共查询到20条相似文献，搜索用时 453 毫秒
1.
本试验旨在研究日粮中添加不同比例的氨化稻草及精组比例对体外发酵产气规律的影响。以2头安装有永久性瘤胃瘘管的西门塔尔牛作为瘤胃液供体,以未氨化、4%尿素和6%尿素氨化的稻草为粗饲料,分别与精料混合料配制成6种比例日粮,其中精料与粗饲料的比例为0∶100、20∶80、40∶60、60∶40、80∶20、100∶0。采用体外产气法测定各种日粮体外发酵的产气规律。结果表明:同一尿素氨化水平下,随着精料比例增加,产气量显著增加(P<0.05),并且精料∶粗料为100∶0组极显著高于0∶100组(P<0.01);不同尿素氨化水平下,精料∶粗料为40∶60时,4%尿素氨化组48 h产气量显著高于未氨化组(P<0.05),并且高于6%氨化组,而精料∶粗料为0∶100、20∶80、60∶40、80∶20、100∶0时,3种尿素氨化水平产气量之间差异不显著(P>0.05)。表明使用4%尿素对稻草进行氨化处理、日粮精料∶粗料为40∶60时,日粮的可消化性最好。 相似文献
2.
尿素氨化稻草饲喂绵羊效果 总被引：2，自引：0，他引：2
本试验用21只1岁阉羊分为3组,在日粮以供试粗料为基础,精料比例相同情况下比较研究稻草、氨化稻和草青干草的饲用价值。化学分析结果表明:稻草氨化后其粗蛋白由3.7％提高到8.5％,中性洗涤纤维(NDF)有所降低。76天饲养试验结果证明,日粮采食量氨化稻草组稍高于稻草,比青干草组略低,但各组间没有显著差异(P>0.05);试羊体增重氨化稻草组显著高于未氨化稻草组(P<0.05),较青干草组也稍高,组间差异不显著(P>0.05),通过消化试验证明氨化稻草的干物质(DM)、有机物(OM)、粗蛋白(CP)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)的消化率均比未氨化稻草有明显增加(P<0.05),和青干草相比,除有机物消化率(OMD)外,其他各营养成分的消化率也稍高于青干草,而酸性洗涤纤维的消化率则显著地高于青干草(P<0.05)。以上结果表明氨化稻草的饲用价值与青干草相当或稍高。 相似文献
3.
选用4只体重28 kg左右,安装永久瘤胃瘘管甘肃高山细毛羯羊,采用4×4拉丁方试验设计,通过体内消化代谢试验对棉桃壳和氨化棉桃壳进行营养价值评定。结果表明,绵羊对棉桃壳和氨化棉桃壳消化能、干物质消化率、氮消化率、有机物质消化率、中性洗涤纤维消化率、酸性洗涤纤维消化率、钙消化率、磷消化率和氮存留率分别为11.42 和10.90 MJ/kg,68.41%和66.30%,60.30%和60.68%,70.25%和67.57%,57.44%和54.55%,54.78%和52.21%,27.66%和24.88%,34.56%和27.57%及49.48%和50.34%。氨化棉桃壳和棉桃壳的消化率无显著性差异(P>0.05);饲粮中添加棉桃壳和氨化棉桃壳对绵羊瘤胃液中乙酸、丙酸、丁酸和其他酸摩尔比及乙/丙和氨态氮与蛋白氮浓度均产生了显著的影响(P<0.05),对瘤胃液pH及TVFA、总氮和尿素氮浓度无显著影响(P>0.05)。试验表明棉桃壳和氨化棉桃壳养分表观消化率无显著差异,利用尿素进行氨化处理时绵羊瘤胃内释放氨的速度较快,瘤胃微生物合成强度较低。 相似文献
4.
