禁食时间对3周龄肉用仔鸡消化道内容物及其排空率变化的影响

鸡饲料营养物质生物学效价多数是以体重１８ｋｇ以上成年来航公鸡为试验动物而得到的,鸡只的代谢较为稳定。而肉用仔鸡生长迅速,代谢旺盛,在２个月的生长期内体重可达２ｋｇ左右。因而成年公鸡所得到的数据是否适用于肉用仔鸡,有待于进一步探讨。用代谢试验等方法测定饲料营养物质生物学效价时,应考虑到消化道中食糜排空的时间;禁食时间太短,排空不完全,影响试验结果,禁食时间过长,对鸡本身是一个不利应激,影响鸡正常生理状态,亦影响结果。以往禁食时间的选择存在较大差异,从１２小时（杨诗兴,１９８３）〔１〕,２４小时（…     

羔羊的育肥技术及管理要点

养羊业是我国畜牧产业的重要组成部分,随着人们生活水平的不断提高,我国养羊业结构也逐渐发生了调整和转化,高效养羊模式逐渐建立,现代养羊业日益规模化、集约化及高效化.羔羊肉因其鲜嫩易消化、脂肪少、瘦肉多等诸多优点,深受人们喜爱.高效的羔羊育肥技术利用了羔羊生长发育快、饲料报酬高等特点,对断奶羔羊直接转入育肥舍进行集中育肥,在短时间内快速生产培育出高标准的羔羊.高效羔羊育肥技术可大大缩短育肥时间,羔羊的出肉率、屠宰率及商品率显著提高,且肉质好,具有生产周期短、成本低、饲料报酬高、羔羊增重快及经济效益高等优点.目前羔羊育肥生产已成为养殖业发达国家发展养羊业的重点,本文综合论述了羔羊育肥技术,以期对我国养羊业的发展提供参考与借鉴.     

浅谈羔羊育肥的概念及特点

羔羊育肥是利用羔羊周岁前生长速度快、饲料报酬高等特点而进行的育肥。根据我国的情况,羔羊的育肥主要指岁以内羔羊的育肥,其中包括哺乳羔羊的育肥、早期断奶的强度育肥、断奶羔羊的育肥、当年羔的育肥。1特点1.1生产周期短在放牧的羊群,生产一只羯羊饲养2～3年,甚至4～5年,而在实行羔羊育肥的羊群,育肥羊是当年育肥当年屠宰,甚至4～5个月龄就可屠宰,比放牧育肥生产周期缩短1～2年,进而加快了畜群周转。1.2生长速度快,饲料报酬高目前用于羔羊肥育的羊,绝大部分是二元、三元杂交羊,其父本早熟,生长速度快,胴体品质好,母本繁殖力高、多胎,杂…     

羔羊育肥方式的探讨及经济效益的分析

<正> 一、试验目的 (一)不同育肥方式的育肥效果及经济效益。 (二)畜舍温度对育肥效果的影响。二、试验方法和步骤 (一)试验用羊 1987年出生的苏联美利奴高代杂种细毛羊公羔,共30只,开始体重全群平均24.5公斤。     

寒冷地区羔羊直接育肥效果及对母羊繁殖率的影响

羔羊直接育肥不但可以使肥羔生产与市场变化充分衔接，还有效地利用了羔羊维持代谢需要最少、生长速度最快的阶段，以最小的投入获得了最大的回报。同时，为生产母羊保持较高繁殖率创造了有利条件，试验结果表明：新疆高寒养羊地区在应用了包括绵羊冷季饲养技术、繁殖技术、羔羊提早断乳技术的基础上，配套以羔羊直接育友有关的饲养和疫病防制技术，羔羊在5月龄出栏，平均活重可达35kg以上，屠宰率达到47.4%，每人羊较秋季育肥多获利76元。同时，羔羊实施直接育肥，提前断乳，生产母羊繁殖率明显提高，有29.26%（84／287）的母羊在夏牧场产羔（当年产第二胎），高于对照组14.26个百分点，较晚春羔母羊4.7％（3／64）高24个百分点，差异显著（P＜0.01）。     

