced when fed diets containing >1 ppm DON.     

Deoxynivalenol-contaminated wheat in swine diets

Two studies were conducted using Fusarium graminearum-infected (scabby) wheat containing 6.8 ppm deoxynivalenol (DON), commonly called vomitoxin, substituted for normal wheat in starter pig diets to give varying levels of DON. After 3 wk on experimental treatments, one-half of the pigs in trial one were sacrificed to evaluate the effects of DON on heart, kidney, spleen and liver. Analyses for DON residues in these tissues were also performed. The remaining 16 pigs were placed on a conventional diet for 4 wk to evaluate effects of DON on subsequent animal performance. A different sample of scabby wheat containing 4.9 ppm of DON was substituted for sorghum grain in growing-finishing pig diets to give varying concentrations of DON. At the end of the 42-d feeding period, eight pigs were slaughtered to evaluate the effects of DON on selected tissues. Results of the three trials suggest that feed intake was reduced when DON concentrations in the swine diets neared or exceeded 1 ppm. No apparent signs of disease, including vomiting, were observed in experimental animals. Histological evaluation revealed no significant lesions or abnormalities related to DON ingestion in tissues examined. Traces of DON (8 to 28 ppb, wet weight) were found in kidney, liver, spleen and heart of starter pigs consuming the diets containing DON up to time of slaughter. No DON was found in tissues of growing-finishing pigs that were withdrawn from feed about 12 h before slaughter.     

Effect of long-term feeding of graded levels of deoxynivalenol on performance,nutrient utilization,and organ health of grower-finisher pigs (35 to 120 kg)

The objective of this study was to evaluate the effect of long-term feeding of graded levels of deoxynivalenol (DON) on performance, nutrient utilization, and organ health of grower-finisher pigs. A total of 240 mixed-sex grower-finisher pigs (35.9 ± 1.1 kg initial body weight, BW) were randomly assigned to 1 of 4 dietary treatments (6 pigs/pen; 10 pens/treatment) for 77 d. Diets consisted of a control diet without DON (CONT) and diets containing 1, 3, or 5 ppm DON (DON1, DON3, or DON5). Nitrogen-balance was determined in 1 pig/pen during weeks 6 and 12 of the study. Growth performance measures were taken weekly for average daily feed intake (ADFI), average daily gain (ADG), and gain:feed (GF) until day 77. Blood samples were collected on days 0, 14, 42, 56, and 84 from 1 pig/pen for analysis of indicators of liver and kidney function. On day 7, ADG and ADFI for pigs fed DON3 and DON5 diets were lower (P < 0.05) compared with DON1- and CONT-fed pigs. Overall, ADG and ADFI (days 0 to 77) were lower in DON3- and DON5-fed pigs compared with CONT and DON1 pigs (P < 0.05), with no difference in GF (P > 0.05). Final BW was reduced in DON3- and DON5-fed pigs (P < 0.05) compared with CONT and DON1, which were not different (P > 0.05). No significant (P > 0.05) treatment effects were observed on carcass characteristics. In the grower-phase, protein deposition (PD) was reduced in DON3 and DON5 pigs compared with CONT and DON1 pigs (P < 0.05). In the finisher phase, PD was not affected by dietary treatment (P > 0.05). There was no effect of dietary treatment on the majority of selected serum chemistry (P > 0.05). In summary, pigs exposed to diets containing > 1 ppm DON had reduced growth performance with little or no effect on nitrogen utilization, organ health, or carcass characteristics, suggesting that the negative effects of DON may be largely due to depressed feed intake.     

Effects of chronic exposure of diets with reduced concentrations of aflatoxin and deoxynivalenol on growth and immune status of pigs

