养兔方法改一改 饲养效益自然来

1改养土杂兔为良种兔土杂兔种的价格虽然便宜,容易购买,但饲养周期长,饲料转化率低。良种兔生长快,饲养周期短,饲料转化率高。良种兔90日龄体重能达2.5kg,而土杂兔90日龄体重却只有1.5kg。而养一只良种兔要比土杂兔的经济效益高出40%~60%。     

不同限饲方式对肉兔生长性能的影响

为研究不同的限饲方式对肉兔生长性能的影响,以480只35日龄的健康断奶仔兔为试验动物,设4个组,每组6个重复,每个重复20只仔兔,4组试验仔兔35~71日龄分别采用不同的方式饲喂。结果表明,Ⅲ组死亡率较高,与其他组差异显著(0.05);各组试验兔71日龄活体重差异显著(0.05),只有Ⅰ组对活体重有积极影响;各组试验兔35~71日龄日增重、采食量、饲料转化率3项生长性能指标均差异显著(0.05),其中Ⅰ组在采食量不变的前提下,日增重、饲料转化率均优于对照组Ⅳ,Ⅱ和Ⅲ组虽然饲料转化率优于对照组和Ⅰ组,但日增重明显低于对照组和Ⅰ组,长势大大减小。因此,每天禁食10 h对兔的生长性能最有利。     

肉兔引种的原则和技术要求

1种兔的选购 质量好的种兔是经过专家精心培育。在众多的个体中选择出来的,在生产性能、生长速度等各方面都占有一定的优势,因而好的种兔生产的后代一般都具有抗病力强、成活率高、生长速度快、饲料报酬高、品种特征明显的特点,在市场上有极强的竞争力。而劣质种兔往往是未经选育的退化品种,所产后代遗传性能和抗病力差,仔兔、幼兔成活率低,生长速度缓慢,饲料报酬率低。好的种兔所产的商品兔只要饲养得当,70日龄就能长到2．5kg,料肉比为2．5：1;而劣质种兔所产的商品兔100～120日龄才能长到2．5kg。     

早期断奶兔日粮中添加不同剂量纤维素酶的效果研究

120只仔兔在23日龄时进行断奶并考虑大小、体重因素分为四组。仔兔自由采食添加了高、中、低不同计量的纤维素酶的不添加药物的商品日粮，其酶活性分别相当于较早应用的70．40FPU／kg饲料应用剂量的75％、50％和17％。对照组自由采食未加酶的同样的商品日粮。在63至77日龄期间，所有组兔饲喂对照纽基础日粮。仔兔在舍内条件下（15～20℃，光照周期16：8）单育肥笼（30cm×61cm×28cm）饲养。结果表明，早期断奶仔兔日粮中添加纤维素酶计量35．20FPU／kg与52．80FPU／kg提高了仔兔的生产性能，也就是说，仔免在23至77日龄期间饲料转化率较高（H、M、L与c组分别为2．97、2．91、3．04与3．03；P=0．039）。所有组从23至77日龄的日增重和77日龄的体重分别相近。在育肥期间，肠炎引起的死亡率较低，分别是3％，13％，13％和20％。     

补充不同量β-胡萝卜素和VA对兔生产和繁殖能力的影响

该试验旨在研究补充不同量β－胡萝卜素和VA对兔繁殖和生产能力的影响，从而为以后的兔业生产提供科学依据。１方法按照表１配方生产的半合成日粮，除了β－胡萝卜素和VA以外，都能满足生长兔的全部营养需要，以此作为基础日粮。加入β－胡萝卜素和VA补充成分，然后制成颗粒料作β－胡萝卜素和VA的分析。该试验用新西兰成年兔单独饲养，新生仔兔由母兔带养３周（哺乳期），在体重达到１kg左右时，互相分开，用于试验。公兔喂以商品兔饲料。全部兔均自由采食和饮水。２结果生长和繁殖（试验１）：２０只６周龄的母兔分为对照组和试验组，…     

