纤维素酶对玉米秸青贮营养成分及其奶牛瘤胃降解率的影响

本研究探讨了添加纤维素酶制剂对玉米秸青贮营养成分含量变化及其瘤胃内降解率的影响。以去穗玉米秸为试验材料,分别以0.00 g/1kg(C)、0.05g/1kg(Ⅰ)、0.2g/1kg(Ⅱ)、1g/1kg(Ⅲ)进行添加纤维素酶,贮藏4周后进行常规营养成分含量变化分析和饲养试验。用4头装有永久性瘘管荷斯坦乳牛,按4×4拉丁方设计进行瘤胃内降解率的试验。结果为:Ⅰ组、Ⅱ组和Ⅲ组玉米秸青贮DM含量差异不显著,但均显著低于C组;不同处理组的玉米秸青贮CP含量随纤维素添加量增加而显著提高,以1g/1kg纤维素酶添加处理的提高幅度最大;NDF和ADF含量均随着纤维素添加量增加而显著下降,其中1g/1kg纤维素酶添加处理的下降幅度最大。Ⅲ组、Ⅱ组和Ⅰ组玉米秸青贮的DM和CP奶牛瘤胃有效降解率均显著高于C组,并且Ⅲ组显著高于Ⅱ组和Ⅰ组;不同处理组的玉米秸青贮NDF有效降解率之间差异显著,Ⅲ组>Ⅱ组>Ⅰ组>C组;玉米秸青贮ADF有效降解率Ⅲ组、Ⅱ组和Ⅰ组之间无显著差异,但均显著高于C组。表明纤维素酶处理能提高青贮营养价值,且纤维素酶以1g/1kg添加量为宜。     

不同切碎长度和发酵方式对全株饲用谷子青贮质量的影响

本研究旨在探索不同切碎长度和发酵方式对全株饲用青贮谷子质量的影响。采用2×3双因子试验设计,切割长度分别为1.5 cm、2.5 cm和3.5 cm,发酵方式分为复合菌剂发酵和乳酸菌发酵两个类型,每处理3个重复。常温发酵40 d后取样,进行感官评定,分析基础养分,测定挥发性成分。结果表明,随着切碎长度增加,气味评分和总分总体呈降低趋势,中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)含量呈增加趋势,丁酸含量显著增加;相比乳酸菌发酵组,复合菌剂发酵组整体气味评分和乳酸含量较高,pH值和NDF、ADF含量较低。综上,不同切碎长度和发酵方式对于全株饲用谷子青贮质量均有显著影响。降低切碎长度和使用复合菌剂发酵均有助于促进纤维分解,减少丁酸产量,改善青贮感官评分。     

棉花秸秆作为绵羊粗饲料的研究

将18只平均体重为38．6kg的罗姆尼为父本、军垦型细毛羊为母本的杂交一代公羊分为三组，测定在补饲350g精料的情况下绵羊限饲粉碎棉花秸秆(试验1组)、自由采食粉碎棉花秸秆(试验2组)和自由采食玉米青贮(试验3组)时的采食量和消化率，以研究比较绵羊对粉碎棉花秸秆的利用性。结果表明，粉碎棉花秸秆作为粗饲料，可被绵羊采食和利用。绵羊对棉花秸秆的自由采食量达693g／d／羊，其干物质、有机物、粗蛋白、纤维素和半纤维素的消化率分别为34．6％，39、7％．43，0％，5％和65．8％。纤维素消化率低，是棉花秸秆消化利用中需研究的问题之一。在本试验条件下，根据推算，绵羊每采食4.3kg棉花秆可增加1kg体重．因此．可以考虑在生产中较大范围地使用粉碎棉花秸秆饲喂牛羊。     

