脂肪在保育猪日粮中的应用

猪营养学家、饲料加工商及养猪生产者都一致地在保育日粮中使用动物和植物性脂肪。他们使用这些重要脂类来源的原因是因为脂肪:可提供丰富的能量含量比大多数谷物高出2.25倍;在某些情况下价格也许比其它能量来源低;可降低饲料源的尘埃,尤其是日粮以粉料形式饲喂时;可通过润滑压模而有助于压粒过程。然而,迄今尚没有研究资料可以证明,在现代复杂的断奶日粮中,猪可以在营养上从高脂肪含量中获得益处。     

互动平台——畜禽业百事通咨询热线

黑龙江读者田甜:尿素在反刍动物日粮中的添加量和注意事项?百事通:在蛋白质含量低、能量含量高或谷物和玉米青贮饲料含量低的日粮中应该加尿素。谷物混合料中可用1%尿素,玉米青贮料中可有0.5%尿素,最好用量不超过精饲料的3%,成年牛日用量200～300g,成年羊日用量20～30g。饲喂尿     

断奶仔猪日粮中添加脂肪的误区

<正>自50年代起,人们就在断奶仔猪日粮中添加脂肪以提高能量,但越来越多的证据表明,断奶后两周内,仔猪日粮添加脂肪不但无益反而可能有害。李德发研究表明,早期断奶20 d后11 d内仔猪日粮中添加豆油、椰子油等不同类型脂肪都没有提高仔猪日增重,有的组日增重反而下降;但在断奶后11~35 d内,添加豆油、椰子油均使日增重、耗料量明显上升,这说明只有在断奶两周后的仔猪日粮中添加脂肪才有效果。造成这种现象的主要原因是仔猪肠道脂肪酶的分泌不足。     

玉米、高梁饲料中添加酶制剂的研究

以大麦、小麦为主的家禽日粮中添加酶制剂，如今已十分普遍。本文是探讨在低粘性谷物，如玉米、高梁作为家禽饲料中添加酶的可行性。直至最近，人们都认为玉米和大豆日粮不会造成家畜的消化障碍，因此这种饲料中不需添加酶制剂。然而，最新研究成果显示，使用一些通常在粘性较大的饲料中添加的酶，能使雏鸡更好地消化低粘性饲料。     

关注维生素E

猪日粮中维生素E的添加量是否应高于推荐的最低量,需要考虑到日粮中的其他组分,特别是含硫氨基酸的含量和能量来源.     

缓解鸡热应激的营养学方法

在现代养鸡业的高密度饲养方式下,夏季的高温很容易使鸡产生热应激.热应激导致鸡的新陈代谢和生理机能的变化和紊乱,从而使肉鸡的增重,蛋鸡的产蛋率和种蛋的受精率和孵化率下降,蛋重减轻,蛋壳变薄,破蛋率上升,饲料利用率下降,严重时衰竭而亡.通过调整饲粮、添加抗热应激添加剂,可提高鸡的抗热应激能力. 1.调整饲粮营养水平 1.1.提高饲粮能量浓度 能量摄入量降低是热应激期间鸡生产性能下降的原因之一.因此提高日粮营养浓度,可在一定程度上克服热应激造成的不良影响.在实际生产中常添加脂肪以提高日粮能量浓度.脂肪热增耗较低,能量在体内的潴留量增加;同时,日粮中添加油脂能改善适口性,降低饲料在胃肠道的流通速度,从而提高家禽的生长率.在高温条件下用脂肪代替等能量的碳水化合物,明显改善热应激家禽的生产性能.不过在高温气候下,更要注意防止脂肪的氧化.     

复合氨基酸微量元素螯合物对生长育肥猪生产性能与屠宰性能的影响

该试验通过添加相同水平的复合氨基酸微量元素螯合物和无机微量元素在生长育肥猪日粮中进行试验,测定对生产性能和屠宰性能的影响。添加氨基酸微量元素螯合物为试验组,添加无机微量元素为对照组。试验表明,实验组的日增重比对照组提高3.21%,料重比低0.13;实验组的屠宰率比对照组高2.5个百分点;实验组的肝脏形态外观、肉质颜色和系水力优于对照组。有机微量元素将成为常规的矿物元素添加到动物日粮中,值得在饲料中商业化使用,也是食品安全的需要和未来使用的趋势。     

反刍动物日粮阴阳离子平衡的研究

生理体液中的酸碱平衡对于维持动物的正常生理活动和最佳的生产性能十分重要,日粮阴阳离子平衡(DCAB),又称日粮电解质平衡,将直接参与维持机体酸碱平衡,从而对反刍动物的健康、机体的酸碱平衡、食欲和采食量、生产性能等产生重要影响。根据动物的体液酸碱平衡情况,通过在日粮中合理添加使用矿物质来调节日粮阴阳离子浓度,使体液中的酸碱平衡达到动物最佳生产性能已在近年的反刍动物营养研究中受到广泛重视。     

