哺乳仔猪的精氨酸营养

精氨酸对于哺乳仔猪来说是一种必需氨基酸,但最近的研究表明母乳中的精氨酸量和哺乳仔猪肠道内精氨酸的合成并不能满足其最佳生长需要,精氨酸不足可能是限制哺乳仔猪获得最佳生长的一个主要因素。因此,探讨和研究国外有关哺乳仔猪精氨酸营养的最新研究进展,对国内重视和开展哺乳仔猪精氨酸营养的研究很有必要,对发挥和提高哺乳仔猪的最大生长潜力极有帮助。     

酸化剂在哺乳仔猪日粮中的应用效果

用6窝共63头哺乳仔猪,进行了5周的饲料酸化剂添加效果试验。试验设3个组,即乳香酸组（0．2％）、柠檬酸组（1．5％）及对照组。3组基础饲料组成一致,2周龄起试,7周龄结束试验。试验结呆表明,饲料中添加酸化剂能提高哺乳仔猪日增重及改善饲料利用率。酸化剂对哺乳仔猪日增重的影响随着酸化剂的种类及仔猪的日龄而有所不同。复合酸化剂乳香酸比单一酸化剂柠檬酸效果好而稳定;酸化剂在仔猪4同龄前效果不明显,4-5周龄效果最好,乳香酸组日增重比对照组提高31.0个百分点（P＜0．05）,柠檬酸组日增重比对照组提高24.1个百分点,6周龄以后效果减弱。本试验中,酸化剂对哺乳仔猪降低腹泻率及提高成活率的影响均主要发生在4周龄以后,且复合酸化剂的效果优于单一酸化剂。     

注射初乳对哺乳仔猪的增重效果

哺乳仔猪采取注射初乳的试验组,与未注射初乳的对照组,试验全期两组日均增重分别为225g±22g和195g±27g,两组差异极显著（P＜0．01）,经济效益试验组比对照组提高15．4％。另外,注射初乳后,还能大大降低哺乳仔猪的发病率。     

生菌素、维吉尼霉素对哺乳仔猪生长和血清代谢物的影响

将90头平均体重4.98kg哺乳仔猪(杜×大×长)分成2组,日粮中分别添加维吉尼霉素(对照组)和生菌素(普乐宝)。结果表明,与对照组相比,试验组日增重、饲料转化率和血清球蛋白水平提高(P>0.05或P<0.05);仔猪腹泻率、血清尿素氮、血糖和胆固醇含量下降(P<0.05);仔猪每千克增重收益增加2.85%。     

农户饲养哺乳仔猪的技术要点

哺乳仔猪的饲养是整个仔猪饲养的关键时期,不少农村个体养殖户缺乏科学饲养的基本知识,致使经济效益较差。为此将哺乳仔猪的饲养分为饲养初期、中期和后期3个阶段进行阐述,初期应让哺乳仔猪吃好初乳、吃足母乳,管理上应做好保温防压。中后期应注意营养需要、饲喂方法和适时断奶。     

哺乳仔猪的饲养管理与疾病防控要点

随着我国经济社会的快速发展,生猪养殖业发展迅速,其中哺乳仔猪是规模化养殖健康持续发展的基础。根据哺乳仔猪特殊的生理发育情况,阐述了哺乳仔猪饲养管理要点,同时针对哺乳仔猪的疫病防控工作提出了几点建议,以期提高哺乳仔猪的成活率及生产性能,促进生猪养殖业的健康发展。     

浅谈哺乳仔猪的饲养管理

仔猪由于其自身的生理特点,哺乳期较难饲养,如管理不善便极易死亡。简述仔猪初生期、开食补料期的管理要点及疾病防疫策略。     

哺乳仔猪黄痢的发生与防治技术探讨

仔猪黄痢,与仔猪白痢一样同为大肠杆菌引发,因一般发生在出生1周内的新生仔猪,且出生8～12 h就会发病,故又称早发性大肠杆菌病,或与仔猪红痢一道称"仔猪三日痢"。临床上患猪一般以剧烈腹泻,拉黄色或黄白色粪便为临床特征,发病急、病程短,发病率和死亡率高的一种急性传染病。该病在德宏州分布广泛,呈地方流行,特别是在德宏州内的那些仍采用传统猪舍养猪的场户一年四季都可能发生,是多年来德宏州新生仔猪的一种常见病和多发病。     

