我国常用玉米自交系秸秆品质性状及其相关分析

利用近红外反射光谱法对我国91份常用普通玉米自交系和11份高油自交系秸秆的体外干物质消化率（IVDMD）、粗蛋白（CP）、粗脂肪（EE）、可溶性糖（WSC）、酸性洗涤纤维（ADF）、酸性木质素（ADL）、中性洗涤纤维（NDF）7个品质性状进行了分析评价,以探讨秸秆品质性状间的关系以及影响秸秆品质的主要成分。结果表明,各品质性状变异较大,各性状自交系间差异均达极显著水平,IVDMD及其相关品质的含量近似正态分布。不同品质性状变异程度不同,其中WSC含量变异最大,变异系数达33.15%。IVDMD与NDF、ADF、ADL呈极显著负相关,与WSC、EE含量呈极显著正相关,与CP含量显著正相关。影响秸秆品质的性状依次是IVDMD、ADF、NDF、WSC、ADL、CP和EE含量。根据青贮玉米育种的要求,筛选出5份IVDMD和WSC含量高、NDF、ADF含量低的自交系。     

不同氮用量下玉米不同部位生物量、养分含量及饲用品质的比较研究

为探讨玉米不同部位生物量和养分含量大小及饲用品质的高低,于2016年在四川农业大学雅安农场进行,以川单428为试验材料,研究了不同氮用量(0,90,180,270,360 kg/hm~2,分别记为N_0、N_1、N_2、N_3、N_4)下玉米不同部位生物量、养分含量及饲用品质。结果表明,总体上,玉米茎、叶和籽粒生物量随着施氮量的增加有先增加后降低的趋势,并在N_2时达最大,相比N_0分别增加34.9%,28.0%和107.3%;玉米叶鞘、苞叶和芯的生物量随着施氮量的增加有增加的趋势,在N_4时达最大,相比N_0分别增加28.7%,102.1%和69.4%。施氮显著提高了玉米秸秆不同部位氮含量,降低了磷、钾含量。施氮显著提高了玉米不同部位粗蛋白(CP)含量,降低了中性洗涤纤维含量(NDF)和酸性洗涤纤维(ADF)含量,但当施氮量高于N_2或N_3时,玉米茎、叶和芯NDF含量有些略微升高,玉米茎、叶、苞叶和芯ADF含量有升高的趋势。同一施氮处理内,在施氮量为90 kg/hm~2及以上时,玉米不同部位间生物量大小依次表现为籽粒﹥茎﹥叶﹥芯﹥苞叶﹥叶鞘。综上所述,适量施氮有利于提高玉米产量,改善玉米品质,本研究条件下,玉米施氮量以180 kg/hm2为宜。     

甜高粱饲草品质综合分析

为探究饲用甜高粱不同饲草指标间的关系以及综合评价饲用甜高粱品系，提高饲用甜高粱育种进程，以新组配的13个甜高粱品系为研究材料，对19个饲草指标进行变异分析、相关性分析、主成分分析和聚类分析。结果表明，最能够反映饲草品质的粗蛋白、ADF（酸性洗涤纤维）、NDF（中性洗涤纤维）变异系数均小于10%，而淀粉、锤度和元素类指标变化范围较大，变异系数均大于15%，饲用甜高粱育种仍然需要创制高蛋白种质资源。相关性分析发现，ADF与NDF呈显著正相关(P<0.01)，钙元素含量与总可消化养分、RFV（相对饲用价值）呈极显著正相关(P<0.01)。主成分分析将19个饲草指标综合为4个主成分，累计贡献率达到90.49%，综合分析表明J205、TP3、TP14、TP83、TP5等5个品种排名靠前，饲草品质综合表现较好。聚类分析把13个品系分为3类，其中J205、TP3为综合饲草品质优良的一类。     

不同发酵类型乳酸菌对全株玉米青贮发酵品质及营养价值的影响

为研究同型乳酸菌和异型乳酸菌对全株玉米青贮发酵品质和营养成分的影响,以短乳杆菌(L.brevis)和植物乳杆菌(L.plantarum)为添加剂,分别设置无添加组(CK组)、添加短乳杆菌组(LB组)和添加植物乳杆菌组(LP组),60d后对全株玉米青贮进行分析。结果表明:乳酸菌发酵剂均提高了全株玉米青贮饲料的发酵品质。相比于对照组,添加剂组p H、氨态氮/总氮、酸性洗涤纤维(ADF)、中性洗涤木质素(ADL)含量显著降低(P0.05),乳酸含量显著增加(P0.05),丙酸、丁酸和中性洗涤纤维(NDF)含量差异不显著(P0.05)。在各组中,LP组产生的乳酸、粗蛋白含量最高,p H值、氨态氮/总氮和中性洗涤纤维含量最低;LB组产生的乙酸含量最高。综合评分结果表明LP组青贮发酵品质分数最高,比LB组改善青贮品质的效果更显著。     