肉兔育肥的影响因素和方法

1影响因素 适时育肥出栏,缩短育肥期,提高出栏率和饲料报酬。前期生长快,4月龄以后由于性器官的发育,生长速度明显减慢。据报道,肉兔平均日增重为,1月龄24克,2月龄33.1克,3月龄34.8克,4月龄22.2克,5月龄18.6克。可见,2-3月龄是肉兔生长最快的时期,在这期间如能加强饲养,可以发挥肉兔的生长优势,取得增重效果。为此,饲养肉兔要抓好两个关键时期：一是提高仔兔的断奶重,在仔兔哺乳阶段就要养好;二是做好仔兔断奶后的饲料转换,使仔兔不因断奶而影响生长。如40日龄断奶重为1千克,断奶后平均日增重30克,到90日龄即可达到2.5千克的屠宰体重。现将主要影响因素简介如下。     

分阶段育肥法降低商品兔饲养成本示范观测

选取600只商品兔,随机分为3组,对照组饲喂全价饲料,试验1组56日龄前饲喂全价料,56日龄后以青草为主+精料补充料,试验2组以青草为主,饲喂精料补充料,测定56日龄以前及56日龄以后各组的日增重和成活率。结果表明:商品兔56日龄以前使用全价饲料,可提高其成活率,降低死亡;从56日龄后,使用青草加精料补充料的方式,每只兔的养殖成本比喂全价料的低0.72元。可见商品肉兔生产采用分阶段育肥法,既能保证成活率,又能降低饲料成本,获取最大的经济效益。     

促肉鸡快速生长的方法

在生长速度和饲料利用率方面的遗传进展，使肉鸡能在很短时间内得到较大的上市重量。在过去的发展阶段，肉鸡上市重量增加了30％而饲养时间缩短了27％。而且通过遗传选育提高体重及饲料转化率仍是一个可发展的课题。　　目前，肉鸡饲养者经常遇到一些直接影响肉鸡生长的问题，如腹水，猝死症，腿畸形等。　　许多年来，通过限食来提高肉鸡效益是可考虑的办法，其目标是降低总消耗量而获得上市时的补偿性生长。有人试验在4～6日龄限食从而提高4～6日龄的饲料转化率，降低腹脂而不影响上市体重。在肉鸡饲养中，有许多好的方法可以减少腹水，猝…     

日本大耳兔生后时期若干性状的初步研究

本研究对日本大耳兔初生、２１、３５、６０、９０、１２０、１５０、１８０日龄和成年等不同生长阶段生长发育和繁殖力、肥育性能进行跟踪观察和测定。结果表明，初生至９０日龄生长速度呈直线上升，之后则急剧下降。初生、２１、３５、６０、９０、１２０、１５０、１８０日龄和成年体重分别为６３．５、２３６．８、５１８、１１４７、２０６３．２、２８６８．７、３５０５．６、３９８７．７和４１５９．２ｇ；窝均产仔８．１５只，仔兔２１日龄窝重１９２９．５ｇ，３５日龄断奶成活率９６．９％；肥育期（３５～９０日龄）日增重３３．３ｇ，屠宰率４７．１％，料肉比３．９９；３月龄鲜皮重２４５．０ｇ，皮板面积８８９．３ｃｍ２。由此可见，日本大耳兔繁殖力和母兔哺育力较强，早期生长发育快，符合正常生长发育规律，由于屠宰率和饲料转化率不高，不宜作商品兔生产，但作为杂交母本生产商品兔可取得较好效果     

提高商品肉用母兔生产力的技术措施

母兔生产是商品肉兔生产的基础,使商品母兔生产多而壮的仔兔是生产者的追求。如何提高母兔生产力呢？１　饲养优良品种,开展品种间杂交饲养新西兰兔、比利时兔、加利福尼亚兔、青紫蓝兔、日本大耳白兔等优良品种兔,具有生长发育快、饲料利用率高、适应性强、屠宰率高等优点;利用上述品种开展品种间杂交或与本地母兔杂交,其杂种一代生长速度快、饲料转化率高、耐粗饲、抗病,能够表现出显著的杂种优势。２　把好母兔配种关键环节,让母兔多配多怀２．１　适龄配种　商品生产中中型肉用母兔宜在５月龄开始配种,此时的母兔已具备了良好繁…     

