Identification of companion small grains for midmar Italian ryegrass

Abstract

In a preliminary investigation four small grain species, oats (Avena sativa), rye (Secalae cereale), wheat (Triticum aestivum) and triticale (Triticum × secalae) were planted alone and in combination with Lolium multiflorum cv Midmar under irrigation. The dry matter (DM) yield of Midmar was also compared to that of four other annual ryegrass cultivars. All species combinations were harvested at either three‐ or six‐week cutting intervals and fertilized with either 200 or 400 kg N/ha.

As a group the pure ryegrasses had a greater yield potential than the small grain‐Midmar group which in turn out‐yielded the small grain group. Increasing cutting interval from three to six weeks had a far stronger positive influence on DM production than that of doubling the amount of nitrogen. Rye was the most successful small grain in being able to fill the winter gap in the fodderflow of Midmar ryegrass.

The small grains on average contributed about 25 % towards the total DM production in the small grain‐Midmar mixtures. Oats, although initially slow, had significantly (P≤0,05) higher yields than any of the small grains and had a longer, more evenly distributed growing season.     

The long-term effects of fire regime on primary production of montane grasslands in South Africa

Natural grasslands deliver essential ecosystem services through plant production, which enhances water supply, nutrient cycling, soil retention and greenhouse gas mitigation. Although the condition of montane grasslands for provision of ecosystem services is maintained by regular annual or biennial burning, controversy exists over the impact of different frequencies and seasons of burning on grassland productivity. The objective of this study was to determine the long-term effects of different burning regimes on primary production and quality of the montane grasslands of the KwaZulu-Natal Drakensberg. There were no significant differences in the mean standing live mass between 30 years of annual winter and biennial spring burning. However, in unburnt areas productivity was 20% lower (118.2?g m?2) than in regularly burnt grassland (144.7–154.5?g m?2). Crude protein did not vary between the annual winter and biennial spring treatments (95–113?kg ha?1), but was significantly lower in unburned areas (45?kg ha^?1). However, an infrequent fire in a protected area caused a temporary spike in crude protein (16%) compared with regular burning (5–10%), which can benefit wildlife. We conclude that montane grasslands can be burnt annually or biennially in the dormant season to promote long-term productivity.     

Voorlopige evaluasie van sporobolus fimbriatus as aangeplante weiding in die sentrale oranje‐vrystaat

Uittreksel

Die potensiaal van Sporobolus fimbriatus as aangeplante weiding is ten opsigte van relatiewe groeitempo, kumulatiewe groei, droëmateriaalproduksie, weikapasiteit, blaar : stingel verhouding en kwaliteit (ruproteïen en verteerbaarheid) geëvalueer.

Die groeipatroon is tipies van ‘n tropiese grasspesie. Die droëmateriaalproduksie van onbeweide en beweide S. fimbriatus was gemiddeld 3 329 kg/ha en 2720 kg/ha onderskeidelik. ‘n Gemiddelde weikapasiteit van 4,22 ha/GVE/jaar is verkry. Die blaar : stingelverhouding het heelwat tussen seisoene verskil, terwyl die verhouding deurgaans meer gunstig onder snytoe‐stande as onder beweiding was. Beide die ruproteïeninhoud en verteerbaarheid van dieregeselekteerde plantmateriaal het feitlik deurgaans aan die behoefte van herkouers voldoen.     

Effect of particle size distribution of maize and soybean meal on the precaecal amino acid digestibility in broiler chickens

1. Herein, it was investigated whether different particle size distributions of feed ingredients achieved by grinding through a 2- or 3-mm grid would have an effect on precaecal (pc) amino acid (AA) digestibility. Maize and soybean meal were used as the test ingredients.

2. Maize and soybean meal was ground with grid sizes of 2 or 3 mm. Nine diets were prepared. The basal diet contained 500 g/kg of maize starch. The other experimental diets contained maize or soybean meal samples at concentrations of 250 and 500, and 150 and 300 g/kg, respectively, instead of maize starch. Each diet was tested using 6 replicate groups of 10 birds each. The regression approach was applied to calculate the pc AA digestibility of the test ingredients.

