奶牛十二指肠和空肠瘘管手术方法的探讨

为探讨一种稳定可行的奶牛肠道瘘管手术方法,分别对4头成年荷斯坦奶牛进行十二指肠和空肠瘘管手术。结果表明,用半径30mm的T形硅胶管及硅胶网做肠道瘘管材料,瘘管形成良好且不易与腹壁粘连,术后并发症少。     

奶牛人造瘤胃瘘管及十二指肠瘘管的手术体会

永久性瘤胃瘘及十二指肠瘘是研究反刍动物消化功能试验的主要手段之一，广泛应用于教学和科研等实践中。因科研需要，笔者于2006年3月对3头体重为450～500kg的奶牛做了永久性人造瘤胃及十二指肠瘘管手术，由于手术方法合理，瘘管材料优良，术后护理得当，手术成功率较高。手术后1个月，3头牛的创口均愈合良好，均可满足科研需要。为了推广奶牛人造瘤胃瘘管技术在营养研究方面的应用，现将奶牛人造瘤胃及十二指肠瘘管安装技术总结如下。     

奶牛消化道三位体瘘管术的后期护理

奶牛三位体瘘管就是通过手术的办法,将软体硅胶瘘管埋殖于瘤胃、十二指肠前端、回肠末端,用于反刍动物营养教学和研究的永久性瘘管。它具有成本低、使用时间长、效率高等特点。可直接有效地对各种营养物质灌注和取样。目前被广泛应用于反刍动物营养研究领域。中国农业科学院畜牧研究所反刍动物营养研究室2005年3月对4头一岁奶牛成功地实施了消化道三位体瘘管手术。“三位体瘘管术”的后期护理是瘘管牛能否存活的关键。笔者作为试验牛场的兽医,对这四头瘘管牛实施了全程护理。经过60天的护理和观察,四头瘘管牛的创面已痊愈,各项生理体征和饮…     

肉牛安装瘤胃十二指肠回肠瘘管的术后护理

随动物营养学生理学的不断深入 ,特别是近年来反刍动物营养科学的发展 ,消化器官的瘘管技术已成为科学研究的基本试验方法。在瘘管安装手术中 ,手术成败的关键在 3个方面 :(1 )瘘管的安装方法及手术操作 ;(2 )瘘管的材料性质 ;(3)术后护理。由于瘘管安装术属污染手术 ,术后感染很难避免 ,大多数动物术后淘汰的原因是由于护理不善 ,导致严重感染。故术后护理工作十分重要。笔者们于 1 997年～ 1 998年先后参与了 9头肉牛瘤胃、十二指肠、回肠三位点瘘管安装术 ,并负责了术后护理工作。到目前为止 ,除 3头瘘管牛因十二指肠瘘管创口愈合不紧 ,…     

奶牛试验用瘤胃瘘手术的尝试

奶牛瘤胃功能的研究是目前科研与临床实践教学的一项重要内容。而永久性瘤胃瘘是研究反刍动物消化功能试验的主要手段之一，广泛应用于教学和科研等实践中，但相关资料所介绍的手术方法不尽相同。因科研需要，我们于2003年1月对3只成年奶牛做了永久性人造瘤胃瘘管手术。术后全部奶牛的瘤胃瘘管都保持良好，术后健康状况正常。现总结如下，供同行参考。     

夏季高温天气崂山奶山羊瘤胃瘘管手术及术后护理

瘤胃瘘管安装术属污染手术,瘤胃瘘管的内侧直接与瘤胃接通,术后感染很难避免,大多数动物术后淘汰的原因就是由于护理不善,导致严重感染。尽管此次手术选择在高温高湿季节,由于术后护理工作到位,术后瘘管奶山羊全部愈合良好,健康状况正常。     

肉牛三位点永久性瘘管手术及术后护理

本试验是对鲁西黄牛采用手术方法安装消化道多位点永久性瘘管,以便于研究牛的消化道的功能.选择5头体重约为400～450 kg的鲁西黄牛进行了瘤胃、十二指肠和回肠末端三位点“T”型瘘管二次手术.与传统方法相比较,本试验手术方法对牛损伤小,利于术后护理和牛体况恢复快.     

宣汉黄牛消化道多位点瘘管手术

牛消化器官的造瘘技术已成为反刍动物营养科学研究的主要手段之一。笔者于2010年3月对7头试验宣汉黄牛进行了同体消化道多位点瘘管手术,由于手术方法合理,术后护理得当,手术成功率100%。本文对宣汉黄牛的永久性瘤胃瘘管和十二指肠、回肠末端"T"型瘘管的手术过程及术后护理进行总结,为其推广运用提供一定参考。     

肝脏、乳腺和体脂活体采样对奶牛生产性能影响研究

为了探讨肝脏、乳腺和体脂活体采样对奶牛生产性能的影响,本研究对8头荷斯坦泌乳牛进行了活体采样手术,记录采样操作和术后护理过程,同时测定体温、采食和产奶量的变化状况。结果表明,规范的活体采样手术操作和良好的术后护理对奶牛体温和干物质采食量影响较小,产奶量可在术后第3天恢复正常。     

