奶牛低血钙症的防治新途径

低血钙症是影响成母牛产后健康的一个常见疾病,可给奶牛养殖带来巨大的经济损失。对于大型规模化奶牛场而言,用灌水补钙、输液补钙防治奶牛产后低血钙症均有一定的局限性。博威钙是一种新型钙丸,投服方便,含钙量高,可同时起到快速补钙和持久补钙的作用。对全国8个大型规模化奶牛场544头奶牛进行试验,结果表明,投服2丸博威钙可以有效提高产后1h、13h和24h时血液中离子钙水平,使产后瘫痪发病率降低92.5%,乳房炎发病率降低41.9%,胎衣不下发病率降低52.9%,产奶量提高6.3%,每头泌乳牛可以多创造353.2元的净利润,投入产出比为1∶4.5,是防治奶牛产后低血钙症的有效新途径。     

奶牛产后低血钙的预防

奶牛低血钙症是奶牛分娩后常见的一个主要病理表现,奶牛血钙正常含量为8 mg/dL-12mg/dL。据报道,绝大部分荷斯坦高产奶牛在分娩后都会发生低血钙症。低血钙可以导致奶牛生产瘫痪,     

日粮阴阳离子平衡对奶牛生产的影响

随着动物营养学的深入研究，人们认识到酸碱平衡对反刍动物的重要性，体内酸碱平衡的失调将影响奶牛的健康和生产性能。影响体内酸碱平衡的因素很多，饲料是其中的主要因素。如果奶牛饲料中主要的阳离子（Na＋、K＋）和主要的阴离子（Cl－、SO２－４）之间的比例失调，就会使血液中的pH升高或降低，严重时会使酸碱平衡失调，影响奶牛的正常代谢活动和生产性能。在不同的泌乳阶段由于血液中pH、HCO－３浓度有差异，因此DCAB对奶牛的不同泌乳阶段影响不同，一般认为在泌乳前期、中期易发生酸中毒，在泌乳后期易发生碱中毒，所以大多数研…     

围产期奶牛低血钙症的发生及预防措施研究进展

围产期奶牛经历妊娠后期、分娩和泌乳等一系列生理变化,抵抗力下降,容易诱发奶牛产后诸多疾病,其中低血钙症就是本阶段易发的疾病之一.本文就围产期奶牛低血钙症的发生原因、危害、影响因素及目前的预防措施进行了总结,为奶牛围产期的饲养管理提供相应的理论参考.     

奶牛围产期低血钙症的发生及营养调控措施

文章介绍了围产期奶牛的生理状况及低血钙症的发生机理、危害、影响因素等,提出通过营养调控手段预防奶牛围产期疾病发生、改善奶牛健康状况的措施.通过合理的营养调控手段可以降低奶牛围产期低血钙症的发生几率,促进奶牛健康,提高奶牛养殖的经济效益.     

奶牛产后瘫痪症的治疗

奶牛产后瘫痪给养牛户造成的经济损失是巨大的。它是一种急性低血钙症，产后瘫痪多因产前营养不良或产后泌乳过多引起，一般产后3d内发病居多，特别是高产奶牛多发。一般认为与钙、磷比例失调，缺乏运动，饲草料搭配比例失衡，管理不当和地面潮湿等因素有关。     

日粮阴阳离子平衡对奶牛的影响

本文根据国内外近年来关于奶牛日粮阴阳离子平衡的研究,综述了阴阳离子平衡对奶牛采食、消化、生产性能、生理代谢和健康等方面的影响。     

奶牛饲粮阴阳离子平衡的研究进展

饲粮阴阳离子平衡(DCAB)是指饲粮1 kg干物质中所含阳离子和阴离子毫摩尔之差(mEq/kg DM),其可用于全面研究饲粮中矿物质的相互作用。DCAB水平可以影响奶牛机体酸碱平衡、采食量、生产性能、能量代谢和健康。本文主要综述了DCAB的发展背景、生理功能及其在奶牛生产中的应用现状,以期为DCAB在奶牛生产中的进一步应用和相关机制研究提供参考。     

