微生物发酵配合饲料对断奶仔猪生产性能的影响

试验选用25日龄体重相近、健康度良好的杜长大三元杂交断奶仔猪120头,随机分为3组,每组5个重复,每个重复8头猪(公母各半)。对照组为基础日粮+抗生素+酸化剂,试验1组为基础日粮+发酵剂A(1 kg/t)发酵,试验2组为基础日粮+发酵剂B(1 kg/t)发酵,旨在研究微生物发酵配合饲料对断奶仔猪生产性能的影响。结果表明,配合饲料添加微生态制剂发酵后,饲料pH值分别降低0.77和0.68(P0.01)。与对照组相比,饲喂发酵配合饲料的2个试验组仔猪采食量有提高的趋势,腹泻率有降低的趋势,料重比有增加的趋势,但差异均未达到显著水平(P0.05)。     

自然霉变饲粮添加酵母细胞壁对仔猪养分消化率和消化酶活性的影响

本试验旨在研究自然霉变饲粮添加酵母细胞壁(YCW)对仔猪养分消化率、肠道消化酶活性的影响。选取40头体重相近(8.32±0.49)kg健康的三元(杜×长×大)杂交仔猪,随机分为4个处理,每个处理10个重复。对照组用优质玉米和玉米蛋白粉配制基础饲粮,50%M组(玉米赤霉烯酮849.4μg/kg;伏马毒素5 661.55μg/kg;呕吐毒素1 576.80μg/kg)为霉变玉米和玉米蛋白粉替代对照组中50%的玉米和玉米蛋白粉,0.10%YCW和0.25%YCW组为50%M组基础上添加0.10%和0.25%的YCW。结果表明:自然霉变饲粮显著降低仔猪养分消化率及十二指肠和空肠淀粉酶(AMS)、胰蛋白酶(TRS)和脂肪酶活性(LPS)(P0.05);YCW显著改善仔猪养分消化率以及消化酶活性(P0.05),并具有剂量效应。由此可知,自然霉变饲粮降低了仔猪养分消化率及AMS、TRS和LPS活性,酵母细胞壁具有一定的改善和脱毒效果。     

低聚木糖和酸化剂对断奶仔猪生产性能的影响

试验通过在仔猪日粮中添加低聚木糖和酸化剂,来研究其对早期断奶仔猪增重、料重比以及腹泻率的影响,并探讨低聚木糖与酸化剂是否具有协同作用.按体重和性别分成4个处理组:对照组(饲喂玉米-豆粕基础日粮)、低聚木糖(200 mg/kg)组、酸化剂(8 g/kg)组、合用组(添加低聚木糖(200 mg/kg)和酸化剂(8 g/kg)).结果表明,试验组平均日增重、料重比得到改善(P＜0.05),腹泻率显著下降(P＜0.01).研究认为低聚木糖和酸化剂合用可在一定程度上提高断奶仔猪的生产性能.     

日粮亮氨酸水平与宫内发育迟缓对断奶仔猪肝脏抗氧化功能的影响

研究日粮亮氨酸水平与宫内发育迟缓(IUGR)对断奶仔猪肝脏抗氧化功能的影响。挑选16头正常初生重(NBW)仔猪和16头IUGR仔猪,公母各半。仔猪于14日龄断奶,采用2×2因子设计,一半NBW与IUGR断奶仔猪饲喂基础日粮,剩余断奶仔猪饲喂添加0.35%亮氨酸的实验日粮,即4个处理组,每个处理组8个重复,每个重复1头仔猪。实验期为21 d。结果表明:与NBW断奶仔猪相比,IUGR断奶仔猪肝脏总超氧化物歧化酶(T-SOD)活力显著降低,丙二醛(MDA)含量显著升高(p0.05)。IUGR断奶仔猪肝脏线粒体锰超氧化物歧化酶(Mn-SOD)活力、谷胱甘肽过氧化物酶(GSH-Px)活力、还原型谷胱甘肽(GSH)含量较NBW断奶仔猪均显著降低(p0.05)。另外,IUGR显著降低断奶仔猪肝脏核转录因子2(Nrf2)、超氧化物歧化酶1(SOD1)、超氧化物歧化酶2(SOD2)、谷胱甘肽过氧化物酶1(GPx1)mRNA表达量(p0.05)。日粮添加0.35%亮氨酸可显著降低断奶仔猪肝脏MDA含量,显著提高SOD2 mRNA表达量(p0.05)。高亮氨酸水平日粮可显著缓解IUGR介导断奶仔猪线粒体GSH含量降低与肝脏SOD2和GPx1mRNA表达下调(p0.05)。因此,日粮添加0.35%亮氨酸,可降低断奶仔猪肝脏脂质过氧化程度,一定程度缓解了IUGR对断奶仔猪肝脏抗氧化功能的不良影响。     

