鹅排泄物收集技术及蛋白质净利用率研究

本文借鉴鸭排泄物收集方法对肉鹅的蛋白质净利用率进行初步研究。当日粮蛋白质水平为15%时,蛋白质的净利用率为56.25%;当日粮蛋白质水平为8%时,蛋白质的净利用率为59.33%。结果表明,当日粮蛋白质水平增高时,蛋白质的净利用率有降低趋势。     

鹅真代谢能测定法适宜绝食排空期与排泄物收集期的研究

24只成年扬州鹅公鹅按体重一致的原则，随即分成4组，每组6只，每只单笼饲养。旨在探讨鹅饲料真代谢能测定（TME）中适宜消化道排空期和排泄物收集期。试验排空处理期为24、32、40h，排泄物收集期为16、24、32、40、48h。结果表明：①随着绝食排空时间的增加，排泄物量逐渐减少，鹅对饲料干物质的利用率和AME、TME值逐渐增大，绝食40h组最大。分析结果表明，绝食24、32、40h组之间，ME值两两差异不显著。②随着收集时间的延长，排泄物量增大，鹅对饲料干物质的利用率和代谢能值下降。AME值除24h显著高于48h外，24、32、40、48h两两差异不显著；TME值不同时间段之间差异均不显著。综上所述，鹅TME法测定饲料代谢能值时，适宜消化道排空期和排泄物收集期建议为“24h＋24h”模式。     

鹅日粮不同纤维源与蛋白质利用率关系的研究

鹅是以食草为主的家禽了,对粗纤维有一定的利用能力.通过测定日粮中不同粗纤维的表观消化率对粗蛋白质利用率的关系,在保证蛋白质较高消化率的前提下,尽可能扩大粗饲料种类及其在配合饲料中的比例,增加由粗饲料供给鹅的能量,降低饲养成本,提高养鹅经济效益.     

提高猪饲料蛋白质利用率的措施

在养猪生产中,常用以下几种方法来饲料蛋白质的利用率. 　　……     

果胶酶对鹅净蛋白利用率及氨基酸消化率的影响

为了研究日粮中添加不同水平的果胶酶对鹅干物质消化率、净蛋白利用率（NPU）和氨基酸消化率的影响,选取24只24月龄的健康五龙鹅,随机分为4组,日粮中果胶酶添加水平分别为0％、0．1％、0．2％、0．3％,采用全收粪法进行代谢试验。结果表明：在代谢能（ME）和粗蛋白（CP）摄入量基本一致的条件下,随着果胶酶添加水平的提高,0．2％添加组粪中的氨态氮（NH3-N）浓度最低,为1．20mg／kg,与其他组相比差异显著或极显著（P〈0．01或P〈0．01）;甘氨酸表观消化率偏低,但是,组间差异不显著,其它各种氨基酸表观消化率（AAAD）均较高（72．19％～94．27％）,说明日粮中添加适量的果胶酶制剂能够有效地提高鹅对营养物质的消化吸收率。     

提高饲料蛋白质利用率的技术措施

蛋白质饲料原料紧缺,价格昂贵,在全价配合饲料中所占比例较大(一般占20%左右)。随着农业经济结构的调整,舍饲养殖成为农民经济收入的主要组成部分,养殖规模越来越大,饲料用量随之加大,蛋白质饲料紧缺的矛盾更加突出。而在畜禽的实际饲养中,饲料中含氮物质或多或少会损失一些,为了减少这部分损失,设法提高饲料中蛋白质的营养价值和利用率具有十分重要的意义。笔者在饲料生产与养殖实践中总结出了一套技术措施,供同行参考。1合理搭配日粮通常选用多种饲料搭配成日粮,不仅使蛋白质在数量上满足畜禽需要,而且使限制性氨基酸在种类上和数量上互相…     

肉用中型仔鹅能量和蛋白质需要量的研究

将93只初生雏鹅(公母各半)随机分为3组,分别饲以高、中、低不同营养水平的日粮。各组的饲养管理条件一致,均以全价配合饲料舍饲,自由采食。结果表明:①各生长阶段各组平均生长速度以Ⅲ组为最优,与其它组间的差异显著,G值分别为育雏期0.317、生长期0.432、肥育期0.415;②总体上各营养水平组间料重比差异不大,约3.8~4.0:1;③屠宰性能测定。屠宰性能组间及性别间差异不显著。屠宰率:85.9%,半净膛率:82.6%,全净膛率:76.0%;④中型仔鹅营养需要。1~2周龄,ME:11.6MJ/kg,CP:19%为宜;3~4周龄,ME:11MJ/kg,CP:18%为宜;5~8周龄,ME:10.7MJ/kg,CP:15%;9~10周龄,ME:11MJ/kg,CP:14%为宜。     

