黄曲霉毒素B1和玉米赤霉烯酮在肉鸡体内残留及消解规律的研究

试验旨在研究黄曲霉毒素B1(AFB1)和玉米赤霉烯酮(ZEA)在肉鸡体内残留及消解规律。选取22日龄健康罗斯308肉仔鸡150只,随机分为3组,每组5个重复,每个重复10只鸡。分组为:(1)基础日粮;(2)基础日粮+AFB1 50μg/kg+ZEA 500μg/kg;(3)基础日粮+AFB1 50μg/kg+ZEA500μg/kg+生物解毒剂(MBDP)。结果表明:AFB1主要存在于粪便、肝脏、胸肌、血清中。ZEA主要存在于粪便、肝脏和血清中。在第7 d时,添加生物解毒剂组胸肌、血清、粪便中AFB1含量和肝脏、血清、粪便中ZEA含量显著低于2组(P0.05);在1～7 d内,添加生物解毒剂组AFB1和ZEA净排出总量显著低于2组(P0.05)。这表明饲料中添加生物解毒剂能够减少霉菌毒素在组织和粪便中的残留,但7 d内不能完全排除体内沉积的毒素。     

玉米赤霉烯酮的毒性及其脱毒方法

玉米赤霉烯酮(ZEA)又称F-2毒素,主要是由镰刀菌产生的2,4-二羟基苯甲酸内酯类化合物,具有雌激素样活性.因目前我国南方部分省份空气湿度较大,玉米储存过程中很容易霉变,造成畜禽ZEA中毒,现笔者针对ZEA的毒性和脱毒方法进行综述.     

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。     

蒸汽压片玉米中添加不同比例尿素对其防霉效果的影响

本试验旨在探究蒸汽压片玉米中添加尿素对其防霉效果的影响,并确定尿素适宜的添加比例。试验采用单因素有重复试验设计,设5个尿素添加水平和4个测定时间点,以感官评价、常规营养成分含量和黄曲霉毒素B1为主要评价指标。结果表明:本试验条件下,尿素添加量在1%以上、贮藏至21 d时感官指标未见明显变化,且未检出黄曲霉毒素B1;添加尿素能显著提高蒸汽压片玉米中的粗蛋白(CP)含量(P0.01),且对中性洗涤纤维(NDF,P=0.04)、淀粉(Starch,P=0.02)和淀粉糊化度(Gel,P0.01)均有显著影响;随着贮藏时间的增加,蒸汽压片玉米的DM含量逐渐升高(P0.01),CP含量逐渐增加(P0.01),虽然Gel(P0.01)、NDF(P0.01)、ADF(P0.01)和EE(P0.01)含量各时间点差异显著,但未呈现明显的变化趋势。试验表明,蒸汽压片玉米中添加尿素可以显著提高粗蛋白含量,添加高水平(1%以上,鲜重基础)的尿素可在一定程度上抑制微生物的生长,常规密封条件下可延长蒸汽压片玉米贮存时间至20 d左右。     

不同加工处理玉米对断奶仔猪生长性能的影响

将150头21日龄断奶仔猪(杜×长×大)随机分成5个处理组,即A组(100%普通玉米)、B组(50%普通玉米+50%蒸汽压片玉米)、C组(100%蒸汽压片玉米)、D组(50%普通玉米+50%膨化玉米)、E组(100%膨化玉米),每处理组设3个重复,每重复10头仔猪,进行5 d预试及14 d正试期,测定其生长性能。结果表明:使用蒸汽压片玉米或膨化玉米均可以提高21日龄断奶仔猪日增重及采食量、降低仔猪腹泻频率,对料重比的影响呈不规则结果;各处理组生长性能指标差异不显著(P0.05)。     