不同种植密度对青贮玉米品质的影响

本研究以青贮玉米‘中原单32’(ZYD32)和‘大京九26’(DJJ26)为试验材料,设置低密(67 500株/hm2)、中密(90 000株/hm~2)和高密(112 500株/hm2) 3个种植密度,研究了不同种植密度对青贮玉米23项营养品质指标的影响。结果表明,青贮玉米的营养品质和品种自身特性以及种植密度相关,其中品种对可溶蛋白占总蛋白的比例(SP)、脂肪(Fat)含量的影响达到显著或极显著水平,密度对瘤胃可降解蛋白占总蛋白的比例(DP)、钾(K)含量的影响达到显著或极显著水平。品种、密度同时对粗蛋白(CP)、总可消化养分(TDN)、水溶性碳水化合物(WSC)、非纤维性碳水化合物(NFC)、淀粉(SH)、单糖(ESC)、酸性洗涤纤维(ADF)、中性洗涤纤维(NDF)、木质素(LN)、48 h中性洗涤纤维的消化率(NDFD)、灰分(Ash)、钙(Ca)含量的影响达到显著或极显著水平。随着种植密度的升高,两品种的瘤胃可降解蛋白占总蛋白的比例(DP)、酸性洗涤纤维(ADF)、中性洗涤纤维(NDF)、木质素(LN)、钙(Ca)、镁(Mg)、钾(K)含量均呈现逐渐升高的趋势,总可消化养分(TDN)、非纤维性碳水化合物(NFC)、淀粉(SH)、灰分(Ash)含量均呈现逐渐降低的趋势,水溶性碳水化合物(WSC)、单糖(ESC)、48 h中性洗涤纤维的消化率(NDFD)、每吨产奶量含量均呈现先升高再降低的变化趋势。粗蛋白(CP)、脂肪(Fat)含量方面2品种随密度变化的表现不一致‘,ZYD32’的粗蛋白(CP)、脂肪(Fat)含量随密度的升高而降低,‘DJJ26’的粗蛋白(CP)、脂肪(Fat)含量则无显著性变化。综上所述,不同青贮玉米品种‘ZYD32’和‘DJJ26’均在种植密度为90 000株/hm~2时所获得的青贮玉米品质最好,在种植密度为67 500株/hm~2时,2品种的每吨干物质产奶量最高。     

不同饲用玉米品种产量及青贮品质比较分析

为筛选出适宜安徽省种植的饲用玉米品种,进行了10个饲用玉米品种的产量及青贮品质比较研究。结果表明：品种间产量和青贮品质存在显著差异。其中,‘玉草3号’的产量最高,YA473182的产量仅次于‘玉草3号’;YA473182的氨态氮(NH3-N)含量略低于‘玉草3号’,乳酸(LA)含量显著高于‘玉草3号’,发酵品质较好;YA473182的可溶性碳水化合物(WSC)含量及粗蛋白(CP)含量显著高于其他品种,且中性洗涤纤维(NDF)及酸性洗涤纤维(ADF)含量相对较少,饲用品质较好。综合考虑各玉米品种的产量及青贮品质,YA473182和‘玉草3号’最适合安徽省种植利用,‘瑞德2号’和‘豫青3230’也有推广价值。     

不同肥料配施对青贮玉米产量和品质的影响

采用“3414”最优回归设计,研究了不同施肥处理对青贮玉米品种‘大京九26号’的产量和营养品质的影响。结果表明,适量增施氮肥对提高青贮玉米鲜重产量和干物质产量的作用大于磷钾肥,并显著提高粗蛋白(CP)含量,对改善酸性洗涤性纤维(ADF)、中性洗涤性纤维(NDF)和脂肪(Fat)含量均有有益作用;钾肥对改善青贮玉米营养品质的作用较小;磷肥的增施对营养品质改善不利;在14个处理中,以N₂P₁K₂处理的综合表现较好。本研究结果为冀西北地区高产、优质青贮玉米的栽培技术的制定奠定理论基础。     

