营养补偿初期苏尼特母羊对NDF、ADF消化能力的研究

将45只处于妊娠后期(90～150d)的苏尼特母羊随机分成4组,以不同的营养水平(代谢能:0.20、0.33、0.44、0.86MJ/kgW0.75·d)分组饲养,分娩后进行补偿生长试验,研究妊娠后期不同营养限制程度的母羊在补偿初期(分娩后0～6周)对中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)消化率的影响。结果表明:在补偿初期,各组母羊对ADF、NDF的消化率随着营养限制程度的增强而下降。     

不同方法测定反刍动物饲料NDF、ADF和木质素含量的比较

采用传统抽滤、ANKOM滤袋和CAU滤袋技术测定16种反刍动物饲料的中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)和木质素(PL,高锰酸钾法)含量。结果表明:3种方法测定的大部分饲料的NDF、ADF和PL含量间没有差异(P>0.05),但在测定谷物性饲料NDF含量时,ANKOM滤袋技术测定值明显低于其他2种方法(P<0.05);在测定动物性蛋白质饲料时,CAU滤袋测定的NDF值明显高于其他2种方法(P<0.05)。3种方法测定的NDF、ADF和木质素含量均具有显著的线性相关关系(R2=0.990～0.996),其中2个滤袋技术测定值之间的相关程度最高(R2=0.992～0.996);2个滤袋技术测定值的变异系数(CV=2.20%～3.96%)均小于传统抽滤(CV=3.21%～4.91%)。     

Effect of Genotypes and Plant Maturity on Forage Quality of Certain Forage Legume Species Under Rainfed Conditions

Evaluation of plant species for animal feed requires the quantitative and qualitative comparison of different genotypes. Promising lines of annual legumes comprising seven genotypes of vetche ( Vicia spp.) and chicklings ( Lathyrus spp.) were compared for herbage quality. The content of crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) in herbage and pods were measured at different stages of plant maturity. The proportion of the leaves to shoots (leafiness) and in vitro dry matter digestibility (IVDMD) were also determined. As plants matured IVDMD, CP and leafiness decreased and NDF and ADF increased. For all the genotypes maximum digestible dry matter (DDM) and CP yields were more or less attained at 50–100 % podding. Narbon vetch had the highest DDM. The possible uses of the different genotypes as animal feed are discussed based on the partitioning of the DDM and CP yield as plants matured.     

甘肃省农村居民收入与消费均衡关系的实证分析

文章利用ADF单位根检验、Engle-Granger协整分析等计量经济理论,对1978-2005年甘肃省农村居民人均可支配收入和人均消费支出的年度数据进行了相应的分析,并且当收入消费方程不协整时引入了虚拟变量,有效克服了变量在整个研究期间不协整的问题,并据此建立了相应的误差修正模型。     

奶牛主要植物性蛋白质饲料蛋白质和纤维物质瘤胃降解率的研究

选用3头安装永久性瘤胃瘘管的健康荷斯坦泌乳奶牛为试验动物,选取8种北方地区奶牛常用蛋白质饲料原料为试验样品,每个样品设3个重复,用尼龙袋法分别测定各个样品的粗蛋白质（CP）、中性洗涤纤维（NDF）和酸性洗涤纤维（ADF）在瘤胃内的动态降解率和有效降解率。结果表明,①所选8种蛋白质饲料原料中葵花粕的粗蛋白质（CP）有效降...     

斯氏艾美耳球虫ADF基因部分序列的克隆与分析

为了获得我国斯氏艾美耳球虫长春株ADF基因并分析其与柔嫩艾美耳球虫长春株相应序列的同源性,试验根据GenBank中公布的柔嫩艾美耳球虫ADF基因序列设计引物,采用RT-PCR方法获得我国斯氏艾美耳球虫长春株ADF基因部分序列,然后将其克隆到pMD18-T载体中,应用DNAStar软件对测得序列进行序列分析。结果表明:斯氏艾美耳球虫长春株ADF基因大小为357 bp;经DNAStar分析,我国斯氏艾美耳球虫长春株与柔嫩艾美耳球虫长春株ADF核苷酸序列和氨基酸序列同源性均为99.2%。说明ADF基因在进化过程中高度保守。     

海南坡鹿对采食部位的选择与饲草酸性洗涤纤维含量的相关性

在海南大田国家级自然保护区围栏内用食痕法(evidence of feeding on forage)观测海南坡鹿Cervus eldi hainanus(简称坡鹿)对18种草本和18种灌木类饲草的采食部分占整株草本植株或占整枝灌木主枝条的尺寸比,同时测定各饲草的酸性洗涤纤维(ADF)含量.结果显示,按旱季与雨季的(全年)平均值,坡鹿对草本类饲草的采食尺寸比为49.29%,对灌木类饲草为57.3%;草本类饲草的ADF含量为9.91%,灌木类饲草为9.19%;无论草本还是灌木类,坡鹿的采食尺寸比随饲草ADF含量的增加而显著降低.研究表明,在大田自然保护区围栏内,坡鹿对ADF含量在10%以上的饲草不喜食,饲草纤维物质含量是坡鹿在围栏内扩充采食部位以增加营养摄入量的限制性因子,在旱季种植并收割饲草投喂坡鹿时,应避免其纤维物质含量增高.     