提高哺乳仔猪成活率的综合技术措施

随着社会经济快速发展,畜牧行业向着集约化、规模化方向不断发展。在畜牧业养殖过程当中仔猪管理是一项重要工作。由于仔猪抵抗力弱,容易患病及死亡,若管理不当会给养殖场势造成严重的经济损失。对提高哺乳仔猪成活率的技术措施进行介绍,以供相关专业人士进行参考和借鉴。     

Arginine effects on biochemical composition of sperm in rainbow trout,Oncorhynchus mykiss

The present study investigated the effect of arginine on seminal plasma composition in rainbow trout. Male rainbow trout broodstocks (2500 ± 200 g) were fed five practical diets (each consisting of three triplicates) supplemented with Arginine at 0.50%, 1.50% and 2.00%. The control group were fed without arginine. Broodstock feeding lasted for 90 days, and then fish semen was sampled. Results indicated no significant differences in LDH, ALP, Fe²⁺ and phosphorous content among the different treatments. The lowest levels of AST and ALT and the highest levels of Ca²⁺ and Mg²⁺ ions were observed in the treatment fed with 1.50% arginine, which showed significant differences from other treatments (P < 0.05). Moreover, the amount of Cl^?, Na⁺ and K⁺ ions was significantly increased in the seminal plasma in fish fed diets containing arginine in comparison with the control. As the amount of arginine was increased, the levels of uric acid became significantly greater in contrast to urea and glucose levels. The highest amounts of cholesterol, fructose and total protein were observed in treatments fed on 2.00%, 0.50% and 1.00% arginine, respectively, showing significant differences from other treatments (P < 0.05). The highest pH value was assayed in the 1.50% arginine treatment. Results indicated that arginine had a potential efficacy on semen quality in rainbow trout broodstocks.     

不同铵离子浓度与pH人工海水对栉江瑶精子激活效果的比较

栉江瑶(Atrina pectinata)为我国重要的海洋经济双壳贝类,近年来,其养殖生产活动备受养殖企业关注,为发展和优化其人工繁殖技术,本研究探究了人工海水中铵离子浓度和pH的变化对栉江瑶新鲜精子游泳运动的激活作用,定量描述了高度活化状态下精子曲线运动速率(VCL)、直线运动速率(VSL)、平均路径运动速率(VAP)和鞭毛摆动频率(BCF)的运动学特征,并对精子ATP含量、ATP酶与超氧化物歧化酶(SOD)活性进行了记录。结果显示,简单提高海水pH可略微提高栉江瑶精子运动率,但无法使精子进入高度活化状态;含有铵离子的碱化海水可有效激发精子游泳运动,3 mmol/L氨海水激活效果最佳。经3 mmol/L氨海水激活后,精子活力等级(MI)在21 min内一直保持在≥4的状态,在激活的前3 min内精子运动率都在80%以上,VCL>56 μm/s,VSL>17 μm/s,VAP>30 μm/s,BCF>6 Hz。精子ATP含量在激活5 min后降低至初始含量的30.29% [(128.80± 66.92) μmol/g prot],随后,无显著变化(P>0.05)。精子Na+-K+-ATP酶和Ca2+-Mg2+-ATP酶活性在运动过程中较为稳定,其中,Na+-K+-ATP酶活性较低[(0.62±0.03) U/mg prot],Ca2+-Mg2+-ATP酶活性较高[(6.08± 0.04) U/mg prot]。精子SOD活性在15 min内逐步降低至[(1.23±0.73) U/mg prot],随后维持稳定。本研究可为栉江瑶精子激活机制深入研究提供基础,助力发展栉江瑶人工繁育技术。     

