不同品种及不同成熟期的青贮玉米秸秆营养成分及体外发酵评定

通过化学成分分析和活体外人工瘤胃发酵法,对3种玉米(高油玉米HOC115、普通玉米3138及青贮专用玉米)及3个籽粒成熟期(2/4乳线期(ML)、3/4 ML和4/4 ML)的秸秆青贮品质进行了比较。结果表明:随籽粒成熟期的延长,HOC115和3138青贮秸秆的品质及青贮发酵品质均下降,而青贮专用玉米各期的发酵品质均良好。其中HOC115的NDF和木质素含量以3/4 ML为最高(P<0.05),ADF含量无显著变化(P>0.05),3138的NDF、ADF和木质素含量在成熟期上呈明显的二次曲线增加趋势(P<0.01),干物质(DM)和NDF消化率明显降低(P<0.05),而青贮专用玉米秸秆的NDF、ADF和木质素含量在成熟期上呈显著的下降趋势(P<0.01),48 h的DM消化率有明显的增加(P<0.05)。由此得出HOC115和3138玉米秸秆在2/4 ML具有较佳的青贮效果,而青贮专用玉米的最佳青贮期可延长至籽粒3/4 ML或4/4 ML。     

收刈时间对不同品种玉米秸秆营养成分和干物质降解率的影响

大田试验种植4个早中熟玉米品种,包括农大108、高油298、冀丰58、郑单958,在生长期的92 d、96 d、100 d和104 d收刈秸秆,研究收刈时间对秸秆营养物质含量和干物质降解率的影响,试验结果表明,收刈时间明显影响玉米秸秆的粗蛋白质、纤维性物质含量,所选种的玉米品种秸秆蛋白质含量和干物质降解率在100 d达到峰值.     

佛州侧耳对玉米秸秆干物质体外降解率的影响

<正>粮食短缺、环境污染以及能源浪费是我国现代农业发展亟待解决的问题,采用微生物处理农作物秸秆提高木质纤维素的降解率,开发饲料资源,是解决人畜争粮矛盾、改善生态环境、节约能源的重要环节。     

不同玉米品种秸秆青贮饲料干物质消化率对比研究

采取牛瘤胃液 ,应用离体消化试验方法测试了 5个品种的玉米秸秆青贮饲料的干物质消化情况。结果表明 ,其中 3个粮饲兼用型品种的秸秆青贮饲料干物质消失率都显著的高于粮食玉米秸秆青贮饲料。     

佛州侧耳对玉米秸秆干物质体外降解率的影响

试验从秸秆培养基的营养水平和发酵时间两方面来研究佛州侧耳对秸秆发酵的影响.第一个试验是针对目前秸秆培养料多以生产食用菌为目的且营养水平偏高,发酵秸秆饲料的成本较高,试验中用麦麸的不同比例来调节培养基碳氮比,要寻求一个既可以满足佛州侧耳对秸秆的正常发酵处理,又可以提高经济效益的理想配比.     

玉米秸秆及其青贮饲料干物质降解率相关分析

本研究利用安装有永久性瘤胃瘘管的西门塔尔杂种阉公牛,应用尼龙袋技术,测定了玉米尊秆及其相应青贮饲料的干物质瘤胃降解变化,并进行相关分析。试验结果表明：秸秆干物质瘤胃降解率（X）与秸秆青贮干物质瘤胃降解率（Y）二者间存在强正相关关系（P〈0．01）,回归方程为：Y=0.4718＋1．1620X（r2=0．9835,n=5）。     

玉米秸秆降解真菌的筛选及鉴定

为了筛选到高效玉米秸秆降解真菌。实验以树林、稻田、玉米田等地土层下5 cm取得的腐殖质土壤为样品进行富集培养,通过刚果红染色法进行初步筛选,滤纸崩解法复筛,分别以羧甲基纤维素钠和玉米秸秆粉为唯一碳源,经30℃、120 r/min摇床培养72 h测定纤维素酶活性,液态发酵方法考察实际降解能力,通过分子学方法鉴定菌株。获得2株具有较高纤维素酶活和玉米秸秆降解能力的真菌菌株Z_(2-6)和Z_(3-5),液体发酵15 d后,秸秆降解率分别是59.43%和59.13%,通过分子学鉴定都为尖孢镰刀菌。真菌菌株Z_(2-6)和Z_(3-5)是具有较好研究价值的玉米秸秆纤维素降解真菌。     