利用H/L值分析鸡抗应激能力差异

通过H/L值的比较,对不同品种鸡的抗应激能力进行评价。随机抽取如皋鸡、文昌鸡以及安卡鸡各80只,分别检测了41、56、71和89日龄的异嗜性粒细胞(H)、淋巴细胞(L)及H/L值。结果表明:(1)在41、56日龄时,如皋鸡与文昌鸡、安卡鸡相比H、L及H/L值呈极显著差异(P<0.01);89日龄的H/L值在文昌鸡和安卡鸡之间呈极显著差异(P<0.01)。(2)如皋鸡在41日龄和71日龄间H、L及H/L值呈极显著差异(P<0.01),其余差异均不显著。文昌鸡H、L及H/L值在各日龄间变化较大,41和71日龄间呈显著差异(P<0.05),41和89日龄、56和71日龄以及56和89日龄间呈极显著差异(P<0.01)。安卡鸡各值只在56和89日龄间呈显著差异(P<0.05),其余差异均不显著。研究初步表明家禽的抗应激能力存在品种间差异,如皋鸡的抗应激能力优于安卡鸡,文昌鸡晚期表现出较好的抗应激能力,随着日龄的增加,品种之间的抗应激能力差异会减小。     

饲粮蛋氨酸水平对湖羊公羔营养物质消化、胃肠道pH及血清指标的影响

本试验旨在研究饲粮蛋氨酸水平对湖羊公羔营养物质消化、胃肠道pH及血清指标的影响。选取12对7日龄断奶的湖羊双胞胎公羔,采用配对试验设计,分为对照(CON)组和低蛋氨酸(LM)组,1对双胞胎羔羊分别分到2个组中。试验分2个阶段进行,第1阶段(8~56日龄),CON组羔羊饲喂基础代乳粉和基础开食料;LM组羔羊饲喂的代乳粉和开食料在CON组基础上分别全部扣除(0.70%和0.40%)额外添加的蛋氨酸,其余营养水平保持一致。第2阶段(57~84日龄),2组羔羊停止饲喂代乳粉且饲粮均为基础开食料。分别在第1阶段结束前(46~55日龄)和第2阶段结束前(74~83日龄)随机选取4对双胞胎羔羊进行消化代谢试验。结果表明:1)56日龄,LM组羔羊对饲粮粗蛋白质、粗脂肪、中性洗涤纤维的表观消化率均显著低于CON组(P0.05);84日龄,2组羔羊在营养物质表观消化率上均差异不显著(P0.05)。2)56日龄,LM组羔羊胃肠道中除十二指肠pH显著低于CON组(P0.05)外,其他胃肠道pH均差异不显著(P0.05);84日龄,2组羔羊在胃肠道pH上均差异不显著(P0.05)。3)除了56日龄LM组羔羊的生长激素和胰岛素浓度显著低于CON组(P0.05)外,2组羔羊其他血清指标56和84日龄均无显著性差异(P0.05)。由此可见,8~56日龄,饲粮低蛋氨酸水平可降低湖羊公羔营养物质表观消化率,以及抑制十二指肠pH和血清中生长激素、胰岛素浓度的增加;57~84日龄,提高饲粮蛋氨酸水平后,湖羊公羔的营养物质表观消化率、胃肠道pH及血清激素指标随之得到补偿。     