黄曲霉毒素B1、玉米赤霉烯酮和呕吐毒素的累加细胞毒性研究

由于饲料中多种霉菌毒素并存的几率比较高，本研究以仔猪肠上皮细胞（IPEC-J2）为模型，研究黄曲霉毒素B1（AFB1）、玉米赤霉烯酮（ZEA）和呕吐毒素（DON）的叠加细胞毒性。细胞毒性试验选用AFB1、ZEA和DON三种毒素作为响应面Box-Behnke设计的三个因素，以AFB1：10、20、30 μg/L，ZEA：150、300、450 μg/L，DON：500、1000、1500 μg/L作为Box-Behnke设计的三个编码水平。利用响应面设计构建得到17组复合霉菌毒素组合，以其对IPEC-J2细胞活力的影响作为参考指标，得到对细胞损伤程度最高和最低的霉菌毒素添加比例。结果表明：经方程预测后，得到细胞活力最低（霉菌毒素毒性最高）的AFB1、ZEA和DON组合为30、150 μg/L和1500 μg/L，经测定细胞活力为32.32%|得到细胞活力最高（霉菌毒素毒性最低）的AFB1、ZEA和DON组合为10、150 μg/L和600 μg/L，经测定细胞活力为53.01%。该结果为多种霉菌毒素叠加毒性的研究提供了依据。 [关键词] IPEC-J2细胞|黄曲霉毒素B1|玉米赤霉烯酮|呕吐毒素|细胞毒性     

不同能量水平及玉米加工饲粮对瘤胃体外发酵参数的影响

利用体外产气法研究不同能量水平与不同加工方式玉米对瘤胃体外发酵参数的影响。试验以玉米秸秆为主要粗饲料来源设计精粗比为65∶35的等氮饲粮,选用玉米青贮与过瘤胃脂肪调整低、高能量水平,普通玉米与蒸汽压片玉米作为不同加工方式,采用2×2因子试验设计。结果表明,高能水平饲粮的理论最大产气量、48 h总产气量、干物质降解率均显著高于低能(P<0.05),普通玉米高能组的乙酸、丙酸含量显著高于低能组(P<0.05)。同一能量水平下,蒸汽压片处理组的48 h总产气量均显著高于普通玉米组(P<0.05);而低能条件下蒸汽压片组的总挥发酸、丙酸含量显著高于普通玉米组(P<0.05)。不同饲粮营养水平与体外产气参数相关性分析表明48 h总产气量与中性洗涤纤维(NDF)呈显著负相关(P<0.05),与中性洗涤可溶物(NDS)、非纤维性碳水化合物(NFC)和NDS/CP呈显著正相关(P<0.05)。因此,使用蒸汽压片方式处理玉米以及提高饲粮能量水平均可以显著增加体外发酵48 h总产气量;低能水平下,蒸汽压片玉米对改善瘤胃的发酵特性更为明显。     