有机铬对母猪繁殖性能及其仔猪生长的影响

选择胎次、体重及体况相近的长×约二元杂交经产母猪 14头 ,随机分成对照组和试验组两组进行饲养试验。从配种日起 ,至仔猪断奶后母猪下一次发情为止。对照组饲喂实用饲粮 (不添加有机铬制剂 ,含铬 0 μg/kg) ;试验组饲喂试验饲粮 (实用饲粮中添加有机铬制剂 ,含铬2 0 0 μg/kg)。研究结果表明 ,与对照组比较 ,试验组母猪繁殖性能有所改善 ,窝产活仔数增加4.0 7% (P >0 .0 5 ) ,初生活仔猪窝重增加 7.48% (P >0 .0 5 ) ;2 1日龄窝活仔数增加 10 .0 0 %(P >0 .0 5 ) ,窝重增加 2 2 .39% (P <0 .0 5 ) ,个体重增加 11.33% (P <0 .0 5 ) ;2 9日龄断奶窝仔猪数增加 10 .30 % ,断奶窝重增加 12 .5 8%。     

低聚壳聚糖对断奶仔猪血清生化指标、抗氧化性能和粪便微生物的影响

研究在断奶仔猪饲粮中添加不同水平的低聚壳聚糖对其血清生化指标、抗氧化性能及粪便菌群的影响.结果显示:与未添加低聚壳聚糖组相比,低聚壳聚糖组断奶仔猪血清总蛋白、白蛋白、球蛋白、总胆固醇和低密度脂蛋白胆回醇差异不显著(P＞0.05);100mg/kg低聚壳聚糖组的谷草转氨酶活性极显著提高(P＜0.01),碱性磷酸酶活性极显著降低(P＜0.01);50、100mg/kg低聚壳聚糖组过氧化氢酶活性提高显著(P＜0.05);低聚壳聚糖对血清中的三碘甲状腺原氨酸、甲状腺素均有提高趋势,其中添加25 mg/kg可显著提高血清中生长激素含量(P＜0.05);低聚壳聚糖组断奶仔猪粪便中大肠杆菌、乳酸杆菌数量均呈下降趋势,其中添加50 mg/kg低聚壳聚糖可显著降低大肠杆菌的数量(P＜0.05).低聚壳聚糖适宜的添加水平为50 mg/kg.     

饲粮中添加不同抗氧化剂对熟化期羊肉嫩度的影响及动力学分析

选取100只遗传背景一致的3月龄断奶湖羊公羔,随机分为10组,每组10只。对照组(CON组)饲喂基础饲粮,苜蓿皂苷(alfalfa saponins,AS)处理组的添加水平分别为500(AS500)、1 000(AS1000)、2 000(AS2000)、4 000(AS4000)mg/kg基础日粮,番茄红素(lycopene,LP)处理组的添加水平分别为200(LP200)、400(LP400)mg/kg基础日粮,维生素E(vitamin E,VE)处理组的添加水平分别为200(VE200)、400(VE400)、2 000(VE2000)mg/kg基础日粮。90 d饲养实验结束后屠宰,取羊肉半膜肌,测定其在熟化期的剪切力,研究饲粮中添加不同种类和水平的抗氧化剂对熟化期湖羊半膜肌嫩度的影响。结果表明:不同熟化时间和不同添加水平的抗氧化剂对羊肉嫩度有极显著影响,熟化期第5天羊肉嫩度的变化最大,饲粮中单独添加1 000~4 000 mg/kg基础日粮的AS、200 mg/kg基础日粮的LP或200 mg/kg基础日粮的VE可以不同程度地改善熟化期的羊肉嫩度;动力学分析表明,CON组的嫩度变化既符合零级反应也符合一级反应,AS和VE处理组的嫩度变化更符合一级反应,而LP处理组的嫩度变化符合零级反应。由此可见,选择适宜种类和添加水平的抗氧化剂可以改善熟化期羊肉的嫩度。     