复合酶制剂在肉仔鸡低蛋白水平日粮中使用效果研究

将100只0日龄艾维茵公母混合雏鸡随机分为A、B两组,每组各50只,A组饲予饲养标准蛋白水平日粮,B组饲予低于A组蛋白水平两个百分点,等能量的日粮,观察复合酶制剂在低于正常蛋白水平日粮中对肉仔鸡生长发育、日粮能量转化效率ME、日粮净蛋白质利用率NPU的影响以及经济效益分析。结果表明:B组在6周龄末体重与A组比较有增加趋势,差异不显著P>0.05B组日粮ME较A组在3周龄增加1.6%,在5周龄增加6.7%;B组NPU较A组在3周龄增加2.94%,在5周龄增加1.78%。添加酶制剂对肉仔鸡4～6周龄饲料能量转化效率有明显影响,酶制剂在维持正常生长性能条件下,具有良好的经济效益和社会效益。     

能量蛋白对种公猪血液生化指标的影响

选用大约克公猪18头,分为6个处理,每个处理3个重复,日粮消化能设12.96MJ/kg和13.79MJ/kg二个水平,日粮粗蛋白设13.0%、15.0%和17.0%3个水平,采用2×3因子设计,考察不同日粮能量和粗蛋白质水平对种公猪血液生化指标的影响。结果表明,日粮能量、粗蛋白水平对血液中T3影响差异不显著(P>0.05)。日粮的蛋白水平提高血液中的TP也有提高的趋势但差异不显著(P>0.05)。在日粮的蛋白水平和能量水平互作影响下血液中的BUN差异显著(P<0.05),GLU的影响极显著(P<0.01)。     

水产诱食剂在虾料中的应用

近年来,对虾养殖业发展迅速,由传统的自然放养转向高密度集约化养殖,水产饵料的需求量不断攀升,大量的集约化饲养几乎全靠人工饵料.然而,人工饵料与传统天然饵料相比,其风味和适口性往往存在很大差异,饵料中添加诱食成分即诱食剂,用来提高饵料产品的诱食作用是当前饵料生产中面临的主要问题之一.下面就对虾饵料中的诱食剂作用及原料选择问题谈一下自己的观点.     

绿色饲料添加剂在水产饲料中的应用

在饲料工业的发展历程中，抗生素和化学抗菌合成物、重金属盐类、激素类物质的使用，曾经一度在防治动物疾病、提高动物生产性能等方面起到了巨大的作用，但因为它们的滥用所造成的严重后果也日益得到广泛的认识：药物残留、耐药性、免疫功能下降、动物易受应激的影响等，对生物本身、环境及人类生存均造成了严重的威胁。近年来，人们一直希望找到一些既安全又能有效地提高动物生产性能的饲料添加剂，它既有利于动物本身的生长，又能保持或改善动物的肌体品质，还不会影响生态环境和人类的健康，有利于可持续发展。“绿色饲料添加剂”正是在…     

Radiological risk assessment of fish feed and feed raw materials

In this study, natural radioactivity concentrations of fish feed and feed raw materials were assessed. Several feeds and raw materials were provided from the suppliers who dominate the aquaculture sector. ²²⁶Ra, ²³²Th and ⁴⁰K concentrations were determined by using a high‐purity germanium detector. The measured activity concentrations of samples ranged from 3.28 ± 0.27 to 15.90 ± 1.36, from 1.27 ± 0.10 to 12.07 ± 1.21 and from 52.01 ± 2.60 to 1,158.96 ± 54.42 Bq/kg for ²²⁶Ra, ²³²Th and ⁴⁰K respectively. The gamma dose rate and annual effective dose rate of samples were calculated to be in the range of 1.99–50.47 nGy/h and 2.44–61.89 µSv/yr respectively. Since the calculated radiological risk parameters of the samples were lower than the world wide average values, the radiation hazard is insignificant for human handlers.     

福建省水产饲料业的崛起与学科进步

水产养殖业的迅速发展带动了水产饲料业的进步。福建省水产饲料业经过近30年的稳步发展,饲料研发能力、产品产量与质量等均有较大的提高。本文概述了福建省水产饲料业的崛起与学科建设,指出了福建省水产饲料学科建设的重点发展方向。     

软质饲料与鲜杂鱼饵料饲养大黄鱼对比试验

为比较研究网箱养殖大黄鱼过程中分别投喂软质饲料与鲜杂鱼饵料的养殖效果,2011年5月于福建省马鼻玉井网箱养殖海区,选取平均规格为152 g/尾的大黄鱼,经过60 d的饲养,试验组全投软质饲料,对照组全投鲜杂鱼。结果显示：试验组与对照组每尾平均体重分别为256.9 g、231.3 g,饲料系数分别为2.505、7.306,大黄鱼每增重1 kg所需的饲料成本分别为15元、19.7元,投喂软质饲料进行饲养可节省成本4.7元。结果表明：投喂软质饲料的养殖效果优于鲜杂鱼,存活率更高,更具环保等综合效益。     