早期断奶羔羊饲粮的可消化性及对消化道发育的影响

将平均35．5日龄的24只无角陶赛特羊（♂）与小尾寒羊&#215;滩羊（♀）的三元杂交一代断奶羔羊分为3组,每组♂1、♀7,单栏饲养;经15d预试后,正试期50d中分别饲喂不同消化能（DE）与粗蛋白质（CP）水平的强度育肥饲粮,Ⅰ组为0．9倍NRC,Ⅱ组为1．0倍NRC,Ⅲ组为1．1倍NRC水平;正试期第21～26天,从每组选5只母羔进行消化试验收集,测定各组饲粮的可消化性;正试期结束后,每组屠宰4只接近组体重均值的母羔,测定消化道发育状况。结果表明,经分析饲粮的DM、OM、CP和ADF表观消化率（DMD、OMD、CPD、ADFD）均随其营养水平提高而线性上升。饲粮Ⅲ的DMD与OMD显著高于Ⅰ（P〈0．01）和Ⅱ（P〈0．05）;Ⅲ的CPD显著高于Ⅰ、Ⅱ（P〈0．01）,Ⅱ也显著高于Ⅰ（P〈0．05）;饲粮Ⅰ的ADFD极显著低于Ⅲ（P〈0．01）。钙与磷的表观消化率（CaD、PD）的变化与饲粮营养水平间规律性不强。饲粮营养水平对羔羊全消化道相对重（％宰前活重）和各胃室相对重（％全胃重）的影响不显著（P〉0．05）;各组羔羊的瘤网胃相对重均达到成年羊的水平。     

育肥方式对呼伦贝尔羊及其与杜泊羊杂交1代羔羊消化道酶活性的影响

本试验旨在研究育肥方式对呼伦贝尔羔羊及呼伦贝尔羊与杜泊羊杂交1代羔羊小肠及胰腺酶活性的影响。采用2×2完全随机试验设计,第1因素为育肥方式,分自然放牧和放牧补饲;第2因素为品种,分呼伦贝尔羔羊及呼伦贝尔羊与杜泊羊杂交1代羔羊(由呼伦贝尔母羊与杜泊公羊杂交而来)。选择体重相近的健康4月龄断奶呼伦贝尔羔羊和呼伦贝尔羊与杜泊羊杂交1代羔羊各60只,各分为2组,每组30只。育肥阶段分为育肥前期、育肥后期2个阶段,共60 d。放牧补饲组羔羊每只每天补饲精料在育肥前期为0.27 kg,育肥后期为0.53 kg。育肥试验结束时,分别从每组羔羊中随机选取5只羔羊进行屠宰,取小肠及胰腺组织测定酶活性。结果表明:与自然放牧相比,放牧补饲可显著提高羔羊十二指肠的胰蛋白酶、脂肪酶及糜蛋白酶活性,空肠、回肠与胰腺的淀粉酶、脂肪酶及胰蛋白酶活性(P0.05)。与呼伦贝尔羔羊相比,呼伦贝尔羊与杜泊羊杂交1代羔羊的十二指肠淀粉酶、糜蛋白酶活性,空肠及回肠的脂肪酶和胰蛋白酶活性显著增加(P0.05);十二指肠胰蛋白酶、胰腺脂肪酶活性的增加趋于显著(0.05≤P0.10)。总之,与自然放牧相比,放牧补饲能够提高羔羊的小肠及胰腺的消化酶活性,呼伦贝尔羊与杜泊羊杂交1代羔羊的小肠及胰腺的消化酶活性高于呼伦贝尔羔羊。     

羔羊育肥期间易发的疾病及防治对策

近几年，在舍饲养羊过程中，羔羊育肥已成为我县养羊户作为肉羊生产的一种主要形式，投入少、饲料利用率高、方式灵活、效益好。但在育肥过程中，羔羊易发生多种疾病，给养殖户带来了一定的经济损失。笔者根据几年的调查结果，总结出羔羊在育肥期间易发生的5种疾病及其防治对策，介绍如下。     

萨、苏杂种羔羊与苏尼特羔羊育肥增重及屠宰率的比较

苏尼特羊与萨福克羊进行经济杂交的杂种羔羊,通过育肥能够提高产肉率。为市场提供优质美味的苏尼特羊肉和肥羔肉,并可获取更高的经济效益。试验证明,杂种羔羊舍饲育肥和放牧育肥日增重比苏尼特羔羊舍饲育肥日增重平均分别提高0．0611kg和0．03kg。屠宰率平均分别提高4％和2％。     

Serum opsonic activity and neutrophil phagocytic capacity of newborn lambs before and 24-36 h after colostrum uptake