鹅对菜籽粕代谢能和营养物质利用率的评定

【目的】利用套算法评定不同来源菜籽粕的鹅代谢能及营养物质利用率。【方法】选取健康、体重接近的200日龄成年公鹅30只,随机分为5组(Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ组),每组6个重复,每个重复1只鹅。4种菜籽粕分别由加拿大进口油菜籽及江苏省苏州市、宿迁市、盐城市本地生产的油菜籽榨油而成。采用强饲法进行代谢试验,强饲量80 g,试验Ⅰ、Ⅱ、Ⅲ、Ⅳ组分别以4种菜籽粕替代30%基础饲粮,试验Ⅴ组强饲基础饲料,并收集内源粪便,做内源校正。【结果】(1)4种菜籽粕中的总能(GE)、干物质(DM)、粗蛋白质(CP)、粗脂肪(EE)、粗灰分(Ash)、酸性洗涤纤维(ADF)、中性洗涤纤维(NDF)、钙(Ca)、总磷(TP)含量的平均值分别是17.48 MJ/kg、88.95%、42.22%、2.47%、7.93%、22.42%、37.81%、0.83%和1.09%。(2)鹅对4种菜籽粕的表观代谢能(AME)、真代谢能(TME)平均值分别为12.27和13.05 MJ/kg,且AME、TME存在显著的组间差异(P<0.05);鹅对4种菜籽粕CP真利用率平均值为44.84%,对DM、EE、Ash、ADF、NDF...     

Urea utilization in growing lambs. 6. N balance with 15N urea

Lambs of an age of 2 or 4 months and of an average live weight of 14.7 and 27.4 kg resp. received rations consisting of 44% cereals, 46% dried sugar beet pulp, 6% wheat starch, 2% urea and 2% mineral-vitamin mixture. The crude protein content was 17.1 and 15.9% resp. in the dry matter, that of native crude protein 10.6 and 9.4% resp. During a 6-day N balance period 8 and 16 g 15N urea resp. with a 15N excess (15N') of 9.26 and 9.40 atom-% were fed orally instead of commercial feeding urea. There were no significant differences between the two age groups with regard to the digestibility of the organic matter and the crude nutrients. The average N balance of 372 +/- 85 mg/kg LW 0.75/day were in the intermediate range of N retention capacity and accounted for 26 +/- 5% of the consumed N. N retention in per cent. was slightly lower in younger lambs. Projections of urea utilization in a quasi stationary state resulted in an efficiency of the utilization of 33 +/- 4%. The dismembering of the lambs at the end of the main period showed between 0.02 and 0.22 atom-% 15N' in the total N, TCA precipitable N and amino acid N of the meat. At between 0.24 and 0.38 atom-% 15N' they were highest in the heart and jaw muscles. The quota of 15N' amounts found in the total N of the meat were 10.6 +/- 3% of the 15N-intake and 20.1 +/- 5.1% of the 15N' amount remaining in the body. The bones contained 7.7 +/- 1.7% and the fleece 7.9 +/- 3.1% of the 15N'-intake. Generally seen, the total N and urea utilization was slightly lower in younger lambs than in older ones.     

Influence of energy concentration and source on the utilization of feed protein and NPN in lambs. 2. 15N balance and utilization of pure protein and NPN

In an experiment 12 lambs of the merino species were divided into 4 groups. The variants HE received 740 or 718 EFU cattle/kg DM and the variants NE 689 or 671 EFU cattle/kg DM. The different energy concentrations resulted from differentiated quotas of dried sugar beet chips and wheat starch supplements. Within the variants, sub-variants with (HESZ, NESZ) or without (HES, NES) sugar supplements were formed. Due to varied DM intake, the average energy intake in all groups was 42 EFU cattle/kg LW0.75. N balance experiments using 15N-labelled urea were carried out, and 15N accumulation of N excretion was projected to a steady state. The partial utilization of pure protein and NPN in the ration was ascertained with the help of a 3-pool compartment model of N utilization in ruminants. In the non-amino acid N pool HE utilized 84% of NPN and NE 77% for the synthesis of amino and nucleic acids. The efficiency of protein synthesis in the amino acid N-pool were in HESZ 64%, HES 70%, NESZ 70% and NES 73%, resp. The total utilization of NPN is the sum of the partial utilization in the two pools, whereas the total utilization of pure protein is calculated from the true digestibility and the efficiency of the utilization in the AA-N pool. The total utilization of NPN for the synthesis of protein for the protein pool amounted to 40/35/41/33% and that of pure protein to 54/51/49/50%. Energy intake being identical, energy concentration did not have an influence on the utilization of pure protein and NPN, whereas NPN utilization was better in rations containing sugar. The pure protein in the ration was by 19 ... 52% better utilized than NPN.     

Validation of a method for collection and assay of pentane in the exhaled breath of the horse

Oxidative stress refers to an imbalance between the production of oxidising free radicals and the antioxidant defenses of the cell, and is associated with many pathogenic processes. Oxidative damage to cellular lipids results in the evolution of pentane and ethane gas, and detection of these hydrocarbons in the exhaled breath can be used to monitor in vivo oxidative stress. The aim of this study was to validate a gas chromatography (GC) method for measurement of breath pentane in the horse. The GC-system developed showed good specificity for discrimination of pentane from other breath hydrocarbons, and was sensitive to 0.5 ppb pentane. Pentane was detected in the exhaled breath of five horses investigated on two occasions. The results of this preliminary study demonstrate that breath pentane can be measured in the horse, and further work is now justified to investigate the feasibility of applying this method for monitoring in vivo oxidative stress in the horse.     

