锌、铁、钼肥对紫花苜蓿草产量和品质的影响

为了满足紫花苜蓿Medicaco sativa对微量元素的需求,提高其产量和品质,采用田间试验方法,在比较贫瘠的土壤条件下,研究了锌、铁、钼肥单独施用及组合施用对紫花苜蓿草产量及品质影响。结果表明：施用微量元素锌、铁、钼肥均能显著提高紫花苜蓿的草产量,其中铁单施（15 kg/hm2）和锌钼配施（12 kg/hm2,0.5 kg/hm2）处理效果最好,分别增产15.9%和5.9%。微肥对粗蛋白含量没有明显影响,但铁单施、钼单施、锌钼配合施用能显著提高苜蓿粗蛋白产量。微肥能降低粗脂肪含量和产量;对粗纤维含量没有影响,但能提高其产量;对粗灰分和无氮浸出物含量的影响不显著,但能提高其产量;显著降低钙含量,对钙产量无显著影响;能提高磷含量和产量。     

腐殖酸钠对紫花苜蓿营养品质的影响

在温室进行盆栽试验,采用基施的方法研究腐殖酸钠(SH)单施及SH与磷肥(P)配施对紫花苜蓿营养品质的影响。结果表明:各处理中第2次刈割较第1次刈割,紫花苜蓿CP、EE、Ash含量下降,NDF、ADF含量提高。同一刈割条件下,SH单施及其与P配施对紫花苜蓿品质均有改善作用,而且SH与P配施的改善作用更为显著;同时,SH-P1和SH-P22个处理组相比,紫花苜蓿CP、EE含量及RFV值明显提高,NDF、ADF含量显著降低,Ash含量也有一定程度的提高,说明SH与P1配施能更有效改善苜蓿品质;在SH-P1处理组中,SH5-P1处理和SH4-P1处理表现较为理想,且2个理间差异不显著。综合品质性状和饲用价值,SH5-P1为试验最佳的施肥处理,即SH5为11.25g/盆,P1为3.41g/盆。     

添加剂对紫花苜蓿青贮饲料发酵品质的影响

为提高紫花苜蓿青贮饲料的发酵品质,抑制不饱和脂肪酸的损失,以无添加剂为对照,研究了添加剂：苯甲酸钠、酪蛋白酸钠、十六烷酸、糖蜜和丙酸,对紫花苜蓿青贮饲料发酵品质和脂肪酸的影响。青贮65 d后开窖,检测发酵品质指标和各种脂肪酸的含量。结果表明：对照组的pH低于4.50,乳酸含量达到54.25 g·kg^-1 DM,丁酸含量低于5.00 g·kg^-1 DM,弗氏评分为64.33,具有良好的发酵品质。与青贮前相比,青贮后苜蓿青贮饲料中的亚油酸（C18：2n6）和亚麻酸（C18：3n3）的含量显著增加（P<0.05）。青贮后,与对照组相比,十六烷酸和酪蛋白酸钠添加组分别不显著（P>0.05）和显著地（P<0.05）降低了乳酸含量;酪蛋白酸钠添加组增加了丁酸含量（P<0.05）;二者的弗氏评分低于50.00,降低了发酵品质。与此相反,苯甲酸钠、丙酸和糖蜜添加组不同程度地增加了乳酸含量,降低了pH,减少了氨态氮和酸性洗涤纤维的含量,弗氏评分分别为70.33、74.33和67.67,进一步提高了青贮发酵品质。与对照相比,苯甲酸钠和丙酸添加组不同程度地增加了C18：2n6或C18：3n3的含量,而糖蜜添加组降低了C18：2n6和C18：3n3的含量（P<0.05）。综上所述,丙酸和苯甲酸钠适宜于作为青贮添加剂生产优质紫花苜蓿青贮饲料。     

喷施硫酸锌对紫花苜蓿草产量和品质的影响

采用叶面喷施的的方法研究了不同施锌水平200,500和800mg／kg对紫花苜蓿（Medicaco sativa）干草产量及品质影响。结果表明：喷施硫酸锌显著（P〈0．05）提高苜蓿草产量,其中施锌量为500mg／kg的处理产量最高。适量的锌水平可以显著提高粗蛋白含量,施锌量为500mg／kg时,可以显著提高紫花苜蓿粗脂肪、粗纤维、磷的含量,对粗灰分含量影响不大。喷施不同浓度Zn处理,除第1茬外,苜蓿中的钙含量有增加趋势。营养物质的年积累量均以施锌浓度为500mg／kg时达到最高。     