蛹虫草菌发酵五味子药渣菌质的免疫活性

为了研究蛹虫草菌发酵五味子药渣菌质的免疫活性,选择28日龄"杜×长×大"断奶仔猪90头,随机分为空白对照组(基础日粮)、阳性对照组(基础日粮添加0.5%的五味子)和实验组(基础日粮添加0.2%的蛹虫草菌发酵五味子药渣菌质),每组3个重复。实验期21d。每周从每个重复中随机选取1头,流式细胞仪检测脾脏T淋巴细胞亚群分类,CCK-8法检测脾脏淋巴细胞增殖活性,ELISA检测血清中IgA、IgG和IgM含量。结果表明:阳性对照和实验组脾脏CD3+、CD3+CD4+百分率,CD4+/CD8+比值在1~3周均高于空白对照组(p<0.05或p<0.01);脾脏淋巴细胞增殖指数显著提高(p<0.01),血清免疫球蛋白IgA、IgG和IgM含量升高。实验表明:五味子药渣经蛹虫草菌发酵后能提高仔猪的免疫功能。     

姜黄素对宫内发育迟缓断奶仔猪肠道抗氧化功能的影响

目的：探讨姜黄素对宫内发育迟缓（intrauterine growth retardation,IUGR）断奶仔猪肠道抗氧化功能的影响。方法：选取16 头正常初生体质量（normal birth mass,NBM）仔猪和16 头IUGR仔猪,公母各半。26 日龄断奶,分别饲喂基础日粮或姜黄素日粮（基础日粮＋400 mg/kg姜黄素）,分为N组（NBM仔猪＋基础日粮）、NC组（NBM仔猪＋姜黄素日粮）、I组（IUGR仔猪＋基础日粮）和IC组（IUGR仔猪＋姜黄素日粮）,每组8 头。饲养至50 日龄屠宰取样,进行抗氧化指标的检测。结果：1）日粮中添加姜黄素后,与I组相比,IC组仔猪空肠蛋白质羰基（protein carbonyl,PC）、8-羟化脱氧鸟苷的含量和回肠丙二醛、PC的含量显著降低（P＜0.05）;2）与I组相比,IC组仔猪空肠总抗氧化能力、过氧化氢酶（catalase,CAT）活力显著升高（P＜0.05）,谷胱甘肽含量显著增多（P＜0.05）;回肠CAT活力显著升高（P＜0.05）,过氧化氢（H2O2）含量显著降低（P＜0.05）;3）与I组相比,IC组仔猪空肠核因子E2相关因子2（nuclear factor- erythroid 2-related factor 2,Nrf2）、CAT、超氧化物歧化酶、谷胱甘肽硫转移酶（glutathione S-transferase,GST）和NAD(P)H:醌氧化还原酶（NAD(P)H : quinone oxidoreductase l,NQO1）基因的表达显著升高（P＜0.05）;回肠Nrf2、GST、NQO1和硫氧还蛋白还原酶基因的表达显著升高（P＜0.05）。结论：向日粮中添加400 mg/kg姜黄素对缓解IUGR诱导的仔猪肠道氧化应激、提高肠道抗氧化功能有一定作用。     

饲粮中添加甘露寡糖对肉仔鸡生长性能及组织天然免疫相关基因表达的影响

旨在探讨饲粮中添加不同浓度甘露寡糖(MOS)对肉仔鸡生长性能及肝脏、脾脏、回肠和盲肠中Toll样受体(TLR)和抗菌肽等天然免疫基因表达的影响。选用176只1日龄雄性科宝-500白羽肉仔鸡,随机分成4个处理组,每组4个重复,每个重复11只鸡,四个处理组分别饲喂在基础饲粮中添加0.0、0.3、0.6和0.9 g/kg甘露寡糖的饲粮,试验时间为42 d。结果表明:与对照组相比,饲粮中添加0.3～0.9 g/kg MOS显著提高肉仔鸡1～42日龄的平均日采食量和平均日增重(P0.05或P0.01);饲粮添加MOS显著提高肉仔鸡21日龄法氏囊指数和42日龄胸腺指数(P0.05)。与对照组相比,饲粮中添加MOS可不同程度地提高21和42日龄肉鸡回肠、盲肠、肝脏和脾脏TLR2、TLR4、β-防御素9(AvBD9)和cathelicidin-B1(Cath-B1)mRNA表达(P0.05或P0.01)。饲粮中添加适宜水平的MOS可不同程度地提高肉仔鸡生长性能,并可能通过提高肉仔鸡组织TLRs表达并由TLRs介导上调β-防御素和cathelicidins等抗菌肽表达而提高肉仔鸡天然免疫防御功能。     

