代乳品饲喂荷斯坦犊牛的效果分析

乳用犊牛是优质奶牛群发展的基础,为了更经济地饲养犊牛,保证奶牛后代的稳定性,创造更高的经济效益,可以对犊牛实施早期断奶,进行低奶量培育.     

犊牛代乳品的研究与应用

现代养牛业的工厂化和集约化生产要求犊牛早期断奶并生长发育良好，采用营养全面、易于消化吸收的代乳品既可以促进后备犊牛的瘤胃和肠道等消化器官的发育，为其发挥高产性能奠定基础；同时，又可以节约大量鲜奶，降低饲养成本，取得更大的经济效益，提高牛场的综合效益。     

复合酶制剂饲喂犊牛效果研究

选择体质状况相近的健康母犊牛14头,按试验要求随机分为试验组和对照组,每组7头,分别饲喂添加复合酶制剂和不添加酶制剂的日粮,比较分析专用复合酶制剂对犊牛的饲养效果。结果表明：试验组犊牛每头每天添加50g复合酶制剂,其日增重明显高于对照组（P〈0.05）;体质状况较对照组显著改善,腹泻率降低;经济效益十分明显。     

羔羊代乳品的研制与应用效果研究

系统论述了羔羊代乳品的营养和免疫特点及所需原料的生产特性。新研制的羔羊代乳品用波尔山羊进行的规范试验研究结果表明，使用代乳品羔羊90天体重达到21kg以上，代乳品具有良好的实用性，用新型代乳品可以使羔羊早期断奶。     

早期断奶羔羊饲喂代乳料的研究

针对母羊产奶不足会影响羔羊的生长发育及肉羊规模化生产的需要,该试验对人工哺喂羔羊代乳料的效果进行了研究.采用单因子随机分组设计,将24只羔羊(无角陶赛特♂×小尾寒羊♀的F1代)随机分为3组,分别为对照组、试验组Ⅰ和试验组Ⅱ,试验组饲喂代乳料和优质干草,对照组自然哺乳和饲喂优质干草,进行了60 d的饲养试验.结果表明,对羔羊实行早期断奶饲喂代乳料是可行的,饲喂代乳料的羔羊和自然哺乳羔羊生长发育速度差异不显著(P>0.05).     

犊牛代乳应用试验效果观察

选择20日龄的小犊牛45头,随机分为对照组、试验组A、试验组B,试验组A为15头,试验组B为16头,对照组为14头。采用犊牛代乳粉和犊牛代乳料,与鲜奶做对比试验,连续饲喂70天,结果试验组B日均增重1.057±0.144kg/头,比对照组0.961±0.345kg/头增加0.096kg,提高9.99％,差异显著(P<0.05),试验组A日均增重0.980±0.3849kg/头比对照组0.961±0.345kg/头增加0.019kg,提高1.98％,差异不显著(P>0.05)。     

哺乳期犊牛代乳品中蛋白质来源的研究进展

代乳品中的蛋白质来源是哺乳期犊牛培育过程中决定培育效果和经济效益的重要因素。20世纪60年代至今,哺乳期犊牛代乳品中的蛋白质来源经历了乳蛋白、酪蛋白、乳清蛋白、非乳源动物蛋白和植物蛋白等几个阶段。由于乳源蛋白价格上涨,使得代乳品成本升高,寻求能够提供与乳源蛋白相同饲喂效果但价格低廉的非乳源蛋白已成为重要的研究方向。本文在概述不同蛋白质源营养特性及蛋白质组分功能特性的基础上,针对其在哺乳期犊牛代乳品中的应用进行综述,重点阐述不同蛋白质来源代乳品对哺乳期犊牛生长性能、营养物质消化率、胃肠道发育、免疫与健康方面的研究进展,为后续非乳源蛋白的开发提供理论依据。     

犊牛代乳粉与鲜奶的饲喂效果比较

本试验选用10～20日龄的健康荷斯坦母犊牛12头,随机分为2组,每组6头（经独立样本t检验组间初始体重差异不显著）,对照组正常饲喂牛奶,试验组饲喂犊牛代乳粉,饲喂期1个月。本试验结果表明,对照组平均日增重0.768 kg,试验组平均日增重0.841 kg,比对照组高0.073 kg,经t检验,两者无显著差异。对照组腹泻率5.6%,试验组腹泻率3.8%,比对照组低32%。     

