饲料中添加柠檬酸对罗非鱼的养殖效果分析

为考察在饲料中添加柠檬酸对罗非鱼生长的影响，采用300尾平均体重为10．3g的全雄奥尼罗非鱼鱼种，在基础饲料（对照组）中分别添加0．15％、0．30％、0．45％柠檬酸。经37d饲养后，各组增重率分别为152．4％、158．5％、171．5％和170．9％，饲料系数为1．58％、1．49、1．45和1．46，添加0．30％柠檬酸和0．45％柠檬酸分别提高罗非鱼增重率12．5％（P＜0．05）和11．2％（P＜0．05），降低了饲料系数，每公斤鱼体增重成本分别下降0．27元和0．22元。回归分析结果表明，柠檬酸的适宜添加水平为0．28％－0．34％。     

集约化猪场液体饲料自动饲喂系统研究

集约化猪场微生物发酵液体饲料具有猪胃的pH值,抑制猪肠胃有害菌群的繁衍,激活内外源酶的作用,促进猪对饲料的消化和营养吸收能力。液体饲料自动饲喂系统在双MCS-80C31的控制下,根据饲料原料的各种营养成分和猪生长对其需要量,自动计算、采集饲料原料将其送人计量混合罐内,并在其中完成可控的精量均匀混合、发酵过程,MCS- 80C31根据不同猪群组的饲喂曲线,自动计算、投喂育肥猪需要饲喂的液体饲料重量。试验表明:液体饲料饲喂育肥猪能使育肥猪群的平均饲料转化率比干配合饲料饲喂改善6．77％,育肥猪群的平均日增重提高9．33％,效果显著。     

高含量乳清粉的仔猪配合饲料热特性及调质温度控制

为探究热敏性饲料原料乳清粉及不同含量乳清粉的仔猪配合饲料的热物理特性,该文以仔猪料配方中的4种主要饲料原料玉米、豆粕、乳清粉和鱼粉为研究对象,采用混料设计的方法得到33种不同含量(0～30％)乳清粉的仔猪配合饲料,并利用差示扫描量热法(differential scanning calorimetry,DSC)测定了4种单一原料在25～120℃范围内以及33种仔猪配合饲料在25～110℃范围内的比热,分析了乳清粉及高含量乳清粉(质量分数≥14.548％)的仔猪配合饲料的热变性过程.结果显示:玉米、豆粕和鱼粉的比热分别与温度(25～120℃)呈线性、对数和二次关系,而乳清粉的比热与温度(25～110℃)遵循三次多项式的关系;当配合饲料中含有≥6.25％的乳清粉时,其比热与温度遵循三次多项式的关系;配合饲料的比热显著受温度、原料配比以及二者交互作用的影响(P＜0.001),其中,温度的影响最为显著,而乳清粉含量的影响次之.DSC热焓曲线上,乳清粉在109.79℃会出现吸热峰,为乳清蛋白的热变性导致;而随着温度由20℃升高到110℃,乳清粉颗粒由存在许多凸起与微孔的粗糙表面结构逐渐过渡为光滑、粘结的状态.与乳清粉相似,高含量乳清粉的配合饲料也会在77.95～87.69℃出现吸热峰.在仔猪配合颗粒饲料的加工过程中,为降低乳清蛋白的变性程度、减少环模制粒机的堵机现象,应将调质温度降低至70℃以下为宜.研究结果为高含量乳清粉的仔猪配合饲料的调质、制粒等热处理过程的工艺优化提供理论指导.     