蛋氨酸水平对羔羊体况发育、消化道组织形态及血清抗氧化指标的影响

本试验旨在研究蛋氨酸水平对羔羊体况发育、消化道组织形态及血清抗氧化指标的影响。试验选取12对7日龄断母乳的湖羊双胞胎公羔,采用配对试验设计,分为对照(CON)组和低蛋氨酸(LM)组,1对双胞胎羔羊分到不同的组中。试验分2个阶段进行,第1阶段(8~56日龄),CON组羔羊饲喂基础代乳粉和基础开食料;LM组羔羊饲喂的代乳粉和开食料在CON组基础上分别全部扣除(0.70%和0.40%)额外添加的蛋氨酸,其余营养水平保持一致。第2阶段(57~84日龄),2组羔羊停止饲喂代乳粉且饲粮均为基础开食料。在56和84日龄,各选取6对双胞胎羔羊进行屠宰,分离消化道组织,采集血清样品。结果表明:1)在采食量方面,LM组羔羊对蛋氨酸采食量在8~56日龄、8~84日龄阶段均极显著低于CON组(P0.01),而干物质采食量却均显著高于CON组(P0.05);在体尺指标方面,56日龄,LM组除体重、体斜长、胸围和体长指数显著低于CON组(P0.05)外,其他体况发育指标2组间均无显著性差异(P0.05);84日龄,2组间体况发育指标均无显著性差异(P0.05)。2)56日龄,LM组羔羊的瘤胃乳头宽度显著低于CON组(P0.05),2组羔羊的其他消化道形态发育指标差异不显著(P0.05)。3)56日龄,LM组羔羊血清中超氧化物歧化酶活性极显著低于CON组(P0.01);84日龄,LM组羔羊血清中除谷胱甘肽过氧化物酶活性显著低于CON组(P0.05)外,2组羔羊的其他血清抗氧化指标差异均不显著(P0.05)。结果提示,饲粮低蛋氨酸水平抑制了羔羊体况(体重、体斜长、胸围、体长指数)发育及瘤胃乳头宽度的增加,同时降低了机体血清中超氧化物歧化酶活性,然而却提高了干物质采食量;提高饲粮蛋氨酸水平后,羔羊体况发育及消化道组织形态发育也随之得到补偿,但机体抗氧化防御系统仍未得到完全改善。     

The effect of mating age on the reproductive performance,food utilisation and liveweight change of the female pig

Sixty-four crossbred gilts were used to study the effect of mating at the first oestrus period following puberty. Puberty was induced at different ages by the introduction of the gilts to boars at either 160 or 200 days of age. Mating was delayed until second oestrus, when the mean age of the two groups was 197.8 and 237.2 days respectively. The difference of 39.4 ± 5.14 days was significant (P < 0.001). There were no significant differences in the number of weight of pigs born or reared in any of the first five parities. Thirty four sows (seventeen from each treatment) completed five parities. The gilts mated at 237 days of age consumed 159 ± 38 kg (P < 0.01) more food between 160 days of age and weaning their fifth litters. The gilts mated at the younger age consumed 6.2% less food per unit of weaner liveweight over the five litters. Initial differences in liveweight between the two groups had disappeared by the middle of the second pregnancy.     

The effects of slaughter age on growth and carcass traits in an intensively managed crossbred beef herd

The purpose of this study was to determine and describe the effects of slaughter age (at constant weights) on pre- and post-weaning growth rate and carcass traits of unselected steer and heifer progeny from a crossbred beef herd. The data were obtained from 340 heifers and 377 steers weaned at 305 days of age and fed a high-energy post-weaning diet. Heifers and steers were slaughtered at individual unshrunk weights of 420 and 470 kg, respectively, and divided into slaughter age classes based on 25-day intervals. There were differences (P < 0.01) between slaughter age classes for all growth traits including 305-day (weaning) weight, post-weaning daily gain, days on feed, and weight/day. Mean 305-day weight of steers in the youngest slaughter age class (347.8 kg; 376–400 days of age) was 28% greater than the mean of steers in the oldest age class (272.2 kg;>501 days of age). The youngest steer class averaged 63% more for daily gain than the oldest steer class (1.462 vs. 0.894 kg); the corresponding value for heifers was 64%. Post-weaning time in the feedlot ranged from 84.7 days for the youngest steer to 215.6 for the oldest steer class. Calculations based on mean differences between age classes in 305-day weight, daily gain and days on feed indicated that variability in weaning weight and in daily gain were of similar importance in determining slaughter age. Marbling score was greater (P < 0.01) for older steer classes, but was not different in the heifer data. Fat thickness of the oldest steer class was 25% more than the youngest steer class (1.89 vs. 1.51 cm); the corresponding percent in heifers was 30%. With the exception of differences in untrimmed rib and chuck percents in steers (P < 0.05), and rib specific gravity in heifers (P < 0.05), carcass quantity traits were essentially unaffected by slaughter age class when marbling score and fat thickness were included as continuous independent variables. None of the organoleptic traits (tenderness, juiciness and flavour) were affected by slaughter age class.     

