干奶期不同能量摄入水平对奶牛产后能量负平衡的影响

选择围产期健康奶牛30头,随机分为三组,产前第28d开始,饲喂不同能量日粮,即对照组(C组)、高能量组(H组)和低能量组(L组);产后各组奶牛均饲喂标准泌乳日粮,至产后56d结束。研究干奶期不同能量摄入水平对产后奶牛能量负平衡的影响。结果表明:低能量组奶牛产后干物质摄入量显著高于其它两组、体重消耗较低,能量负平衡状态缓解。     

奶牛能量负平衡与产后疾病高发相关性的研究

奶牛产后疾病高发是导致奶牛淘汰率增加的最主要因素,造成奶牛产后疾病高发的因素很多,其中围产期奶牛体质下降是主要原因。而围产期奶牛体质下降主要归结为能量负平衡。通过对能量负平衡的发生机理,以及奶牛能量负平衡与产后疾病高发的相关性进行分析,为早期预防奶牛疾病,保障奶牛健康提供相关指导。     

能量负平衡对奶牛繁殖的影响及相关机理

高产奶牛繁殖力低下是世界性难题。能量负平衡(NEB)影响脂肪动员,改变血液代谢指标,诱发能量代谢紊乱及相关疾病,影响卵泡发育及子宫胚胎内环境,影响机体多种激素的分泌,损害奶牛生殖免疫机能,提高该状态下子宫疾病的易感性并诱发炎症反应,延缓产后子宫恢复,制约奶牛的繁殖性能。本文主要阐述NEB对奶牛繁殖的影响及相关机理,为奶牛生产和繁殖研究工作提供参考。     

丙二醇对围产期奶牛能量平衡及代谢产物的影响

为了研究丙二醇对围产期奶牛能量平衡、血液指标和肝脏甘油三酯与糖原含量的影响。选用24头体质量(683.1±14.9)kg、胎次(2.5±0.2)、上一泌乳期305d产奶量(7 339±18)kg和预产期(24.5±0.2)d的经产奶牛,随机分为4组,从分娩前19d开始分别在基础日粮中添加丙二醇0、150、300和450mL.d-1。结果表明:与对照组相比,添加丙二醇300和450mL.d-1,显著提高了奶牛分娩后7、21和35d体况评分,缓减了奶牛体质量下降程度,改善了奶牛分娩前14d和分娩后7、21和35d奶牛能量平衡(P<0.05)。300和450mL.d-1组奶牛分娩前14d和分娩后7、21和35d血糖和胰岛素浓度显著高于对照组(P<0.05)。300和450mL.d-1组奶牛分娩后7、21和35d血浆游离脂肪酸、β-羟丁酸和甘油三酯浓度显著低于对照组(P<0.05)。300和450mL.d-1组奶牛分娩后7、21和35d肝脏甘油三酯含量显著低于对照组(P<0.05),但分娩后7、21和35d肝脏糖原含量显著高于对照组(P<0.05)。结果提示在日粮中添加丙二醇能够减少肝脏脂肪沉积,加强葡萄糖异生作用,改善奶牛能量平衡,适宜添加量为300mL.d-1。     

能量负平衡对围产期奶牛的影响及调控措施

围产期是奶牛的特殊生理时期,经历妊娠、产犊、泌乳、采食量和饲养环境剧烈变化,容易引起奶牛能量负平衡,同时也是酮病、真胃移位、胎衣不下等多种代谢性疾病高发期,对后续生产和繁殖性能产生难以逆转的影响。本文综述了奶牛能量负平衡的原因、影响和改善措施,旨在为围产期奶牛健康养殖提供理论依据及技术参考。采食量下降和营养不足是产生能量负平衡的主要原因,导致奶牛泌乳性能、繁殖性能和免疫力下降。为解决这些问题,应采取合理的营养和管理调控措施,如根据奶牛围产期前后对饲料能量的不同需求,在保证日粮组成原料不变的情况下改变日粮的营养成分,同时根据奶牛不同时期的生理特点调整饲养管理方案,从而改善能量负平衡。     