3. The reduction of the grid size from 3 to 2 mm reduced the average particle size of both maize and soybean meal, mainly by reducing the proportion of coarse particles. Reducing the grid size significantly (P < 0.050) increased the pc digestibility of all AA in the soybean meal. In maize, reducing the grid size decreased the pc digestibility of all AA numerically, but not significantly (P > 0.050). The mean numerical differences in pc AA digestibility between the grid sizes were 0.045 and 0.055 in maize and soybean meal, respectively.

4. Future studies investigating the pc AA digestibility should specify the particle size distribution and should investigate the test ingredients ground similarly for practical applications.     

上海地区高产优质紫花苜蓿品种的筛选

2001-2003年在上海交通大学农学院农场和实验室分别进行了53个国内外紫花苜蓿Medicago sativa品种的引种比较试验,以期为上海的牧草生产提供高产、优质的紫花苜蓿品种.结果表明,比较适合上海夏季高温潮湿的环境条件,干草和粗蛋白产量相对较高的紫花苜蓿品种主要有:Defi,其秋眠级数(FD)为5,试验中编号为A43(下文用"Defi(FD5,A43)"方式表示),Arriba(FD7,A61),Lobo(FD6,A62和A10),Abilene Z(FD5,A53),Ameri Graze 702(FD7,A59)和Durango(FD5,A51)等.这些品种在播种后19个月内7次收获的鲜草产量超过110 t/hm2,折合干物质产量超过26 t/hm2,折合粗蛋白产量超过6 t/hm2.生产者也可以根据市场供应的品种和价格情况,参考试验结果,选用在产量和质量上与上述推荐品种相近的其他品种.     

Effect of amino acid deficiency on precaecal amino acid digestibility in broiler chickens

In this study, we determined whether deficient dietary amino acid (AA) concentrations influence the precaecal (pc) AA digestibility when determined using the regression approach. We mixed two basal diets. Basal diet 1 was deficient in essential AAs, whereas adequate AA concentrations were ensured in basal diet 2 by adding free AAs. Rapeseed cake and full‐fat soya beans as test ingredients were included in the basal diets at levels of 100 and 200, and 150 and 300 g/kg, respectively, at the expense of maize starch. Each diet was tested with six replicates of 10 broiler chickens each. The feed intake of the chickens that were fed diets based on basal diet 2 was similar, whereas the feed intake of the chickens that were fed diets based on basal diet 1 differed considerably. The numerical differences in pc AA digestibility determined with basal diet 1 or 2 ranged from 2.6 percentage points to 20.8 percentage points in rapeseed cake and from 0.5 percentage points to 15.2 percentage points in soya beans. Across all measured AAs, the average differences were 10.1 percentage points and 5.4 percentage points in rapeseed cake and soya beans, respectively. The differences in the estimated pc AA digestibility between the basal diets were probably caused by different basal endogenous AA losses in the digesta between treatments as a consequence of different feed intake. Adequate AA concentrations and test ingredient levels that are specifically adjusted to avoid a negative effect on feed intake are recommended for future studies.     

多花黑麦草在生长肉兔上的营养价值评定

本试验旨在评定初花期多花黑麦草在生长肉兔上的营养价值。试验选取60日龄平均体重(2.20±0.32)kg的健康新西兰兔24只,随机分为2组,每组12个重复,每个重复1只。试验饲粮采用套算法进行配制,多花黑麦草的替代比例为20%;试验采用全收粪法进行消化试验,预试期和正试期各7 d。结果表明:1)多花黑麦草中总能、干物质、粗蛋白、粗脂肪、粗纤维、中性洗涤纤维、酸性洗涤纤维、粗灰分、钙、总磷和无氮浸出物含量分别为16.78 MJ/kg、92.24%、10.20%、1.64%、26.09%、51.80%、31.35%、7.72%、0.66%、0.28%和46.59%;2)多花黑麦草在生长肉兔中的表观消化能为7.21 MJ/kg,生长肉兔对多花黑麦草中总能、干物质、粗蛋白、粗脂肪、粗纤维、中性洗涤纤维、酸性洗涤纤维、粗灰分、钙、总磷和无氮浸出物的表观消化率分别为33.45%、48.36%、44.18%、84.45%、25.91%、22.73%、22.25%、26.10%、62.87%、13.94%和61.42%。由结果可知:初花期多花黑麦草中粗纤维、中性洗涤纤维、酸性洗涤纤维含量相对较高,总磷含量相对较低;生长肉兔对初花期多花黑麦草中不同营养成分的消化率存在一定差异,其中以粗脂肪、粗纤维、钙、无氮浸出物的表观消化率较高,总磷的表观消化率较低。     