Individual and combined effects of subclinical doses of deoxynivalenol and fumonisins in piglets

Scope: Deoxynivalenol (DON) and fumonisins (FB) are the most frequently encountered mycotoxins produced by Fusarium species and most commonly co‐occur in animal diets. These mycotoxins were studied for their toxicity in piglets on several parameters including plasma biochemistry, organ histopathology and immune response. Methods and results: Twenty‐four 5‐wk‐old animals were randomly assigned to four different groups, receiving separate diets for 5 wk, a control diet, a diet contaminated with either DON (3 mg/kg) or FB (6 mg/kg) or both toxins. At days 4 and 16 of the trial, the animals were subcutaneously immunized with ovalbumin to assess their specific immune response. The different diets did not affect animal performance and had minimal effect on hematological and biochemical blood parameters. By contrast, DON and FB induced histopathological lesions in the liver, the lungs and the kidneys of exposed animals. The liver was significantly more affected when the two mycotoxins were present simultaneously. The contaminated diets also altered the specific immune response upon vaccination as measured by reduced anti‐ovalbumin IgG level in the plasma and reduced lymphocyte proliferation upon antigenic stimulation. Because cytokines play a key role in immunity, the expression levels of IL‐8, IL‐1β, IL‐6 and macrophage inflammatory protein‐1β were measured by RT‐PCR at the end of the experiment. The expression of these four cytokines was significantly decreased in the spleen of piglets exposed to multi‐contaminated diet. Conclusion: Taken together, our data indicate that ingestion of multi‐contaminated diet induces greater histopathological lesions and higher immune suppression than ingestion of mono‐contaminated diets.     

Effect of the ratio of zinc amino acid complex to zinc sulfate on the performance of Holstein cows

Multiparous (n = 70) and primiparous (n = 66) Holstein cows were balanced by 305-d previous mature-equivalent milk yield and parity and assigned to 1 of 3 dietary treatments to evaluate the ratio of zinc sulfate to zinc amino acid complex (CZ) in pre- and postpartum Holstein cows fed diets containing 75 mg of added zinc/kg. Treatments were (1) 75 mg of supplemental zinc/kg of dry matter (DM) provided entirely as zinc sulfate (0-CZ); (2) 0-CZ diet, except 33.3 mg of zinc sulfate/kg of DM in the prepartum and 15.5 mg of zinc sulfate/kg of DM in the postpartum diet were replaced by CZ from Availa-Zn (16-CZ; Zinpro Corp., Eden Prairie MN); and (3) 0-CZ diet, except 66.6 mg of zinc sulfate/kg of DM in the prepartum and 40.0 mg of zinc sulfate/kg of DM in the postpartum diet was replaced by Availa-Zn (40-CZ). Cows were housed at the Iowa State University Dairy Farm and were individually offered a total mixed ration containing dietary treatments beginning at 28 ± 15 d before expected calving date until 250 d in milk. Relative to 0-CZ, multiparous cows (but not primiparous) fed CZ (16-CZ or 40-CZ) had increased (20%) colostrum IgG concentrations. Prepartum DM intake (DMI) was decreased with CZ supplementation. Postpartum DMI was decreased in cows fed CZ, whereas milk yield (MY) was increased in the 40-CZ-fed cows relative to those fed both 0-CZ and 16-CZ. Feed efficiency increased linearly when measured as MY/DMI, 3.5% fat-corrected MY/DMI, and solids-corrected MY/DMI. Regardless of level, feeding CZ decreased services per conception. Feeding 16-CZ decreased milk fat concentration and feeding CZ linearly increased milk urea nitrogen concentration. In summary, supplementing zinc as a mixture of CZ and zinc sulfate, as opposed to supplementing only zinc sulfate, has beneficial effects on production parameters in dairy cows, with those benefits becoming more apparent as the ratio of CZ to zinc sulfate increases.     