木薯叶粉饲喂肉鸭效果及影响其利用因素的研究

本试验的目的是探讨木薯叶饲喂肉鸭的效果和影响木薯叶利用的因素。将３３０只１０日龄樱桃谷鸭随机分为１０组，每组３３只。１组（对照组）日粮按商业部饲料局提供的内用鸭饲养标准配制，２，３，４组日粮分别使用５％～１０％（前期５％，后期１０％），１０％～２０％和２０％～３０％木薯叶粉，饲料中粗蛋白质水平与１组相同；５，６，７组分别在１组日粮基础上添加氰化钾、单宁及氰化钾加单宁；８，９，１０组分别在４组日粮基础上补加猪油、蛋氨酸及猪油加蛋氨酸。结果表明：随日粮中木薯叶粉含量的增加，饲料中氰化物和单宁含量也增加，鸭增重、饲料能量和粗蛋白质的利用率逐渐降低，但５％～１０％木薯叶粉组与对照组无显著差异；补加猪油和蛋氨酸能显著改善增重、饲料报酬及能量利用率，粗蛋白质利用率也提高。综合试验结果表明，限制木薯叶利用的因素是其能量低，蛋氨酸缺乏及抗营养因子的存在。５％～１０％木薯叶粉组与对照组无论增重、饲料报酬及能量、粗蛋白质利用率均无显著差异。建议肉鸭饲料中前期添加５％，后期添加１０％的木薯叶粉。     

玉米对土壤中菲芘修复作用的初步研究

采用系列浓度菲芘进行盆栽试验，研究玉米对污染土壤菲芘的去除效果与累积机理。结果显示，玉米对菲芘的去除效果明显，60d试验完成后，玉米生长的土壤中平均大约有69．8％-91．2％的菲与77．0％，88．4％的芘被去除，平均去除率分别比对照1（加叠氮化钠）高63．6％和72．3％；比对照2（无叠氮化钠）高15．1％与38．2％。玉米能明显地吸收与累积污染土壤中菲和芘，并随土壤菲芘含量的增加而增大。生物富集因子（BCFs）随着土壤菲芘含量的增加而减小，芘的生物富集因子大于菲，不同种类多环芳烃以及植物不同部位间BCFs差异较大，菲的叶片BCFs（0．79，2．45）大于茎（0．17—1．76），根BCFs（0．42—1．21）最小，芘处理时叶片和茎的BCFs分别是1．03，3．31与0．2，2．17，明显低于根BCFs（2．07—6．40）。玉米能够在高浓度多环芳烃污染土壤中正常生长，并且能累积与去除污染土壤中的菲和芘，表明用玉米修复多环芳烃污染土壤是一种可行的方法。     

北京集约化养殖畜禽饲料Zn含量及粪便Zn残留特征研究

针对集约化养殖中大量使用含Zn饲料添加剂及其在畜禽粪便中的残留问题,采集北京6个郊区县集约化养殖场208个猪、奶牛、鸡饲料样品和204个粪便样品,分析测定了其中Zn含量。结果表明,北京地区集约化养殖饲料和粪便中Zn含量差异很大,猪饲料和猪粪中Zn含量远高于奶牛和鸡。猪、奶牛、鸡饲料中Zn的含量范围分别为72．77～3170．37mg·kg^-1、13．63—471．39mg·kg^-1、32．64—344．67mg·kg^-1,平均含量分别为347．57、86．44、138．76mg·kg^-1;猪、奶牛、鸡粪便Zn的平均含量分别为2333．97、119．41、391．01mg·kg^-1,含量范围分别在458．21—14031．79、10．36～502．39、73．15～678．91mg·kg^-1之间。猪饲料和猪粪Zn超标率分别为9．3％和15．0％,奶牛、鸡的饲料和粪便均未超标。畜禽粪便中Zn含量与其饲料中zn含量之间呈显著或极显著正相关（P〈0．05）,猪、奶牛、鸡粪便中Zn的平均含量分别是其饲料的6．7倍、1．4倍、2．8倍,表现出一定的“浓缩”效应,其中断奶仔猪饲料和粪便中zn的平均含量最高,分别为645．37和5133．64mg·kg^-1,“浓缩系数”高达6．61。高Zn含量的畜禽粪便在土地利用时可能会带来土壤污染风险。     

集约化猪场液体饲料自动饲喂系统研究

集约化猪场微生物发酵液体饲料具有猪胃的pH值，抑制猪肠胃有害菌群的繁衍，激活内外源酶的作用，促进猪对饲料的消化和营养吸收能力。液体饲料自动饲喂系统在双MCS-80C31的控制下，根据饲料原料的各种营养成分和猪生长对其需要量，自动计算、采集饲料原料将其送入计量混合罐内，并在其中完成可控的精量均匀混合、发酵过程，MCS-80C31根据不同猪群组的饲喂曲线，自动计算、投喂育肥猪需要饲喂的液体饲料重量。试验表明：液体饲料饲喂育肥猪能使育肥猪群的平均饲料转化率比干配合饲料饲喂改善6.77%，育肥猪群的平均日增重提高9.33%，效果显著。     