<正> 近年来,我省水牛挤奶业发展较快,为解决奶水牛的部分粗饲料来源,充分利用我省丰富的稻草资源,提高水牛挤奶业的经济效益,我们在揭西县进行了本次试验。 1.材料和方法 1.1 氨化稻草的制作本试验选用尿素作氨化氮源,稻草则选用晚造收割的半干稻草。稻草、水、尿素的用量比例为100∶40∶4。选择地势较高防水浸的地方(长×宽约为3×2.5米)作氨化地,先在地上铺一层稻草作垫草,再铺一层薄膜,然后每200公斤稻草铺作一层,用88公斤尿素液均匀泼洒在草层上,人工踏实,再铺上稻草,这样依次堆叠,一直堆至约2米高,用塑料薄膜覆盖,用封口纸密封。稻草氨化时间从1992年3月开始,计30天。氨化后的稻草质 相似文献
5.
6.
7.
张育英 《广东畜牧兽医科技》1993,(2):28-29
我省稻草资源丰富,广大农民素有利用稻草喂牛的习惯。近年来,我省水牛挤奶业发展较快,为了充分利用稻草资源丰富的优势,采用尿素氨化处理稻草,改善稻草适口性,提高稻草营养价值,使氨化稻草成为奶水牛的优质饲料,为今后利用氨化稻草喂牛越冬春,解决养牛业粗饲料不足,提供科学数据。我们在省畜牧局的指导下,于1992年3月开始,连续3个月进行了尿素氨化稻草饲喂奶水牛效果试验,现将试验报告如下: 相似文献
8.
我省广大农村习惯使用稻草喂牛,尤其在冬春季使用更普遍,但用稻草喂牛越冬春,易出现掉膘现象。稻草经过氨化处理后,可提高营养价值。我省盛产水稻,稻草资源十分丰富,为发挥这一资源优势,解决养牛业粗饲料的不足,探讨利用氨化稻草喂牛越冬春的可行性,我们在曲江县示范牧场进行本试验,现将结果报告如下: 相似文献
9.
<正> 奶水牛是否高产稳产主要取决于遗传、环境和饲料等因素。对稻草进行氨化处理是改善饲料因素的一个重要方法。为此,我们在吴川县畜牧试验场进行了氨化稻草饲喂奶水牛试验。 1.试验材料及氨化稻草的制作 1.1 氨化二联池的建造根据1头牛1立方米的大小确定容积,砌成壁厚7厘米、池壁长8米、宽1米、深1米的长方形池。中间垒一隔壁,两个池容积均为4立方米。两个池一个氨化,另一个取喂,交替使用。 1.2 氨化液的配制选用尿素作氨化氮源,每100公斤稻草用尿素4公斤,加水50公斤,先用少量水把尿素溶解后再加足水,尿素溶液保持水温40℃左 相似文献
10.
不同氨化方法对稻草氨化效果及羔羊生产性能的影响 总被引：3，自引：1，他引：2
选用平均体重(21.11±3.5)kg的陶赛特(公)和萨福克(公)与东北半细毛羊的杂交后代公羊各12只,按单因素随机区组设计,随机分为4组,每组设6个重复,分别饲喂快速负压氨化罐处理、负压袋装处理、常压袋装处理和未氨化稻草的对照组,测定每一种处理的表观消化率和羔羊的生产性能;选用4只体重40 kg左右的健康瘘管公羊,按4×4拉丁方设计,测定稻秸各养分瘤胃48 h消失率。结果表明:各氨化组稻草的DM、CP、DNF和ADF的表观消化率的变化趋势相同,由高到低顺序为负压袋装处理组快速负压氨化罐处理组常压袋装处理组对照组。各氨化组稻秸在瘤胃内DM、CP、NDF和ADF的48 h消失率均极显著高于未处理稻秸(P0.01)。各氨化组的粗饲料采食量和平均日增重显著高于对照组(P0.05)。综上所述,快速负压氨化罐处理可以代替传统的氨化方式,不仅处理效果较理想,且氨化时间短,适合各类秸秆氨化的工业化生产。 相似文献
11.