Efficacy of feeding hydroxy-selenomethionine on plasma and milk selenium in mid-lactation dairy cows

In this study, we aimed to determine the amount of Se transferred to milk and blood of mid- to late-lactation dairy cows when supplemental Se from hydroxy-selenomethionine (OH-SeMet) was fed compared with an unsupplemented group and a group supplemented with a seleno-yeast (SY). Twenty-four lactating Holstein cows (178 ± 43 d in milk) were used in a complete randomized block design for 91 d (7-d covariate period and 84-d treatment period). Treatments were (1) basal diet with an analyzed Se background of 0.2 mg of Se per kg as-fed (control); (2) basal diet + 0.3 mg of Se/kg as-fed from SY (SY-0.3); (3) basal diet + 0.1 mg of Se/kg as-fed from OH-SeMet (OH-SeMet-0.1); and (4) basal diet + 0.3 mg of Se/kg as-fed from OH-SeMet (OH-SeMet-0.3). During the trial, plasma and milk were analyzed for total Se, and plasma was analyzed for glutathione peroxidase activity. The mean plasma and milk Se concentrations exhibited the same relationship, where OH-SeMet-0.3 resulted in the highest values (142 µg/L of plasma and 104 µg/kg of milk), followed by SY-0.3 (134 µg/L and 85 µg/kg), OH-SeMet-0.1 (122 µg/L and 67 µg/kg), and the control group had the lowest values (120 µg/L and 50 µg/kg). The increment of Se in milk induced by OH-SeMet-0.3 (+54 µg/kg) was 54% higher than that induced by SY-0.3 (+35 µg/kg). Additionally, dietary supplementation of 0.2 mg/kg Se from OH-SeMet in the total mixed ration was estimated to be similar to 0.3 mg/kg Se from SY in the total mixed ration when considering the level of Se in the milk. There was no difference in plasma glutathione peroxidase activity between groups; however, OH-SeMet-0.3 significantly decreased somatic cell count. The results confirmed that supplementation with organic Se increases milk and plasma Se concentrations. Moreover, when administered at the same level of supplementation, OH-SeMet was shown to be more efficient than SY in improving milk quality by increasing Se content and decreasing milk somatic cell count.     

Effect of zinc source and dietary level on zinc metabolism in Holstein calves

Forty-eight Holstein male calves were stratified by origin and body weight and randomly assigned to one of 4 treatment groups. Dietary treatments were administered in 2 phases. In phase 1, treatment groups received the basal diet with no supplemental Zn (control), basal diet plus 20 mg of Zn/kg of DM as ZnSO4 or Zn proteinate (ZnProt), or basal diet plus 20 mg of Zn/kg of DM with 50% of the Zn supplied from each source (ZnM) for 98 d. In phase 2, calves continued to receive the same Zn source fed in phase 1; however, half of the calves in each treatment group were randomly selected to receive 500 mg of Zn/kg of DM (HiZnSO4, HiZnProt, HiZnM) for 14 d. Gain, feed intake, and feed efficiency of calves were not affected by treatment in either phase of the experiment. Treatment had no affect on plasma Zn concentration or alkaline phosphatase activity in phase 1, but liver Zn concentration was greater in calves fed ZnSO4 than those fed ZnProt. In phase 2, plasma Zn was greater in calves fed HiZnProt and HiZnM than in those fed HiZnSO4. Liver Zn was greater in calves fed HiZnProt than in those fed HiZnSO4. Duodenal Zn concentrations were greater in calves supplemented with HiZnProt and HiZnM than those supplemented with HiZnSO4. Liver metallothionein was greater in calves that received 500 mg of Zn/kg than in calves that received 20 mg of Zn/ kg, but was not affected by Zn source. Calves fed HiZnProt and HiZnM had greater kidney Zn concentrations than those fed HiZnSO4. Heart, spleen, testicular, and bone Zn concentrations were not affected by Zn source. Hoof wall samples contained nearly 3-fold greater Zn concentrations than hoof sole. Calves fed ZnSO4 had greater Zn concentration in hoof wall samples than those fed ZnM. Hoof sole Zn concentration was not affected by Zn source or concentration. Plasma and tissue Zn concentrations at harvest were generally similar in calves supplemented with 20 mg of Zn/kg from ZnSO4 or ZnProt. However, when supplemented at 500 mg of Zn/kg, ZnProt was absorbed to a greater extent than ZnSO4, based on higher plasma, liver, duodenal, and kidney Zn concentrations.     