牛至精油与有机钴协同对青贮玉米秸秆降解及绵羊瘤胃发酵特性的影响

试验选用5只10月龄左右体重约(45±5)kg且安装有永久瘤胃瘘管的健康公羊(小尾寒羊♂×本地绵羊♀的杂交2代)作为试验动物,通过瘤胃瘘管投饲4种添加剂:载体(Car)、载体+牛至精油(CarEO)、载体+有机钴(CarCo)和载体+精油+有机钴(CarEOC)于不同绵羊瘤胃中,同时以不加任何添加剂作为对照(CK),即5个处理,对应5只羊.采用拉丁方设计,进行5轮试验.采用尼龙袋法测定瘤胃内青贮玉米秸秆降解0、6、12、24及48 h营养品质动态变化,并探究不同添加剂对绵羊瘤胃发酵特性的影响.结果表明:各处理组青贮玉米秸秆干物质降解率(DMD)、粗蛋白降解率(CPD)、中性洗涤纤维降解率(NDFD)和酸性洗涤纤维降解率(ADFD)均随瘤胃降解时间的延长而增加,且在48 h时达到最大.48 h添加CarEOC青贮玉米秸秆NDFD和ADFD均高于CK,但差异不显著(P>0.05).与CK相比,添加CarEO、CarCo和CarEOC后青贮玉米秸秆DMD均有所提高,48 h时添加CarEOC后DMD和CPD分别较CK提高了3.33％ 和3.89％,且24和48 h时CPD在CarEOC处理组与CK之间差异显著(P<0.05).各添加剂处理对绵羊瘤胃液pH无显著影响(P>0.05),但添加CarEOC后瘤胃液pH和氨态氮(NH3-N)呈现出先降低后升高的趋势,而添加CarEO后NH3-N变化不明显.添加CarEO与CarEOC后瘤胃液总挥发性脂肪酸、乙酸、丙酸和丁酸均表现出先升高后降低的趋势,尤其添加CarEOC后表现明显,说明添加CarEO与CarEOC有利于瘤胃微生物活动,促进了瘤胃发酵.本试验添加Car后瘤胃降解指标和发酵指标在各时间与CK之间均无显著差异(P>0.05).经灰色关联综合分析,青贮玉米秸秆在瘤胃内的降解品质和发酵特性的关联值表现为CarEOC>CarCo>CarEO>Car>CK,说明CarEOC可促进绵羊瘤胃内纤维类化合物的降解,可作为促进绵羊高效利用粗饲料资源的绿色饲料添加剂在生产实践中推广使用.     

不同玉米品种秸秆饲用品质的研究

为探讨不同玉米品种秸秆饲用品质状况,本研究采用近红外光谱技术,分析评价了44个玉米品种秸秆的体外干物质消化率(IVDMD)、酸性洗涤纤维(ADF)、中性洗涤纤维(NDF)和可溶性糖(WSC)含量4个品质性状。结果表明,品种间IVDMD、ADF、NDF和WSC含量存在极显著差异,44个玉米品种秸秆各品质性状近似正态分布,其变化范围分别为38.60%~51.74%(IVDMD)、27.01%~35.67%(ADF)、51.55%~65.81%(NDF)和4.69%~12.21%(WSC)。各性状变异程度不同,WSC含量变异系数最大,达23.59%。相关分析表明,IVDMD与ADF和NDF含量极显著负相关,与WSC含量极显著正相关,ADF含量与NDF含量极显著正相关,WSC含量与NDF和ADF含量极显著负相关。根据各性状的相关关系,筛选出5个秸秆IVDMD和WSC含量高而ADF和NDF含量低的玉米品种。     

生物处理对秸秆的瘤胃干物质降解率的影响

试验采用３个重复对比设计,将玉米,小麦和稻草秸秆生物处理样与原样放置在永久瘘管牛体内,分别在６、１２、２４、３６、４８和７２ｈ时间点取出样本进行降解率试验测定分析。结果表明：秸秆处理样在各个时间点的瞬间降解率和有效降解率均显著优于原料（Ｐ〈０．０１）,而玉米秸秆处理样也极显著优于小麦和稻草处理样（Ｐ〈０．０１）。     

ORIGINAL ARTICLE: Effects of variety,sowing season and maturity stage on ruminal phosphorus release from whole maize stover and its morphological fractions