Development and Evaluation of Monoclonal Antibodies for Paxilline

Paxilline (PAX) is a tremorgenic mycotoxin that has been found in perennial ryegrass infected with Acremonium lolii. To facilitate screening for this toxin, four murine monoclonal antibodies (mAbs) were developed. In competitive indirect enzyme-linked immunosorbent assays (CI-ELISAs) the concentrations of PAX required to inhibit signal development by 50% (IC₅₀s) ranged from 1.2 to 2.5 ng/mL. One mAb (2-9) was applied to the detection of PAX in maize silage. The assay was sensitive to the effects of solvents, with 5% acetonitrile or 20% methanol causing a two-fold or greater increase in IC₅₀. For analysis of silage samples, extracts were cleaned up by adsorbing potential matrix interferences onto a solid phase extraction column. The non-retained extract was then diluted with buffer to reduce solvent content prior to assay. Using this method, the limit of detection for PAX in dried silage was 15 µg/kg and the limit of quantification was 90 µg/kg. Recovery from samples spiked over the range of 100 to 1000 µg/kg averaged 106% ± 18%. The assay was applied to 86 maize silage samples, with many having detectable, but none having quantifiable, levels of PAX. The results suggest the CI-ELISA can be applied as a sensitive technique for the screening of PAX in maize silage.     

The influence of feeding crimped kernel maize silage on growth performance and intestinal colonization with Campylobacter jejuni of broilers

An infection trial and a production trial over 35 days were conducted in parallel to study the influence of feeding crimped kernel maize silage (CKMS) on the intestinal Campylobacter jejuni colonization and broiler performance, respectively. The CKMS was used at dietary inclusion levels of 15% and 30% in maize-based diets. Broilers were orally inoculated with 2?×?10⁵?log?cfu/ml C. jejuni on day 14. Four birds from each pen were randomly selected and killed by cervical dislocation on days 3, 6, 9, 14 and 21 post infection and intestinal contents from ileum, caeca and rectum as well as liver samples were taken. Body weight and feed consumption of broilers were registered on days 13, 22 and 35. On day 35, litter dry matter (DM) was measured and the condition of the foot pads was evaluated. There was no significant effect of CKMS on the colonization of C. jejuni. Body weight of the broilers supplemented with 15% CKMS was comparable with the control maize-based feed, whereas addition of 30% CKMS reduced broiler body weight (P?Campylobacter colonization, but improved the foot pad health of broilers.     

Effect of Lactic Acid Bacteria on the Fermentation Quality and Mycotoxins Concentrations of Corn Silage Infested with Mycotoxigenic Fungi

This study was conducted to evaluate the effect of lactic acid bacteria (LAB) on fermentation quality, mycotoxin concentrations, and microbial communities of whole-crop corn silages infested with mycotoxigenic fungi. Cultured spores (10⁶ cfu/mL) of mycotoxigenic Aspergillus flavus and Fusarium graminearum were sprayed (5 mL) on corn forage on 27 July and 10 August 2018. On 21 August 2018, sprayed (FI; 3 plots) and unsprayed (NFI; 3 plots) corn forage were harvested at the 1/2 kernel milk line stage, followed by chopping and ensiling without inoculants (CON), or with Lactobacillus buchneri (LB, 1 × 10⁶ cfu/g FW), Lactobacillus plantarum (LT, 1 × 10⁶ cfu/g FW), or L. buchneri + L. plantarum (BT: both L. buchneri and L. plantarum applied at 0.5 × 10⁶ cfu/g FW). After 90 d of ensiling, FI silages had a higher (p < 0.05) pH value and higher acetic acid (ACA), ethanol, and ammonia nitrogen (ammonia N) concentrations, but lower (p < 0.05) lactic acid (LA) concentrations than NFI silage. The inoculants decreased pH and increased LA concentration and LA/ACA compared with CON. The aflatoxin B₁ (AFB₁) was only detected in FI fresh corn and silages; ensiling decreased (p < 0.05) AFB₁ concentration compared with fresh corn, and LB and BT decreased AFB₁ concentration compared with CON. The zearalenone (ZEN), deoxynivalenol (DON), and fumonisin B₁ (FB₁) concentrations were similar (p < 0.05) for NFI silages, while ZEN concentration in BT was the lowest (p < 0.05) among all FI silages; DON and FB₁ concentrations in LB, LT, and BT silages were significantly lower (p < 0.05) than those of CON in FI silages. The fungal infestation increased the bacterial and fungal diversity of silages compared with NFI silages. The FI silages had a higher relative abundance (RA) of Lactobacillus, Weissella, Wickerhamomyces, Pichia, and Epicoccum than the corresponding NFI silages. The RA of Aspergillus and Fusarium markedly decreased after 90 d of ensiling, and the inoculation expanded this trend irrespective of fungal infestation. The Penicillium in FI silages survived after 90 d of ensiling, while the inoculants decreased the RA of Penicillium. Inoculants mitigate the adverse effects of fungal infestation on corn silage quality by changing the bacterial and fungal communities.     