高粱原花青素对生长育肥猪抗氧化、免疫以及养分消化率的影响

研究高粱原花青素(sorghum procyanidins,SPC)对生长育肥猪生长性能、养分消化率、消化酶活性、免疫力和抗氧化能力的影响。160头70日龄、平均体重为(31. 28±1. 12) kg的杜×长×大三元杂交猪,按照单因素完全随机设计分为4个组,分别饲喂玉米-豆粕基础日粮,以及基础日粮中添加100、150、200 mg/kg SPC。实验期为14周,生长期和育肥期各7周。在每个实验阶段开始和结束时称重,每天记录采食量,计算各阶段平均日增重(ADG)、平均日采食量(ADFI)和料重比(F/G)。在每个实验阶段的最后3 d,收集粪样测养分消化率。在每个实验阶段结束时,采血测血清抗氧化指数和免疫参数,同时,每个重复随机屠宰2头猪,取胰腺组织,测消化酶活性。结果表明,日粮添加SPC对生长育肥猪的生长性能没有显著的促进作用(P 0. 05)。在生长猪阶段,日粮添加150 mg/kg和200 mg/kg SPC显著降低了消化酶的活性,对养分消化率有降低的趋势。在育肥猪阶段,日粮添加150 mg/kg显著提高了粗蛋白的表观消化率(P 0. 05),200 mg/kg SPC显著地抑制了消化酶的活性(P 0. 05)。与对照组相比,不论是在生长期还是育肥期,添加150 mg/kg或200 mg/kg的SPC均显著地增强了猪血清谷胱甘肽过氧化物酶(GSH-Px)和超氧化物歧化酶(SOD)的活性以及血清总抗氧化能力(T-AOC)(P 0. 05),降低了血清丙二醛(MDA)浓度(P 0. 05),提高了猪血清IgG、IgM和白细胞介素2(IL-2)的浓度(P 0. 05)。总之,SPC有利于提高生长育肥猪抗氧化能力,增强免疫力,但是对于生长育肥猪的生长性能及养分消化率没有显著的促进作用,相反,高浓度的SPC甚至抑制了消化酶的活性,从而影响养分的消化利用。     

Influence of dietary α-tocopheryl acetate supplementation of pigs on oxidative deterioration and weight loss in sliced dry-cured ham

The effect of feeding high levels of α-tocopherol to pigs on the susceptibility to oxidative deterioration and weight loss in dry cured hams was investigated. The α-tocopherol concentration in thigh muscle from pigs fed the basal and the supplemented diet (200 mg kg(-1) α-tocopheryl acetate) in unprocessed thighs was 8.69 and 16.87, μg g(-1) dry matter, not including ash, respectively (p-value=0.015), while the concentration was 6.65 and 14.28 μg g(-1), respectively, in the final products (p-value=0.011). Hams from pigs fed the basal diet oxidized more during storage (p-value=0.015) as measured by formation in thiobarbituric acid reactive substances and had a higher rate of weight loss (p-value=0.0001). The total loss in red color after 4 days of storage was similar in all treatments. However, the rate of discoloration was more pronounced during the first 2 days of storage in hams from pigs fed the basal diet (p-value=0.016). This result indicates that high dietary level of α-tocopheryl acetate to pigs increases the oxidative stability in dry cured hams manufactured on the basis of such pigs.     

Iodine in milk and meat of dairy cows fed different amounts of potassium iodide or ethylenediamine dihydroiodide

Relationships between I intake by lactating Holstein cows and iodine concentrations in milk and meat were investigated. Six treatment groups with seven cows assigned to each treatment were fed a basal diet containing .8 mg I/kg alone or supplemented with I at 1, 2, or 4 mg/kg in four 5-wk periods. Basal alone was fed in the first and third periods and the I supplement was potassium iodide in the second period and ethylenediamine dihydroiodide in the fourth period. Iodine concentrations in milk increased with each increase in dietary I from 205 ng/ml for basal periods to 404, 477, and 757 ng/ml when 1, 2, or 4 mg/kg I was fed as potassium iodide; and 467, 535, and 869 ng/ml when 1, 2, or 4 mg/kg I was fed as ethylenediamine dihydroiodide. Concentrations of I in skeletal muscle after the fourth period were not affected by 2 mg/kg I and only increased from 166 to 199 ng/g when supplemental I was 4 mg/kg. Moderate changes in dietary I are quickly reflected in milk I, but I in meat is relatively stable.     