An in situ degradation technique was used to investigate the effects of variety, season and maturity stage on ruminal Phosphorus (P) release from whole maize stover and morphological fractions from five varieties of maize (conventional maize, CM; sweet maize, SM; waxy maize, WM; high oil maize, HOM; and fodder maize, FM). Maize plants were harvested in 2005, 17 and 31 days after tasselling and manually separated into leaf blade, leaf sheath, stem and husk. Results showed that the values of rapidly released P fractions (a), slowly released P fractions (b), rate constant of P release for fraction b (c) and effective disappearance (ED) of P were significantly influenced by variety, sowing season and maturity stage (p < 0.05). The ED of P in whole maize stover among the varieties decreased in the following order: FM (89.8%) > HOM (87.9%) > CM (87.0%) > SM (86.9%) > WM (83.9%). Advanced maturity stage increased (p < 0.001) the a and ED values of P in the leaf blade and leaf sheath, but decreased (p < 0.001) these parameters in the husk. The a fraction and ED of P were higher (p < 0.001) for maize sown in spring than those sown in summer. Significant (p < 0.05) interactions among variety, sowing season and maturity stage were noted in the a and ED values of P. Effective disappearance of morphological fraction varied significantly (p < 0.001) and followed the order: stem (90.3%) > leaf sheath (88.2%) > leaf blade (85.2%) > husk (84.9%). In conclusion, most of P in maize stover could be released in the rumen. The potential pollution resulting from P excretion in faeces may be alleviated, when maize stover is largely used as the main forage source of ruminants.     

干旱胁迫对玉米耐旱自交系与旱敏感自交系苗期生理特性的影响

为了探讨玉米(Zea mays)的耐旱机理,为玉米耐旱种质改良提供材料,本试验以前期筛选出的玉米耐旱自交系廊黄、昌7 2和旱敏感自交系TS141为试验材料,在自然干旱条件下,用盆栽法对其形态与生理变化进行研究。结果表明,干旱胁迫条件下,3个玉米自交系的存活率降低,叶片中的相对含水量呈下降趋势,相对电导率、游离脯氨酸含量、保护酶SOD和POD的活性增加。干旱胁迫下,与旱敏感自交系TS141相比,耐旱系廊黄和昌7 2存活率较高,叶片的相对含水量、游离脯氨酸含量、保护酶SOD和POD的活性也比较高,相对电导率则较低。     

Variety diversity effect on the chemical composition and dry matter degradation characteristics of residue and by-products of oil palm fruits

The materials palm press fibre (PPF), palm calyx (PCL) and palm oil sludge (POS) obtained from three varieties of oil palm: dura, oleifera and tenera were investigated for the effect of variety on their nutritive value. Analysis of proximate composition, cell wall fractions, some mineral concentration as well as in‐situ dry matter degradation in the rumen of steers were carried out. Significant effects of materials (i.e. PPF, PCL and POS) as well as variety (i.e. dura, oleifera and tenera) were noticed in all the parameters studied except sodium (Na) and organic matter (OM) components. Crude protein (CP) values in all the varieties were lowest in PCL (3.15–5.48%) and highest in POS (9.02–10.02%), while crude fibre (CF) values were highest in PCL (33.00–46.19%) and lowest in POS (3.15–5.48%). The upper and lower values respectively for CP and CF in the materials were in most cases for the tenera variety. The cell wall fractions (NDF, ADF, Lignin, cellulose and hemicellulose) were all higher in PCL and lowest in POS. In the three varieties, POS had highest concentration of Mg (0.117–0.231 g/100 g), K (1.21–2.33 g/100 g) and Cu (75.07–87.34 mg/kg) but lowest content of Ca (0.016–0.089 g/100 g) while PPF had lowest concentration of Mg (0.031–0.039 g/100 g) and Cu (20.96–22.28 mg/kg). Iron (Fe, mg/kg) values were generally high, but highest in PCL (2015.41–4042.16). Dry matter degradability and effective degradability values were best in POS irrespective of the variety and least in PCL. Among the three varieties, dry matter degradation characteristics of tenera were the best and oleifera the least. Generally the residue and by‐products irrespective of the variety of oil palm they are obtained from can be ranked for their nutritive value as POS > PPF > PCL, while nutritive ranking based on variety is tenera > dura > oleifera. Conclusively, POS and PPF from any variety of oil palm could be adopted directly as feed resources for ruminant livestock, while PCL will require hydrolytic nutritive value enhancement treatment. Ruminant livestock will however be at an advantage if materials from tenera variety are fed.     

肉牛常见饲料干物质和蛋白质瘤胃降解特性和小肠消化率研究

[方法]选用装有瘤胃瘘管和小肠瘘管的肉牛作为试验动物,尼龙袋法测定肉牛常见饲料干物质(DM)和粗蛋白(CP)的瘤胃降解特性和小肠消化率。[结果]结果表明,DM瘤胃有效降解率由高到低为玉米粉、麦麸、苜蓿干草、豆粕、菜籽粕、玉米青贮、醋糟、白酒糟;CP瘤胃有效降解率由高到低为苜蓿干草、麦麸、豆粕、醋糟、玉米粉、玉米青贮、菜籽粕、白酒糟;DM小肠消化率由高到低为豆粕、菜籽粕、玉米粉、白酒糟、醋糟、麦麸、苜蓿干草、玉米青贮;CP小肠消化率由高到低为豆粕、菜籽粕、玉米粉、苜蓿干草、麦麸、白酒糟、玉米青贮、醋糟。[结论]试验表明,不同饲料瘤胃降解特性不同,为小肠提供过瘤胃可消化蛋白的能力不同,且饲料的DM小肠消化率小于CP小肠消化率。     