青贮饲料的优点及制作技术

国内外畜牧业发展成功的经验证明,青贮饲料是现代畜牧业发展不可替代的重要饲料形式。笔者从长期的科研工作实践,结合相关资料分析整理总结出了青贮饲料的优点及贮制方法,饲喂要点等。可供广大农牧民在生产实际操作中参用。     

优质青贮饲草料调制与品质鉴定及利用技术探讨

调制青贮饲料优越性很多。营养损失少,消化率高,适口性好,能保持营养平衡。要大力推广青贮饲料的调制技术。优质青贮饲料的调制,需要有相关的技术和制作工艺,掌握好其要领才能调制出优质的青贮饲料。如科学、合理的利用青贮饲料饲喂家畜,定会收到良好经济效益。     

添加剂不同组分对罗姆尼羔羊体增重影响的研究

本试验采用120只罗姆尼杂交一代公羔羊作为试验动物,根据体重分为6组,每组20只羊。除对照组以外,其余5组分别饲喂成分依次叠加的添加剂。即试验1组为微量元素、试验2组在试验1组添加剂的基础上添加维生素、试验3组在试验2组添加剂的基础上添加常量元素、试验4组在试验3组添加剂的基础上添加氨基酸、试验5组在试验4组添加剂的基础上添加抗菌素,以研究添加剂不同组分对羔羊体增重的影响。结果表明,微量元素和抗菌素等组分的添加可使动物日增重分别比对照组（88.3g/d)提高29．2％和40．9％（P＜0．01）;粗饲料采食量分别提高6．9％和15．7％;精料转化率分别提高5％和7％。维生素、常量元素及氨基酸等添加剂组分在本试验中对体增重无显著作用（P＞0．05）;但分别提高粗饲料采食量6．4％、6．4％和11．4％。添加剂不同组分对动物的DM、OM和NDF等消化率无显著影响。     

ESI-Mass spectrometric and HPLC elucidation of a new ergot alkaloid from perennial ryegrass hay silage associated with bovine reproductive problems

This case report involves four dairies in the Willamette Valley, Oregon, which experienced reproductive problems associated with the presence of a large, previously unidentified, peak eluting at 5?min in a standard ergovaline high-performance liquid chromatography assay of perennial ryegrass silage fed to those animals. Mycotoxin analysis of the silage was negative, as was serological screening of the herds for infectious bovine rhinotracheitis, bovine diarrhea virus and Leptospirosis, including culturing of urine for Leptospira hardjo hardjobovis. Prolactin concentrations were low in most cattle, consistent with ingestion of ergot alkaloids. We believe that this peak represents a novel ergot alkaloid-related compound due to its extractability with Ergosil, its detectability due to fluorescence, and its chromatographic retention between ergovaline (mw?=?533) and ergotamine (mw?=?581). Its molecular weight was calculated as 570 owing to the predominance of a m/z 593.5 ion in the full scan ESI(+)MS and its deduced tendency to complex with Na⁺ (as m/z 593) or K⁺ (as m/z 609) ions. We offer rationales for elucidation of the structure of this compound, with the closest starting point comprising an m.w. of 566—a fructofuranosyl-(2-1)-O-beta-D-fructofuranoside derivative of 6,7-secoergoline from Claviceps fusiformis. This m.w. requires modifications, such as reduction of two double bonds in the secoergoline component to give the target 570 m.w. Despite the lack of a definitive structure, the analysis herein provides a starting point for eventual elucidation of this apparently new ergot alkaloid, and to guide and encourage further investigation as to its association with endophyte toxicosis in livestock.