越年生和多年生冷地型禾本科牧草的品种比较

2000-2002年在上海交通大学农业与生物学院农场对46个禾本科牧草品种进行比较试验,并在实验室内进行耐盐性鉴定与品质分析.通过对参试材料的鲜草产量、干草产量、粗蛋白含量、耐盐性等性状的考察和比较分析,筛选出越年生黑麦草Lolium multi florum是高产牧草种.其中秋播早发类型品种有泰蒂拉(英文名:Tetila;试验编号:G16;下文同),Grazer(G38),Total(G41),初春第1茬干草产量超过6 t/hm2;春播产量较高的品种有FaGrow(G30),97-3(G23),泰蒂拉和特高(Tatragold,G18)等,当年6月中旬1次收获的干革产量超过8.6 t/hm2;4次收获鲜草总产较高的品种有9724(G22),FaGron(G30),Total(G41),特高和泰蒂拉等,折合干草产量超过20 t/hm2;耐盐性较强的品种有特高,Minaret(G37)和上农四倍体(G45),能在含0.6%NaCl的1/4 Hoagland营养液中萌发和生长良好;高产品种中乳熟期粗蛋白含量较高的品种有9724(G22)和Tetila(G16),分别超过或接近占干物质的10%;乳熟期牧草干鲜比较高的品种有特高和上农四倍体(G45),超过0.3.在46个品种中,综合性状评定最好的5个品种有9724(G22),特高,泰蒂拉,FaGrow(G30),和Total(G41),它们都适合在上海及其周边地区加以推广应用.     

Effects of feeding diets containing low crude protein and coarse wheat bran as alternatives to zinc oxide in nursery pig diets

Two experiments were conducted to determine the effects of crude protein (CP) level in diets containing coarse wheat bran (CWB) with or without pharmacological levels of Zn (provided by zinc oxide: ZnO) on growth performance and fecal DM of nursery pigs. In experiment 1, 360 barrows (Line 200 × 400, DNA, Columbus, NE, initially 5.6 kg) were allotted to 1 of 6 dietary treatments from d 0 to 21 after weaning with 5 pigs per pen and 12 pens per treatment. Treatments included a positive control diet (21% CP) with 3,000 mg/kg Zn in phase 1 and 2,000 mg/kg in phase 2; negative control (21% CP) with 110 mg/kg added Zn, and 4 diets containing 4% CWB and 110 mg/kg added Zn formulated to contain 21%, 19.5%, 18%, or 16.5% CP. The 2 control diets and 21% CP CWB diet contained 1.40% standardized ileal digestible (SID) Lys in phase 1 and 1.35% SID Lys in phase 2, while the 19.5%, 18%, and 16.5% CP diets contained 1.33, 1.25 and 1.20% Lys, respectively, in both phases. Pigs fed the positive control diet containing pharmacological ZnO had increased (P < 0.05) ADG and G:F compared with the negative control and the 21% CP CWB diet. Reducing CP (concurrently with SID Lys) in diets containing CWB decreased ADG and G:F (linear, P = 0.002); however, fecal DM increased (linear, P = 0.005). In experiment 2, two groups of 300 and 350 pigs, initially 7.0 and 6.2 kg, respectively, were used with 5 pigs per pen and 26 pens per treatment. The objective was to determine if adding back essential AA would improve growth performance of pigs fed the low CP diets. All dietary treatments were fed for 13 days, contained 4% CWB, and consisted of: (1) positive control with 2,000 mg/kg of Zn and 21% CP (1.35% SID Lys); (2) no ZnO and 21% CP; and 3 diets with no ZnO formulated to 18% CP and (3) 1.2% SID Lys; (4) 1.35% SID Lys by the addition of feed grade amino acids (AA), and (5) diet 4 with non-essential amino acids (NEAA; Gly and Glu). Pigs fed 21% CP with ZnO had increased (P = 0.001) ADG compared to those fed 18% CP (1.35% SID Lys) with high levels of feed grade amino acids or those fed the reduced SID Lys (1.2%) diet. Overall, G:F was improved (P < 0.001) for pigs fed 21% CP diets and those fed the 18% CP diet with NEAA compared to pigs fed 1.2% SID Lys and pigs fed high levels of feed grade amino acids. Fecal DM was increased for pigs fed the reduced SID Lys diet. In summary, pharmacological levels of Zn improve pig growth performance, but reducing CP (and subsequently SID Lys) decreased nursery pig growth performance.     