Using blood urea nitrogen to predict nitrogen excretion and efficiency of nitrogen utilization in cattle, sheep, goats, horses, pigs, and rats 总被引：3，自引：0，他引：3
The objectives of this study were to evaluate the potential for using blood urea N concentration to predict urinary N excretion rate, and to develop a mathematical model to estimate important variables of N utilization for several different species of farm animals and for rats. Treatment means (n = 251) from 41 research publications were used to develop mathematical relationships. There was a strong linear relationship between blood urea N concentration (mg/100 mL) and rate of N excretion (g x d(-1) x kg BW(-1)) for all animal species investigated. The N clearance rate of the kidney (L of blood cleared of urea x d(-1) x kg BW(-1)) was greater for pigs and rats than for herbivores (cattle, sheep, goats, horses). A model was developed to estimate parameters of N utilization. Driving variables for the model included blood urea N concentration (mg/100 mL), BW (kg), milk production rate (kg/d), and ADG (kg/d), and response variables included urinary N excretion rate (g/d), fecal N excretion rate (g/d), rate of N intake (g/d), and N utilization efficiency (N in milk and gain per unit of N intake). Prediction errors varied widely depending on the variable and species of animal, with most of the variation attributed to study differences. Blood urea N concentration (mg/100 mL) can be used to predict relative differences in urinary N excretion rate (g/d) for animals of a similar type and stage of production within a study, but is less reliable across animal types or studies. Blood urea N concentration (mg/100 mL) can be further integrated with estimates of N digestibility (g/g) and N retention (g/d) to predict fecal N (g/d), N intake (g/d), and N utilization efficiency (grams of N in milk and meat per gram of N intake). Target values of blood urea N concentration (mg/100 mL) can be backcalculated from required dietary N (g/d) and expected protein digestibility. Blood urea N can be used in various animal species to quantify N utilization and excretion rates. 相似文献
12.
本研究以武功山草甸为研究对象,采用随机区组试验设计,研究不同施氮水平(N0:不施氮;N_1:施氮量75kg·hm-2;N_2:施氮量150kg·hm-2;N_3:施氮量300kg·hm-2)下草甸土壤氮素时空变化规律和草甸植被根系形态特征及其对氮素吸收利用的影响。结果表明:土壤碱解氮含量随着施氮量的增加而增加(P0.05),各施氮处理土壤碱解氮含量随时间推移呈先升高后降低的趋势,并在7-9月间平均值降到最低(N0:111.7 mg·kg~(-1);N_1:140.6mg·kg~(-1);N_2:162.7mg·kg~(-1);N_3:1 169.0mg·kg~(-1));各处理0-20cm土层根系生物量密度由高到低依次为N_3(10.27mg·cm~(-3))N_2(10.02mg·cm~(-3))N_1(8.0mg·cm~(-3))N0(6.28mg·cm~(-3)),根长密度由高到低依次为N_3(20.1cm·cm~(-3))N_2(20.09cm·cm~(-3))N_1(17.2cm·cm~(-3))N0(14.3cm·cm~(-3)),其中N0、N_1和N_2这3个处理差异显著(P0.05);在0-150kg·hm-2的施氮范围内,根系对氮素的积累(N0:13.7kg·hm-2;N_1:23.3kg·hm-2;N_2:31.2kg·hm-2)随着施氮量的增加而显著增加(P0.05)。因此,在武功山草甸施用氮肥时应注意其氮肥施用量(推荐施氮范围为0-150kg·hm-2),避免氮素流失引起环境污染及资源浪费。 相似文献
13.