Hematologic and biochemical reference ranges for captive California condors (Gymnogyps californianus).

To provide proper medical evaluation and care for the endangered California condor (Gymnogyps californianus), veterinarians need accurate hematologic and biochemical reference ranges. A retrospective study of blood samples from captive California condors housed at the San Diego Wild Animal Park assessed the samples by sex and age of condor to determine serum biochemical and hematologic reference ranges, including lead and zinc levels. Condors were grouped by age as follows: group 1 included birds less than 30 days of age; group 2 included birds between 30 days and 6 mo of age; group 3 included birds between 6 mo and 5 yr of age; group 4 included all birds greater than 5 yr of age. Significant differences between sexes included higher chloride, cholesterol, and total plasma protein concentration in males as compared to females (P < 0.05). Significant differences between age groups were identified in glucose, potassium, phosphorus, calcium, albumin, total plasma protein, globulin, cholesterol, bile acid, and zinc concentrations, as well as aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase, and creatine phosphokinase activities (P < 0.05). Additionally, significant differences between age groups were noted in white blood cell count, hematocrit, heterophils, lymphocytes, and eosinophils (P < 0.05). A steady increase in glucose and a decrease in alkaline phosphatase and lactate dehydrogenase activities, as well as cholesterol, bile acid, calcium, and phosphorus concentrations, were correlated with age (P < 0.05). Following application of statistical analysis, condors less than 6 mo of age were identified as unique compared to older cohorts; therefore, two reference ranges are proposed by calculating a 90% confidence interval. Reference ranges obtained from other published avian data, including those for psittaciformes, ratites, galliformes, anseriformes, and raptors, were similar to condors in this study.     

Immune Competence,Resistance to Escherichia coli and Growth in Male Broiler Parent Chicks Fed Different Levels of Crude Protein

Immune competence, resistance to Escherichia coli and growth were measured in female chicks of broiler male parent lines from four different commercial sources. These chicks were fed with three levels of dietary crude protein (CP) from day-old. The protein contents in the diets were 18%, 20.5% and 23%; these diets are referred to as the low-, medium- and high-protein diets, respectively. There was a significant genotype by dietary protein interaction for body weight at 35 days of age but not at 14 or 28 days of age. At 14 days of age, the chicks fed on the high-protein diet weighed significantly more than those fed on the low-protein diet, but there were no differences between the chicks fed on the medium- and low-protein diets. The influence of CP content on body weight had disappeared by 28 days of age. There were significant differences between the genotypes in antibody production in response to sheep red blood cell (SRBC) inoculation, but no such differences were observed between the chicks fed the different levels of dietary protein. Chicks fed on the high-protein diet had lower lesion scores following E. coli inoculation than those fed on the low-protein diet. There were also significant differences in lesion scores among the genotypes. Genotypes with heavier body weights had significantly higher lesion scores and lower antibody titres than those with less body weight. Also, genotypes of lower body weight had a greater cutaneous basophilic hypersensitivity response to phytohaemaglutinin-P inoculation, and a better humoral response against SRBC and a lower heterophil to lymphocyte ratio.     

Use of FAMACHA system to evaluate gastrointestinal nematode resistance/resilience in offspring of stud rams