日粮阴阳离子平衡在奶牛生产中的应用

日粮阴阳离子平衡（DCAB）已成为奶牛营养学研究的一个新方向，它直接影响到奶牛业生产和经济效益。本文介绍了DCAB的概念和计算方法；DCAB对奶牛干物质采食量、饲料利用率、产奶性能、热应激及奶牛健康的影响；DCAB在奶牛日粮配合中的应用。     

Role of sulfur and chloride in the dietary cation-anion balance equation for lactating dairy cattle

Ten Holstein cows averaging 120 d in lactation were arranged in replicated 5 x 5 Latin squares with 3-wk periods to evaluate the role of sulfur (S) in the dietary cation-anion balance equation. Diets were based on corn silage in Exp. 1 and sorghum silage in Exp. 2. Supplemental S and chloride (Cl) from the double sulfate of potassium and magnesium and CaCl2 were used to manipulate dietary cation-anion balance from 0 to +30 meq when expressed as meq [(Na + K)-(Cl + S)]/100 g diet DM and from +19 to +49 meq when expressed as meq [(Na + K)-Cl]/100 g diet DM. Blood pH was not affected by cation-anion balance, although both S and Cl supplementation tended to lower pH. Blood HCO3- and urine pH decreased and plasma calcium (Ca) and urinary Ca excretion increased as anion was added to the diet. Milk fat production tended to be increased by the low S supplementation. Dietary Cl and S had similar effects on acid-base status. Therefore, we suggest that S be included with Cl in the dietary cation-anion balance equation for lactating dairy cows as follows: meq [(Na + K)-(Cl + S)]/100 g diet DM. Although response of acid-base status to S and Cl was similar, as more data comparing the acidogenicity of S vs Cl become available, it may be necessary to include a modifying coefficient for S in the equation to adjust for differences between S and Cl in acid-generating potential. This coefficient may be further dependent on the dietary source of S.     

日粮阴阳离子差在泌乳奶牛日粮中的应用

日粮阴阳离子差（DCAD）可调控家畜体内的酸碱平衡。近年来,由于其对泌乳奶牛生产性能的影响而越来越受到研究者的重视。文章就阴阳离子差的计算,阴阳离子差对泌乳奶牛干物质采食量、泌乳量和乳成分、瘤胃参数的影响,及对DCAD在我国泌乳奶牛日粮中的应用的展望作了综合阐述。     

Tolerance of cattle to increased dietary sulfur and effect of dietary cation-anion balance