乳果糖和富氢水对断奶仔猪采食霉变玉米后引起卵巢机能障碍的缓解作用

旨在研究禾谷镰刀菌属霉变玉米对断奶仔猪卵巢抗氧化水平和NOS的影响以及乳果糖和富氢水的缓解作用。本研究将24头21日龄,平均体重(7. 25±1. 02) kg的三元杂交断奶仔猪(杜×长×大)随机分为4组(对照组、霉变玉米组、乳果糖缓解组、富氢水缓解组),每组6头。对照组饲喂基础日粮,霉变玉米组、乳果糖缓解组和富氢水缓解组饲喂霉变饲料(呕吐毒素(DON)与玉米赤霉烯酮(ZEA)的含量分别为0. 4 mg·kg~(-1)和0. 55 mg·kg~(-1))。此外,乳果糖和富氢水缓解组分别用乳果糖(500 mg·kg~(-1))和富氢水(10 mL·kg~(-1))每天进行两次灌胃。试验期25 d。25 d后屠宰仔猪,收集卵巢,称重;对仔猪卵巢进行组织学观察;检测卵巢组织CAT、GSH-PX、T-SOD、SDH、Caspase-3活性以及NO含量、NOS活性;并用免疫组织化学对nNOS、iNOS和eNOS进行表达定位。结果显示:1)霉变玉米组仔猪相对卵巢重量显著高于对照组(P 0. 05),与霉变玉米组相比,乳果糖与富氢水缓解组相对卵巢重量有下降趋势; 2) HE结果显示,4组仔猪卵巢均未出现明显病理变化,但霉变玉米组生长卵泡数量显著高于对照组(P 0. 05),乳果糖与富氢水缓解组生长卵泡数量与霉变玉米组相比有下降趋势。3)与对照组相比,霉变玉米组CAT活性显著升高(P 0. 05),GSH-PX与SDH活性显著下降(P 0. 05),T-SOD有下降趋势,Caspase-3活性、NO含量、总NOS活性显著升高(P 0. 05)。4)与霉变玉米组相比,乳果糖缓解组GSH-PX与SDH活性显著升高(P 0. 05),富氢水缓解组GSH-PX与SDH活性有升高趋势;乳果糖、富氢水缓解组CAT活性有下降趋势,T-SOD活性有上升趋势;乳果糖、富氢水缓解组Caspase-3活性、NO含量显著降低(P 0. 05);乳果糖缓解组总NOS活力有下降趋势,富氢水缓解组NOS活力显著下降(P 0. 05)。5)免疫组化结果显示,3种NOS(nNOS、iNOS、eNOS)在各级卵泡的卵母细胞、颗粒细胞、膜细胞均有定位,而且呈细胞特异性表达。霉变玉米中的DON与ZEA可能介导仔猪卵巢组织抗氧化水平降低,从而导致细胞凋亡程度加深;而乳果糖与富氢水通过升高抗氧化水平有效缓解DON与ZEA对仔猪卵巢造成的危害。     

复合益生菌和霉菌毒素降解酶对黄曲霉毒素B1、玉米赤霉烯酮和呕吐毒素的同步降解

面对多种霉菌毒素的危害，依据本实验室建立的黄曲霉毒素B1（AFB1）、玉米赤霉烯酮（ZEA）和呕吐毒素（DON）联合导致的细胞毒性模型，通过复合益生菌、霉菌毒素降解酶及其配伍来降解这三种霉菌毒素。本研究首先选用拉丁方试验设计获得枯草芽孢杆菌、酿酒酵母菌和丁酸梭菌的最佳组合，然后再与霉菌毒素降解酶配伍。结果表明：当枯草芽孢杆菌、酿酒酵母菌和丁酸梭菌的活菌数皆为1×105 cfu/mL时，对AFB1、ZEA和DON的联合降解效果最好。高含量霉菌毒素组AFB1、ZEA和DON的降解率分别为40.55%、56.05%和47.22%（P < 0.05），低含量霉菌毒素组AFB1、ZEA和DON的降解率分别为43.05%、38.26%和80.49%（P < 0.05）。复合益生菌与霉菌毒素降解酶的配伍试验结果表明，在高剂量霉菌毒素的降解试验中，单一复合益生菌、单一霉菌毒素降解酶及两者的配比为30:1时，对三种霉菌毒素的总降解率最高，分别到达了190.08%、175.10%和184.44%，显著高于其他组（P < 0.05）|在低剂量霉菌毒素的降解试验中，单一霉菌毒素降解酶对三种霉菌毒素的总降解率最高，达到了219.23%（P < 0.05）|其次为单一复合益生菌及两者的配伍比例为30:1和3:2时，对三种霉菌毒素的总降解率较高，分别达到了178.07%、181.84%和170.33%，显著高于其他组（P < 0.05）。综上所述，复合益生菌、霉菌毒素降解酶及其两者适宜配伍，可同步降解AFB1、ZEA和DON三种霉菌毒素，为多种霉菌毒素的同步降解奠定了基础。 [关键词] 复合益生菌|霉菌毒素降解酶|黄曲霉毒素B1|玉米赤霉烯酮|呕吐毒素|同步降解     