晋西北黄土丘陵区小叶锦鸡儿人工灌丛营养动态特征研究

研究了小叶锦鸡儿（Caragana microphylla）人工灌丛不同生育期、不同生长年限及不同器官的营养特征。研究结果表明：小叶锦鸡儿枝条和叶片营养丰富．枝条在开花期粗蛋白含量达到19．61％．嫩叶的粗蛋白古量高达27．50％，粗纤维含量仅为12．3％。枝条和叶片的矿质养分含量高且比例合理．Ca／P为1．7：1～2．1：1．接近家畜日粮中Ca／P最佳比例2：1，是优质的灌木饲料。从休眠期到开花期．小叶锦鸡儿的营养元素含量呈上升趋势．以后逐步降低，花期是最佳利用季节。随着小叶锦鸡儿生长年限的延长，各种营养成分逐渐减少．从生态学的角度分析，平茬后第3年是小叶锦鸡儿最佳的利用时间。小叶锦鸡儿枝条氨基酸总量在6．0％左右．高于玉米秸秆饲料，而且维生素含量丰富．是优质的家畜饲料和北方生态建设的优质树种。     

微量元素氨基酸螯合物对生长猪生产性能和血清微量元素含量的影响

用微量元素氨基酸螫合物按不同比例替代生长猪饲粮中无机微量元素，研究其对生长猪生长性能和血清微量元素含量的影响。用0、12．5％、25．0％和37．5％的氨基酸螫合铁、铜、锌、锰分别替代基础日粮中的相应无机元素的0、25％、50％和75％，分4个处理，每处理3个重复，每个重复4只猪，实验期56d。实验结果表明：添加微量元素氨基酸螫合物对生长猪的生长性能有一定的改善作用，与对照组（1组）比较．2、3、4组的平均日增重分别提高9．85％（P〈0．05）、7．51％（P〉0．05）、1．34％（P〉0．05）饲料增重比（F／G）分别比对照组降低6．74％（P〈0.05），7．45％（P〈0．05）．1．42％（P〉0．05）；血清中微量元素铁（Fe）、锌（Zn）、铜（Cu）、锰（Mn）含量比对照组均有所增加。微量元素螫合物替代无机元素的适宜比例为25％。     

不同季节蛋鸡饲料养分浓度的研究Ⅱ.高温期罗曼蛋鸡日粮的优化研究

在高温夏季（１９９３年７月１日～９月３０日，合肥地区，开放式鸡舍，舍温２７．９～３８．７℃，平均３２．３℃），用６种不同配方的日粮饲喂处于相同生境的６组２３～３６周龄罗曼蛋鸡。按罗曼公司推荐的饲养标准配制第１组日粮；对第２～６组日粮养分浓度作适当调整。饲养结果表明：各组间罗曼蛋鸡产蛋率、饲料转化率和产蛋饲料成本有显著（Ｐ＜０．０５）或极显著（Ｐ＜０．０１）差异。其中，第５组鸡产蛋率（８３．９３％）和饲料转化率（４３．６４％）均为最高（Ｐ＜０．０１），比第１组鸡产蛋率（７８．９１％）和饲料转化率（４１．２６％）分别提高６．３６％（Ｐ＜０．０５）和５．７７％（Ｐ＜０．０５）；第５组鸡产蛋饲料成本（２．５５元／ｋｇ）比第１组鸡产蛋饲料成本（２．９２元／ｋｇ）降低１４．５１％（Ｐ＜０．０１）。第５组日粮配方（％）为：玉米６１．０、小麦麸３．０、大豆粕１７．０、鱼粉４．０、菜籽饼４．３、蛋氨酸０．１４、赖氨酸０．０５、骨粉０．８、石粉８．５、磷酸氢钙０．８、食盐０．３１、禽用微量元素添加剂０．１２、罗曼多维素０．０１８。     