陇东雨养农区紫花苜蓿叶片氮、磷、钾重吸收与生物固氮的偶联关系 总被引：2，自引：0，他引：2
叶片养分重吸收是植物提高养分利用效率、增强环境适应性的重要机制之一,易受多种因素影响。在豆科植物中,养分重吸收与生物固氮有何关联尚不可知。为揭示养分重吸收与生物固氮间的偶联关系,以陇东雨养农区已建植2、4、7、11和14年龄的陇东苜蓿草地为对象,测定了叶片N、P、K浓度及δ15N,分析了叶片N、P、K重吸收效率(NRE、PRE和KRE)、重吸收度(NRP、PRP和KRP)及其与生物固氮率的关系。随紫花苜蓿建植年龄增长,叶片NRE、PRE呈先增大后减小的趋势,NRE和PRE分别为36.5%(28.4%~43.4%)和52.6%(38.1%~68.2%),其中7年龄苜蓿的NRE和PRE最高;2、11和14年龄苜蓿KRE为17.8%(23.0%~27.5%),但4和7年龄为负值。随紫花苜蓿年龄变化,叶片NRP、PRP和KRP均无明显变化趋势。随紫花苜蓿年龄增长,生物固氮率先降低后升高,平均固氮率为51.0%,其中7年龄苜蓿的最低。紫花苜蓿生物固氮率与叶片NRE、PRE和KRP负相关,但与叶片KRE、NRP和PRP不相关。紫花苜蓿生物固氮与叶片的氮、磷、钾重吸收存在偶联关系,对氮、磷重吸收效率和钾重吸收度有显著影响。 相似文献
14.
Martin Hughes Victor Mlambo Cicero HO Lallo Paul GA Jennings 《African Journal of Range and Forage Science》2016,33(4):253-264
This study evaluated whether the FieldScout CM 1000 NDVI and Yara N–Tester models can produce accurate and reliable estimates of nitrogen (N), buffer-soluble nitrogen (BSN), buffer-insoluble nitrogen (BISN), non-protein nitrogen (NPN) and in vitro ruminal nitrogen degradability after 3, 12 and 24?h incubation (ND3, ND12 and ND24) in three tropical grasses: Brachiaria hybrid, Megathyrsus maximus and Paspalum atratum. Correlation between the Yara N-Tester and N, BISN and in vitro ruminal N degradability of the Brachiaria hybrid and M. maximus were high (r 0.67–0.83). The Yara N-Tester accounted for 81% and 86% (p 0.000) of N variability in the Brachiaria hybrid and M. maximus, respectively. The Yara N-Tester prediction models explained 72% and 70% (p 0.000) BISN variability in the Brachiaria hybrid and M. maximus, respectively. In vitro ND24 of the Brachiaria hybrid (R?2 0.75) and M. maximus (R?2 0.75) was also best predicted with the Yara N-Tester. Model validation showed generally low (≤0.90) concordance correlation coefficients except for Yara N-Tester N and ND24 in M. maximus. Random error was the main source of error. We conclude that the accuracy of the Yara N-Tester prediction models was superior to that of the FieldScout CM 1000 NDVI models, and that the Yara N-Tester can produce accurate and reliable estimates of Brachiaria hybrid and M. maximus N and M. maximus ND24. 相似文献
15.