This study investigated the growth and immune responses of pigs fed diets containing reduced concentrations of aflatoxin (AF) and deoxynivalenol (DON) from naturally contaminated corn. Sixty gilts (13.9 ± 0.2 kg of BW) were randomly assigned to 4 treatments (5 replicate pens per treatment and 3 pigs per pen): A (a control diet without detectable AF and DON); B (a diet with 60 μg of AF/kg and 300 μg of DON/kg); C (a diet with 120 μg of AF/kg and 600 μg of DON/kg); and D (a diet with 180 μg of AF/kg and 900 μg of DON/kg). Pigs were allowed ad libitum access to feed and water for 33 d. Feed intake and BW were measured weekly and pigs were bled (8 mL) on d 33 to measure the numbers of blood cells, to conduct liver function tests, and to measure immunological variables including IgG, IgM, interferon γ, IL4, IL6, and tumor necrosis factor α. One pig representing the average BW of each pen was killed to obtain the liver, kidneys, and spleen for weight, tissue color measurement, and histological evaluation of tissue damage. When compared with A, pigs in C and D tended to have reduced ADG (0.52 vs. 0.43 and 0.41 kg/d, respectively; P = 0.058) and ADFI (1.04 vs. 0.92 and 0.88 kg/d, respectively; P = 0.061). White blood cell count of pigs in D (23.4 × 10(3) cells/μL) was greater (P < 0.05) than those in A, B, and C (18.4, 18.5, and 16.8 × 10(3) cells/μL, respectively. Serum tumor necrosis factor α concentration of pigs in D (335 pg/mL) differed (P < 0.05) from those in A and C (299 and 290 pg/mL, respectively). Pigs in B and D had greater (P < 0.05) fibrosis in liver tissues than those in A. Collectively, this study shows that diets containing both AF and DON greater than 60 and 300 μg/kg, respectively, may reduce growth and decrease feed intake, whereas diets containing 120 μg of AF/kg and 600 μg of DON/kg may result in altered immune health, systemic inflammation, and partial liver damage, causing further reduction in growth of pigs.     

Absorption, metabolism and excretion of 3-acetyl DON in pigs.

The absorption, metabolism and excretion of 3-acetyldeoxynivalenol (3-aDON) in pigs were studied. Pigs with a faecal microflora known to be able to de-epoxidate trichothecenes were used in the experiment. The pigs were fed a commercial diet with 3-aDON added in a concentration of 2.5 mg/kg feed for 2.5 days. No traces of 3-aDON or its de-epoxide metabolite were found in plasma, urine or faeces. Deoxynivalenol (DON) was detected in plasma as soon as 20 min after start of the feeding. The maximum concentration of DON in plasma was reached after 3 h and decreased rapidly thereafter. Only low concentrations close to the detection limit were found in plasma 8 h after start of the feeding. A significant part of the DON in plasma was in a glucuronide-conjugated form (42 +/- 7%). No accumulation of DON occurred in plasma during the 60 h of exposure. The excretion of DON was mainly in urine (45 +/- 26% of the toxin ingested by the pigs) and only low amounts of metabolites of 3-aDON (2 +/- 0.4%) were recovered in faeces. De-epoxide DON constituted 52 +/- 15% of the total amount of 3-aDON-metabolites detected in faeces. The remaining part in faeces was DON. DON was still present in the urine and faeces at the end of the sampling period 48 h after the last exposure. The results show that no de-epoxides are found in plasma or urine in pigs after trichothecene exposure, even in pigs having a faecal microflora with a de-epoxidation activity. The acetylated form of the toxin is deacetylated in vivo. Furthermore, the experiment shows that the main part of DON is rapidly excreted and does not accumulate in plasma, but a minor part of the toxin is retained and slowly excreted from the pigs.     

The effects of naturally deoxynivalenol-contaminated oats on the clinical condition,blood parameters,performance and carcass composition of growing pigs

A feeding trial with naturally deoxynivalenol (DON)-contaminated oats included in feed mixtures at graded levels was conducted in growing pigs. The DON concentrations were 0, 0.7, 1.7, and 3.5 mg/kg of complete feed mixture givenad libitum to different groups. The data recorded were feed consumption, body weight gain, slaughter weight, biochemical and haematological data including serum immunoglobulin A, clinical condition and post-mortem pathology including histopathology.Significantly decreasing body weight gain throughout the experimental period, decreased slaughter weight and reduced feed utilization efficiency were observed for the group fed a diet containing 3.5 mg/kg of DON. At the same DON concentration, there were increased liver weights and decreased concentrations of serum protein and albumin, and a temporary fall in packed blood cell volume, serum calcium and serum phosphorus. For the groups fed diets containing 1.7 and 3.5 mg/kg of DON, a statistically significant, dose-related decrease in daily feed consumption was observed. No other effects on haematological, biochemical or immunological parameters were recorded. The carcass quality was not affected in any group.It was concluded that significant effects in growing pigs may be observed at a dietary DON concentration of 1.7 mg/kg, originating from naturally contaminated oats included in a diet that was otherwise adequate and contained only minor traces of other mycotoxins.Abbreviations ALAT alanine aminotransferase - ASAT aspartate aminotransferase - CFU colony-forming units - DON deoxynivalenol - 3-ac-DON 3-acetyl-deoxynivalenol - F.U. feed unit - FUS-X fusarenon-X - HPLC high-pressure liquid chromatography - IgA immunoglobulin A - NFSA nutrient-free sporulation agar - NIV nivalenol - PDA potato dextrose agar     