霉变饲料中添加酯化葡甘露聚糖对肉鸡肝脏霉菌毒素含量和免疫功能的影响

本试验选取108羽1日龄AA肉鸡,随机分为6组,每组设3个重复。第1组饲喂常规饲料;第2组饲喂霉变饲料;第3~5组分别饲喂添加0.05%、0.1%和0.2%酯化葡甘露聚糖(EGM)的霉变饲料;第6组饲喂添加0.1%霉可吸的霉变饲料,研究霉变饲料中添加EGM对肉鸡肝脏霉菌毒素含量和免疫功能的影响。结果表明:与饲喂霉变饲料组相比,霉变饲料中添加0.1%、0.2%EGM和0.1%霉可吸,肉鸡肝脏中黄曲霉毒素B1(AFB1)含量分别降低了62.02%、79.44%和57.27%,玉米赤霉烯酮(ZEN)含量分别降低了66.33%、70.72%和52.01%,呕吐毒素(DON)含量分别降低了55.72%、81.33%和81.05%(P0.05);肉鸡血液新城疫(NDV)抗体水平分别提高了36.86%、66.27%和52.94%,传染性法氏囊病(IBDV)抗体水平分别提高了26.81%、46.81%和32.72%,淋巴细胞转化率分别提高了13.22%、14.83%和13.31%(P0.05)。霉变饲料中添加0.2%EGM时,肉鸡肝脏AFB1、ZEN含量及血液NDV、IBDV抗体水平与对照组差异不显著(P0.05)。综上,EGM可以有效吸附AFB1、ZEN和DON,霉变饲料中适宜添加剂量为0.2%。     

Effect of ensiling process of total mixed ration on fermentation profile,nutrient loss and in situ ruminal degradation characteristics of diet

This experiment aimed to determine the changes in chemical composition, fermentation profile, in situ disappearance characteristics, and nutrient losses of ensiled total mixed ration (TMR) containing steam‐flaked corn or brown rice (BR) during storage. TMRs for dairy cows, containing either steam‐flaked corn or BR at 31.9% with 15.2% rye silage, 40.5% alfalfa silage, 5.0% beet pulp and 7.0% soybean meal, were prepared (dry matter (DM) basis). Each TMR was placed in a plastic drum silo, stored at 23°C in an air‐conditioned room and sampled 0, 7, 14, 30, 90 and 210 days after preparation. In both grain sources, the fermentation products increased, while DM and starch storage losses increased and starch content greatly decreased during storage. The rapidly degradable fraction and effective ruminal degradability of DM, crude protein and starch increased during storage. These changes of dietary characteristics were large during 30 days of storage, but small after 90 days of storage. Replacing corn with BR led to increased fermentation products, starch loss and effective ruminal degradability of the ensiled TMR. These results indicate that the ensiling process of TMR changes the dietary characteristics and replacing corn with BR in TMR had a large impact on these dietary characteristics.     

Plasma haptoglobin and immunoglobulins as diagnostic indicators of deoxynivalenol intoxication

This study aimed to discover potential biomarkers for dioxynivalenol (DON) intoxication. B6C3F1 male mice were orally exposed to 0.83, 2.5 and 7.5 mg/kg body weight (bw) DON for 8 days and the differential protein expressions in their blood plasma were determined by SELDI - Time-of-Flight/Mass Spectrometry (TOF/MS) and the immunoglobulins (Igs) G, A, M and E in the serum were investigated. 11.7 kDa protein was significantly highly expressed according to DON administration and this protein was purified by employing a methyl ceramic HyperD F column with using optimization buffer for adsorption and desorption. The purified protein was identified as a haptoglobin precursor by peptide mapping with using LC/Q-TOF/MS and MALDI-TOF/MS and this was confirmed by western blotting and ELISA. IgG and IgM in serum were decreased in a dose-dependent manner and IgA was decreased at 7.5 mg/kg bw DON administration, but the IgE level was not changed. To compare the expressions of haptoglobin and the Igs patterns between aflatoxin B1 (AFB1), zearalenone (ZEA) and DON intoxications, rats were orally administered with AFB1 1.0, ZEA 240 and DON 7.5 mg/kg bw for 8 days. Haptoglobin was increased only at DON 7.5 mg/kg bw, while it was slightly decreased at ZEA 240 mg/kg bw and it was not detected at all at AFB1 1.0 mg/kg bw. IgG and IgA were decreased by DON, but IgG, IgA, IgM and IgE were all increased by AFB1. No changes were observed by ZEA administration. These results show that plasma haptoglobin could be a diagnostic biomarker for DON intoxication when this is combined with examining the serum Igs.     