Neutrophil (PMN) counts, immune complex (IC) uptake by PMN, and serum opsonising activity for promoting yeast uptake were used to evaluate infection clearing capacity in 16 lambs prior to colostrum feeding (two lambs fed bovine colostrum, 14 suckled lambs) and at 2 days of age. At 2 days of age lambs had more circulating PMN than they had prior to colostrum uptake (P less than 0.01). Colostrum feeding caused a significant increase in the percent of lamb PMN phagocytosing IC, although at Day 2 the percent phagocytosis was significantly lower (32.2%) than for adult controls (90%). Yeast opsonophagocytosis was greater when 24-36 h post-feeding serum was the source of opsonin than when pre-feeding serum was used (P less than 0.001). When adult serum was the opsonin, yeast opsonophagocytosis was approximately twice the phagocytosis mediated by 24-36 h post-feeding serum. The peripheral neutrocytosis and the enhancement of opsonophagocytosis generated by absorption of either ovine or bovine colostrum did not differ. The results of this study suggest that the parameters evaluated may be used for indicating the presence (or absence) of passively acquired protective immunity.     

Role of magnesium in the aetiology of ovine urolithiasis in fattening store lambs and intensively fattened lambs

High dietary levels of magnesium (greater than 2 g/kg drymatter [DM]) have been implicated as the main causal factor of urinary calculi in concentrate-fed lambs. Experiments were performed to try to reproduce this effect of high magnesium (from added calcined magnesite) on the incidence of urolithiasis in lambs. In the first, store lambs were given diets containing magnesium in the following concentrations: A,2.9; B,8.6 g/km DM. Twenty-four blackface lambs were each allocated to A and B and the control group of 160 lambs was fed a combined dried grass/sugar beet pulp pellet and hay ad libitum (diet C). The animals were housed and fed ad libitum until they were killed at an average liveweight of 35 kg. No animals showed clinical signs of urolithiasis and post mortem only a trace of calculous material was recovered from one lamb fed diet A. In the second experiment housed Suffolk and Suffolk cross lambs were fed a starter beginning at three to four weeks old and changed to a finisher at a liveweight of 23 kg. The feeds were either high magnesium starter (5.7) and finisher (6.0) or low magnesium starter (2.3) and finisher (2.8 g/kg DM). Twenty-two single lambs and 32 twins were assigned to both high and low magnesium diets. Lambs fed additional magnesium drank more water/kg DM intake and one of the single lambs showed clinical signs of urolithiasis and was killed. No others showed clinical signs and from the 62 killed there was no post mortem recovery of calculous material.     

果园生混合干草对羔羊胃肠道细菌多样性的影响

利用渭北果园行间种植的优质牧草,研究不同配比混合干草对奶山羊公羔瘤胃及肠道细菌微生物区系的影响,为渭北旱塬"果–草–畜"生态种养循环模式提供理论基础.选择24只2月龄体重相近且健康的萨能奶山羊公羔,随机分成4组,每组3个重复,每个重复2只羊.以当地传统饲喂方式为对照组(CK),主要为农作物秸秆[玉米(Zea mays)秸秆和小麦(Triticum aestivum)秸秆]、紫花苜蓿(Medicago sativa)和少量田间杂草;3个处理组,分别由两种干草按1?1的比例混合组成,即紫花苜蓿+燕麦(Avena sativa)混合干草(Ⅰ组)、紫花苜蓿+多年生黑麦草(Lolium perenne)(Ⅱ组)、毛苕子(Vicia villosa)+多年生黑麦草(Ⅲ组),饲喂85 d后进行取样测定.利用16S rDNA技术对瘤胃和盲肠细菌组成进行测定分析.结果显示:1)与CK组相比,Ⅱ组可以显著提高羔羊肠道菌群Alpha多样性(P<0.05),Ⅰ组和Ⅲ组高于CK组,但不显著(P>0.05).2)在肠道细菌相对丰度中,3个处理组厚壁菌门相对丰度显著高于CK组(P<0.05),Ⅱ组中拟杆菌门相对丰度显著高于其他3个组(P<0.05),3个处理组罗姆布茨菌(Romboutsia)、梭状芽胞杆菌(Clostridium)的相对丰度显著高于CK组(P<0.05);瘤胃细菌菌群相对丰度中,Ⅲ组中拟杆菌门(Bacteroidetes)的相对丰度显著高于其他3个组(P<0.05),同时Ⅱ组的变形菌门(Proteobacteria)相对丰度显著高于其他3个组(P<0.05),Ⅲ组普氏菌属(Prevolla)的相对丰度显著高于其他组(P<0.05);Ⅱ和Ⅲ组中理研菌科(Rikenellaceae)RC9的相对丰度显著高于CK组(P<0.05).综上,饲喂不同果园混合干草可以提高羔羊胃肠道细菌群落多样性,增加胃肠道中有益细菌的丰度,减少致病菌的丰度,促进羔羊健康,其中以紫花苜蓿+多年生黑麦草混合干草效果最佳.     