血液能量平衡指标对高产奶牛产后卵巢静止的影响

本试验旨在确立能量平衡对奶牛产后卵巢静止的作用,为今后预防该病提供科学依据。从黑龙江省某集约化牛场随机选取产后14~21d奶牛80头(年龄2~4岁,胎次1~3次,泌乳量(34.82±9.51)kg/d),跟踪观测至产后60~90d,进行奶牛发情鉴定,结合B超观察与生殖激素检测从观测奶牛中选出卵巢静止与发情奶牛各16头。对2组奶牛产后14~21d和60~90d的血浆能量代谢及肝功能指标进行了统计比较。结果显示:产后60~90d卵巢静止奶牛血浆β-羟丁酸和游离脂肪酸含量高于发情奶牛(P0.05),血浆促卵泡素、雌二醇和孕酮浓度极显著低于发情奶牛(P0.01);根据受试者工作特征曲线分析确定产后14~21d血浆β-羟丁酸0.69 mmol/L、游离脂肪酸0.52mmol/L作为产后卵巢静止预警值,灵敏度和特异度分别为85.7%和83.30%,92.3%和86.70%,产后60~90d2项指标的预警值分别为0.42,0.17mmol/L。奶牛产后14~21d与60~90d血浆β-羟丁酸和游离脂肪酸浓度超过预警值,奶牛产后发生卵巢静止的风险会增大。     

miRNA调控奶牛能量负平衡的研究进展

由于奶牛产后摄入能量不足以维持大量产奶需求,导致奶牛产后出现能量负平衡（NEB）,NEB不仅影响奶牛产奶量,还会引发多种产后代谢和炎性疾病,这对奶牛生产力具有重要影响。微小核糖核酸（microRNA,miRNA）作为转录后调控因子参与NEB相关基因表达,调节奶牛能量和代谢平衡。本文主要从脂代谢、糖代谢和繁殖机能3个方面综述了miRNA对NEB奶牛分子调控的研究进展,以期为后续研究miRNA在奶牛NEB的调控作用提供参考。     

解决高产奶牛能量负平衡的有效方法

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能量负平衡影响奶牛卵泡发育的机制

奶牛能量负平衡(negative energy balance, NEB)是奶牛产后泌乳初期常会发生的一种代谢性疾病,当奶牛摄入能量无法满足其消耗能量时就会达到NEB状态。奶牛处于NEB状态时易引起患病率增加、妊娠率降低、生产性能下降,给集约化奶牛生产带来很大的经济损失。随着分子、组学技术的广泛应用,奶牛泌乳初期NEB对牛卵泡发育的影响机制得到进一步揭示。本文根据近年来相关报道,综述奶牛早期泌乳NEB对牛卵泡发育分子机制相关研究进展并进行展望,以期为减少NEB对奶牛繁殖性能的不利影响提供理论参考。     

围产期奶牛能量负平衡营养调控研究进展

随着我国畜牧养殖业的快速发展,奶牛养殖业得到了进一步的发展,市场需求量持续增加。奶牛产量不断提升,奶牛被动淘汰率持续增加。奶牛生产前,胎儿快速发育,为满足产奶需求奶牛乳房会快速发育,营养需要持续增加,母牛的采食量大幅度降低,导致营养摄入量无法满足于奶牛的生长所需,进而造成能量负平衡。     

淀粉和脂肪对奶牛能量负平衡的改善作用

作者简述了奶牛能量负平衡产生的原因、对奶牛的危害及其防治措施。主要从淀粉和脂肪补充能量的角度出发，结合有关淀粉和脂肪的互补作用，探讨如何对奶牛进行有效的能量补充，为生产中使用淀粉和脂肪减缓能量负平衡对奶牛的影响提供理论依据。     

饲粮中添加复合益生菌对奶牛瘤胃发酵及纤维素酶活的影响

本文旨在研究不同荆量的复合益生菌制剂对荷斯坦奶牛瘤胃发酵及纤维素酶活的影响.选用3头装有永久性瘤胃瘘管,体况相近的荷斯坦奶牛,饲喂不同剂量复合益生菌,分为对照组(0 cfu/d)、低剂量组(0.6×1011 cfu/d)与高剂量组(1.2×1011 cfu/d),采用3×3拉丁方试验设计,试验分为3期,每期18 d.结...     