Effect of replacing corn with brown rice grain in a total mixed ration silage on milk production,ruminal fermentation and nitrogen balance in lactating dairy cows

Nine multiparous Holstein cows were used in a replicated 3 × 3 Latin square design to determine the effects of substituting corn grain with brown rice (BR) grain in total mixed ration (TMR) silage on milk yield, ruminal fermentation and nitrogen (N) balance. The TMR silages were made from the ensiling of TMR containing (dry matter basis) 50.1% forage in rice silage and corn silage combination, and 49.9% concentrate. The grain portion of the diets contained 31.2% steam‐flaked corn, 31.2% steam‐flaked BR or an equal mixture of corn and BR. Dietary treatments did not affect dry matter intake, milk yield and milk fat, protein and lactose yields. The ruminal pH and total volatile fatty acid concentrations were not affected by dietary treatment. The urinary N excretion decreased linearly (P < 0.01) in response to increased levels of BR, with no dietary effect on N intake, N secretion in milk and fecal N excretion. Our results indicate that steam‐flaked BR is a suitable replacement for steam‐flaked corn in dairy cow diets, and that it can be included in rations to a level of at least 31.2% of dry matter without adverse effects on milk production, when cows were fed rice silage and corn silage‐based diets.     

不同加工方式玉米粉对6月龄伊犁马消化代谢、血浆生化指标及生长发育的影响

本试验旨在研究不同加工方式玉米粉对6月龄伊犁马消化代谢、血浆生化指标及生长发育的影响,为蒸汽压片玉米粉、膨化玉米粉在马饲粮中的应用提供参考。本试验选取平均体重为(105.10±11.83)kg、健康状况良好的6月龄伊犁公马20匹,按体重相近原则,随机分为4组,每组5匹。每天每匹马饲喂0.3 kg粉状浓缩料和3.5 kg苜蓿干草,在此基础上对照组、试验Ⅰ组、试验Ⅱ组、试验Ⅲ组每天每匹再分别饲喂0.3 kg粉碎玉米粉、0.3 kg粉碎玉米粉+1 gα-淀粉酶、0.3 kg蒸汽压片玉米粉、0.3 kg膨化玉米粉,进行为期20 d的消化代谢试验,其中预试期13 d,正试期7 d。结果表明:试验Ⅲ组干物质、有机物、粗蛋白质、中性洗涤纤维、酸性洗涤纤维消化量以及中性洗涤纤维、酸性洗涤纤维消化率显著高于对照组(P0.05);试验Ⅲ组氮、钙、磷沉积率显著高于对照组、试验Ⅰ组(P0.05);试验Ⅲ组消化能、代谢能显著高于对照组、试验Ⅰ组(P0.05),而对照组、试验Ⅰ组、试验Ⅱ组之间差异不显著(P0.05);试验Ⅲ组试验期间增重和平均日增重均高于其他各组,但各组间差异不显著(P0.05);就体斜长增加而言,试验Ⅲ组显著高于其他组(P0.05);试验Ⅱ组胸围增加显著高于其他3组(P0.05);各组间血浆生化指标差异不显著(P0.05)。由此得出,饲喂膨化玉米粉可提高饲粮中营养物质的消化率及能量代谢,并促进马的生长发育;而饲喂含酶制剂的粉碎玉米粉或蒸汽压片玉米粉对6月龄伊犁马的营养物质消化率及生长发育无显著促进作用。     