The objective of this study was to determine if dietary cation-anion balance (DCAB) affects the concentration of S that can be tolerated by growing and finishing cattle without adversely affecting performance. Angus cross and Bradford steers (n=114; average initial BW=252.8 kg) were blocked by BW and breed, and randomly assigned within a block to treatment. The design was a 3 × 2 factorial arrangement of treatments with S (from NH(4)SO(4)) supplemented at 0, 0.15, or 0.30% of DM, and NaHCO(3) added at 0 or 1.0% of DM. Each treatment consisted of 3 pens containing 5 steers and 1 pen containing 4 steers. Steers were used in an 84-d growing study followed by a finishing study. A corn silage-based diet was fed during the growing study and a corn-based diet was fed during the finishing study. Steers were not randomized between experiments. The analyzed concentrations of S in the growing diets were 0.12, 0.30, and 0.46%, whereas the analyzed concentrations of S in the finishing diets were 0.13, 0.31, and 0.46% for treatments supplemented with 0, 0.15, and 0.30% S, respectively. Increasing DCAB by approximately 15 mEq/100 g of DM, by the addition of NaHCO(3,) did not affect (P > 0.36) performance during the growing or finishing studies. During the growing study DMI was not affected (P=0.29) by dietary S. Steers fed diets containing 0.30% S had greater ADG (P=0.02) and G:F (P=0.01) than those receiving 0.46% S, but similar (P > 0.36) performance to steers fed 0.12% S. During the finishing study, steers fed diets containing 0.46% S had less ADG than steers fed 0.13 (P=0.004) or 0.31% S (P=0.07), whereas ADG did not differ (P=0.18) among steers fed 0.13 and 0.31% S. Steers fed diets containing 0.31 (P=0.01) or 0.46% S (P=0.001) had less DMI than controls, but G:F was not affected (P=0.52) by S during the finishing study. Carcass characteristics did not differ (P > 0.18) among steers fed diets containing 0.13 and 0.31% S. Steers receiving diets containing 0.46% S had decreased HCW (P=0.001), quality (P=0.02), and yield grades (P=0.04) than steers receiving 0.13% S. Plasma Cu concentrations on d 101 of the finishing phase and liver Cu concentrations at slaughter were greater (P ≤ 0.05) in control steers compared with those fed diets containing 0.31 or 0.46% S. This study indicates that steers fed growing diets can tolerate up to 0.46% S with minimum effects on performance. Finishing steers tolerated diets containing 0.31% S without adverse affects on ADG or G:F. However, 0.46% S greatly decreased ADG and DMI, and increasing DCAB did not prevent these depressions.     

日粮阴阳离子差理论在奶牛生产中的应用

1奶牛上使用的阴阳离子差概念及计算公式 DACD（Dietary cation-anion difference）即日粮阴阳离子差．由Beede等于20世纪90年代初总结前人的研究并提出．表达了饲粮中各种离子的含量及这些离子之间的比例关系．是综合考虑饲粮中的离子．探讨其共同效应的概念。在近期的研究中．研究者发现对离子营养的研究不应只关注个体营养素自身对代谢的作用．     

Preventive effect of mildly altering dietary cation-anion difference on milk fever in dairy cows

In the present study, we examined whether mildly altering dietary cation-anion difference (DCAD) contributes to the prevention of milk fever in dairy cows. Thirty multiparous cows and ten primiparous cows (heifer group) were used in this study and the multiparous cows were randomly divided into three groups of ten animals each (anion, non-anion and control groups). The cows in the anion group were given supplemental salts that slightly lowered DCAD. These salts consisted of 115 g of CaCO3, 42 g of CaHPO4, 65 g of MgSO4 x 7 H2O and 80 g of CaCl2 x 2 H2O as a daily dose for each cow, using a catheter from 21 days before the expected date of parturition until parturition. The cows in the non-anion group were given only the same Ca, Mg and ip supplement but no sulfate and chloride salts as that in the anion group. The cows in the control and heifer groups were not given any additional supplement. The incidence of hypocalcemia in the anion group decreased to approximately half of those in the non-anion and control groups, while the heifer group did not develop hypocalcemia at all. In addition, the number of days spent for the treatment of hypocalcemia and the number of drug bottles (calcium borogluconate solution) used for the treatment decreased to less than half in the anion group compared with those in the non-anion and control groups. At parturition, the serum Ca concentration in the control (6.2 +/- 1.9 mg/dl, mean +/- standard deviation) and non-anion groups (6.4 +/- 1.7 mg/dl) were significantly lower than that in the heifer group (8.3 +/- 0.4 mg/dl), and the level in the anion group was intermediate (7.3 +/- 1.3 mg/dl). The change in ionized Ca concentration was almost the same as that in serum Ca concentration, but only the concentration in the anion group tended to increase slightly from a week before parturition and was significantly higher than that in all other groups three days before parturition. Urinary pH in the anion group was maintained at a mildly acidic level (6.8-7.0) for the last two weeks before parturition, compared with those in the control (7.3-7.5) and non-anion groups (7.9-8.1), and similar to that in the heifer group (6.3-7.3). The urinary Ca excretion was the highest in the anion group among all groups during the prepartum period. There were no specific changes in the excretion of parathyroid hormone and 1,25-dihydroxyvitamin D in all groups of multiparous cows while the levels of these hormones remained low in the heifer group throughout the experimental period. The data in the present study indicates that the administration of anion salts that slightly lowered DCAD in the preparum period was effective for preventing milk fever in multiparous cows. Safe and mild metabolic acidosis induced by the anion salts could be evaluated by urinary pH (6.8-7.0), and might increase the responsiveness to Ca requirement at parturition through some complex mechanisms unrelated to the excretion of Ca-related hormones. In addition, it was clarified that primiparous cows have a high potential to respond to sudden Ca demand unrelated to hormone excretion, and their Ca metabolism was in some respects similar to that in multiparous cows fed anion salts. Therefore, manipulating mildly DCAD is expected to be an effective, safe and natural method for preventing milk fever in dairy cows.     