甘南牦犊牛代乳饲料应用试验

试验期为160 d牦犊牛180日龄时试验组和对照组公、母犊牛平均体重分别为65.3 kg和60.5 kg、58.3 kg和53.2 kg,平均日增重分别为0.291 kg和0.267 kg、0.250 kg和0.211 kg,试验组公、母犊牛的平均体重比对照组分别提高了7.0 kg和7.3 kg,平均日增重比对照组增加了0.041 kg和0.046 kg。经过t检验,试验组公、母犊牛180日龄体重比对照组差异极显著(P0.01),平均日增重比对照组差异显著(P0.05)。试验组平均产奶量为1.79 kg?头.d,对照组平均产挤奶量为0.89 kg?头.d,试验组比对照组产奶量提高0.9 kg?头.d。     

哺乳期犊牛代乳品中蛋白质来源的研究进展北大核心CSCD

代乳品中的蛋白质来源是哺乳期犊牛培育过程中决定培育效果和经济效益的重要因素。20世纪60年代至今,哺乳期犊牛代乳品中的蛋白质来源经历了乳蛋白、酪蛋白、乳清蛋白、非乳源动物蛋白和植物蛋白等几个阶段。由于乳源蛋白价格上涨,使得代乳品成本升高,寻求能够提供与乳源蛋白相同饲喂效果但价格低廉的非乳源蛋白已成为重要的研究方向。本文在概述不同蛋白质源营养特性及蛋白质组分功能特性的基础上,针对其在哺乳期犊牛代乳品中的应用进行综述,重点阐述不同蛋白质来源代乳品对哺乳期犊牛生长性能、营养物质消化率、胃肠道发育、免疫与健康方面的研究进展,为后续非乳源蛋白的开发提供理论依据。     

低锌日粮补锌对断奶前后犊牛免疫机能的影响

本文报道了低锌基础日粮中添加不同水平锌对断奶前后犊牛日增重及免疫机能的影响。结果表明：日粮中添加２０、４０，８０ｍｇ／ｋｇ锌可明显提高犊牛日增重，提高外周血Ｔ淋巴细胞转化指数和淋巴细胞ＡＮＡＥ染色率以及特异性抗原兔血红细胞的抗体滴度，降低血清中γ－球蛋白含量，其中以４０ｍｇ／ｋｇ组效果最佳。     

Dynamics of viral spread in bluetongue virus infected calves

The kinetics of viremia and sites of viral replication in bluetongue virus (BTV) infected calves were characterized by virus isolation, serology and immunofluorescence staining procedures. In addition, the role of the regional lymph node and lymphatics draining inoculated skin in the pathogenesis of BTV infection was determined by analyzing efferent lymph collected from indwelling cannulas. Viremia persisted for 35 to 42 days after inoculation (DAI) and virus co-circulated with neutralizing antibodies for 23 to 26 days. Virus was first isolated from peripheral blood mononuclear (PBM) cells at 3 DAI, after stimulation of PBM cells with interleukin 2 and mitogen. BTV was frequently isolated from erythrocytes, platelets and stimulated PBM cells but never from granulocytes and rarely from plasma during viremia. Virus was consistently isolated from erythrocytes late in the course of veremia. Interruption of efferent lymph flow by cannulation delayed the onset of viremia to 7 DAI. BTV was infrequently isolated from lymph cells, and few fluorescence positive cells were observed after lymph and PBM cells were labelled with a BTV-specific monoclonal antibody. Virus was isolated from spleen by 4 DAI and most tissues by 6 DAI, whereas virus was isolated from bone marrow only at 10 DAI. Virus was not isolated from any tissue after termination of viremia. It is concluded that primary viral replication occurred in the local lymph node and BTV then was transported in low titer to secondary sites of replication via infected lymph and PBM cells. We speculate that virus replication in spleen resulted in release of virus into the circulation and non-selective infection of blood cells which disseminated BTV to other tissues. Virus association with erythrocytes likely was responsible for prolonged viremia, although infected erythrocytes eventually were cleared from the circulation and persistent BTV infection of calves did not occur.     

Subarachnoid butorphanol augments lidocaine sensory anaesthesia in calves

To determine the efficacy and safety of subarachnoid butorphanol combined with lidocaine, six calves were studied. Each calf underwent two treatments, at least one week apart, via subarachnoid injection: (1) butorphanol (0.03 mg/kg) plus 2% lidocaine (4 mg/kg) and (2) 2% lidocaine (4 mg/kg) alone. Subarachnoid injections were performed at the lumbosacral space. Analgesia, motor block, sedation, heart rate, arterial blood pressure, respiratory rate, arterial oxygen saturation as measured by pulse oximetry, and rectal temperature were compared before and after subarachnoid administration of drugs. Subarachnoid administration of the butorphanol-lidocaine combination induced bilateral prolonged analgesia extending from the coccygeal to the T11-T13 dermatomes in the calves, with minimal sedation and severe ataxia. Cardiovascular effects were significant in both treatments: heart rate was increased, and there was a minimal decrease in arterial pressure. It was concluded that adding a small dose of butorphanol to subarachnoid lidocaine in calves is effective and safe.     