ZEA、DON及其联合染毒对CTLL-2细胞因子分泌的影响

为研究镰刀菌毒素玉米赤霉烯酮（ZEA）、脱氧雪腐镰刀菌烯醇（DON）及其联合作用对动物免疫功能的影响,试验以CTLL-2细胞（细胞毒性T淋巴细胞株）为材料,用不同浓度的ZEA （0、5、10、20 μg/mL）、DON （0、0.5、1、2 μg/mL）及联合（空白组、5 μg/mL ZEA、0.5 μg/mL DON、5 μg/mL ZEA＋0.5 μg/mL DON）处理CTLL-2细胞48 h,采用ELISA法检测了细胞内及培养上清液中颗粒酶B （GZMB）、穿孔素（PFP）、干扰素γ（IFN-γ）和肿瘤坏死因子α（TNF-α）等细胞因子的含量。结果显示,ZEA、DON能够降低CTLL-2细胞胞内及培养上清液中PFP、GZMB、IFN-γ的浓度,增加TNF-α浓度,染毒组与对照组相比均有显著或极显著差异（P＜0.05;P＜0.01）,且均呈剂量效应关系;ZEA、DON联合染毒表现为加性效应。结果表明,ZEA、DON及其联合作用可通过影响免疫细胞因子的分泌,降低免疫细胞杀伤活力,间接影响机体体液免疫和细胞免疫的负调节,从而导致动物机体免疫机能下降。     

Effects of ZEA,DON and Their Combined Effects on the Secretion of Cytokines in CTLL-2 Cells

To analyze the effects of ZEA or/and DON on the immunologic function,CTLL-2 cell was used as experimental materials. After exposing the CTLL-2 cell to different concentrations of ZEA (0,5,10,20 μg/mL),DON (0,0.5,1,2 μg/mL) and ZEA+DON (blank group,5 μg/mL ZEA,0.5 μg/mL DON,5 μg/mL ZEA+0.5 μg/mL DON) for 48 h,the concentration of GZMB,PFP,IFN-γ and TNF-α in CTLL-2 cell and supernatant fluid were detected by ELISA method. The result showed that DON and ZEA could reduce the concentration of PFP,GZMB and IFN-γ in the CTLL-2 cells and the culture supernatant fluids,and increase the concentration of TNF-α. The intoxicated group had significant or extremely significant difference compared to control group (P <0.05;P <0.01),which showed the dose effect. The group exposed to the combined of ZEA and DON showed an additive effect. The result indicated that ZEA,DON and the two combined could reduce the killing activity of immunological cell by affecting the secretion of immunological cytokines, and indirectly affect the negative feedback regulation of humoral immunity and cellular immunity,which led to the decline of immune function in animals.     

不同添加剂发酵处理对汽爆玉米秸秆发酵品质及微生物数量的影响

为研究不同添加剂对汽爆玉米秸秆发酵品质与微生物数量的影响,本研究以干黄玉米秸秆为原料,经蒸汽爆破处理后,添加Sila-Max、Sila-Mix、纤维活性菌(活性菌)进行密封发酵,以不添加任何添加剂为对照(CK),发酵60 d后取样分析不同处理秸秆营养成分、发酵品质以及微生物数量变化.结果表明:1)不同添加剂处理下汽爆玉米秸秆粗蛋白(crude protein,CP)、中性洗涤纤维(neutral detergent fiber,NDF)、酸性洗涤纤维(acid detergent fiber,ADF)和粗灰分(crude ash,Ash)含量无显著差异(P>0.05),但与汽爆前干黄玉米秸秆相比,青贮后的汽爆玉米秸秆CP含量提高了2.01～2.05倍,NDF和ADF含量则分别降低了18.16％～20.17％和2.38％～3.94％,淀粉含量活性菌组最高,与Sila-Max、Sila-Mix组无显著差异(P>0.05).2)发酵过程中,活性菌组、CK组出现霉变情况,霉变量分别达5.07％和7.75％,而其余处理组未出现霉变现象.3)活性菌组乳酸含量显著高于其他处理(P<0.05);Sila-Max组汽爆玉米秸秆的乙酸、丙酸、丁酸含量显著高于其他处理(P<0.05).4)不同添加剂处理下,发酵后汽爆玉米秸秆中微生物数量出现不同变化,乳酸菌数量Sila-Max组显著高于其他处理组(P<0.05);好氧细菌和梭菌数CK组显著高于其他处理(P<0.05),但与Sila-Max组无显著差异(P>0.05);霉菌在Sila-Max、Sila-Mix组均未检测到,在CK组和活性菌组中分别达3.17和3.47 lg cfu·g-1.5)主成分与隶属函数综合分析得出,Sila-Max(0.55)>Sila-Mix(0.42)>活性菌(0.41)>CK(0.20).综上,不同添加剂发酵处理对汽爆玉米秸秆发酵品质及微生物数量有一定影响,活性菌虽能增加乳酸含量,但在抑制有害微生物,防止霉变方面有所欠缺;Sila-Max可以提高乳酸菌、乙酸、丙酸含量,抑制有害微生物活动,防止霉变,并具有抑制二次发酵的潜力;Sila-Mix能够提高汽爆玉米秸秆乳酸菌数量,抑制有害微生物的活动,防止霉变.综合主成分与隶属函数得分,汽爆玉米秸秆青贮时添加Sila-Max综合表现最优,可以推广使用.     

