Effect of Fusarium roseum corn culture containing zearalenone on early pregnancy in swine

A corn culture of Fusarium roseum was added to a standard corn-soybean swine gestation ration. Low, middle, and high dosage mixed feeds contained 7, 38, and 64 mg of zearalenone/kg of feed (7, 38, and 64 ppm) and 0.5, 2.5, and 4.5 mg of deoxynivalenol/kg, respectively. Control feed was the standard ration without added F roseum corn culture. Mature gilts were bred by natural service and fed control or F roseum molded feed from 3 to 34 days after breeding. The main effect of the molded feed was an inhibition of fetal development, with decreased numbers of fetuses present in treated animals at slaughter (38 to 43 days after breeding). Normal litters were present in 7 of 8 control animals, in 2 of 4 gilts given the low-dosage feed, in 1 of 4 gilts given the medium dosage, and in 0 of 4 given the high-dosage feed. Corpora lutea were maintained in all treated animals, as evidenced by serum progesterone concentrations. Serum estradiol concentrations were decreased in gilts in the middle- and high-dosage groups. The genital system of the gilts fed low- and middle-dosage feeds had a gross and microscopic appearance similar to that of the pregnant controls and reflected prolonged progesterone stimulation. Morphologic changes in the genital system of the high-dosage group were intermediate between changes induced by progesterone and those induced by estrogen. Clinical signs of hyperestrogenism and partial feed refusal were noticed in only some of the high-dosage group animals.     

Effects of the mycotoxin zearalenone on swine reproduction

Concentrations of 25, 50, or 100 ppm of 95% purified zearalenone fed to groups of healthy, multiparous sows during preestrus or throughout the gestation period (or both) produced multiple reproductive deficiencies. These reproductive disorders included infertility, constant estrus, pseudopregnancy, diminished fertility, reduced litter size, smaller offspring, malformation, juvenile hyperestrogenism, and probably fetal resorption. Gross and histologic examinations of sows revealed lesions in the reproductive organs. Marked epithelial changes characterized by squamous metaplasia were noticed in the uterus, uterine duct, cervix, vagina, and mammary glands.     

母猪玉米赤霉烯酮中毒的诊断

玉米赤霉烯酮是由禾谷镰刀菌产生的代谢物质，它是一种生长在玉米、高梁和小麦上的具有雌激素样作用的霉菌毒素。玉米赤霉烯酮是一种取代的2，4-二羟基苯甲酸内酯，其结构与牛用合成代谢剂玉米霉醇相似。饲喂这种发霉变质的谷物饲料，可引起母猪的繁殖障碍，怀孕母猪流产，后备母猪屡配不孕，生长期小母猪阴道炎等。     

Effect of dietary phosphorus on selenium retention in postweaning swine

Two experiments were conducted to evaluate the effect of dietary Se and P levels on Se retention in postweaning swine. A 20% protein corn-soybean meal diet at two dietary Se levels (.3 and 5.0 ppm) and four total P levels (.50, .70, .90, 1.10%) were fed. Supplemental Se was provided from sodium selenite with inorganic P from dicalcium phosphate. In Exp. I, 151 pigs weaned at 4 wk of age were allotted by sex, litter and weight and fed their treatment diets for 28 d after a 7-d adjustment to a basal diet. Dietary Se level had no effect on performance measurements. As dietary P level increased, there was an increase in daily gain, feed intake and a decrease in feed to gain ratio. Dietary P resulted in similar plasma, longissimus muscle and kidney tissue Se values within each dietary Se level, while liver Se declined as dietary P level increased. Dietary P level had no effect on plasma, heart or liver glutathione peroxidase (GSH-Px) activity. In Exp. II, 32 barrows, after being fed their diets for a 28-d period, were placed in individual metabolism crates where a balance trial was conducted. Dietary P level reduced absolute and percentage Se retention, particularly at dietary P levels of .90 and 1.10%. Phosphorus retention was not affected by dietary Se. Neither dietary P nor Se level had any effect on N retention. These results suggest an effect of dietary P level on Se retention and liver Se, particularly at dietary P levels above the pig's P requirement, while the effect is minimal at or below the pig's P requirement.     