猪回肠末端“T”型人工瘘管术的改进

随着现代动物营养学的发展,动物消化器官的人工瘘管技术已成为科学研究的基本实验方法,通过安装人工瘘管以收集机体各种代谢产物进行试验。本文全面介绍了一种猪回肠末端"T"型瘘管安装技术,并从瘘管选择、术部选择、固定方法等方面与传统瘘管安装技术进行比较。结果表明,试验猪术后存活率100%,且具有瘘管不易脱落、术部恢复快、术后护理方便等优点,为回肠末端人工瘘管的安装提供参考。     

改性柠条粉对奶牛采食量及消化率的影响

柠条(Caragana korshinskii)平茬时收获的枝条经粉碎制成柠条粉可作为奶牛粗饲料,但因其适口性差、采食量少、消化率利用率低,导致柠条饲用转化产业发展缓慢。试验研究了一种新型的改性加工方法处理柠条,利用该方法加工出的改性柠条粉饲喂泌乳奶牛,结果表明:与普通柠条相比,奶牛对改性柠条粉的采食利用率、日粮中的NDF消化率、日粮中的DM消化率分别提高了11.0、2.08、2.09个百分点。     

Evaluation of the feed intake models in the Nordic feed evaluation system NorFor

Abstract

The objective of this study was to evaluate the feed intake models in the Nordic feed evaluation system NorFor. Data from 196 feeding experiments with dairy cows, and 17 experiments of periodical data, and 135 experiments of complete data with growing cattle were used in the evaluation by mixed model regression. The feed intake by both dairy cows and growing cattle were overestimated by the models. A linear bias indicated that over prediction increased with level of intake both by dairy cows and growing cattle. Most animal and diet factors were significantly related to the residuals, which indicated that those factors did not act independently in the predictions of feed intake. This kind of errors can restrict future ration formulation and animal performance, since animal production parameters included in the prediction models will be a consequence of the diet fed at the time they were measured.     

Development of a model for the prediction of feed intake by dairy cows: 1. Prediction of feed intake

A study was undertaken to develop a model for the prediction of dry matter intake by lactating Holstein Friesian dairy cows. To estimate the model parameters, a calibration dataset was compiled with the data from 32 feeding experiments conducted at 9 different sites. The database contained weekly information on 1507 lactating Holstein Friesian dairy cows regarding their diet composition and feed analysis, together with their individual voluntary feed intake, milk yield (MY), milk composition, parity, days in lactation and days pregnant.Dry matter intake was predicted from feed and animal characteristics. The feed chemical composition and digestibility can be related to feed degradation, bulk volume, intake rate, palatability and other factors influencing feed intake. Therefore, the data of standard feed analysis were used to estimate the satiety value of numerous commonly used feeds and forages. The satiety value is the measure of the extent to which a feed limits intake. The cows' ability to process the intake-limiting satiety value-units is expressed as the feed intake capacity, which is predicted from parity, days in milk and days of pregnancy which are indicators of the size and physiological state of the cow. This study shows that feed intake can be predicted using a limited number of easy-to-measure inputs that are available on commercial farms, yet reasonably biologically sound. Because the model inputs are not related to animal output (milk yield or body weight), future extension of the intake model with models for the prediction of animal performance is possible.     

热应激对泌乳盛期奶牛的采食量和消化率的影响

[目的]探讨热应激对奶牛采食量和饲料中营养物质消化率的影响。[方法]通过采用单因子水平随机设计。[结果]奶牛热应激时采食量显著下降,在轻微和中度热应激期采食量分别下降3.65%和13.46%;营养物质的消化率也显著下降(P0.05),奶牛在轻度和中度热应激期粗脂肪的消化率分别降低了6.17%、13.03%;钙的消化率分别降低了25.09%、34.97%;磷的消化率分别降低了22.77%、36.27%。[结论]奶牛热应激时采食量显著下降(P0.05);饲料中营养物质消化率粗脂肪、钙、磷的消化率与非热应激期相比,差异显著(P0.05)。     

EM发酵玉米秸秆和青贮玉米秸秆对奶牛生产性能的对比试验

本试验应用EM发酵玉米秸秆和青贮玉米秸秆饲喂奶牛,以观察两种方法处理的玉米秸秆对奶牛生产性能及经济效益的影响效果。结果表明,用EM发酵的玉米秸秆饲喂奶牛较青贮玉米秸秆饲喂奶牛,每天每头奶牛采食量提高1.03%,平均产奶量提高2.02%,经济效益提高0.13元;EM原液发酵的玉米秸秆和青贮玉米秸秆1∶1混合饲喂奶牛,每天每头奶牛采食量、平均产奶量、经济效益分别比饲喂青贮玉米秸秆的奶牛提高2.85%、2.99%和1.15元。     

Triennial Lactation Symposium: Opportunities for improving milk production efficiency in dairy cattle