水氮互作对河西走廊紫花苜蓿品质的影响

通过研究不同灌溉量(W₁:117 mm;W₂:156 mm;W₃:192 mm)和施氮量(N₁:0 kg·hm^-2;N₂:40 kg·hm^-2;N₃:80 kg·hm^-2;N₄:120 kg·hm^-2)互作条件下河西走廊紫花苜蓿水分利用效率、品质和相对饲用价值的变化特征,旨在确定紫花苜蓿品质最优时的水氮配置模式。结果表明,水氮互作显著影响了紫花苜蓿水分利用效率、粗蛋白质含量、中性洗涤纤维含量和相对饲用价值(P<0.05),但对紫花苜蓿地上生物量、粗脂肪、粗灰分含量和酸性洗涤纤维含量影响不显著。紫花苜蓿水分利用效率、粗蛋白质含量、中性洗涤纤维含量和相对饲用价值随灌溉量和施氮量的增加均呈开口向下的抛物线,最大值出现的组合分别为W₂N₃和W₂N₂,说明只有水氮合理配置才能提高紫花苜蓿品质和相对饲用价值。     

日粮添加苜蓿皂甙对鸡蛋品质的影响

本文旨在研究苜蓿皂甙对鸡蛋品质的影响，并初步探讨其作用机制。选用288只400日龄海兰褐商品蛋鸡．随机分为4个处理，每组72只鸡，设4个重复，每个重复18只鸡．采用单因素方差设计。在玉米-豆粕型日粮基础上分别添加0、30、60、90mg／kg的苜蓿皂甙饲喂蛋鸡，试验期60d。结果表明：日粮中添加苜蓿皂甙，能够提高蛋壳厚度和蛋白哈氏单位。其中蛋壳厚度，Ⅲ、Ⅳ组与对照组相比．差异显著（P〈0．05）：哈氏单位，Ⅲ组与对照组相比，差异显著（P〈0．05）。综合分析得出，目粮中添加60mg／kg的苜蓿皂甙效果最佳。     

Effects of monensin on monovalent ion metabolism and tissue concentrations in lambs

A study consisting of two trials was conducted to determine the effects of monensin on the apparent absorption and retention of sodium (Na) and potassium (K) and to examine changes in tissue and ruminal fluid concentrations of these minerals in lambs. Eight lambs (39 kg) were used in trial 1 and 10 lambs (37 kg) were used in trial 2. Animals were used in randomized block designs, blocked by weight, and fed a high concentrate diet with or without 20 mg/kg monensin. Trials began with a dietary adjustment period lasting 18 d in trial 1 and 21 d in trial 2. Animals were then placed in metabolism stalls for a 10-d stall adjustment period followed by a 12-d collection period. Collections for mineral balance were made during the first 10 d of the collection period. Blood and ruminal fluid samples were obtained on d 11 of the collection period. Lambs were slaughtered on d 12 of the collection period and tissue samples were collected. Sodium retention decreased (P less than .05) 86.2% when monensin was fed. Apparent K absorption increased (P less than .05) 16.7%, while K retention increased (P less than .10) 52.6% when monensin was fed. In lambs fed monensin, ileal Na decreased (P less than .10) 13.8%. These results indicate that dietary monensin alters the metabolism of Na and K in lambs.     

水分和添加剂对紫花苜蓿青贮品质的影响

分别对含水量为54.27%和42.67%的紫花苜蓿设不添加、添加乳酸菌+葡萄糖、纤维酶剂和饲料益菌素(suk B)进行青贮,在贮藏后的第65天开封,分析各处理青贮饲料的发酵品质和主要营养成分含量。以探讨不同水分和添加剂及其互作对紫花苜蓿(Medicago sativa)青贮品质的影响。结果表明,各处理组紫花苜蓿青贮后的感官评分均在13.6～16.1,感官评定均为优良青贮饲料。以添加纤维素酶组的感官评分最高,总分为16.1,达优质青贮饲料。水分和添加剂对苜蓿青贮营养成分含量均没有显著影响(P0.05);但两因素的交互作用可显著提高紫花苜蓿青贮后的嗅觉评分(P0.05),54.27%的含水量较42.67%的青贮效果更好,可显著降低青贮pH值(P0.05),改善青贮品质,这说明低水分紫花苜蓿可不用添加剂直接青贮,但水分过低,不利于降低酸度。添加剂只在适宜水分条件下才可改善紫花苜蓿青贮发酵品质。     