Effect of dietary calcium on selenium retention in postweaning swine

Two experiments were conducted to evaluate the effect of dietary Se and Ca on Se utilization in postweaning swine. Two levels of dietary Se (.3 or 5.0 ppm) supplemented as sodium selenite and four levels of total dietary Ca (.50, .80, 1.10 or 1.40%) in a 20% protein, corn-soybean meal diet were evaluated. Inorganic Ca was supplied from dicalcium phosphate and limestone. In Exp. I, 135 pigs weaned at 4 wk of age were allotted by sex, litter and weight and fed a basal diet for 7 d and then their treatment diets for a 28-d period. Plasma and tissue were collected at the end of the trial for Se concentration and glutathione peroxidase (GSH-Px) activity. Dietary Ca had no effect on gain or feed measurements but 5.0 ppm Se depressed daily gain slightly. When 5.0 ppm dietary Se was fed, there resulted higher liver, kidney, heart and longissimus muscle Se concentrations than when .3 ppm was provided, but dietary Ca had no effect on tissue Se values within each dietary Se level. Plasma GSH-Px increased when higher dietary Se was provided, whereas neither heart nor liver GSH-Px activity was affected by dietary Se or Ca level. In Exp. II, a 5-d balance trial was conducted with 32 barrows after adjustment to their treatment diet for a 28-d period. Selenium retention increased quadratically as dietary Ca increased, whereas Ca retention was not affected by dietary Se. These results suggest that low dietary Ca levels may reduce total Se retention but not Se metabolism within body tissue.     

Effect of dietary cysteine supplements on canola meal toxicity and altered hepatic glutathione metabolism in the rat.

Experiments were conducted to determine the effects of feeding canola meal (Brassica campestris and Brassica napus) on the rat hepatic glutathione detoxification system and whether dietary cysteine supplements might modify such effects. Rats were fed test diets for 14 d. Body weight change, feed consumption, hepatic glutathione concentration, and hepatic glutathione-S-transferase (GSH-S-T) activities were determined. Weight gain was decreased when canola meal was fed, whereas hepatic glutathione concentrations increased, as did hepatic GSH-S-T activity. All effects correlated with total glucosinolate concentration in the canola meal. Dietary cysteine supplements, however, did not influence the growth reduction and increased hepatic glutathione concentrations caused by feeding canola meal. Supplemental cysteine prevented the elevation in hepatic GSH-S-T activity. The elevation in hepatic glutathione concentration caused by canola meals was not an overcompensation caused by an initial depletion and therefore reflected a general hepatotoxicity. Feeding supplemental cysteine increased hepatic glutathione levels at early time intervals and delayed the induction of GSH-S-T caused by canola meal toxicity. There was no beneficial effect of supplemental dietary cysteine in overcoming the toxicity of high levels of canola meal, but supplemental cysteine did modify the canola meal-induced changes in hepatic glutathione metabolism.     

苜蓿皂苷对SD大鼠胆固醇代谢的影响及其分子机理的初步探讨

研究了苜蓿皂苷对SD大鼠胆固醇代谢的影响,并初步探讨其分子机理。取雄性健康SD大鼠32只,随机分为4组,分别为:正常对照组、苜蓿皂苷组、高脂模型组和高脂皂苷组,每组8只。前4周为高脂模型建立期,后4周为灌胃期,正常对照组和苜蓿皂苷组饲喂基础饲粮,其余2组饲喂高脂饲粮,苜蓿皂苷组和高脂皂苷组从第5周开始灌胃240 mg/kg苜蓿皂苷,灌胃4周。测定试验大鼠体重、肝脏系数、血脂水平、粪便和肝脏中的胆固醇、胆汁酸含量,并用实时荧光定量PCR技术检测大鼠肝脏胆固醇7α-羟化酶(CYP7a1)和三磷酸腺苷结合盒转运体G5/三磷酸腺苷结合盒转运体G8(ABCG5/ABCG8) mRNA的表达量。结果表明,1)苜蓿皂苷显著降低高脂大鼠体重、肝脏系数;降低血清中总胆固醇含量,加速胆固醇向肝脏的聚集;增加粪便中胆固醇和胆汁酸的排出; 2)显著增加正常血脂水平大鼠粪便中胆固醇的含量,但对其体重、肝脏系数等影响不大;3)添加苜蓿皂苷后正常和高脂水平SD大鼠肝脏CYP7a1和ABCG5/ABCG8 mRNA的表达量均成倍增加。提示苜蓿皂苷能够调节SD大鼠体内胆固醇的分布,具有良好的降血脂效应,其效应可能与增加CYP7a1和ABCG5/ABCG8 mRNA表达量,加速体内胆固醇、胆汁酸排泄有关。     