不同保存方法对秸秆营养价值的影响

研究高粱秸、玉米秸、豆秸和甘薯藤4种秸秆在不同保存方法（露天保存、棚舍保存、青贮和氨化）下主要营养物质的变化情况。并选用2头安装有永久性瘤胃瘘管的去势本地黄牛(450±15kg)来研究不同保存方法对其DM、OM、NDF和ADF瘤胃降解率的影响。结果表明：不同保存方法对CP影响差异极显著(P<0.01)；对OM高粱秸差异极显著(P<0.01)，甘薯藤差异显著(P<0.05)；NDF差异均显著(P<0.05)；ADF差异均显著(P<0.05)，WSC差异极显著(P<0.01)；提高DM、OM、NDF和ADF降解率的方法为烘干，氨化，豆秸除外。     

碱性双氧水处理对玉米秸秆营养价值的影响

用 1 % ,4% ,8% ,1 2 5 % 4种浓度的碱性双氧水处理玉米秸秆。研究表明碱性双氧水处理显著改变秸秆NDF和半纤维素含量 (P <0 0 5) ,极显著改变秸秆纤维素、ADF和木质素含量 (P <0 0 1 )。羊粪液替代瘤胃液作两级离体消化试验结果表明 ,秸秆干物质消化率得到显著提高 (P<0 0 5)。8%浓度的碱性双氧水处理 ,使秸秆木质素含量降低 46 43% (5 85 %vs1 0 92 % ) ,干物质消化率提高 1 1 1 93 % (2 8 42 %vs1 3 41 % ) ,对提高秸秆营养价值最有效     

酶和乳酸菌对多年生黑麦草与玉米秸秆混合青贮发酵品质的影响

为研究酶和乳酸菌对多年生黑麦草(Lolium perenne L.)与玉米(Zea mays L.)秸秆混合青贮发酵品质的影响,试验设4个处理,分别为对照(C)、酶制剂(E)、乳酸菌制剂(LAB)、酶+乳酸菌制剂(E+LAB),60天后测定青贮饲料发酵品质。结果表明:添加酶或乳酸菌制剂均提高了多年生黑麦草与玉米秸秆混合青贮饲料的发酵品质。添加剂组p H、丙酸和丁酸含量显著降低(P0.05),氨态氮/总氮值低于(P0.05)或显著低于(P0.05)对照组,乳酸、粗蛋白和水溶性碳水化合物含量增加;E和E+LAB组的中性洗涤纤维和酸性洗涤纤维含量均低于其他各组,而LAB组的中性洗涤纤维和酸性洗涤纤维含量与对照组无显著差异。V-Score评分结果表明LAB处理组青贮发酵品质分数最高。因此,在多年生黑麦草与玉米秸秆混合青贮实际生产过程中,单独使用乳酸菌即可达到理想的效果。     

东乡野生稻与普通栽培稻中性洗涤纤维、酸性洗涤纤维等含量的对比研究

为研究不同种类、不同生育时期水稻植株细胞壁化学组分变化规律,应用Van Soest法对普通栽培稻与东乡野生稻在不同生育时期的植株NDF、ADF等含量进行了研究。结果表明,NDF、ADF、ADL含量（％）的平均值变化范围分别是55.63～71.70、31.98～49.61、2.68～5.71,其中以蜡熟期的东野各含量为最高,以抽穗期的协青早B各含量最低。在同一生育时期,不同种类水稻的NDF、ADF含量（除抽穗期的NDF）有显著性差异（P<0.05）,以东野的含量为最高,秀水110其次,以协青早B含量为最低。在同一种类水稻中,不同生育时期的水稻NDF、ADF含量差异均达到显著性水平（P<0.05）,以抽穗期的含量为最低,乳熟期其次,至蜡熟期含量达到最高峰。     

Agronomic Factors in Evaluating Forage Crops II. Predicting Fiber Components (NDF, ADF, ADL) from Crop Leafiness

The relationship of the stage-to-stage changes in alfalfa herbage leaf percentage and the corresponding changes in fiber components represented by neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) was tested in alfalfa crop diverse in stand and canopy ages, stages of maturity harvested across seasons in two separate years. Regression analyses showed that for all fiber components, leaf percentage consistently provided highly significant linear relationships for predicting herbage fiber content; NDF (r²= 0.915), ADF (r²= 0.937) and, ADL (r²= 0.851). These were highly comparable with the application of the mean stage by weight (MSW) system for predicting NDF (r²= 0.946), ADF (r²= 0.891) and ADL (r²= 0.841) thus indicating the practical use of leaf percentage as a good alternative approach for predicting fiber content of the alfalfa crop.     