Growth and feed utilisation of rainbow trout subjected to changes in feed lipid concentrations

Rainbow trout Oncorhynchus mykiss grew from 44 to 326 g in 96days when held at 12 °C. Fish were fed to satiation twice dailywith either high (L₁: 30.8%, L₂:31.4%) or lower-lipid feeds (C₁: 18.8%,C₂: 21.8%). Four feeding treatments were studied.Group C₁C₂ received feed C₁ for 43 days(days 0–43) and C₂ thereafter (days 44–96).Groups L₁L₂, L₁C₂ andC₁L₂ were subjected to dietary changes asindicated by the feed designations. After a short period of feedadaptation, fish ingested similar amounts of feed energy i.e., they ateless by weight of the lipid-rich (L) feeds. Feed lipid content did notaffect growth but fish fed L-feed had reduced feed conversion ratio(FCR) compared to fish fed C-feed (0.731 vs. 0.773) during days0–43 (P < 0.01). After 96 days,L₁L₂-fish were lower in body protein(15.8%) than the C₁C₂-fish (16.8%)(P < 0.01). L-feeds also tended to increase percentage lipidand reduce percentage whole body moisture and ash. A higher net proteinutilisation (NPU) was recorded in fish fed L-feeds (43.6%)compared to fish fed C-feeds (38.8%) in days 0–43(P < 0.05). This seemed to be the result of a lower proteinintake rather than a protein-sparing effect of feed lipid. Above athreshold value of approximately 6.5 mg protein eaten·g bodywt_{minus 1}·day_–1, NPU decreased.     

中草药复合饵料投喂草鱼后肾脏组织学观察

目的观察草鱼在投喂中草药复合饵料后不同阶段肾脏组织结构的变化。方法将5 000尾草鱼(约0.5 kg)随机平均分成两组,一组为对照组投喂普通饵料,一组为实验组投喂中草药复合饵料,分别于0、1、2、4、5周在每组取1尾剖取肾脏,制成石蜡切片,HE染色,10×40倍光学显微镜下观察。结果实验组草鱼肾脏组织中部分肾小管上皮细胞大小不一,致使管腔变窄且相互挤压程度加重;胞核数量增加,部分肾小球增生肥大。结论中草药复合鱼饵饲喂草鱼,可引起草鱼部分肾脏组织形态结构发生改变。     

Environmental effects on feed utilization

Both external and internal factors affect the response of fish to variations in dietary quantity and quality. An attempt is made to review major, recent studies on the series of intermediate steps (intake, digestion, metabolism, excretion and retention) involved in the global response of fish to environmental changes. Among these external factors, greater attention is however devoted to those that are the most important natural effectors within the aquatic environment: temperature, ambient oxygen and salinity. The changes brought about by a change in temperature at different levels of nutrient utilization have been studied to a great extent in the recent past. As temperature affects in the first instance, the voluntary food intake, a discussion on current nutrient requirement data should preferably be dealt with in absolute terms. While critical levels of oxygen below which growth is hindered are sufficiently defined for many species, precise data on the direct effects of oxygen deficiency on nutrient utilization are still fragmentory. With regard to salinity, a distinction between stenohaline and euryhaline species and a knowledge of the physiological mechanisms corresponding to their life cycles are required before attempting comparative analyses. Within euryhaline species, best performances are noted at salinities isotonic to the internal medium. Despite accumulating evidence on the effects of cyclical phenomena, the chronobiological approach to fish culture remains practically unexplored.     

鲆鲽鱼类饵料研究现状

鲆鲽鱼类隶属于硬骨鱼纲(Osteichthyes),鲽形目(Pleuronectiformes),俗称比目鱼类(Flatfishes),可分为鲆科(Bothidae)、鲽科(Pleuronectidae)和鳎科(Soleoidae).鲆鲽鱼类是中国海水鱼养殖种类中重要的组成部分,其肉质鲜美细嫩,营养丰富,具有极高的营养价值和经济价值[1].     

Fat content in turbot feed: influence on feed intake, growth and body composition

The influences of dietary fat concentration on growth and energy deposition were studied in two replicated groups of turbot, Scophthalmus maximus (L.). Individually tagged turbot (202.3 g) held at 15.6 °C were offered dry pellets in excess. These contained either high-fat (25.4%) or low-fat (16.6%) concentration and identical protein (43.2%). After 3 months, feed treatments were crossed in two replicates, and the remaining fish were offered a mix of feeds for a further 2 months. Fish were sacrificed for analysis of body composition at the start of the experiment, at the time of feed treatment changes and when the experiment was terminated. There were no significant differences in energy intake, specific growth rate or weight between treatments at any time during the experiment. At the time of the feed treatment change fish offered high-fat feed had a significantly higher relative body fat (8.2 vs. 6.3% w/w) and lower body water (71.2 vs. 73%), but there were no differences in protein or ash content. By the end of the experiment, differences in body composition had diminished. The results indicate that fat content in the turbot may be manipulated by changing the dietary fat content, apparently without major influences on weight gain.