氨基酸平衡日粮对奶牛生产性能、血清生化指标及经济效益的影响

试验旨在研究氨基酸平衡日粮对奶牛生产性能、血清生化指标及经济效益的影响。选择36头体况良好的泌乳初期的健康荷斯坦奶牛,平均泌乳天数(DIM)为(39.69±12.48) d、平均胎次为(3.02±0.64)胎。采用单因素随机试验设计,按年龄、产奶量、胎次相同或相近的原则,将36头荷斯坦奶牛区组配对后随机分为3组,每组12头奶牛,其中对照组奶牛饲喂仅添加有瘤胃保护性蛋氨酸(HMBi)的TMR日粮;试验1、2组日粮在对照组的基础上分别添加2种水平的瘤胃保护性赖氨酸,以平衡日粮中的氨基酸。结果表明,①与对照组相比,试验1、2组奶牛饲料转化率分别提高10.60%和11.26%(P>0.05),而干物质采食量没有显著变化(P>0.05),平均每日4%校正乳产量分别显著提高了8.65%和10.58%(P<0.05),并可显著或极显著增加乳脂和乳蛋白产量(P<0.05;P<0.01);饲喂氨基酸平衡日粮对奶牛繁殖性能、健康状况无显著影响(P>0.05)。②饲喂氨基酸平衡日粮60 d时,奶牛血清中葡萄糖、总氨基酸含量显著升高(P<0.05),尿素氮含量显著降低(P<0.05)。③与对照组相比,试验1、2组奶牛经济效益分别增加了15.09和16.36元/(头·d)。综上所述,饲喂氨基酸平衡日粮能显著提高奶牛的生产性能,具有改善奶牛代谢状况的趋势。     

Effect of Amino Acid Balance Diet on Production Performance,Serum Biochemical Indexes and Economic Benefits in Dairy Cows

This experiment was conducted to study the effect of amino acid balance diet on production performance,serum biochemical indexes and economic benefits in dariy cows.36 healthy Holstein cows in the early lactation period were selected,the average number of lactation (DIM) was (39.69±12.48) d,the average parity was 3.02±0.64.Principle of experiments using single factor randomized experimental design accroding to age,milk yield,parity identical same or similar,the 36 Holstein cows were assigned by random block design to 3 groups,and each group were 12 cows.The control group cows were fed with TMR diets only adding rumen-protected methionine (HMBi);Diets of group 1 and 2 were on the basis of control group,respectively adding two kinds of rumen-protected lysine levels in order to balance the amino acid in diet.The results showed as follows:① Compared with control group,the feeding conversion ratio in groups 1 and 2 were increased by 10.60% and 11.26% (P>0.05),respectively,while the dry matter intake had no significantly changed (P>0.05),the 4% average daily milk yield in groups 1 and 2 were significantly increased by 8.65% and 10.58% (P<0.05),respectively,and the milk fat and milk protein yield in groups 1 and 2 were significantly or extremely significantly increased (P<0.05;P<0.01),respectively.Adding amino acid balance diet had no significantly effects on reproductive performance and health conditions in dariy cows (P>0.05).② When feeding the amino acid balance diets for 60 days,the contents of GLU and TAA in serum of dairy cows were significantly increased (P<0.05),while the BUN content was significantly decreased (P<0.05).③ Compared with control group,the economic benefits of groups 1 and 2 were increased by 15.09 and 16.36 yuan/(head·d).The results indicated that feeding the amino acid balance diets could significantly improve production performance of dairy cows,and there was a tendency to improve metabolic conditions.     