Added dietary sulfur and molybdenum has a greater influence on hepatic copper concentration,intake, and performance in Holstein-Friesian dairy cows offered a grass silage- rather than corn silage-based diet

To test the hypothesis that the metabolism of Cu in dairy cows is affected by basal forage and added S and Mo, 56 dairy cows that were 35 (standard error ± 2.2) days postcalving and yielding 38.9 kg of milk/d (standard error ± 0.91) were offered 1 of 4 diets in a 2 × 2 factorial design for a 14-wk period. The 4 diets contained approximately 20 mg of Cu/kg of dry matter (DM), and had a corn silage-to-grass silage ratio of 0.75:0.25 (C) or 0.25:0.75 (G) and were either unsupplemented (?) or supplemented (+) with an additional 2 g of S/kg of DM and 6.5 mg of Mo/kg of DM. We found an interaction between forage source and added S and Mo on DM intake, with cows offered G+ having a 2.1 kg of DM lower intake than those offered G?, but no effect on the corn silage-based diets. Mean milk yield was 38.9 kg/d and we observed an interaction between basal forage and added S and Mo, with yield being decreased in cows offered G+ but increased on C+. No effect of dietary treatment on milk composition or live weight was noted, but body condition was lower in cows fed added S and Mo irrespective of forage source. We found an interaction between forage source and added S and Mo on milk somatic cell count, which was higher in cows offered G+ compared with G?, but not in cows fed the corn silage-based diets, although all values were low (mean values of 1.72, 1.50, 1.39, and 1.67 log₁₀/mL for C?, C+, G?, and G+, respectively). Mean plasma Cu, Fe, and Mn concentrations were 13.8, 41.3, and 0.25 µmol/L, respectively, and were not affected by dietary treatment, whereas plasma Mo was 0.2 µmol/L higher in cows receiving added S and Mo. The addition of dietary S and Mo decreased liver Cu balance over the study period in cows fed either basal forage, but the decrease was considerably greater in cows receiving the grass silage-based diet. Similarly, hepatic Fe decreased more in cows receiving G than C when S and Mo were included in the diet. We concluded that added S and Mo reduces hepatic Cu reserves irrespective of basal forage source, but this decrease is considerably more pronounced in cows receiving grass silage- than corn silage-based rations and is associated with a decrease in intake and milk performance and an increase in milk somatic cell count.     

Alleviation of zearalenone toxicity by modified halloysite nanotubes in the immune response of swine

Zearalenone (ZEN) has caused significant economic effects on swine production in China. There is growing concern that exposure to ZEN during pregnancy affects the health of the offspring due to changes in the development of the immune system. To assess the risks associated with maternal ZEN exposure, several immunological parameters were assessed in pregnant sows and their offspring. The main aim of the study was to determine if modified hallosite nanotubes (MHNTs) can be used to protect pigs against the adverse effects of ZEN. Eighteen pregnant sows (second parity Yorkshire sows) were randomly divided into three treatment groups: (1) basal diet (control group); (2) contaminated grain (instead of 50% mouldy corn); and (3) contaminated grain (instead of 50% mouldy corn) + 1% MHNTs. The pregnant sows were fed the different treated diets from days 35 to 70 of gestation. Dietary ZEN exposure decreased the organ coefficient and the mRNA expression levels of IFN-γ, TNF-α, and IL-10, and increased ZEN residues and IL-4 mRNA expression in the spleen of pregnant sows and neonatal piglets. Decreases in the serum IgA and IgG levels were observed in the pregnant sows. Maternal ZEN exposure decreased the organ coefficient and the mRNA expression levels of IFN-γ and IL-10, and increased IL-4 mRNA expression in the spleen of weaning piglets. Exposure to ZEN during pregnancy decreased the level of serum IgG in the weaning piglets. Maternal exposure to ZEN induced histopathological damage and oxidative stress in the spleens of pregnant sows and their piglets. The addition of MHNTs to ZEN-contaminated diets can mitigate the negative effects induced by ZEN in the swine.