杭州城市河道生态治理实践及成效

评估杭州市城市河道生态治理成效,为更好地指导城市河道生态修复工作提供借鉴。后横港、沿山河、新塘河和南大河位于杭州市中心城区,水质都处于劣V类,蓝藻水华和黑臭暴发频繁,从2014年开始,分别开展了一系列生态修复工程。测定氨氮、总磷、高锰酸盐指数、溶解氧指标判断水质改善情况,分析浮游植物、浮游动物、底栖动物判断水体生态修复程度。氨氮后横港下降超过80%,沿山河和南大河下降60%左右;总磷后横港下降接近70%,其他河道下降23%~55%;后横港、沿山河、新塘河高锰酸盐指数进一步降低,部分河道高锰酸盐指数能达到II类水水平;溶解氧浓度都明显上升,均能达到III类以上水平。南大河的浮游植物密度达到了水华暴发的水平;各条河道的原生动物和轮虫类密度都较高,但Shannon多样性指数普遍在1~2;枝角类和桡足类密度偏低;底栖动物Shannon指数均低于1,指示河道处于严重污染状态。杭州市城市河道生态治理工作的中心是:沉水植物恢复及以沉水植物恢复为基础、包含浮游动物和底栖动物等在内全水域生物多样性恢复的生态系统恢复。     

Sublethal effects of ammonia in soft water on Atlantic salmon smolts at a low temperature

Atlantic salmon (Salmo salar L.) smolts were exposed to ammonia at 4 °C in an open flow system. The concentrations of un-ionized ammonia nitrogen (NH₃-N) and total ammonia nitrogen (TAN) were increased abruptly twice during a period of 28 days. For concentrations in the range 1–15 µgl^–1 un-ionized ammonia nitrogen (4.3–21.1 mgl^–1 TAN), no effects were observed on the smolts. However, plasma glucose was not measured in this range. The observed results for higher concentrations may be divided into two categories of sublethal effects. (1) In smolts exposed to the concentration range 19–37 µgl^–1 NH₃-N (average 26 µgl^–1 NH₃-N; 34.9–50.5 mgl^–1 TAN), the mean plasma glucose concentration was 1.3 times the mean of the control group. No other measured parameters were significantly altered. (2) For smolts exposed to 37–65 µgl^–1 NH₃-N (average 47 µgl^–1 NH₃-N; 57.7–84.5 mgl^–1 TAN), the mean plasma glucose concentration was increased to 2.3 times, the mean plasma chloride level was reduced to 0.9 times, and mean haematocrit was increased to 1.1 times the control values. Histological examination of the gill tissue revealed extensive lamellar hypertrophy. Weight, length, condition factor and ventilation frequency were not significantly affected and no mortality took place during the exposure period (1–65 µgl^–1 NH₃-N; 4.3–84.5 mgl^–1 TAN). Plasma glucose seemed to be the most sensitive parameter in detecting the sublethal stress response, and this investigation may thus demonstrate the importance of measuring plasma glucose in experiments concerning safe levels for ammonia.     

生物活性肽对断奶仔猪生长性能影响的饲养对比试验

选择平均体重约9.5kg左右的三元杂交生长猪60头,随机分成3个处理组,每个处理设2个重复,每个重复10头仔猪。试验1组和试验2组在日粮中添加0.3%的小肽制剂,经过29d试验,与对照组相比平均日增重分别提高11.9%(P<0.05)和12.9%(P<0.05),料肉比降低10.6%(P<0.05)和11.06%(P<0.05),生长猪腹泻率分别降低25%(P<0.05)和20%(P<0.05)。     

镉污染对鲤鱼超氧化物歧化酶活性的影响

采用毒性试验方法,试验期为10d,研究了不同浓度的镉(Cd2+)对鲤(Cyprinus carpio)几种组织超氧化物歧化酶(SOD)活性的影响,Cd2+浓度设4组,分别为0.1569、0.3138、0.6275、1.2550mg/L,设1个对照组(0mg/L)。结果表明,血液和肝脏SOD比活力随着试验浓度的增大,表现出相似的抑制-诱导-抑制规律;鳃表现为诱导-抑制;肾脏一直表现为抑制,抑制程度为下降-升高-下降;肌肉一直表现为诱导。     

The effect of feeding on oxygen consumption and ammonia excretion of juvenile tench Tinca tinca (L.) reared in a water recirculating system