Enhancement of Ovulatory Follicle Development in Maiden Sheep by Short-term Supplementation with Steam-flaked Corn

The effect of a short‐term nutritional supplementation with steam‐flaked corn on metabolism and folliculogenesis was evaluated in 14 maiden sheep. Oestrus was synchronized with two prostaglandin F_2α doses given 10 days apart. From day 11 to 15 of the oestrous cycle induced with prostaglandins, half of the ewes (group 2M) were supplemented with steam‐flaked corn, double the daily maintenance ration of the control sheep (group 1M). Body weight and condition remained unaffected, but the energetic supply increased plasma concentrations of glucose (3.6 ± 0.1 vs 4.3 ± 0.1 mmol/l, p < 0.0001) for the first 4 days and 3‐hydroxybutyrate (0.323 ± 0.58 vs 0.582 ± 0.04 mmol/l, p < 0.005) from day 2 to 4. The profile of insulin secretion was also affected by the treatment, increasing in group 2M to reach significant differences on days 13 and 14 (p < 0.05). From similar values at the start of the food supply, the treatment induced a higher follicular development in group 2M (1.1 ± 1.2 vs 7.4 ± 1.06 total follicles in day 15, p < 0.05), as evidenced by the lineal increase in the number of larger follicles (>4 mm, p < 0.005). Then, the number of follicles >4 mm in size in 2M was around 60% higher on day 16 (7.86 ± 0.45 vs 4.86 ± 0.63, p < 0.005). Thereafter, the mean number of corpora lutea per ewe was around 30% higher in group 2M (1.43 ± 0.2 vs 1.10 ± 0.1, although differences were not found to be statistically significant). These data suggest that the use of diets containing high starch sources, like the steam‐flaked corn, increases folliculogenesis and ovulation rate in sheep and can be applied in short‐term feeding practices.     

玉米不同处理方式对泌乳奶牛瘤胃降解规律的影响

为了研究不同加工处理方法对玉米在奶牛瘤胃内降解率的影响,本试验选用5头荷斯坦泌乳牛利用尼龙袋法测定玉米渣、膨化玉米、玉米片和蒸汽压片玉米的干物质和淀粉在泌乳奶牛瘤胃中的降解率．．结果表明,48h的瘤胃降解率规律为：玉米片〉膨化玉米〉蒸汽压片玉米〉玉米渣。瘤胃内可降解干物质为：膨化玉米和玉米片〉蒸汽压片玉米和玉米渣;而可降解淀粉则为：膨化玉米〉玉米片〉蒸汽压片玉米〉玉米渣,以上结果表明,加工过程中温度湿度和压力的作用下,玉米籽实的结构发生变化,改变了瘤胃微生物接触淀粉的机会,从而影响玉米在瘤胃内的降解率。