High levels of anthelmintic resistance in gastrointestinal nematodes (GIN) of small ruminants have created the need for animals with greater resistance to these parasites. The objective of this experiment was to evaluate the effectiveness of the FAMACHA system in identification of parasite resilient/resistant offspring, and thus identification of stud rams with greater resilience/resistance. Katahdin ewes bred in separate groups to two sires to lamb in spring (2004, 2005: Ram A and Ram B; 2006, 2007: Ram C and Ram D) at the USDA, Agricultural Research Station in Booneville, Arkansas produced 20-40 offspring/sire each year. Ewes and lambs grazed mixed grass (predominantly bermudagrass and ryegrass) pastures and were supplemented with corn/soybean meal between 30 days pre- and 60 days post-lambing (ewes) and starting 45 days of age until weaning (lambs; 95.0+/-0.6 days of age). Blood samples and feces were collected from the lambs to determine blood packed cell volume (PCV) and fecal egg counts (FEC) and FAMACHA scores were determined at 90, 120, and 150 days of age. Lambs were dewormed if anemic (PCV<19% or FAMACHA score >2) and data removed within 30 days after deworming. Data were analyzed for the 2004/2005 and 2006/2007 groups using general linear models with year, sex of lamb, and sire nested within year as variables. Sire differences were detected (P<0.05 or less) for PCV and FAMACHA at all time points, but not FEC. There tended (P<0.10) to be sire differences for FEC at 90 and 120 days of age, but not at 150 days of age. Lambs sired by Ram D were dewormed less by 150 days of age than those sired by Ram C. The FAMACHA system can be used to identify superior sires for parasite resilience/resistance, thus increasing flock resilience, and perhaps resistance.     

Piglet mortality – A parallel comparison between loose-housed and temporarily confined farrowing sows in the same herd

In literature, piglet mortality is described as a multifactorial complex influenced by factors as litter size, age and health of the sow, farrowing system, management etc. In this study, a parallel comparison was made between two farrowing systems; a temporarily confined (TC) (farrowing – 3 days after) versus a loose sow (L). On average, 0.4 more pigs per litter survived until weaning if the sow was temporarily confined (TC) compared with being loose (L). Cause of death was recorded according to a strict template. Underweight and crushing was the most common causes. For crushing, during 1–3 days after birth, an interaction between sow age and farrowing system was observed, with differences between farrowing systems only for intermediate-aged and older sows (>parity 2). There were no significant differences between systems regarding farrowing duration or number of stillborn pigs, but a significant increase in farrowing problems was recorded for TC-sows.     

Quality of development and adaptation reactions of dairy calves at specific age periods in early life. Effect of rearing variations on proteins and minerals and on metabolic variables of blood

Calves from the dairy herd of the institute reared in groups with changing (Gw, N 16, m 9, w 7) and constant composition (Gk, N 16, m 9, w 7) since the first day of life and single box reared calves (E, N 11, m 7, w 4) were tested at 15, 30, 60 and 90 days of age. Venous blood samples were analysed for total protein, albumin, creatinine, blood urea, glucose, Ca, Mg, P and iron. At 15 days between group differences of mean values existed for total protein, albumin, blood urea, creatinine and at 30 days for rectal temperature, albumin, blood urea, Ca, P and Fe, at 60 days for blood urea, glucose, Ca, Mg, P and at 90 days for total protein, albumin, creatinine, glucose, Mg and P. Interactions between group and gender could not be demonstrated. Significant changes of variables with age were most frequent in calves of group Gk, and more frequent with creatinine, blood urea, Fe and glucose. Creatinine concentration diminished permanently with age of the animals, that one of total protein and albumin increased moderately. Blood urea was higher at 90 days, and serum iron at 60 and 90 days than before. Blood glucose concentration at 90 days was lower in calves of group Gw and Gk comparing group E. Significant group differences appeared at 15 days (total protein, albumin, blood urea, creatinine) and remained till 60 days (blood urea) and 90 days (total protein, albumin) or became stronger at 90 days (creatinine). Total protein, albumin and blood urea were higher in group E than in group Gk and Gw calves. Group Gw calves had smallest glucose concentrations at 60 and 90 days. Significant between groups differences for Ca, Mg, P existed for all sampling points, those for serum iron at 30 days only. Greater Ca and Mg values were found in group Gk and group E calves, greater P concentrations up to 60 days of age in group E calves. P concentrations changed differently in group Gk and group Gw calves with age. Creatinine showed moderately high between sampling point correlations. Changes of variables in calves between age points in relation to the starting situation at 15 days of age showed significant correlations in many cases meaning that there were directed individual and time specific adaptation processes.