Suspected levamisole intoxication in calves

CASE HISTORY: A group of 32 Friesian and four Hereford calves, 3–4 months old with body weights between 100–120?kg, were purchased from a weaner sale. On arrival at the property the Hereford calves were treated with a combination anthelmintic containing 2?g/L abamectin and 80?g/L levamisole hydrochloride. Shortly afterwards they developed tremors and frothing from the mouth, and two died overnight. The Friesian calves were treated with the same anthelmintic on the following day, when some showed hypersalivation and frothing from the mouth.

CLINICAL FINDINGS: Examination of the three most severely affected Friesian calves revealed severe nicotinic-type symptoms including hypersalivation, frothing from the mouth, muscle tremors, recumbency, rapid respiration, hyperaesthesia, and central nervous system depression. Other calves showed mild to moderate signs of intoxication including restlessness, tail switching, salivation, tremors, frequent defaecation, mild colic and jaw chomping. Two calves died shortly afterwards. An adverse drug event investigation revealed that the formulation and quality of the anthelmintic was within the correct specification, and that the drench gun was functioning correctly.

DIAGNOSIS: Suspected levamisole intoxication due to a combination of possible overdosing, dehydration, and stress caused by transportation and prolonged yarding.

CLINICAL RELEVANCE: Susceptibility to levamisole toxicity in New Zealand calves can be increased if factors like dehydration or stress are present. Levamisole has a narrow margin of safety, and overdosing in calves can easily occur if the dose rate is not based on their actual weight or health status.     

High infection rate of Trichophyton verrucosum in calves from Central Italy

Recent epidemiological features of the zoonotic dermatophyte Trichophyton verrucosum were investigated in 294 calves from 20 farms located in Central Italy. By the combination of microscopic examinations and fungal cultures, the total prevalence rate of T. verrucosum infection was found to be high, with 87.7% of samples yielding positive results and 100% of farms being infected. Farm to farm prevalence of infection varied from 25% to 100% of the examined calves. Prevalence rates were higher in females than males (91.6% versus 84%), in >3-< or =6 than >6-< or =9 month old calves (89.8% versus 85.7%), in purebred than in crossbred (88.5% versus 81.8%), and in symptomatic than asymptomatic ones (95.7% versus 80.4%). T. verrucosum was as prevalent in semi-intensive as in intensive breeding system (88.2% versus 87.6%) but more prevalent in calves raised for meat rather than milk production (91.1% versus 84.9%), and reared under conventional than organic production management system (89.3% versus 82.6%). Prevalence rates were also higher when the cattle present in the farm were of mixed origin, rather than when the whole stock was purchased or was born in the farm (92% versus 88.2% and 85.7%), when other cattle in the farm were showing skin signs (90% versus 84.2%), and at least one case of human ringworm was recorded in the farm (90.9% versus 86.1%). No statistically significant association was found. Therefore, T. verrucosum infection may be more widespread in calves from Central Italy than it was previously thought to be. Calves of any sex, breed, age, and of any of the farm condition considered, are highly exposed to the risk of infection. As calves may play a considerable role as reservoirs of the infection, our results highlight the need to determine the incidence and the importance of T. verrucosum ringworm in personnel involved with cattle care in Italy and elsewhere.     

Pharmacokinetic study of an injectable long-acting parenteral formulation of doxycycline hyclate in calves

Doxycycline hyclate (DOX-h) can be regarded as a time-dependant antibacterial. Hence, a parenteral long-acting formulation may be regarded as more pharmacologically sound. A poloxamer-based matrix was used to produce a long-acting injectable preparation (DOX-h-LA) and its serum concentrations vs. time profile investigated after its s.c. injection to calves. Serum concentrations profiles for such a prepartion were compared to the corresponding profiles obtained with an aqueous formulation of DOX-h injected either i.m. or i.v. in 10 calves in a crossover study at dose of 10mg/kg, with washout periods. DOX-h-LA showed the greatest values for bioavailability (602%); maximum serum concentration (C(max)) value was 1.99microg/mL with a time to reach C(max) (T(max)) of 25h and an elimination half-life of 40.81h. Considering minimum effective serum concentration of 0.5microg/mL a dose-interval of 80h can be achieved for DOX-h-LA, and only 9.7h and 17h after the i.v. or i.m. administration of DOX-h, respectively.     