Increasing feed costs and the desire to improve environmental stewardship have stimulated renewed interest in improving feed efficiency of livestock, including that of US dairy herds. For instance, USDA cost projections for corn and soybean meal suggest a 20% increase over 2010 pricing for a 16% protein mixed dairy cow ration in 2011, which may lead to a reduction in cow numbers to maintain profitability of dairy production. Furthermore, an October 2010 study by The Innovation Center for US Dairy to assess the carbon footprint of fluid milk found that the efficiency of feed conversion is the single greatest factor contributing to variation in the carbon footprint because of its effects on methane release during enteric fermentation and from manure. Thus, we are conducting research in contemporary US Holsteins to identify cows most efficient at converting feed to milk in temperate climates using residual feed intake (RFI), a measure used successfully to identify the beef cattle most efficient at converting feed to gain. Residual feed intake is calculated as the difference between predicted and actual feed intake to support maintenance and production (e.g., growth in beef cattle, or milk in dairy cattle). Heritability estimates for RFI in dairy cattle reported in the literature range from 0.01 to 0.38. Selection for a decreased RFI phenotype can reduce feed intake, methane production, nutrient losses in manure, and visceral organ weights substantially in beef cattle. We have estimated RFI during early lactation (i.e., to 90 d in milk) in the Beltsville Agricultural Research Center Holstein herd and observed a mean difference of 3.7 kg/d (P < 0.0001) in actual DMI between the efficient and inefficient groups (±0.5 SD from the mean RFI of 0), with no evidence of differences (P > 0.20) in mean BW, ADG, or energy-corrected milk exhibited between the 2 groups. These results indicate promise for using RFI in dairy cattle to improve feed conversion to milk. Previous and current research on the use of RFI in lactating dairy cattle are discussed, as well as opportunities to improve production efficiency of dairy cattle using RFI for milk production.     

提高奶牛干物质采食量的技术措施

围产期奶牛,特别是高产奶牛普遍处于能量负平衡状态,容易导致生产性能降低和酮病、脂肪肝等代谢病的发生。通过育种、改善日粮和使用添加剂等技术措施,可提高奶牛的干物质采食量（dry matter intake,DMI）,在一定程度上提高奶牛的生产性能和改善奶牛的健康状况。作者对奶牛采食量的意义及其影响因素进行了叙述,并提出了一些可以提高奶牛采食量的技术措施。     

Genetic factors controlling feed efficiency in dairy cows

The direct control of feed efficiency is feasible only in test stations and experimental farms. Here coefficients of heritability were found below those for milk yield. Between milk yield and feed efficiency there exist strong genetic correlations, while the correlations between feed intake and feed efficiency are smaller. In spite of these favourable correlations, breeding for higher milk yield entails a serious energy deficit during the first part of lactation. The feed intake reaches its maximum not earlier than 10 to 12 weeks post partum, but peak daily milk yield has already been reached by two to four weeks post partum. Due to energy deficiency the feed efficiency during the first part of lactation seems to be very high, but in fact the feed intake at this time does not cover the energy demand of the high yielding dairy cow.In future more research on genetic factors controlling the feed intake during the first 10 weeks of lactation is required. As potential single factors the capacity of the digestive tract, the production of saliva, the ruminal fermentation, the rate of passage and the overall physiological status of the animal should be investigated. To estimate the real feed efficiency one should observe not only the direct production in milk, milk fat, protein and lactose but also the metabolism of depot fat, growth, nutrition of the foetus, maintenance requirements and a genetically affected resistance against metabolic disorders. Higher feed intake at beginning of lactation can reduce the feed costs, increase the protein content in milk and improve the conception rate in dairy cows. For breeding purposes we need indirect parameters for feed intake under field conditions, e.g. changes in body measurements, urea content in milk, oleic acid proportion in milk fat or content of ketone bodies.     

脂肪对奶牛采食量及瘤胃消化的影响

随着人们对脂肪营养和生理功能认识的深入,多种脂肪产品用于高产奶牛生产中,大量试验结果证明,日粮中添加脂肪对奶牛采食量和瘤胃消化具有影响,作者综述了日粮脂肪在瘤胃内的代谢、日粮中添加脂肪对脂肪酸、干物质、碳水化合物、粗纤维和粗蛋白质采食量和瘤胃消化影响的研究进展。     

Effects of rice conservation methods on lactation,blood metabolites,and rumen fermentation in dairy cows

We investigated the effect of rice grain conservation methods on feed intake, milk production, blood metabolites, and rumen fermentation in dairy cows. Raw rice grain was dried before crushing (DRY), ensiled after crushing (ENS‐A), or ensiled before crushing (ENS‐B). Twelve multiparous Holstein cows were used in a replicated 3 × 3 Latin square design with three dietary treatments comprising ad libitum access to one of three total mixed rations (TMRs; containing DRY, ENS‐A, or ENS‐B at 17% of dietary dry matter) plus a standard allowance of 2.0 kg/day of dairy concentrates. The dietary treatments did not affect the feed intake, milk yield, or milk composition. The selected blood constituents were not influenced by the rice conservation method. The ruminal lactic acid and total volatile fatty acid (VFA) concentrations and the VFA proportion in the cows were not influenced by the rice conservation method. These results demonstrate that the rice grain conservation method has little impact on lactation performance when cows are fed a TMR containing 17% treated rice grain (dry matter basis).