Grazing sericea lespedeza for control of gastrointestinal nematodes in lambs

Alternatives to chemical dewormers are needed to counter anthelmintic resistance and improve worm control in organic management systems. The objective was to examine the effectiveness of grazing sericea lespedeza (SL) compared with grass pastures for control of gastrointestinal nematodes (GIN) in lambs. In Experiment 1, Katahdin lambs grazed bermudagrass (BG; n=14), tall fescue (TF; n=7), or SL (n=19) pastures during early summer months. In Experiment 2, lambs grazed TF (n=15) or SL (n=13) pastures during late summer. Stocking rate of pastures was based on forage availability; additional lambs grazed pastures in Experiment 2, but were not sampled. Lambs were dewormed with 0.5 g COWP if FAMACHA(?) score was >3. In Experiment 1, FEC were reduced within 35 days in SL compared with BG lambs (forage by time, P=0.03). The PCV was more resilient to changes over time in SL compared with other groups of lambs (forage by time, P=0.001). In Experiment 2, FEC were lower (P=0.02) and PCV tended to be higher (P=0.09) in lambs grazing SL compared with TF forage. Incidence of deworming was similar among forage groups in both experiments. Grazing SL reduced FEC in lambs in early and late summer, despite reluctance by lambs to graze. Grazing forage and selective deworming using COWP was effective in lambs.     

Valine partitioning and kinetics between the gastrointestinal tract and hind limbs in lambs with an adult Trichostrongylus colubriformis burden

Intestinal parasitic infection increases the demand for AA because of increased protein synthesis in the intestine and increased luminal losses of AA, and these increased demands may be supported by increased mobilization of AA from the skeletal muscles. Two experiments were conducted to determine the effects of parasitic infection on valine kinetics within the gastrointestinal tract and hind limbs of lambs fed fresh forages. On d 1, lambs were given 6,000 stage-3 Trichostrongylus colubriformis larvae per day for 6 d (n = 6) or kept as parasite-free controls (n = 6) and fed fresh lucerne (Medicago sativa; Exp. 1) or fresh sulla (Hedysarum coronarium; Exp. 2). On d 48, valine kinetics within the mesenteric- (MDV) and portal-drained viscera (PDV) and hind limbs were obtained by carrying out concurrent infusions of para-amminohippuric acid into the mesenteric vein and indocyanin green into the abdominal aorta (for blood flow), and [3,4-(3)H]valine into the jugular vein and [1-(13)C]valine into the abomasum for 8 h (for kinetics). During the infusions, blood was collected from the mesenteric and portal veins and from the mesenteric artery and vena cava, and plasma was harvested. After the 8-h infusion, lambs were euthanized, ileal digesta were collected, and tissues were sampled from the intestine and muscle (biceps femoris). Tissues, digesta, and plasma were analyzed for valine concentration, specific radioactivity, and isotopic enrichment. In both experiments, intestinal worm burdens on d 48 were greater in parasitized lambs (P = 0.0001 and 0.003). In Exp. 1, parasitic infection increased (P = 0.03) the total valine irreversible loss rate (ILR) in the MDV and PDV. In Exp. 2, luminal ILR of valine in the MDV was reduced (P = 0.01); however, ILR of valine in the PDV was unaffected. Despite these changes within the MDV and PDV, parasitic infection did not affect the ILR of valine within the hind limbs, and valine transport rates were largely unchanged. We suggest that the increased mobilization of AA from the hind limbs that might have occurred in the early phase of inflammation was no longer required when the parasitic infection was established. The MDV and PDV data may indicate that the non-MDV parts of the PDV play an important role in this adaptation, which warrants further study.     