Research note: The silage characteristics of two varieties of forage sorghum mixed in different proportions and at two stages of maturity

Abstract

Two varieties of forage sorghum, low grain Dekalb FS‐5 (FS) and higher grain Pioneer 947 (GS) were harvested at the milk and dough stages of maturity respectively. Each variety was ensiled separately and as mixtures under laboratory conditions. The mixtures comprised FS.GS at ratios of 3:1 and 1:1 respectively. At the milk stage the FS had a dry matter (DM) content of 338 g kg^?1 and water‐soluble carbohydrates (WSC) content of 120 g kg^?1, as compared with 389 g kg^?1 and 63 g kg^?1, respectively for the GS. At the dough stage, these contents were 374 g kg^?1 and 123 g kg^?1 for the FS, and 520 g kg^?1 and 29 g kg^?1 for the GS, respectively. At the dough stage the GS had higher neutral detergent fibre (NDF) and acid detergent fibre (ADF) contents than FS (592 g kg^?1 and 379 g kg^?1 vs. 533 g kg^?1 and 339 g kg^?1 DM, respectively). In the silage harvested at milk stage, the pH of FS alone decreased most slowly, whereas at the dough stage the pH of the GS remained highest. In mixtures the pH decline accelerated with an increasing proportion of FS. Following harvest at the milk stage the 3:1 (FS:GS) had the best ensiling characteristics, whereas following at the dough stage the 1:1 mixture provided the most stable silage. Rumen degradability of the silage of GS was higher than that of the FS silage, especially for material harvested at dough stage of maturity (59.2 g kg^?1 vs. 50.9 g kg^?1). Mixing FS with GS at the ensiling increased the digestibility of the resulting silage as compared with FS alone.     

Effects of replacing grass silage harvested at two maturity stages with maize silage in the ration upon the intake, digestibility and N retention in wether sheep

The objective of this experiment was to study the effects of interactions between medium quality grass silage (GS1) and maize silage (MS) as well as between low-quality grass silage (GS2) and MS on ad libitum intake, digestibility and N retention in wether sheep. Two grass silages (GS1 and GS2) were ensiled in round bales, without additives, from the primary growth of orchard grass (Dactylis glomerata L.) harvested at two different maturity stages. The study consisted of seven feeding treatments incorporating GS1, GS2 and MS fed alone and forage mixtures of GS1 and MS as well as GS2 and MS (67:33% and 33:67%, respectively, DM (dry matter) basis).Delayed harvesting lowered (P < 0.05) the crude protein (CP) concentration in GS2 compared to GS1. The DM content (g kg^− 1 fresh sample) and starch concentration (g kg^− 1 DM) of MS were 264 and 211, respectively.Inclusion of MS in the GS1-based ration had positive linear effects on CP and starch digestibility (P < 0.05 and P < 0.01, respectively) and N intake (P < 0.01) while a negative effect on neutral detergent fibre (NDF) and acid detergent fibre (ADF) digestibility (P < 0.05 and P < 0.01, respectively). A positive associative response of GS1 and MS was observed for DM ad libitum intake (g kg^− 1 M^0.75 day^− 1) (quadratic, P < 0.05), CP digestibility (quadratic, P < 0.01), N intake (quadratic, P < 0.01) and N balance (quadratic, P < 0.05). Inclusion of MS into the GS2-based ration had a positive linear effect on the ration fresh matter ad libitum intake (kg day^− 1 and g kg^− 1 M^0.75 day^− 1) (P < 0.01 and P < 0.001, respectively), NDF ad libitum intake (kg day^− 1 and g kg^− 1 M^0.75 day^− 1) (P < 0.01), digestibility of DM (P < 0.01), organic matter (OM) (P < 0.01), ADF (P < 0.05), starch (P < 0.001), digestibility of OM in DM (D-value) (P < 0.001), and N intake (P < 0.01). Positive associative effects of GS2 and MS were observed on all the intake and digestibility parameters measured, N intake (quadratic, P < 0.001) and N balance (quadratic, P < 0.05). It was concluded that, as expected, a positive associative response of GS2 and MS was recorded for all the measured parameters while that of GS1 and MS for a limited number of parameters, probably due to lower quality of MS (lower starch concentration) than required for improved utilization of the GS1-based ration.