日粮阴阳离子平衡对泌乳前期热应激奶牛血液指标的影响

随着近两年全球气温升高,缓解奶牛的热应激,提高奶牛的生产性能是畜牧工作者急须解决的问题。目前通过调节奶牛的日粮改善热应激奶牛的生产性能成为人们研究的焦点。大量研究表明,向奶牛日粮中添加缓冲剂可通过调节奶牛的机体酸碱平衡改善奶牛的生产性能。国外对日粮阴阳离子平衡(DCAB)对热应激奶牛生产性能的影响十分关注,但国内却很少研究。本试验目的是通过给泌乳前期热应激奶牛饲喂不同水平DCAB ,测定其对奶牛血液指标的影响,为提高生产性能提供科学依据和泌乳前期热应激奶牛DCAB适宜水平的参考值。1　材料与方法1 1　试验动物　…     

奶牛日粮中离子平衡的研究进展

随着反刍动物营养代谢理论和日粮平衡技术的深入研究,在充分考虑日粮能量蛋白平衡、氨基酸平衡(理想蛋白模式)和钙磷平衡后,日粮离子平衡(dietarycationanionbalance,DCAB)的重要性逐渐得到了研究者的重视。研究表明,日粮中离子平衡水平与动物的采食量及氨基酸的代谢等有密切的     

日粮阴阳离子平衡对泌乳中后期奶牛生产性能的影响

试验选择泌乳中后期奶牛15头,随机分成3组,每组5头,采用3×3重复拉丁方设计,分别饲喂3种不同阴阳离子平衡水平的日粮。其中对照组A(DCAB为DM 77 m eq/kg),B组(DCAB为DM 175 m eq/kg),C组(DCAB为DM 325 m eq/kg)。结果表明,DCAB对热应激奶牛的生产性能具有显著影响,其中B组和C组的产奶量分别比对照组提高6.6%(P>0.05)和0.1%(P>0.05);而4%标准乳产量则分别提高8.3%(P<0.05)和0。DCAB对奶牛的乳脂率和乳蛋白率无显著影响。说明在泌乳中后期当DCAB为175 m eq/kgDM,饲喂效果最佳。     

设计奶畜日粮的饲料营养学要点

充分发挥瘤胃微生物消化粗饲料和利用 NPN等的有益功能，并尽量避免微生物对高品质饲料的降解损失，保持瘤胃微生物与反刍动物本身消化代谢活动的协调统一，是设计奶畜日粮的基本出发点。该文从奶畜日粮结构、不同生产水平时日粮蛋白质来源、精粗饲料的饲喂状态、高效添加剂的选用等方面论述设计奶畜日粮的饲料营养学要点。     

日粮阴阳离子对反刍动物的最新研究进展

作者就日粮中阴阳离子平衡(dietary cation-anion balance,DCAB)对奶牛的机体健康、生产性能等方面的最新概况作一概述,提出DCAB可作为反刍动物瘤胃缓冲技术重要的研究内容,并指出DCAB现阶段的研究成果和发展方向.