As cattle mature, the dietary protein requirement, as a percentage of the diet, decreases. Thus, decreasing the dietary CP concentration during the latter part of the finishing period might decrease feed costs and N losses to the environment. Three hundred eighteen medium-framed crossbred steers (315 +/- 5 kg) fed 90% (DM basis) concentrate, steam-flaked, corn-based diets were used to evaluate the effect of phase-feeding of CP on performance and carcass characteristics, serum urea N concentrations, and manure characteristics. Steers were blocked by BW and assigned randomly to 36 feedlot pens (8 to 10 steers per pen). After a 21-d step-up period, the following dietary treatments (DM basis) were assigned randomly to pens within a weight block: 1) 11.5% CP diet fed throughout; 2) 13% CP diet fed throughout; 3) switched from an 11.5 to a 10% CP diet when approximately 56 d remained in the feeding period; 4) switched from a 13 to an 11.5% CP diet when 56 d remained; 5) switched from a 13 to a 10% CP diet when 56 d remained; and 6) switched from a 13 to an 11.5% CP diet when 28 d remained. Blocks of cattle were slaughtered when approximately 60% of the cattle within the weight block were visually estimated to grade USDA Choice (average days on feed = 182). Nitrogen volatilization losses were estimated by the change in the N:P ratio of the diet and pen surface manure. Cattle switched from 13 to 10% CP diets with 56 d remaining on feed or from 13 to 11.5% CP with only 28 d remaining on feed had lower (P < 0.05) ADG, DMI, and G:F than steers fed a 13% CP diet throughout. Steers on the phase-feeding regimens had lower (P = 0.05) ADG and DMI during the last 56 d on feed than steers fed 13.0% CP diet throughout. Carcass characteristics were not affected by dietary regimen. Performance by cattle fed a constant 11.5% CP diet did not differ from those fed a 13% CP diet. Serum urea N concentrations increased (P < 0.05) with increasing dietary CP concentrations. Phase-feeding decreased estimated N excretion by 1.5 to 3.8 kg/steer and nitrogen volatilization losses by 3 to 5 kg/steer. The results suggest that modest changes in dietary CP concentration in the latter portion of the feeding period may have relatively small effects on overall beef cattle performance, but that decreasing dietary CP to 10% of DM would adversely affect performance of cattle fed high-concentrate, steam-flaked, corn-based diets. 相似文献
16.
【目的】研究不同的施氮制度对燕麦/豌豆间作体系中燕麦的吸收情况以及对土壤氮素的影响。【方法】采用随机区组试验设计,设N0(不施氮)、N1(基肥20%+分蘖期追肥20%+开花期追肥60%)、N2(基肥20%+分蘖期追肥30%+开花期追肥50%)和N3(基肥20%+分蘖期追肥40%+开花期追肥40%)4个施氮制度;3种种植模式(燕麦/豌豆间作、燕麦单作和豌豆单作),研究施氮制度对间作燕麦氮素吸收和土壤氮素的影响。【结果】施氮制度和间作对燕麦籽粒产量、氮素吸收和土壤氮素影响显著。间作燕麦籽粒产量在N2处理下最大,较N3增产22.48%。随着生育期的推进,在拔节期、抽穗期、灌浆期和成熟期间作燕麦的吸氮量较单作燕麦分别提高了26.5%、15.8%、7.3%和17.1%;间作燕麦在N2处理下吸氮量最大,为71.2 kg/hm2,较N0增加了49.9%。在0～20 cm土层间作燕麦的土壤全氮含量在N0、N1、N2和N3处理下分别较单作提高12.9%、11.2%、15.4%和6.9%;间作燕麦在拔节期、抽穗期、灌浆期和成熟期的土壤硝态氮含量和铵态氮均高于单作燕麦。【结论】在20～... 相似文献
17.
采用田间试验,单因素随机区组排列,以豆科牧草柱花草和禾本科牧草扭黄茅和孔颖草为试验材料,研究适量氮磷肥的施用对3种牧草旺盛期生长及土壤氮磷吸收的影响和效果。试验结果表明,与未施氮磷肥比较,氮磷的施用有利柱花草、扭黄茅和孔颖草旺盛期(7-9月)的生长,3种牧草物候期有所延迟,可以提高3种牧草旺盛期绝对生长量,显著增加了孔颖草总生物量和氮吸收量(P<0.05)。与未施氮肥对比,施氮(施纯氮120 kg·hm-2)有利柱花草和孔颖草对氮的吸收,显著提高柱花草含氮量和孔颖草氮的吸收量(P<0.05),促进柱花草和孔颖草的生长,提高柱花草和孔颖草地上部和地下部生物量,提高扭黄茅地上部的生长量和生物量。与未施磷肥对比,施磷(施纯磷75 kg·hm-2)显著提高孔颖草氮的吸收量(P<0.05)。本研究为3种牧草和其他牧草氮磷的施用提供理论依据,即:适量的氮磷施用有利3种牧草产量的提高。 相似文献
18.