Influence of temperature on the growth of bermudagrass selections from the Appalachian region

Abstract

The hilly terrain of the Appalachian region creates an environment in which large differences in soil temperature occur over a very short distance on the landscape. The ability of a grass to display adequate growth over a range of temperatures would greatly enhance its adaptability and use as a forage or for soil conservation. A growth chamber experiment was conducted to evaluate the influence of temperature on the growth of six bermudagrass [Cynodon dactylon (L.) Pers.] selections from the Appalachian region. Midland, a cold tolerant bermudagrass, was included in the study for comparison purposes. The grasses were grown under a 14 hour day length with three day/night temperature regimes: 18°C/13°C, 27°C/21°C, and 35^OC/29°C. Two of the selections had significantly higher dry matter production than Midland over the range of temperatures.

This effect was especially pronounced at 35°C where the top growth of Quicksand common and Selection 13 exceeded that of Midland by 206% and 158%, respectively. The higher yielding selections were comparable to the other bermudagrasses when mineral concentrations, neutral detergent fiber, acid detergent fiber and acid detergent lignin levels were considered. Both Quicksand common and Selection 13 seem to have the potential to be particularily useful on south facing slopes where elevated soil temperatures are encountered.     

Response of bermudagrass selections from the Appalachian region to N and P fertilization

Abstract

A greenhouse experiment was conducted to evaluate the influence of N and P fertilization on the yield and forage quality of six cold tolerant bermudagrass (Cynodon dactylon L.) selections from the Appalachian region. Midland bermudagrass and limpograss (Hermarthria altissima) were included for comparison purposes. Each grass was treated with a factorial combination of three N rates (112, 224, and 448 kg N.ha^‐1) and four P rates (0, 25, 75, and 225 kg P.ha^‐1) Two bermudagrass selections from the Appalachian region demonstrated greater dry matter production than Midland bermudagrass. Yields of Quicksand common exceeded those of Midland by 60% to 236% over the range of treatments. High yielding selections were not inferior to low yielding selections when mineral concentrations, neutral detergent fiber, acid detergent fiber and acid detergent lignin levels were considered. The results of this investigation suggest that Quicksand common and Selection 13 merit further study to determine their potential for summer forage production in the Appalachian region.     

Plant density,distribution, and fertilizer effects on yield and quality of irrigated corn silage

Abstract

Grain deficits frequently occur in the Southeastern Atlantic Coastal Plain because erratic rainfall patterns and soil properties often limit corn (Zea mays L.) yields, however, harvesting corn for silage may enable farmers to produce a second grain crop during the same calendar year. Effects of row spacing, plant population, and fertilizer program on yield, quality, and mineral concentrations of corn silage grown with irrigation on Typic Paleudult soils were therefore investigated. Two plant population treatments which averaged 7.0 and 10.1 plants m^‐2 were evaluated with two fertilizer programs that differed in N, N and K, and N, P, and K in 1980, 1981, and 1982, respectively. Each plant density by fertilizer combination was evaluated in single rows spaced 96 cm apart and in twin rows which approximately doubled the intrarow plant spacing. Plot size for the 2×2×2 factorial experiment ranged from 30 to 44 m². Yield, quality, and mineral concentrations of corn silage grown in single rows spaced 96 or 75 cm apart and twin rows were also evaluated in large (185 m²) plots under center pivot irrigation during 1981 and 1982.

Dry matter yields of 22 to 26 Mg ha^‐1 were achieved with plant densities of 6.7 to 13.5 plants m^‐2 at both experimental sites. Highest silage yields were produced with stand densities of 9 m or more planted in single 75 cm or twin rows, but yield differences were statistically significant at P(0.05) in only two of five site years. Increasing total N‐P‐K application beyond 200–30–167 kg ha”; increased crude protein slightly in 1980 and significantly in 1981 and 1982. Concentrations of Mn and Zn in silage were increased by higher fertilization, presumably because nitrification reduced surface soil pH and increased their availability. Dry matter yield, fiber, energy, and other mineral nutrients were not significantly influenced by fertilizer program. These experiments identified management practices for the Atlantic Coastal Plain which resulted in corn silage yields equal to those produced in the cooler mountain region of Georgia and that exceeded current average production in South Carolina by approximately 40% without reducing apparent feed quality.     