Effect of dietary electrolyte balance on growth and acid-base status in swine

The effect of dietary electrolyte balance on pigs fed lysine- or tryptophan-adequate or tryptophan-deficient diets was investigated in four experiments using 8- to 12-wk-old pigs. Electrolyte balance, expressed as Na+K-Cl in meq/kg of diet, was varied by altering dietary levels of Na and Cl while holding all other minerals constant. In two experiments in which the basal diet contained a balance of 135 meq/kg, simple lysine or tryptophan deficiences caused depressed growth, feed intake and efficiency of feed utilization, but none of these responses was altered by dietary supplementation with NaHCO3. In one experiment in which the electrolyte balance of the basal diet was 61 meq/kg and in which both lysine and tryptophan were limiting. NaHCO3 supplementation significantly increased growth and feed intake. This did not occur if the diet was also supplemented with tryptophan. A final experiment was conducted to determine the response of pigs to a range of electrolyte balance (-85 to 341 meq/kg) in a practical corn-soy diet containing adequate levels of all amino acids. Growth and feed intake appeared to be maximal for balances of 0 to 341 meq/kg Na+K-Cl, but were decreased at -85 meq/kg (P less than .05). Acid-base balance was adversely affected at 0 meq/kg. The results suggest that the response of lysine-deficient pigs to sodium bicarbonate is dependent upon the electrolyte balance of the diet, and also is influenced by other dietary amino acids.     

硒中毒对猪血清自由基的影响

通过在仔猪基础日粮中添加亚硒酸钠,然后定期检测猪血清中的部分自由基及相关指标,以观察自由基在硒中毒猪体内的变化规律.结果表明硒中毒时,猪血清内的丙二醛(MDA)、羟自由基(·OH)和一氧化氮(NO)的含量明显升高,而超氧化物歧化酶(SOD)则明显降低,一氧化氮合酶(NOS)和NO的变化规律一致.结果显示自由基与硒中毒有着密切的关系.     

玉米赤霉烯酮对小鼠肝脏及肾脏的毒性作用

单剂量(50 mg/kg)连续3 d腹腔注射玉米霉烯酮(ZEA)后,肝脏出现弥漫性坏死、肝细胞局灶性脂肪变性;肾脏髓质、肾小管淤血,肾小球萎缩,近曲小管上皮细胞出现肿胀、颗粒变性.单剂量(100 mg/kg)单次腹腔注射ZEA后,血生化结果显示小鼠肝功能指标AST、ALT水平明显升高(P<0.05)、TP、ALB含量显著降低(P<0.05),肾脏功能指标尿素、尿酸水平明显升高(P<0.05).结果表明,ZEA肝脏、肾脏有严重的损害作用,能引发肝肾组织退行性变化,造成肝肾功能紊乱.     

玉米赤霉烯酮猪卵巢颗粒细胞的毒害及其解毒

玉米赤霉烯酮（zearalenone，ZEA），又称F-2毒素，是由镰刀菌产生的一种真菌毒素，也是一种植物雌激素，化学名为6-（10羟基-6氧基一十一-碳烯基）β-雷锁酸内酯。F-2毒素对畜禽的主要毒副作用表现为雌激素中毒，引起猪和牛的不孕和流产。近年来，养殖业中F-2毒素中毒现象发生频繁，如何对其进行有效的防治已成为研究热点，但尚未见有关F-2毒素对猪卵巢颗粒细胞毒害及其解毒的报道。本文采用体外细胞培养方法，研究F-2毒素对卵巢颗粒细胞的毒害作用，并探索维生素E对F-2毒素的解毒功效。     

干旱胁迫对紫花苜蓿叶片和根系多胺代谢的影响

采用盆栽试验方法研究了紫花苜蓿(品种:陇东) 叶片和根系中游离态腐胺(Put)、亚精胺(Spd)、精胺(Spm)及精氨酸脱羧酶(ADC)、鸟氨酸脱羧酶(ODC)、多胺氧化酶(PAO)活性的动态变化。结果表明,干旱胁迫下紫花苜蓿叶片和根系中的多胺含量增加,随着胁迫时间的延长, Put、Spd、Spm及ADC、ODC、PAO活性均呈先上升后下降的趋势,且随胁迫程度加重而增大。ADC、ODC活性与Put含量呈极显著正相关,参与了紫花苜蓿Put的合成代谢。PAO活性与Spd、Spm含量变化趋势相似且呈极显著相关关系,叶和根中多胺代谢显著相关,表明多胺代谢与紫花苜蓿抗旱性关系密切。     