Influence of protein degradability in range supplements on abomasal nitrogen flow, nitrogen balance and nutrient digestibility 总被引：3，自引：0，他引：3
Two metabolism trials were conducted with yearling steers fed mature native forage to measure the effect of supplemental protein degradability on selected metabolic variables. Supplements contained 40% crude protein equivalence. In Trial 1, four abomasal-cannulated steers weighing 290 to 379 kg were fed supplements containing the following N sources: (1) 15% corn, 85% urea (U); (2) 100% soybean meal (SBM); (3) 10% corn, 40% soybean meal, 50% urea (SBM-U) and (4) 14% corn, 36% blood meal, 50% urea (BM-U). Equal portions of the daily diet (2.2% of body weight) were fed every 2 h. Treatment differences were not significant for organic matter digestibility, abomasal organic matter flow, nonammonia N flow, feed N flow, bacterial N flow and efficiency of microbial protein synthesis. There was a positive (P less than .05) relationship between quantity of slowly degraded protein fed and nonammonia N flow (r = .97) or feed N flow (r = .98). Escape N was determined to be 21.5, 16.5 and 54.2% in SBM, SBM-U and BM-U supplements, respectively. In the second trial, no supplement, SBM, SBM-U and BM-U were fed in a N balance trial. Dry matter, crude protein and neutral detergent fiber digestibilities were higher (P less than .05) for steers fed supplemented diets. Acid detergent fiber digestibility was higher (P less than .05) for steers supplemented with SBM than steers fed the unsupplemented diets. Nitrogen retention was greater (P less than .05) for cattle fed SBM and BM-U than for cattle fed SBM-U or no supplement.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
19.
Our objective was to determine the impact of supplemental energy, N, and protein on feed intake and N metabolism in sheep fed low-quality forage. Six Texel x Dorset wethers (16 mo, 63+/-3.1 kg) fitted with mesenteric, portal, and hepatic venous catheters were used in a Latin square design with five sampling periods. Lambs were fed chopped bromegrass hay (4.3% CP) to appetite, and a mineral mixture was given. Treatments were 1) control (no supplement), 2) energy (cornstarch, molasses, and soybean oil), 3) energy plus urea, 4) energy plus soybean meal (SBM), and 5) energy plus ruminally undegraded protein (RUP; 50:50 mixture of blood and feather meals). Supplements were fed once daily (.3% BW). Forage DMI did not differ (P = .13), but intake of total DM, N, and energy differed (P<.01) among treatments. Apparent digestibilities of DM, OM, and energy were less (P<.01) for control than for other treatments. Apparent N digestibility was least for control and energy and greatest for urea treatments (P<.05). As a result, digested DM, OM, and energy ranked from least to greatest were control, energy, urea, SBM, and RUP, respectively. Apparently digested N was 2.44, 2.24, 11.39, 9.80, and 11.25 g/d for control, energy, urea, SBM, and RUP (P<.01; SE = .10). Hour of sampling x treatment was a significant source of variation for blood concentrations of ammonia N and urea N, net ammonia N release from portal-drained viscera (PDV) and liver, and urea N release from splanchnic tissues. These results were primarily because patterns through time for the urea treatment differed from the other treatments. Net PDV release of alpha-amino N did not differ (P>.05) between control and energy treatments. Values for those treatments were about one-half of values for urea, SBM, and RUP treatments, which did not differ (P>.05). Hepatic net uptake (negative release) of alpha-amino N for control was 53% of values for the other treatments, which did not differ (P>.05). Net release of alpha-amino N from splanchnic tissues did not differ among treatments (P = .34) and did not differ from zero. The data indicate that arterial alpha-amino N concentration, hepatic alpha-amino N uptake, PDV release and hepatic uptake of ammonia N, and hepatic release of urea N were greater in energy than in control treatments. We also found that hepatic uptake of alpha-amino N was 187% of PDV release in energy-supplemented lambs. These results suggest that energy supplementation of a protein-limiting diet stimulated mobilization of body protein. 相似文献
20.