稻茬种植多花黑麦草对土壤肥力和微生物组成的影响

土壤理化性状是农业生产潜力的重要指标,不同耕作制度对土壤微生物的丰富度和数量及土壤肥力的变化有一定影响。为解决我国南方农区冬闲田的有效利用,采用多花黑麦草(Lolium multiflorum)/水稻(Oryza sativa)轮作技术,研究稻田冬种多花黑麦草对土壤肥力和微生物的影响。结果表明,与冬闲/水稻对照区相比,多花黑麦草/水稻处理区土壤有机质含量增加了8.50%,全氮含量增加了8.22%,全磷含量增加了7.58%,全钾含量增加了14.96%;与冬闲/水稻对照区相比,多花黑麦草/水稻处理区土壤中细菌菌群数量增加了13.03%,放线菌菌群数量增加了3.22%,真菌菌群数量增加了4.16%。可见在南方冬闲田种植多花黑麦草不仅能为农区养殖业提供大量饲草,还能改善土壤肥力,增加土壤养分,为后作水稻生长发育提供良好条件。     

Effects of nitrogen fertilizer and harvesting stage on photosynthetic pigments and phytol contents of Italian ryegrass silage

This study aimed to investigate the effects of nitrogen (N) fertilizer application and harvesting stage on the contents of chlorophyll, phytol and carotenoids (β‐carotene and lutein) in Italian ryegrass herbage before and after ensiling, and the extent of phytol preservation after ensiling. Three rates of N fertilizer (0, 60 and 120 kg N/ha) were applied by top‐dressing as an additional fertilizer. The herbage harvested at booting stage (27 weeks of age) or heading stage (29 weeks of age) were wilted for 1 day, then ensiled for 60 days using a small‐scale pouch system. In the pre‐ensiled herbages, increasing N fertilizer application increased the contents of crude protein and photosynthetic pigments, and these contents were also higher at the booting stage compared with the heading stage. In the silage, increasing N fertilizer application also increased the contents of crude protein, the photosynthetic pigments and their derivatives (pheophytin and pheophorbide), while harvesting stage did not affect the contents of β‐carotene, chlorophylls or pheophorbide. Nitrogen fertilizer application and early harvesting of herbage increased lutein and phytol contents in Italian ryegrass silage. Lutein and phytol in Italian ryegrass herbage are indicated to be well preserved during ensiling.     

留茬高度对人工草地牧草产量及质量的影响

试验对黑麦草／白三叶混播草地在不同留茬高度下的生产特性进行了分析研究,研究结果表明,草地牧草的枯死率与留茬高度呈正比关系,在不同留茬高度下,草地牧草青绿物质的生长速度和产量呈抛物线形式变化;青绿牧草产量占牧草总产量的百分比随留茬高度的上升而下降,而死亡物质的数量占牧草产量的百分比随留茬高度的上升而增加。     

半胱胺对银狐饲料消化能力的影响

为研究半胱胺对银狐饲料消化能力的影响,选用2月龄左右、健康银黑仔狐共106只(53♂ 53♀)。随机分96只(48♂ 48♀)为试验组,10只(5♂ 5♀)为对照组。采用复因子试验设计中的析因试验设计,为二因子有重复的试验设计,一个因子为半胱胺的不同添加剂量,另一个因子为半胱胺的不同添加间隔时间,在每间隔3、5、7和9 d分别按每千克体重添加40、70和100 mg的半胱胺。分别测定了干物质采食量、干物质表观消化率和粗蛋白质表观消化率,为消除不同间隔时间对消化试验的影响,正式试验进行12 d(从2004年8月18日~29日),结果发现每间隔5 d按70 mg/kg体重浓度添加1次半胱胺效果最好,它可使银狐干物质和粗蛋白质表观消化率分别比对照组提高16.19%(P<0.01)和15.97%(P<0.01);试验组银狐干物质采食量比对照组低,其中70 mg/kg体重5 d组可比对照组银狐干物质采食量降低4.65%(P<0.01)。     