The effect of feeding frequency (one, three, and continuous feeding), feed ration (0.2, 0.5, 0.8% of total fish biomass), and feeding per se on the oxygen consumption (OC, mg O₂ kg⁻¹ h⁻¹) and ammonia excretion (AE, mg TAN kg⁻¹ h⁻¹) of juvenile tench (body weight 15–19 g) and variations in these parameters in daily cycles were examined. Fish metabolism was studied in a recirculating system (rearing tanks of 0.2 m³, water temperature 23 °C). It was found that oxygen consumption and ammonia excretion depended significantly on feed ration. An increase of feed ration from 0.2 to 0.8% of fish biomass caused an increase of OC and AE from 126.80 mg O₂ kg⁻¹ h⁻¹ and 1.95 mg TAN kg⁻¹ h⁻¹ to 187.35 mg O₂ kg⁻¹ h⁻¹ and 8.80 mg TAN kg⁻¹ h⁻¹ (p<0.05). There was no dependence between feeding frequency and the mean rate of oxygen consumption. However, the relationship between feeding frequency and ammonia excretion by juvenile tench was statistically significant (p<0.05). Feeding frequency significantly affected daily fluctuations of AE and OC. It was found that diurnal variations in metabolic rates were strictly related to tench feeding, and the daily variations of AE were significantly higher than OC.     

盐度对日本囊对虾生长性能影响

在盐度7~42范围内设置8个盐度梯度,每个梯度3个重复。研究盐度对日本囊对虾成虾的生长、存活与饵料系数的影响,结果表明,日本囊对虾生长、存活率、增长率与饵料系数均有统计学意义差异(P0.05),盐度27的生长最快,显著大于盐度组7(P0.05);存活率变化范围为(18.79%±1.94%)~(91.71%±3.68%),盐度27存活率最高,高盐度或低盐度的存活率均低于中间盐度,但高盐度的存活率要比低盐度高;生长性状的增长率变化范围(2.47%±0.25%)~(84.42%±5.22%),增长率最快为盐度22~32;饵料系数最低为盐度27。日本囊对虾成虾最适生长盐度范围为22~32,该盐度范围内对虾生长速率快、存活率较高、饵料系数低;日本囊对虾成虾的最适盐度范围较窄,并且高盐度下的日本囊对虾存活率更高。     

饥饿对真鲷生长及生化组成的影响

在２０℃条件下,对真鲷进行了不同时间的饥饿处理后再投饵的恢复生长实验。饥饿１５ｄ的真鲷体重下降７．０５％,鱼体水分含量略有上升,蛋白质含量的比能值略有下降,脂肪含量和灰分含量没有明显改变。这表明真鲷在饥饿过程中主要消耗蛋白质作为身体的能量来源。分别给饥饿处理０（对照）、３、６、９、１２和１５ｄ的真鲷投饵,在饱足摄食的条件下生长２周。各饥饿处理组的鱼体生化组成及比能值均接近,并恢复到对照组水平。饥饿３、６ｄ处理组在恢复生长的特殊生长率、摄食率明显高于对照组,而食物转化率与对照组无显著差异;饥饿９、１２和１５ｄ处理组的特殊生长率和食物转化率均显著高于对照组,而摄食率与对照组无显著差异。结果表明真鲷幼鱼具有超补偿生长能力,短期饥饿的真鲷在恢复生长中通过显著提高摄食水平来达到补偿生长;而继续延长饥饿时间则通过显著提高食     

饥饿对南美白对虾生化组成及补偿生长的影响

对南美白对虾(初始湿重1.427±0.018g)在29.5±1.5℃条件下进行不同饥饿时间处理后再投喂的实验。实验设对照组C以及饥饿处理组S_1、S_2、S_3、S_4、S_5和S_6共7组,分别饥0d(对照组)、1d、2d、3d、4d、5d和6d后再投喂。实验共进行20d。在饥饿1-6d的过程中,南美白对虾体重、脂肪含量、碳水化合物含量和能值下降,而水分、灰分含量增加,但蛋白质含量没有明显改变。实验结束时,S_1、S_2和S_3组体重与C组没有显著差异(P>0.05),虾体的生化组成也均接近或达到了C组水平,而S_4、S_5和S_6组体重则显著低于对照组(P<0.05),且虾体的生化组成与C组还有一定的差异。在恢复生长过程中,各饥饿处理组的生长率、食物转化率,以及S_4、S_5和S_6三组的摄食率均显著高于C组(P<0.05)。研究结果表明,南美白对虾继饥饿后具有补偿生长效应,这主要是由于恢复摄食后摄食率和食物转化率提高共同作用的结果。