Characterization of effects of zearalenone in swine during early pregnancy

Mature gilts (n = 16) were hand mated and randomly assigned to 1 of 4 groups of 4 gilts each. Treated gilts had 108 mg of purified zearalenone added to their diet on postmating days (PMD) 2 to 6, 7 to 10, or 11 to 15. Control gilts were given the same diet without added zearalenone. On PMD 6, 10, and 15, control gilts had venous cannulas placed in the jugular vein, and blood samples were taken at 20-minute intervals for 4 hours before feeding and 4 hours after feeding. Samples were collected from treated gilts on the last day that zearalenone was consumed. Samples were analyzed for follicle stimulating hormone, luteinizing hormone (LH), and prolactin. Single blood samples were taken by venipuncture on PMD 8, 12, 16, 20, 24, and 28 and at euthanasia and were analyzed for serum concentration of progesterone and estradiol-17 beta. All gilts were euthanatized 30 to 32 days after mating, and fetal development was assessed. Three gilts that were given zearalenone on PMD 7 to 10 were not pregnant and had regressing corpora lutea on the ovaries at euthanasia. All other treated and control gilts were pregnant. Serum samples from treated gilts on PMD 10 and 15 had lower mean prolactin concentrations than did those from controls. The number of LH spikes were fewer (P less than 0.05) in gilts that were given zearalenone on PMD 15 compared with those in controls on PMD 15. Serum progesterone concentrations indicated that corpora lutea regressed between PMD 20 and 28 in nonpregnant gilts.(ABSTRACT TRUNCATED AT 250 WORDS)     

Natural contamination of dietary rice straw with zearalenone and urinary zearalenone concentrations in a cattle herd

The present study was conducted to 1) identify the natural source of feed contamination by zearalenone (ZEN), which was suspected to have caused persistently increased urinary ZEN concentrations in one of our experimental cattle herds, and 2) evaluate the effects of intervention against this source of contamination. As an experimental model, a fattening Japanese Black cattle herd showing persistently increased urinary ZEN concentrations was identified. Urinary ZEN concentrations of cows fed with new rice straw (experimental group, n = 6) vs. cows that continued to feed on the old rice straw (control group, n = 4) were measured at the start (d 1) and at 2 wk (d 14) after the onset of feeding with straw. In addition, the ZEN concentration in feed and water samples was measured by using both the ELISA and HPLC methods. Furthermore, isolation and identification of fungi from rice straw and concentrate feed samples were performed. The urinary ZEN concentration [ZEN (pg/mL)/creatinine (mg/mL) = pg/mg of creatinine] of cows fed with new rice straw was significantly (P < 0.05) less (843 pg/mg of creatinine) than that of cows fed with old rice straw (15,951 pg/mg of creatinine). On both d 1 and 14, the ZEN concentrations of old rice straw were greater than those of new rice straw. In addition, fungal colonies were observed in the culture media that was obtained from the old rice straw suspected of ZEN contamination, but not in the culture media from new rice straw or other feed samples. In conclusion, our field trials clearly indicate that the rice straw fed to the cows was naturally contaminated with ZEN, and that the monitoring of urinary ZEN concentrations could prove to be a useful tool for detecting the exposure of cattle to ZEN contamination at the farm level.     