早期补饲粉状精料和颗粒料对羔羊生长性能及胃肠道发育的影响

旨在研究断奶前补饲粉状精料和颗粒料对羔羊生长性能及整个胃肠道发育的影响,为颗粒料在幼龄反刍动物上的合理使用提供依据。试验选取18只体重相近、体况良好的新生湖羊(公羔),在其12日龄时与母羊分离,饲喂按一定比例配置好的羊奶粉(羊奶粉:水=1:10)。经过3 d适应期后将其随机分为对照组(control group,n=9)和试验组(treatment group,n=9):对照组羔羊自由采食粉状精料,试验组羔羊自由采食颗粒料。两组羔羊每只每天均给予相同的奶粉量(600 mL·d^-1),所有羔羊自由饮水。试验过程每天记录羔羊采食量,每周于晨饲前称量羔羊体重。羔羊42日龄时颈静脉采血后屠宰采样,称量胃肠道各部位重量,采集胃肠道各部位组织样品进行上皮形态测定。结果显示,与补饲粉状精料相比,补饲颗粒料显著增加羔羊第6周龄(P=0.047)的平均日采食量,显著增加羔羊第4(P=0.030)和第5周龄(P=0.019)的平均日增重。早期补饲颗粒料显著增加第4(P=0.048)、5(P<0.001)和6周龄(P<0.001)的羔羊体重。与补饲粉状精料相比,补饲颗粒料对羔羊胃肠道重量和肠道长度无显著(P>0.05)影响;显著增加羔羊瘤胃乳头的长(P<0.001)、宽(P<0.001)和上皮吸收面积(P=0.038),但对瘤胃上皮乳头个数(P=0.230)无显著影响。通过HE染色观察胃肠道上皮结构,结果显示,与补饲粉状精料相比,补饲颗粒料显著增加了羔羊瘤胃上皮颗粒层厚度(P=0.027),但对瘤胃上皮角质层(P=0.577)、棘基层(P=0.153)和上皮总厚度无显著影响(P=0.486)。补饲颗粒料显著增加了羔羊十二指肠绒毛高度(P<0.001)和绒毛高度与隐窝深度的比值(P<0.001)、显著降低了十二指肠隐窝深度(P=0.010)。补饲颗粒料显著降低了空肠隐窝深度(P=0.010)、对空肠绒毛高度与隐窝深度的比值有增加的趋势(P=0.087),但对空肠绒毛高度无显著影响(P=0.258)。补饲颗粒料显著增加了回肠绒毛高度(P<0.001)和绒毛高度与隐窝深度的比值(P=0.002),但对回肠隐窝深度(P=0.761)无显著影响。两组羔羊盲肠上皮(P=0.266)和结肠上皮(P=0.526)厚度无显著差异。以上结果表明,与补饲粉状精料相比,补饲颗粒料显著促进了羔羊瘤胃上皮和小肠上皮的发育,但对后肠上皮的发育无显著影响。     

Amylolytic activity in the digestive tract of lambs during the first months after birth

Alpha-amylase activity in duodenal chymus and glucoamylase activity in homogenate and microvilli membranes of enterocytes from duodenum, jejunum and ileum of lambs at an age of 1, 7 and 23 days was studied. Alpha-amylase activity in duodenal chymus increases proportionally with increasing the age of lambs, at 7 and 23 days of age rising 2 and 3 times respectively compared to one-day age. Glucoamylase activity in homogenate and Microvilli membranes increases even at 7 day-age 3-6 times depending on the part of small intestine, then keeping on the whole the same level.     

Effect of neomycin, carbadox and length of adaptation to calorimeter on performance, fasting metabolism and gastrointestinal tract of young pigs

Five sets of littermate gilts (8.2 +/- .19 kg average initial weight) were randomly assigned within litter to a 16% protein corn-soybean meal basal diet (B), B + .308% neomycin, or B + 55 ppm carbadox. Each set was equally-fed individually once daily for 16 d in metabolism cages and 5 d in calorimeters. The average daily feed intake for 21 d was 276 g. Oxygen consumption and CO2 production were measured during an 8- to 24-h postprandial period on d 16, 19, 20 and 21, and during a 32- to 48-h postprandial period after the d 21 feeding. Pigs were killed 50 h postprandially for gastrointestinal tract measurements. Dietary supplementation of antimicrobial agents (neomycin and carbadox) resulted in improvements (P less than .01) in daily gain and efficiency of feed utilization and lower (P less than .05) small intestinal mass in pigs. There was no difference (P greater than .05) in daily gain, feed efficiency or small intestinal mass between pigs fed neomycin- or carbadox-supplemented diets. Whole-animal fasting O2 consumption and CO2 production measured during the 8- to 24-h or 32- to 48-h postprandial period were not affected (P greater than .05) by the supplementation or the source of dietary antimicrobial agents. There were no differences (P greater than .05) in 8- to 24-h fasting O2 and CO2 measurements determined on d 16, 19, 20 and 21, indicating that adaptation to calorimeters was not needed by the pigs.(ABSTRACT TRUNCATED AT 250 WORDS)