我国发生Leachii支原体引起的犊牛多发性关节炎

2009年2月～6月我国某奶牛场发生严重的犊牛多发性关节炎,发病犊牛的症状与最早发生于澳大利亚的犊牛Leachii支原体关节炎非常相似。为确定病原,我们无菌采集2份具有典型症状犊牛的关节液样品进行实验室诊断,2份样品中均检测和分离出支原体。将2个分离菌株的16S rRNA基因和LppA基因与参考支原体菌株进行核苷酸序列比对,发现这2株支原体的16S rRNA基因和LppA基因均与Leachii支原体具有最高的核苷酸序列同源性,分别为99.9%和99.6%。结果显示,本研究分离的2株支原体为Leachii支原体,分别命名为GN407和GN408。综合分析发病犊牛的临床病理学观察和关节液样品的实验室诊断结果,我们确定Leachii支原体为该奶牛场犊牛多发性关节炎的病因。     

不同饲养方式对荷斯坦犊牛的影响

试验对1～8周龄的犊牛在不同饲养方式下的体重、体高、体斜长、胸围、腹围增长和疾病发生率进行研究,旨在发现一种良好的、经济的饲养方式。试验结果表明:犊牛在单圈饲养时生长性能和健康状况明显好于双犊一圈饲养和散养;而双犊一圈饲养的犊牛在某些方面性状好于散养犊牛。     

断奶犊牛补饲配合精料配方筛选

[目的]为了筛选出适合攀枝花市地区断奶犊牛补饲配合日粮营养配方。[方法]选1.5~3月龄、体重100~180 kg的西本杂犊牛共32头,随机分为4组,开展断奶犊牛补饲配合精料配方筛选试验。[结果]经90 d的育肥,Ⅰ、Ⅱ、Ⅲ、Ⅳ组头均增重分别为40.63 kg、试验46.38 kg、46.5 kg和47.63 kg。日增重Ⅱ、Ⅲ、Ⅳ组较I组分别提高14.16%、14.47%、17.24%;Ⅲ、Ⅳ组较Ⅱ组分别提高0.27%、2.70%;Ⅳ组较Ⅲ组提高2.42%,组间差异均不显著（P〉0.05）。从经济效益看,I、Ⅱ、Ⅲ、Ⅳ、组头均纯收入分别为102.6元、219.44元、174.63元、140.02元,Ⅱ组较I组提高113.88%、较Ⅲ组提高25.66%、较Ⅳ组提高56.72%,Ⅱ组的经济效益高于其它组。[结论]试验结果表明,Ⅱ号配方是断奶西杂犊牛较为理想的补饲配合精料配方。     

Effect of level of milk replacer fed to Holstein calves on performance during the preweaning period and starter digestibility at weaning

Calves following an enhanced-growth feeding program usually show lower starter intakes during the preweaning period compared with conventionally-fed calves. To assess whether this low intake in calves following an enhanced-growth feeding program affects calf capacity to digest starter after weaning, 19 Holstein male calves were used to measure apparent nutrient digestibility at weaning. Calves were divided in two groups: calves on a conventional feeding program (CF) and calves on an enhanced-growth feeding program (EF). After one week of adaptation to milk replacer (25% CP and 19% fat), the CF calves were fed 4 l/d of milk replacer (MR) at 12.5% DM dilution rate from d 1–28, and 2 l/d from d 29 to weaning day at d 35, and the EF calves were offered MR at 18% DM dilution rate: 4 l/d from d 1–6, 6 l/d from d 7–13, 7 l/d from d 14–20, 6 l/d from d 21–28, and 3 l/d from d 29 to 35. Calf starter (20% CP) was offered ad libitum from the beginning to the end of study at d 42, and its consumption was recorded daily. Calves were weighed at d 3, 17, 24, 31, 38 and 42. Daily total faeces collection was conducted for the last 5 d of study. Final BW was numerically greater in EF than in CF calves (88.6 vs 81.2 ± 3.36 kg, respectively). Starter DMI was greater (P < 0.05) in CF compared with EF calves during the preweaning (0.68 vs 0.36 ± 0.078 kg/d, respectively) and postweaning (2.52 vs 1.90 ± 0.102 kg/d, respectively) periods, but there were no differences in total DMI (1.12 and 1.26 ± 0.078 kg/d, in CF and EF calves, respectively) during the preweaning period. However, apparent DM, OM, NDF, CP, and GE digestibility coefficients were greater (P < 0.05) in CF compared with EF calves (77.4 vs 71.8 ± 1.23%, 78.7 vs 73.2 ± 1.18%, 34.7 vs 20.3 ± 3.79%, 77.1 vs 71.6 ± 1.29%, and 75.6 vs 69.8 ± 1.25%, respectively) the week after weaning. It is concluded that calves in the EF treatment presented lower nutrient digestibility coefficients compared with CF calves the week after weaning.