乳酸菌对苜蓿草粉发酵品质的影响

通过为期60d的发酵,探讨添加乳酸菌对苜蓿(Medicago sativa)草粉发酵品质的影响。试验设4个处理,分别为添加无菌水(对照)、植物乳杆菌(Lactobacillus plantarum,LP)、屎肠球菌(Enterococcus faecium,EF)和植物乳杆菌+屎肠球菌(LP+EF)发酵苜蓿草粉,设5个时间点采样进行相关项目测定。结果表明,与对照组相比,发酵60d时各试验组发酵苜蓿草粉的评分提高,总酸含量显著升高(P0.05),pH显著降低;LP、LP+EF和对照组的干物质含量明显低于EF组;各试验组酸性洗涤纤维含量明显低于对照组;有氧暴露7d后,各试验组的pH均显著低于对照组、总酸含量均显著高于对照组(P0.05),且只有对照组中检测到酵母菌(Saccharomycetes)和霉菌(Mycete)。综上可知,添加乳酸菌对苜蓿草粉的发酵品质、稳定性及营养组成具有良好的改善作用。     

乙酸钾对紫花苜蓿干燥速度和营养品质的影响

对刈割后初花期紫花苜蓿Medicago sativa分别喷洒不同质量分数乙酸钾(CK:0、C1:0.5%、C2:1%、C3:1.5%、C4:2%、C5:2.5%、C6:3%),测定其水分含量变化和干燥后粗蛋白(CP)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)及能量(GE)含量的变化。结果表明:喷洒不同质量分数的乙酸钾可以提高紫花苜蓿的干燥速度,并改善其干草营养品质。除C6外,其余各处理组间紫花苜蓿的CP含量差异不显著(P0.05),其中C2组CP含量最高(19.24%);C2组NDF含量(36.2%)显著低于其他各处理组(P0.05);除C6外,其他各处理组的ADF含量显著的低于CK(P0.05);CK处理GE含量显著的低于其余各处理(P0.05),其中C2组GE含量最高(17 801.67 J/g)。综合考虑,7个处理组中以C2处理组的干燥效果最好,能有效地改善紫花苜蓿干草品质。     

Effects of supplemental dietary phytase and pharmacological concentrations of zinc on growth performance and tissue zinc concentrations of weanling pigs

Three experiments were conducted to determine the effects of phytase, excess Zn, or their combination in diets for nursery pigs. In all experiments, treatments were replicated with five to seven pens of six to seven pigs per pen, dietary Ca and available P (aP) levels were decreased by 0.1% when phytase was added to the diets, excess Zn was added as ZnO, a basal level of 127 mg/kg of Zn (Zn sulfate) was present in all diets, and the experimental periods were 19 to 21 d. In Exp. 1, pigs (5.7 kg and 18 d of age) were fed two levels of phytase (0 or 500 phytase units/kg) and three levels of excess Zn (0, 1,000, or 2,000 ppm) in a 2 x 3 factorial arrangement. Added Zn linearly increased ADG and ADFI during Phase 1 (P = 0.01 to 0.06), Phase 2 (P = 0.02 to 0.09), and overall (P = 0.01 to 0.02). Gain:feed was linearly increased by Zn during Phase 1 (P = 0.01) but not at other times. Dietary phytase decreased ADG in pigs fed 1,000 or 2,000 ppm Zn during Phase 2 (Zn linear x phytase interaction; P = 0.10), did not affect (P = 0.27 to 0.62) ADFI during any period, and decreased G:F during Phase 2 (P = 0.01) and for the overall (P = 0.07) period. Plasma Zn was increased by supplemental Zn (Zn quadratic, P = 0.01) but not affected (P = 0.70) by phytase addition. In Exp. 2, pigs (5.2 kg and 18 d of age) were fed two levels of phytase (0 or 500 phytase units/kg) and two levels of Zn (0 or 2,000 ppm) in a 2 x 2 factorial arrangement. Supplemental Zn increased ADG and G:F during Phase 2 (P = 0.02 to 0.09) and overall (P = 0.07 to 0.08), but it had no effect (P = 0.11 to 0.89) on ADG during Phase 1 or ADFI during any period. Phytase supplementation increased ADG (P = 0.06) and G:F (P = 0.01) during Phase 2. Gain:feed was greatest for pigs fed 2,000 ppm Zn and phytase (Zn x phytase interaction; P = 0.01). Bone (d 20) and plasma Zn (d 7 and 20) were increased (P = 0.01) by added Zn but not affected (P = 0.51 to 0.90) by phytase. In Exp. 3, pigs (5.7 kg and 19 d of age) were fed a basal diet or the basal diet with Ca and aP levels decreased by 0.10% and these two diets with or without 500 phytase units/kg. Supplemental phytase had no effect (P = 0.21 to 0.81) on growth performance. Reduction of dietary Ca and aP decreased (P = 0.02 to 0.08) ADG, ADFI, and G:F for the overall data. These results indicate that excess dietary supplemental Zn increases ADG and plasma and bone Zn concentrations. Dietary phytase did not affect plasma or bone Zn concentrations.     