Genetic basis of nutritional content of stover in maize under low nitrogen conditions

The effect of two different nitrogen treatments on five traits associated with yield and nutrient composition of stover were evaluated using a set of 213 F_2:3 families derived from two elite inbred lines Huang-C and Xu178. Evaluation of the phenotypes expressed under the two nitrogen conditions showed that low nitrogen conditions could increase acid detergent fiber (ADF) and neutral detergent fiber (NDF), and decreased crude protein content (CP), crude fat content (CF), and stover yield (SY), thereby negatively affecting the digestibility and quality of silage maize. Twenty-eight quantitative trait loci (QTL) were identified affecting the five measured traits under two nitrogen conditions, including four for ADF, five for NDF, five for CP, four for CF, and three for SY. Several QTL associated with ADF or NDF were detected under same nitrogen conditions, and were localized to the same chromosomal regions, especially the QTL qADF6 and qNDF6, qADF10 and qNDF10, were only detected under low nitrogen condition. These results suggested that ADF and NDF perhaps were controlled by several common genes, and that the nutritional content of stover may be influenced by additional genetic mechanisms when grown under conditions of low nitrogen.     

Near infrared reflectance spectroscopy analysis of digestibility traits of maize stover

Summary Near infrared reflectance spectroscopy (NIRS) is emerging as a potentially useful tool in breeding plants for quality traits. Information is lacking, however, on its use in forage maize (Zea mays L.). The objectives of the present investigation were to evaluate the prediction of digestibility traits of maize stover using NIRS technique and to study the effect of laboratory (Lab) and NIRS assays on the estimates of variation and covariation. Twelve inbred lines, 66 diallel crosses among them and eight hybrid checks were evaluated at silage and grain harvests for 2 years at two agro-climatically diverse locations in the Federal Republic of Germany. Standard methods were used for Lab analysis of in vitro digestible organic matter (IVDOM), neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid detergent lignin (ADL). In NIRS evaluation, calibration equations were developed by modified stepwise regression. The standard error of calibration was 2.5, 1.7, 1.4 and 0.4 for IVDOM, NDF, ADF and ADL, respectively. The coefficient of multiple determination was high (0.9) except for ADL. The validation statistics (standard error and correlation coefficient) were similar. In the diallel crosses, the estimates of variation (heritabilities in broad and narrow sense, genotypic and error coefficients of variation), generally, did not vary appreciably and consistently in the comparisons between Lab and NIRS methods particulary at silage harvest. Simple and rank correlations between Lab and NIRS analyses were positive and significant. These correlation coefficients based on the mean performance of the diallel crosses at silage harvest were >0.9 and at least 16 hybrids were common between the two analyses, among the upper one-third or lower one-third (22) hybrids. The study showed that NIRS analysis should be useful in maize breeding programmes wherein a large number of genotypes need to be evaluated.Abbreviations NIRS near infrared reflectance spectroscopy - Lab laboratory - IVDOM in vitro digestible organic matter - NDF neutral detergent fibre - ADF acid detergent fibre - ADL acid detergent lignin - SEC standard error of calibration - SEV standard error of validation - SD standard deviation - r simple correlation coefficient - r_s rank correlation coefficient - R² coefficient of multiple determination - h_b ² heritability in broad sense - h_n ² heritability in narrow sense - CV_g genotypic coefficient of variation - CV_e error coefficient of variation - GCA general combining ability effect     

Genetic variation and selection criterion for digestibility traits of forage maize

Summary Variations in feeding value characteristics were studied on a factorial mating design, within a multilocal network. The in vitro digestibility of dry matter (IVDDM), neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), starch, soluble carbohydrate, protein and ash contents were evaluated on whole plant samples. The in vitro digestibility of the non-starch and non-soluble carbohydrate plant part (IVDNSC) was also computed from near infra-red reflectance spectroscopy estimations of IVDDM, starch and soluble carbohydrate contents. Variations due to general combining ability (GCA) were more important, for all traits, than variations due to specific combining ability (SCA). Variations due to the GCA × environment interaction were also sizeable and were partly explained by the earliness of the lines. IVDDM was primarily influenced by the relative proportions of cell walls and starch in the whole plant, which were particularly susceptible to the development stage of the plants, at harvest. When adjusted for earliness, there was generally no significant relation between the line per se value and GCA performance in the biochemical constituent contents of the plant. On the contrary, IVDNSC seemed to be a feeding value trait worth evaluating at the inbred line level. It was also almost independent of the ripening stage and could be easily computed from whole plant samples. IVDNSC, with a simultaneous control of starch content, might be a good selection criterion for evaluating and improving the nutritive value of forage maize.     