"黑麦草-水稻"草田轮作系统的研究 6.冬种黑麦草期间施肥对后作水稻生产的影响

研究了冬种黑麦草期间施肥对后作水稻生产的影响，结果显示：（1）种草施肥处理区，尤其是复合肥施肥处理区的早稻生物量高于休闲区和种草无肥区，但分蘖数有所减少；（2）施肥处理增加早稻和晚稻的稻谷千粒重，施用尿素增加了早稻的有效分蘖，但在一定程度上降低了晚稻的有效分蘖。千粒重和有效分蘖的增加是施肥导致后作水稻增产的主要因素；（3）种草施肥处理的水稻产量较休闲区增产7．9％－14．6％，比种草无肥区增产9．7％－16．5％，而 草无肥区与休闲区相比，水稻减产1．6％，可见，冬种黑麦草期间施肥是后作水稻增产的不可缺少的条件。（4）考虑到从黑麦草收获物中必然带走大量的磷和钾，本研究也证实了单施尿素影响晚稻的有效分蘖，而且单施尿素容易引起肥害，因此，种草期间应施用复合肥，施肥量对后作水稻产量的影响不大，只要施肥量足以维持黑麦草的正常生长（750kg/hm^2)，即可对后作水稻生产产生正面效应。     

"饲用玉米-黑麦草”草地农业系统的研究Ⅰ饲用玉米的品种比较与生产性能

研究表明，在饲用玉米－黑麦草草地农业系统中采用优良的玉米品种。适宜的种植密度，适时的刈割时间和科学的栽培技术，能获得19－27t/hm^2的饲料干物质产量。通过测定饲用玉米乳熟期后整株水分动态变化，为适时刈割和青贮提供了依据。同时还对饲用玉米与黑麦草的时空配置、营养价值和生产成本进行了分析和评价。     

Selenium supplementation improves nutrient intake and digestibility,and mitigates CH4 emissions from sheep grazed on the mixed pasture of alfalfa and tall fescue

Low selenium (Se) in soil and forage can adversely affect on the quality of animal-derived foods, and hence on human health. Lambs grazed on mixed pastures of alfalfa (Medicago sativa) and tall fescue (Festuca arundinacea) were supplemented with five levels of Se [0, 3, 6, 9 and 12 µg/kg body weight (BW)]. The intake of dry matter (DM) and organic matter (OM) varied with the level of Se supplementation, with a peak at 6 µg Se per kg BW (p ≤ 0.05). Gross energy (GE) intake, digestive energy (DE) intake and metabolic energy (ME) intake were higher at 6 µg Se per kg BW than at other Se levels (p < 0.01); in addition, methane energy (CH₄-E) output was lower at 6 µg Se per kg BW. Supplementation with Se significantly increased nitrogen (N) intake, faecal N and urine N, for which the peak values were 20.2 g N/, 5.62 g N/day and 7.92 g N/day, respectively, at 6 µg Se per kg BW. Se intake, blood Se, faecal Se, urine Se and retained Se were negatively correlated with forage crude protein (CP) content (p < 0.001) but were positively correlated with the content of neutral detergent fibre (NDF) (p < 0.001) and acid detergent fibre (ADF) (p < 0.001). Thus, we recommend the addition of 6 µg Se per kg BW to sheep grazed on pastures in regions with low soil Se.     