Effect of bis-glycinate bound zinc or zinc sulfate on zinc metabolism in growing lambs

To assess the efficacy of bis-glycinate bound Zn, 36 crossbred wethers (34 ± 2 kg) were sorted by body weight into three groups and stagger started on a Zn-deficient diet (18 mg Zn/kg dry matter [DM]; 22.5% neutral detergent fiber [NDF]) for 45 d prior to a 15-d metabolism period (10 d adaptation and 5 d collection). On day 46, lambs were randomly assigned to dietary treatments (four lambs treatment⁻¹group⁻¹): no supplemental Zn (CON) or 15 mg supplemental Zn/kg DM (ZINC) as Zn sulfate (ZS) or bis-glycinate (GLY; Plexomin Zn, Phytobiotics). Blood was collected from all lambs on days 1, 44, 56, and 61. Liver, jejunum, and longissimus dorsi samples were collected after euthanasia on day 61. Gene expression was determined via quantitative real-time polymerase chain reaction. Data were analyzed using ProcMixed of SAS (experimental unit = lamb; fixed effects = treatment, group, and breed) and contrast statements assessed the effects of supplemental Zn concentration (ZINC vs. CON) and source (GLY vs. ZS). After 15 d of Zn supplementation, plasma Zn concentrations were greater for ZINC vs. CON and GLY vs. ZS (P ≤ 0.01); tissue Zn concentrations were unaffected (P ≥ 0.27). Liver Cu concentrations were lesser for ZINC vs. CON (P = 0.03). Longissimus dorsi Mn concentrations were greater for ZINC vs. CON (P = 0.05) and tended to be lesser for GLY vs. ZS (P = 0.09). Digestibility of DM, organic matter (OM), and NDF was lesser for ZINC vs. CON (P ≤ 0.05); acid detergent fiber digestibility tended to be greater for GLY vs. ZS (P = 0.06). Nitrogen retention (g/d) tended to be greater for GLY vs. ZS (P = 0.10), and N apparent absorption was lesser for ZINC vs. CON (P = 0.02). Zinc intake, fecal output, retention, and apparent absorption were greater for ZINC vs. CON (P ≤ 0.01). Apparent absorption of Zn was −5.1%, 12.8%, and 15.0% for CON, ZS, and GLY, respectively. Nitrogen and Zn retention and apparent absorption were not correlated for CON (P ≥ 0.14) but were positively correlated for ZINC (retention: P = 0.02, r = 0.52; apparent absorption: P < 0.01, r = 0.73). Intestinal expression of Zn transporter ZIP4 was lesser for ZINC vs. CON (P = 0.02). Liver expression of metallothionein-1 (MT1) tended to be greater for GLY vs. ZS (P = 0.07). Although Zn apparent absorption did not differ between sources (P = 0.71), differences in post-absorptive metabolism may be responsible for greater plasma Zn concentrations and liver MT1 expression for GLY-supplemented lambs, suggesting improved bioavailability of GLY relative to ZS.     