Evaluation of environments for preliminary testing of maize for yield and stover digestibility

Summary The identification of environments suitable for selection should enable plant breeders to test reliably a larger number of genotypes with given resources. This research was undertaken to evaluate discrimination ability (DA) and prediction ability (PA) of eight environments involving two locations. Eckartsweier (Eck) 1 and Voelkenrode (Voe); 2 yer. 1984 (84) and 1985 (85); and two harvests, silage harvest (I) and later (II). It was based on dry matter yield of plant (PDMY), ear (EDMY) and stover (SDMY) and on in vitro digestible organic matter (IVDOM), neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid detergent lignin (ADL) of stover of 12 inbred lines and their 66 diallel crosses in maize (Zea mays L.). Linear regression coefficient of the performance of genotypes in an environment on that averaged across all environments and its degree of determination were used as measures of the DA and PA of environments, respectively. In hybrids, the DA of environments differed significantly for all traits except SDMY and ADL. Environment Eck851 showed better PA (0.63) than other environments for PDMY, EDMY, IVDOM, NDF, and ADF. Among the 12 two-environment combinations. EckI was a better predictor for PDMY, EDMY, IVDOM and NDF (PA0.80). The more productive environments showed better DA and PA for PDMY and FDMY than less productive ones. For IVDOM and NDF the first harvest provided better discrimination and prediction than the second harvest. In inbred lines the DA of environments differed significantly for EDMY only. In the present study, PA and DA seemed to be functions of the environments, PA was improved by combining two environments, and some environments seemed to be suitable for preliminary selection of genotypes for such diverse traits as yield and digestibility.     

Genetic variation, heritability and genetic correlations for forage quality and yield traits of Mediterranean tall fescue germplasm

Higher ruminant intake potential and in vivo digestibility as indicated by lower neutral and acid detergent fibre (NDF and ADF), respectively, and higher crude protein (CP), may be valuable targets in tall fescue breeding. Some 105 full‐sib families from a diallel cross of Mediterranean parent germplasm were grown in a heated greenhouse simulating the temperature pattern of a Mediterranean environment, to estimate genetic parameters for NDF, ADF, CP and dry matter (DM) yield in one autumn and one winter harvest. Family x harvest interaction was large for NDF and ADF, moderate for CP and absent for DM yield. Additive genetic variance was mostly larger than specific genetic variance, and tended to be small for quality traits and large for DM yield. Narrow‐sense heritability was low for CP and ADF in autumn and moderate to fairly high in the remaining cases. Predicted gains per selection cycle never exceeded 5% for quality traits while being greater than 10% for DM yield. An inverse genetic correlation between DM yield and any quality trait emerged in the presence of sizeable genetic variation.     

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.     

Effects of Soil Moisture Deficit on Forage Quality, Digestibility, and Protein Fractionation of Kura Clover

Kura clover (Trifolium ambiguum M.B.) is a persistent rhizomatous forage legume with great potential for permanent pastures. The effects of a soil moisture deficit on forage quality, digestibility and protein fractionation of two cultivars of Kura clover (Endura and Rhizo) were investigated in this study for 1 year. The responses of alfalfa (Medicago sativa L.) and red clover (Trifolium pratense L.) were also characterized. Stands of each species were field‐grown and submitted to two soil water regimes promoting soil moisture deficits and well‐watered (i.e. control) conditions. There were no interactions between species and soil water regimes. Soil moisture deficit increased acid detergent fibre (ADF) but reduced acid detergent lignin (ADL) content and consequently increased forage digestibility. It had only minor effects on protein content and fractionation. Species varied for most parameters measured. Kura clover generally had the lowest neutral detergent fibre (NDF), ADF and ADL contents, and consequently the greatest digestibility (83.9 %). Species also differed in their crude protein fractionation. Kura clover and red clover had a lower proportion of non‐protein nitrogen (NPN; A fraction) and a greater proportion of true protein (B fraction) (30.9 and 64.5 %, respectively) than alfalfa (36.4 and 57.4 %, respectively). Kura clover also had the lowest proportion (i.e. 4.7 %) of acid detergent insoluble protein (ADIP; C fraction) of all species tested. Endura Kura clover often had a higher forage quality than Rhizo. This study confirms that Kura clover produces high‐quality forage and provides the first estimates of protein fractionation in this species.