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.     

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.     

On the effects of a chronic deoxynivalenol intoxication on performance, haematological and serum parameters of pigs when diets are offered either for ad libitum consumption or fed restrictively

Wheat infected naturally with Fusarium, contaminated mainly with deoxynivalenol (DON) (16.6 mg DON/kg), was added to a total constant wheat content of 400 g/kg diet. To distinguish between differences in feed intake and specific effects of the DON contaminated diet, control and DON contaminated feed was administered for 11 weeks under ad libitum and restrictive feeding conditions to 48 pigs of both sexes, which were randomly divided into four groups (n = 12 per group). Feed intake was 2.90 kg/day, live weight gain 987 g/day and feed to gain ratio 2.77 kg/kg for the ad libitum fed control group. The group fed DON contaminated wheat ad libitum significantly consumed 15% less feed and gained 13% less live weight, while the feed to gain ratio was unaffected. Moreover, it was concluded that the lower growth performance by DON contaminated feed resulted mainly from the lower voluntary feed intake, because there were no differences in live weight gain between the groups with the restrictive feeding regimen. On the contrary, metabolizable energy, nitrogen retention digestibility of organic matter, crude protein, crude fat and crude fibre were significantly increased by 3, 10, 3, 6, 9 and 20% in the DON group respectively. Animals fed DON contaminated diets needed more time to consume the restrictive ration than the control group. For example in the first hour after feeding 85% of the control pigs had consumed all feed, but only 39% of the DON group had. There were only few differences in haematological and serum parameters, which were characterized by a high variation between individuals. DON and IgA concentrations in serum were significantly influenced by DON exposure.     

镰刀菌毒素对断奶仔猪血清酶、肝脏抗氧化功能及组织病理学的影响

试验旨在研究镰刀菌毒素污染日粮对断奶仔猪血清酶、肝脏抗氧化功能及组织病理学的影响。选择35日龄体重为(8.45±0.94) kg的健康三元杂交(杜×长×大)断奶雌性仔猪40头,随机分为2组,每组20个重复,每个重复1头猪。对照组饲喂基础日粮,试验组饲喂用霉变玉米和霉变玉米蛋白粉替代基础日粮中50%的玉米和玉米蛋白粉配制而成的镰刀菌毒素污染日粮(玉米赤霉烯酮(ZEN) 0.90 mg/kg,呕吐毒素(DON) 1.43 mg/kg,烟曲霉毒素(FUM) 5.85 mg/kg)。仔猪单栏饲喂,预试期7 d,正试期35 d。结果表明:①与对照组相比,试验组断奶仔猪血清中谷草转氨酶(AST)、谷丙转氨酶(ALT)和碱性磷酸酶(ALP)活性均显著升高(P<0.05),肝脏相对重显著降低(P<0.05);②与对照组相比,试验组断奶仔猪血清和肝脏中谷胱甘肽过氧化物酶(GSH-Px)和总超氧化物歧化酶(T-SOD)活性均显著降低(P<0.05),而丙二醛(MDA)含量显著升高(P<0.05);③病理组织学观察发现,试验组断奶仔猪肝脏出现一定程度的组织损伤,部分肝小叶边缘发生明显的炎性细胞浸润,肝细胞发生局部空泡变性。由此可知,镰刀菌毒素污染日粮(0.90 mg/kg ZEN,1.43 mg/kg DON,5.85 mg/kg FUM)饲喂断奶仔猪可引起仔猪血清酶活性改变,肝脏抗氧化功能降低,肝脏组织出现一定程度的病理损伤,从而影响肝脏功能的发挥。