Kinetics and metabolism of zearalenone in young female pigs

The fate of a single bolus of the Fusarium mycotoxin zearalenone (ZON) given intravenously to pigs was followed up. Pigs were equipped with duodenal re-entrant cannulas, post-valvular T-shape cannulas and with a urinary bladder balloon catheter. The animals were divided into three groups. Pigs of the control group were injected with ZON (Co), and pigs of the second group were also injected with ZON but their duodenal digesta was quantitatively exchanged for 12 h with corresponding pigs of the third group, not injected with ZON. Therefore, the second group had a disrupted entero-hepatic cycling of ZON (DEHC) and the third one had an induced entero-hepatic cycling of ZON (IEHC). The kinetic profile of ZON and its metabolites in plasma and their flow with urine, duodenal and ileal digesta and with faeces was examined over the next 72 h after the bolus was given. Eleven days later, pigs were slaughtered for collection of bile, urine and liver to analyse ZON residues. In all specimens examined, alpha-zearalenol (ZOL) was detected as the only metabolite of ZON. Kinetic evaluation of the plasma data revealed that the terminal elimination half-life of ZON was reduced from 2.63 h in pigs of Co-group to 1.1 h when EHC of ZON was disrupted for 12 h (DEHC-group). The maximum ZON concentration in plasma of pigs with the IEHC was found at 2.73 h after the bolus was given to their counterparts. The percentage of the alpha-ZOL- and ZON-area under the curves (AUC) estimated for the IEHC-group amounted to approximately 18% of the corresponding AUC of the Co-group which would suggest that a substantial proportion of both substances are re-cycled via entero-hepatic re-circulation. Cumulative recovery of ZON and alpha-ZOL, expressed as percentage of the ZON-bolus was characterized by a saturation kinetics in urine and duodenal digesta, and after 72 h, the respective values for Co-, DEH-, and IEHC-groups were 70%, 55% and 12%; and 35%, 22% and 11%. Faecal excretion started to increase steeply after 48 h and still continued to increase after 72 h when the cumulative excretion was 6%, 3% and 2% for Co-, DEHC- and IEHC-groups respectively. Fourteen days after the bolus injection, ZON and alpha-ZOL concentrations in bile, liver and urine were lower than the detection limits of the applied method. The results would suggest that within this period of time a massive single bolus of ZON is nearly completely eliminated from the body.     

苜蓿黄酮对雌性大鼠生长和繁殖性能的影响

为了研究苜蓿黄酮对大鼠生长、繁殖及内分泌系统的影响,本实验设计了3个苜蓿黄酮剂量组(120,400,1 200 mg/kg)和2个对照组(己烯雌酚0.5 mg/kg、空白对照组)。通过化学发光法对大鼠雌二醇(E2)、催乳素(PRL)、孕酮(P)、生长激素(GH)检测,并对大鼠繁殖相关的指标,包括子宫湿重/系数、卵巢湿重/系数、采食量、日增重、产仔数、初生窝重进行测定。结果显示,低剂量的苜蓿黄酮显著提高了性成熟雌鼠的E2水平以及子宫湿重/系数(P<0.05),显著降低了卵巢湿重/系数(P<0.05)。对未性成熟雌鼠,苜蓿黄酮对激素的影响不显著,但中、低剂量组显著降低了子宫湿重(P<0.05)。此外,苜蓿黄酮和对照组比,在采食量上不存在显著差异,但性成熟大鼠的产仔数和初生窝重有提高的趋势,中、高剂量组的产仔数和空白对照比,分别提高0.4%和2.2%。中、高剂量组的初生窝重和空白对照比,分别提高5.14%和0.10%,但差异性并不显著(P>0.05)。配种前灌胃不同剂量的苜蓿黄酮在一定程度上影响了性成熟和未性成熟雌鼠的激素分泌和生殖器官的发育, 但未能明显改善雌鼠的繁殖性能。     

Effect of water restriction and dietary sodium on nutrient metabolism in lambs

Twenty-four Hampshire X Suffolk wether lambs (40 kg) were used in 2 X 2 factorial arrangement of treatments to study the influence of water restriction and high levels of dietary Na on nutrient utilization. Lambs were offered either a normal Na diet (.20% Na) or a high Na diet (1.77% Na). Additionally, the lambs were offered either a normal quantity of water (previously determined voluntary intake of lambs fed normal Na levels) or were restricted to a water intake 80% of normal. Each lamb received 800 g/d of a hay-corn diet (77.5% fescue hay) with an additional 38 g of NaCl offered to lambs on high Na treatments. The complete experiment consisted of 14 d of adjustment and 7 d of total collection with blood and ruminal characteristics measured on the last day of the collection period. A high Na intake decreased (P less than .05) the apparent digestibility of neutral detergent fiber, but tended to increase the apparent absorption of Mg. Plasma urea N concentrations were not affected (P greater than .05) by level of Na or water intake. Plasma Na and K concentrations were not affected (P greater than .05) by treatment regimen. A high Na intake increased (P less than .05) plasma Mg concentrations at 6 h post-feeding with a normal level of water intake, but decreased (P less than .05) Mg concentrations at 6 h with restricted water intake. Ruminal ammonia N and K concentrations at 2 h post-feeding were decreased (P less than .05) by a high level of dietary Na. Ruminal Na concentration was not affected (P greater than .05) by treatment.(ABSTRACT TRUNCATED AT 250 WORDS)