氨基酸复合微肥对苜蓿生产和营养品质的影响

试验阐明了在景泰的土壤条件下施用氨基酸复合微肥对紫花苜蓿Medicago sativa生长、品质和营养吸收的影响,为苜蓿的合理施肥提供了依据.结果表明:氨基酸复合微肥能够不同程度地增加株高并提高草产量.适当施用氨基酸复合微肥还能提高苜蓿粗蛋白和粗脂肪的含量.且在此试验条件下苜蓿喷施氨基酸复合微肥的最佳用量是1 350 mL/hm2.     

氮素添加对中国苜蓿产量与品质效应的Meta分析

氮素在苜蓿产量累积与品质提升中发挥着重要作用,但其不合理添加不仅会造成资源浪费,还会加剧环境污染,且其添加效应因试验区域、添加模式和种植管理等因素不同存在较大差异。本研究通过整合已发表的相关田间试验数据,利用Meta分析方法定量研究了氮素添加对苜蓿产量与品质(粗蛋白含量、酸性和中性洗涤纤维含量)的效应及主要影响因素。结果表明,与不添加氮素相比,添加氮素可显著提高苜蓿产量与品质,其中产量和粗蛋白含量分别平均提高12.6%(置信区间9.0%～16.2%)和7.3%(置信区间4.1%～10.6%),酸性和中性洗涤纤维含量分别平均降低5.6%(置信区间3.5%～7.8%)和3.0%(置信区间1.0%～4.9%)。在甘肃,年平均气温<8℃和年平均降水量200～400 mm的地区,采用硝酸铵分次施肥及灌溉和播种量为26～30 kg·hm^-2时,更有利于添加氮素对苜蓿产量和粗蛋白含量的提高效应及对酸性和中性洗涤纤维含量的降低效应;但适宜的施氮量及生长年限在产量与品质方面存在差异。该研究可为苜蓿生产力提升及氮营养高效利用提供参考。     

不同温度下苜蓿草捆霉变规律及草捆品质变化

采用单因素试验设计,在3个密闭的房间放置自动控温电热器自动控制温度,分别设3个贮藏温度梯度(25、30和35℃),每梯度设3个重复。模拟真实环境研究不同贮藏温度下苜蓿(Medicago sativa)草捆的霉变规律以及霉变对草捆品质的影响,贮藏时间为16 d,同时隔天(即第1、3、5、7、9、11、13、15 d)采样。结果表明,贮藏温度越高、时间越长,苜蓿草捆中霉菌数量增加越快,就越容易发生霉变;不同贮藏温度苜蓿草捆中粗蛋白含量表现为各试验组每天之间差异显著(P0.05),每天中各试验组之间差异也都显著(P0.05),30℃试验组粗蛋白含量最高;各个试验组的霉菌数与粗蛋白的含量呈负相关;贮藏温度对苜蓿草捆中中性洗涤纤维、酸性洗涤纤维的含量均无显著影响(P0.05)。     

刈割茬次和生育期对苜蓿青贮品质的影响

以新疆石河子市第八师147团紫花苜蓿为研究材料,探究不同刈割茬次及生育期苜蓿青贮营养品质和发酵品质间的差异。选择3个刈割茬次,现蕾期、初花期和盛花期3个生育期处理;分别于青贮发酵第3、9、15、30、45、60天取样测定其青贮品质。结果表明:苜蓿青贮过程中,刈割茬次与生育期的交互作用对干物质、中性洗涤纤维、粗蛋白、乳酸和乙酸含量产生极显著影响(P<0.01),苜蓿青贮在发酵过程中会降低营养物质的含量,发酵60 d时,第3茬盛花期苜蓿青贮的DM含量最高,达到39.03%,第3茬现蕾期苜蓿青贮的酸性洗涤纤维和中性洗涤纤维含量最低,第1茬现蕾期CP、WSC含量最高,分别是20.21%和4.39%,第2茬现蕾期的乳酸和乙酸含量相对其他处理较高,第1茬现蕾期氨态氮含量最低。各处理综合评价排序:第1茬现蕾期处理>第3茬现蕾期处理>第1茬初花期处理>第2茬现蕾期处理>第3茬初花期处理>第1茬盛花期处理>第3茬盛花期处理>第2茬初花期处理>第2茬盛花期处理。刈割越早,苜蓿越幼嫩,营养品质高,适口性好,并有利于植株再生,苜蓿青贮的营养品质和发酵品质也较晚刈割的其他处理好。因此,控制苜蓿刈割时间可改善苜蓿青贮营养、发酵品质,提高苜蓿利用率。