中药产后调理提高奶牛生产性能的试验研究

应用中药增乳Ⅰ号进行了产后调理提高奶牛生产性能的试验研究。结果表明,试验组奶牛羊草采食量,产奶量,乳脂率、受胎率均显著高于对照组(P<0.01), 隐性乳房炎发病率显著低于对照组(P<0.01),血清GOT、ALP、钙、磷和血糖浓度两组差异不显著(P>0.05),而且均在正常范围内。说明该方剂能够改善产后奶牛体况,提高奶牛生产性能,对预防多种产后疾病具有一定意义,适宜于奶牛产后应用。     

Turnover of Dominant Follicles prior to First Ovulation and Subsequent Fertility in Postpartum Dairy Cows

Contents: The ovaries of 64 multiparous Holstein cows were scanned twice weekly by ultrasonographyfrom Day 6 postpartum until 60 days or return to normal estrous cycle, and turnover of dominant follicles in relation to subsequent fertility were determined. The mean (SD) number of days from parturition to detection of the first postpartum dominant follicle (10 mm) was 9.0 0.5, which was predominantly located in the ovary contralateral to previous pregnancy in 54/64 cows. The first postpartum dominant follicle ovulated in 34 cows, failed to ovulate in 18, became cystic in 10, and only 2 were diagnosed as ovarian quiescent which delayed the detection of dominant follicles until days 25 and 30 postpartum. Number of dominant follicles in cows with anovulated first dominant follicle was 2.8. 1.1 prior to first ovulation (range 2–5). Growth and regression of cystic follicles were observed 24 times in 6110 cows, and a total of 20 cystic follicles persisted 32.7 9.0 days (range 18–58 days) except one which persisted for 124 days. Conception rate was 89.5% and postpartum interval to conception within 180 d after calving was 96.7 days in cows detected with less than 3 dominant follicles before first ovulation compared with those of 42.9% and 141 days in cows detected with more than 4 dominant follicles. It is concluded that the number of dominant follicles detected prior to first ovulation varied from I to 5, which positively correlated with ovulation intervals, while only those cows which first ovulated less than 3 dominant follicles resulted in reasonable reproductive performance.     

奶牛产后常见病防治

奶牛产后阶段是奶牛饲养管理中最关键的时期。在此期间,由于奶牛分娩后,生理代谢发生了重大变化,如果不及时做好产后护理,或使用了错误的护理方法,容易发生奶牛产科疾病如胎衣不下、子宫脱垂和代谢类疾病如产后瘫痪、酮病等。本文从诊断要点、治疗措施、预防控制等方面,对以上疾病进行了比较系统的梳理总结,以期为广大奶牛养殖场（户）提供一些帮助。     

日粮阴阳离子平衡对热应激奶牛血液生化指标的影响

试验旨在研究日粮阴阳离子平衡（dietary cation-anion balance,DCAB）对热应激条件下奶牛血液生化指标的影响。采用随机完全试验设计,选取75头健康的泌乳中期（104.8 DIM±12 DIM）中国荷斯坦奶牛,根据胎次、产奶量、体重相近的原则随机分为5组,试验Ⅰ、Ⅱ、Ⅲ、Ⅳ组和对照组分别饲喂DCAB值为195.76、186.68、177.77、166.94、239.12 mEq/kg DM的日粮。试验期为67 d,其中预试期7 d,正试期60 d。结果表明,试验Ⅰ、Ⅱ组的O₂分压与试验Ⅲ、Ⅳ组和对照组相比,均有显著提高（P<0.05）,但DCAB对P_CO2、pH、HCO₃^-、TCO₂、SATO₂影响差异不显著（P>0.05）;DCAB对奶牛血清中肌酸磷酸激酶（CK）产生了显著的影响（P<0.05）,试验Ⅰ、Ⅱ组与试验Ⅲ、Ⅳ组和对照组相比,均有不同程度的降低,DCAB对奶牛血清中谷丙转氨酶（GPT）的影响差异不显著（P>0.05）,但试验Ⅰ、Ⅱ组与试验Ⅲ、Ⅳ组和对照组相比,均有不同程度的升高,分别为13.98%、15.99%、10.77%和4.55%、6.40%、1.61%。奶牛血清中T4、T3、COR的浓度受DCAB的影响差异不显著（P>0.05）,但对奶牛血清中尿素氮的浓度有显著影响（P<0.05）,随着日粮DCAB值的升高,血清中尿素氮的浓度呈上升趋势,试验Ⅰ组最高。综合上述指标,在热应激条件下,泌乳中期奶牛饲喂DCAB值为186.68～195.76 mEq/kg DM的日粮时对改善其健康较为适宜。