ADF-IL-2基因重组卡介苗的构建及免疫保护效果

构建柔嫩艾美尔球虫ADF基因和鸡IL-2基因的重组卡介苗,并研究其免疫保护性.将柔嫩艾美尔球虫的ADF基因和鸡的IL-2基因串联后连接到至穿梭表达载体pMV261和整合表达载体pMV361中电转化卡介苗,制备重组卡介苗pMV261-ADF-IL-2和pMV361-ADF-IL-2,将构建的基因重组卡介苗分别以不同免疫途径接种雏鸡,研究其对柔嫩艾美耳球虫的攻毒的免疫保护效果.结果显示,成功构建重组rBCG pMV261-ADF-IL-2和pMV361-ADF-IL-2,且rBCG滴鼻免疫组的免疫效果较好,其抗球虫指数分别为176.08和172.89.结果表明,构建的基因重组卡介苗pMV261-ADF-IL-2和pMV3 61-ADF-IL-2对柔嫩艾美尔球虫卵囊的攻击具有一定的保护作用.     

Vegetation-type effects on performance and meat quality of growing Engadine and Valaisian Black Nose sheep grazing alpine pastures

Lambs of two Swiss mountain breeds, Engadine Sheep (ES; n=55) and Valaisian Black Nose Sheep (VS; n=55), were fattened in 2010 and 2011 on one lowland and three alpine pastures. Groups of six to seven lambs per breed were allocated to pastures of a size allowing ad libitum intake on the following four vegetation types: (i) species-poor and nutrient-rich lowland (400 m a.s.l.) ryegrass–clover ley on flat terrain (‘lowland-rich’); (ii) alpine, species-rich and nutrient-rich vegetation type on a flat terrain (1950 m; ‘alpine-rich’); (iii) alpine, species-rich vegetation type, moderate in nutrients on steep terrain (2150 m; ‘alpine-moderate’); and (iv) alpine, species-rich and nutrient-poor vegetation type on steep terrain (2150 m; ‘alpine-poor’). Lambs were slaughtered after 9 weeks of grazing in a commercial slaughterhouse. Carcasses were subjected to the Swiss CH-TAX classification grid. Meat quality was analysed on the Musculus longissimus dorsi (LD) in the segment of Musculus longissimus lumborum. Forage quality varied among vegetation types as anticipated. Across all sites, ES were superior (P<0.001) to VS in dressing percentage (43.9 vs. 38.4), carcass weight (18.4 vs. 16.4 kg), meat conformation and fat cover scores, even though daily gains had been lower (105 vs. 122 g/d; P<0.05). Meat of ES contained more dry matter, protein, total ash (P<0.001) and fat (P<0.05). Their meat was darker and more intensive red, had lower cooking losses (23.0 vs. 25.1%) but was less tender (65.6 vs. 58.1 N) compared to VS (P<0.001). Vegetation types offering good quality forage (lowland-rich and alpine-rich) enhanced average daily gains, dressing percentage, meat conformation and fat cover scores (mostly P<0.05 against alpine-moderate and -poor). Similarly, a higher vegetation quality promoted a higher intramuscular fat and lower cooking losses. Meat from lowland-rich was darkest and had the lowest shear force (P<0.05). Almost no breed×site interactions occurred in growth performance as well as carcass and meat quality. It was therefore concluded that both breeds are similarly well adapted to the extensive pasture production system in alpine regions. Still, ES seem to be the more efficient one of the two sheep breeds. The results also indicate that growth performance and meat quality clearly vary between vegetation types in animals grazing alpine pastures.     

Influence of non-cellulose structural carbohydrate composition on plant material decomposition in soil

The C mineralisation pattern during the early stage of decomposition of plant materials is largely determined by their content of different carbohydrates. This study investigated whether detailed plant analysis could provide a better prediction of C mineralisation during decomposition than proximate analysis [neutral detergent solution (NDF)/acid detergent solution (ADF)]. The detailed analysis included sugars, fructans, starch, pectin, cellulose, lignin and organic N. To determine whether differences in decomposition rate were related to differences in hemicellulose composition, the analysis particularly emphasised the concentrations of arabinose and xylose in hemicelluloses. Carbon dioxide evolution was monitored hourly in soil amended with ten different plant materials. Principal component and regression analysis showed that C mineralisation during day 1 was closely related to free sugars, fructans and soluble organic N components (R ² = 0.83). The sum of non-cellulose structural carbohydrates (intermediate NDF/ADF fraction) was not related to C mineralisation between days 1 and 9. In contrast, a model including starch and protein in addition to the non-cellulose structural carbohydrates, with the hemicelluloses replaced by arabinose and xylose, showed a strong relationship with evolved CO₂ (R ² = 0.87). Carbon mineralisation between days 9 and 34 was better explained by xylan, cellulose and lignin (R ² = 0.72) than by lignocellulose in the ADF fraction. Our results indicated that proximate analyses were not sufficient to explain differences in decomposition. To predict C mineralisation from the range of plant materials studied, we propose a minimum set of analyses comprising total N, free sugars, starch, arabinose, xylan, cellulose and lignin.