豆科鲜牧草破碎机的研究与试验

针对豆科鲜牧草的物理机械特性,分析了机械破碎作用的力学机理,认为合适的打击作用力是该类物料有效的破碎加工方法。在试验研究的基础上,设计研制了“93D—324型鲜牧草捣泥机”。使得在不加水的情况下,把豆科鲜牧草破碎成细碎纤维状或浆状饲料,满足喂猪的饲养要求。     

Nitrogen application effects on forage sorghum production and nitrate concentration

Abstract

Forage sorghum (Sorghum bicolor (L.) Moench) is an important annual forage crop but prone to high nitrate concentration which can cause toxicity when fed to cattle (Bos taurus and Bos indicus). Two field experiments were conducted over six site-years across Kansas to determine the optimum nitrogen (N) rate for no-till forage sorghum dry matter (DM) yield and investigate the effect of N fertilization on sorghum forage nitrate content. A quadratic model described the relationship between sorghum DM and N rate across the combined site-years. Maximum DM yield of 6530?kg ha^?1 was produced with N application rate of 100?kg N ha^?1. The economic optimum N rate ranged from 55 to 70?kg N ha^?1 depending on sorghum hay price and N fertilizer costs. Crude protein concentration increased with N fertilizer application but N rates beyond 70?kg N ha^?1 resulted in forage nitrate concentrations greater than safe limit of 3000?mg kg^?1. Nitrogen uptake increased with N fertilizer application but nitrogen use efficiency and N recovery decreased with increasing N fertilizer rates. In conclusion, forage sorghum required 55–70?kg N ha^?1 to produce an economic optimum DM yields with safe nitrate concentration.     

Performance of Kura clover compared to that of perennial forage legumes traditionally cultivated in central Europe

Kura clover (Trifolium ambiguum M. Bieb.) is a rhizomatous perennial legume that is native to Caucasia, is extremely persistent in North America, but its performance has not been adequately evaluated in Europe. The objective of this research was to compare forage yield and nutritive value of Kura clover to lucerne (Medicago sativa L.), red clover (Trifolium pretense L.) and white clover (Trifolium repens L.) at two locations in Poland. All clover stands thinned markedly by spring of the second production year because of infection by Sclerotinia crown and stem rot, but lucerne stands remained dense and this legume produced the highest total yield over 3 or 4 production years. Kura clover yields of 7.2–8.3?Mg?ha^?1 were second to lucerne by the third production year but long-term performance was diminished by stand thinning. Kura clover and white clover had lower fiber concentrations and greater protein concentrations and forage digestibility than red clover and lucerne. Kura clover can be a source of high-quality forage in Europe, but cannot be recommended for use in areas with known Sclerotinia trifoliorum presence until resistance to this pathogen is developed.     

Response of Forage Chicory Seedlings to Available Soil Phosphorus in Two Soils in a Controlled Environment

Poor phosphorus (P) fertility is a problem limiting productivity on unimproved Appalachian soils and has been implicated in poor palatability of forage chicory (Cichorium intybus L.). Three cultivars were grown in a greenhouse at varying soil P levels in Gilpin and Hagerstown silt loam soils and harvested 48 and 77 days after planting. In Gilpin soil, available soil P (ASP) was positively associated with dry shoot mass, leaf mass, leaf area, and leaves per plant and negatively associated with specific leaf area. In Hagerstown soil, ASP was positively associated only with only dry shoot and leaf mass. At equivalent ASP levels, dry shoot and leaf mass, leaf area, and shoot concentrations of P, potassium, calcium, and magnesium were always greater in Hagerstown than Gilpin soil, whereas specific leaf area was less. Equalization of ASP concentration and environmental conditions did not eliminate growth-limiting differences between Gilpin and Hagerstown soils for chicory.     