二重PCR检测鸭瘟病毒和鹅细小病毒的初步研究

根据鸭瘟病毒(Duck plague virus,DPV)DNA聚合酶基因和鹅细小病毒(Goose parvovirus,GPV)NS基因序列分别设计2对引物,应用这2对引物对混合样品中鸭瘟病毒和鹅细小病毒进行了二重PCR扩增。PCR产物的琼脂糖凝胶电泳结果表明2条特异性带为563bp(DPV)和1146bp(GPV),与实验设计相符,且与常规单一PCR结果一致。二重PCR反应检测出的DPV含量相当于20个PFU;检测出的GPV含量相当于0.1个ELD50,对禽痘病毒和减蛋综合征病毒的核酸未能扩增出任何条带,特异性良好。该二重PCR能够在一次扩增反应中检测两种病毒,为两种鹅病的病原检测和诊断提供了一种简便、经济、快速的手段。     

鹅副黏病毒NP蛋白间接ELISA检测方法的建立及免疫鹅抗体水平的检测

以纯化的鹅副黏病毒NP蛋白为包被抗原,建立了检测鹅副黏病毒NP蛋白抗体的间接ELISA方法,并确定了间接ELISA的最适反应条件：抗原包被浓度为1.0μg/mL,血清稀释度为1∶200,兔抗鹅IgG辣根过氧化物酶标记抗体稀释度为1∶2 000,抗原和血清、血清和二抗均于37℃反应1 h,底物于37℃显色15 min。此间接ELISA方法的特异性强、重复性好。应用该方法对试验鹅血清进行检测,以HI试验为参照。经统计学处理后,比较了两方法测得的抗体效价,分别建立了各组鹅群的回归方程。显著性检验证明,这两种方法检测的抗体效价呈显著相关关系。     

Energy utilization,nitrogen balance and microbial protein supply in cattle fed Pennisetum purpureum and condensed tannins

The aim of the experiment was to assess the effect of condensed tannins (CT) on feed intake, dry matter digestibility, nitrogen balance, supply of microbial protein to the small intestine and energy utilization in cattle fed a basal ration of Pennisetum purpureum grass. Five heifers (Bos taurus × Bos indicus) with an average live weight of 295 ± 19 kg were allotted to five treatments consisting of increasing levels of CT (0, 1, 2, 3 and 4% CT/kg DM) in a 5 × 5 Latin square design. Dry matter intake (DMI) was similar (p > 0.05) between treatments containing 0, 1, 2 and 3% of CT/kg DM and it was reduced (p < 0.05) to 4% CT (5.71 kg DM/day) with respect to that observed with 0% CT (6.65 kg DM/day). Nitrogen balance, purine derivatives excretion in urine, microbial protein synthesis and efficiency of synthesis of microbial nitrogen in the rumen were not affected (p ≥ 0.05) by the increase in the levels of condensed tannins in the ration. Energy loss as CH₄ was on average 2.7% of the gross energy consumed daily. Metabolizable energy intake was 49.06 MJ/day in cattle fed low‐quality tropical grass with a DMI of 6.27 kg/day. It is concluded that concentrations of CT between 2 and 3% of DM of ration reduced energy loss as CH₄ by 31.3% and 47.6%, respectively, without affecting intakes of dry and organic matter; however, digestibilities of dry and organic matter are negatively affected.     

鹅孵化中异常原因分析及改进方法

在鹅人工孵化的过程中,经常会出现一些异常现象,实际生产中要注意分析其发生原因,采取相应的改进方法,以有效地提高鹅的孵化率.     

Mathematical model for energy and protein balance simulation in broilers

The authors used the empirical equations of mathematical modelling for the energy and protein balance simulation, with the view of calculating the body weight gain in broilers fed various diets. The results found by using the model were compared with the experimental data obtained by several authors. A standard deviation of +/- 1.20% and a mean error of +/- 0.28% and a mean error of +/- 0.28% which proved that the model average was a sufficient estimate of the experimental average were found. Furthermore, using the regression method, a significant correlation of variables was evidentiated.     

植物叶蛋白提取技术及开发利用研究

研究了6种不同的叶蛋白提取方法，采用不同浓度（饱和度）的（NH4）2SO4盐析法和加热法，通过调节原液的pH值（5．0－8．0）并分别从光叶紫花苕、紫花苜蓿、白三叶、多花胡枝子、大叶胡枝子、葛藤及多年生黑麦草中提取叶蛋白，结果表明，上述植株均是较好的原料，其中光叶紫花苕、紫花苜蓿、白三叶LPC提取率较高，分别为89．51％、89．2％、76．32％。单位提取量为19、17．5、16．35g/110g鲜草。就方法论，（NH4）2SO4处理随浓度增高而提取率增高，加热法（60－80℃）中以快速加热效果最好。