刈割期和晒制方法对苜蓿青干草粗蛋白和粗纤维含量的影响

对不同刈割期和晒制方法处理的苜蓿青干草中粗蛋白和粗纤维含量的方差分析结果表明 :始花期收割的粗蛋白极显著的 (P <0 .0 1)高于盛花期并可获得较高产量。搭架晒干的粗蛋白显著 (P <0 .0 5 )高于小捆晒制和薄层摊晒 ,粗蛋白分别提高了 0 .82 %和 1.91% ;粗纤维显著降低 (P <0 .0 5 ) ,降低率分别为 0 .91%和 1.6 1%。因此 ,在始花期选择晴朗天气收割 ,采用搭架晒干可获得优质、高产的苜蓿干草     

不同氮源对反刍动物饲料可利用粗蛋白的影响

本试验应用体外培养技术研究了不同氮源对反刍动物饲料可利用粗蛋白(utilizable crude protein,uCP)的影响,以及不同氮源在培养发酵过程中降解损失的情况。将4种氮源,即尿素、赖氨酸、蛋氨酸和酪蛋白水解物,分别添加到肉牛的典型基础日粮中(粗蛋白,CP14.1%),配制成4种日粮,并使各日粮的粗蛋白水平相近(约20%),作为试验日粮。以未添加氮源的基础日粮作为对照日粮。应用Zhao和Lebzien(2002)的体外培养法测定了4种试验日粮和对照日粮的uCP。结果表明,添加尿素、赖氨酸、蛋氨酸和酪蛋白水解物,均能够有效地提高基础日粮的uCP(P<0.05)。在这4种氮源中,赖氨酸提高uCP的效果最好。在培养发酵过程中,尿素、赖氨酸、蛋氨酸和酪蛋白水解物的氨态氮损失分别占粗蛋白质的72.9%、22.8%、55.2%和70.3%。     

水煮和提取处理对中草药干物质消化率和小肠可消化蛋白质的影响

研究水煮和提取处理对中草药干物质消化率和小肠可消化蛋白质的影响,揭示提取过程对营养价值影响的作用机理,对于客观评定中草药提取残渣的营养价值具有重要意义。采用尼龙袋试验分别测定黄芪、麦芽和甘草3种原料及其经水煮和提取处理后产物的瘤胃降解动力学参数,并分别估算其主要养分在瘤胃的有效降解率(effective degradability,ED);采用移动尼龙袋试验分别测定3种原料及其经水煮和提取处理后产物瘤胃未降解干物质(nondegradable dry matte,UDM)和未降解蛋白质(nondegradable protein,UDP)的小肠消化率(intestinal digestibility,Idg),在此基础上分别估算其干物质消化率(dry matter digestibility,DDM)和小肠可消化粗蛋白质(intestinal digestible crude protein,IDCP)含量。结果表明:1)3种中草药经水煮和提取处理后产物的EDDM(effective degradability of dry matter)和EDCP(effective degradability of crude protein)均分别显著低于其未处理原料(P<0.05),但EDNDF(effective degradability of NDF)和EDADF(effective degradability of ADF)均分别显著高于其未处理原料(P<0.05);2)3种中草药经水煮和提取处理后产物的IdgUDM(intestinal digestibility of UDM)和IdgUDP(intestinal digestibility of UDP)均显著高于其未处理原料(P<0.05);3)水煮处理显著提高了3种中草药处理后产物的DDM(P<0.05),显著提高了麦芽处理后产物的IDCP和IDCP/CP,提取处理显著提高了麦芽提取残渣的DDM、IDCP和IDCP/CP(P<0.05),显著降低了甘草提取残渣的IDCP和IDCP/CP和黄芪的IDCP(P<0.05)。在无特殊需求时完全没有必要对饲料进行水煮处理;麦芽提取残渣具有作为优质精饲料的营养潜力;黄芪和甘草提取残渣具有作为优质粗饲料的营养潜力。     

新尼龙袋使用前瘤胃浸泡处理对饲料瘤胃降解特性的影响

本试验旨在研究瘤胃尼龙袋法中新尼龙袋使用前瘤胃浸泡处理对饲料瘤胃降解特性的影响.以8只装有永久性瘤胃瘘管的云南半细毛羊公羊为试验动物,随机分为2组(每组4只),分别采用预浸泡的尼龙袋(试验组)和未浸泡的尼龙袋(对照组)对玉米、豆粕、麦秸、黑麦干草4种常用饲料干物质(DM)和粗蛋白质(CP)的瘤胃降解特性进行研究.结果显...