Kura Clover Response to Potassium Fertilization

Kura clover (Trifolium ambiguum M.B.) is a persistent perennial forage legume that produces high-quality herbage for grazing, but its response to potassium (K), an essential plant nutrient, is unknown. Our objective was to determine the effect of four dipotassium oxide (K₂O) rates on forage yields and stands of Kura clover compared to birdsfoot trefoil (Lotus corniculatus L.) and alfalfa (Medicago sativa L.). There was a significant linear response in Kura clover and alfalfa forage yields to K₂O fertilization each year. Averaged over 4 years, Kura clover forage yield increased by 0.024 Mg ha^–1 per kg of K₂O applied, and the yield response was similar for alfalfa. Birdsfoot trefoil forage yield response to K₂O fertilization was less than those of alfalfa and Kura clover. In the first 2 years after seeding, Kura clover forage yields were consistently less than for alfalfa at all rates of K₂O fertilizer, but in subsequent years Kura clover yields were similar to or exceeded those of alfalfa. Final groundcover values, an estimate of stand density, of unfertilized (0 K₂O rate) Kura clover, birdsfoot trefoil, and alfalfa were 86, 35, and 21%, respectively. Final groundcover of Kura clover and alfalfa was increased by K₂O fertilization. We conclude that Kura clover has good persistence with low soil K fertility but stands and yields can be increased by fertilization.     

贮备饲料近红外光谱模型快速预测青绿饲料营养成分含量

为快速检测饲料的营养成分,该研究利用贮备饲料的近红处技术(near-infrared,NIR)快速分析模型预测青绿饲料的营养成分含量。基于贮备饲料的NIR定标模型,将建模优化模式转移应用到青绿饲料的营养成分定量检测,以判断模型转移能力。在实验室环境下扫描并记录新鲜的青绿饲料样本和储存的贮备饲料样本的近红外反射光谱,利用230个贮备饲料样本进行光谱定标训练,以修正偏最小二乘(modified-partial least squares,M-PLS)建模方法,结合随机局部样本、局部选参、局部非连续性可调、交叉检验等技术相结合的方式建立局部优化模型,分别测试120个贮备饲料样本和120个青绿饲料样本中的氮(nitrogen,N)、中性洗涤纤维(neutral detergent fiber,NDF)、酸性洗涤纤维(acid detergent fiber,ADF)含量。将贮备饲料的定标校正模型应用于贮备饲料验证样本的营养成分测定,其标准误差(square error of prediction,SEP):N为1.02、NDF为16.56和ADF为13.47,相关系数均在0.9以上,相对预测偏差(relative prediction derivation,RPD)均大于3;该模型具有对青绿饲料样本的营养成分预测能力,其预测SEP:N为0.90、NDF为14.11和ADF为9.98,预测相关系数均在0.9以上,预测RPD均大于3,达到快速检测误差标准。由于局部建模过程中考虑了数据的潜在非线性结构和具有近似光谱响应的样本之间的不均匀性,相对全局建模方式而言具有更好的数据驱动性质,其建模效果优于全局建模方法。结果表明,基于贮备饲料样本建立的NIR定标校正模型可以用于青绿饲料营养成分的预测,特别是局部分析模型的应用能够提高NIR快速分析的预测精度。     

Spectral Measurements of Alfalfa/Grass Fields Related to Forage Properties and Species Composition

The relationship between plant canopy reflectance and plant nutritive value has not been extensively investigated. The goal of this study was to relate spectral canopy reflectance to plant nutritive value and species composition. Multiple grass/alfalfa fields were analyzed using a field spectrometer, and then species composition, forage nutritive quality, and plant biomass were determined. Derivative analyses of spectra as well as narrow-band vegetation indices were used to examine the relationship between canopy reflectance and plant biophysical properties. Derivative analysis found a high correlation between high-order derivatives at multiple wavelengths and some plant properties, which include species composition and neutral detergent fiber (NDF). Wavelengths in the red region and between the red and near-infrared region of the spectrum showed the highest correlation in the derivative analysis. Analysis of whole canopy reflectance using spectroscopy may provide a quick, nondestructive method to determine plant characteristics.