日粮能量和蛋白质水平对奶牛繁殖性能影响的研究进展

奶牛繁殖性能下降与能量和蛋白质有关,本文系统地介绍了日粮能量和蛋白质水平对奶牛繁殖性能影响的研究进展,并着重论述了能量负平衡(NEB)及日粮蛋白质、脂肪酸和氨基酸对奶牛繁殖的影响.     

饲料营养对奶牛繁殖性能的影响

饲料营养是影响奶牛繁殖力的关键因素之一。从日粮蛋白质水平、日粮能量浓度、矿物质元素、维生素等方面介绍了饲料营养对奶牛繁殖性能的影响,旨在指导奶牛养殖场提高奶牛生产水平和养殖经济效益。     

疾病对奶牛繁殖性能的影响及其研究进展Ⅲ:营养代谢性疾病

现代规模化、集约化奶牛养殖生产模式下,不断供给高营养水平日粮是维持后备牛快速生长发育和泌乳母牛高泌乳性能的物质基础。然而,在遗传品质到达"瓶颈期"后,尽管随着日粮营养浓度的不断提高和干物质采食量（DMI）的增加,奶牛单产水平可以继续维持在一定的高水平状态,但是高产奶牛的营养代谢性疾病的发病率也呈现快速增长趋势,特别是围产期能量负平衡（negative energy balance,NEB）引起的酮病,高精日粮引发的酸中毒、高蛋白质日粮引起的血液中尿素氮升高等营养代谢性疾病,负调控奶牛繁殖性能,造成奶牛产后发情不明显,配种率和受胎率下降等,直接影响奶牛生产群的更新速度、优质牛群泌乳性能正常发挥以及奶牛养殖的经济效益。作者详细介绍了近年来国内外不同营养代谢性疾病对奶牛繁殖性能影响的相关研究资料,重点分析了酮病、低血钙、瘤胃酸中毒等围产期高发的营养代谢性疾病影响奶牛繁殖性能的分子机制,并对营养代谢性疾病与高产奶牛繁殖性能今后研究的方向提出了展望和思考,以期为提高中国规模化牧场高产奶牛群繁殖效率和母牛围产期营养管理水平提供一定的借鉴和理论依据。     

奶牛精饲料和日粮营养品质的整体评价技术及其应用

奶牛精饲料品质优劣直接关系到日粮的营养水平,而奶牛日粮营养品质对奶牛的生产性能、繁殖性能和鲜乳品质等具有重要影响。但是到目前为止,用于评定奶牛精饲料和日粮品质及日粮营养平衡度技术的方法还较少。针对于此,本文介绍了奶牛精饲料品质、日粮营养平衡度和营养品质评定的新方法,并对新方法的应用价值进行了阐述。     

奶牛营养与繁殖疾病的关系

奶牛营养与繁殖疾病的关系云南省西畴县畜牧站（６６３５００）刘学剑本文就奶牛日粮中能量、蛋白质、矿物质和维生素的含量水平对奶牛繁殖疾病的影响作一简述，供参考。营养对种牛的发情、性欲、配种、受胎和利用年限及犊牛的成活起决定性作用。适宜的营养是保证中最大繁...     

影响奶牛繁殖性能的营养因素及其调控

本文对影响奶牛繁殖性能的营养因素及其饲养调控技术方面的研究进展进行了综合评述。结论认为奶牛营养状况与繁殖性能密切相关,随着遗传性能和饲养管理技术的改进,奶牛泌乳量得以迅速提高的同时,对营养需要量的要求也随之提高。营养需要量的提高常常导致奶牛特殊生理阶段发生能量负平衡,致使奶牛繁殖能力下降;高蛋白日粮有利于提高产奶量,却往往降低了繁殖性能;日粮中矿物质和维生素含量偏高或偏低以及比例不当都会影响奶牛的繁殖性能;奶牛营养的全过程,包括采食量及采食的营养成分水平都与奶牛的繁殖性能密切相关。     

日粮主要营养指标对奶牛乳尿素氮浓度影响的评价

通过对702头荷斯坦奶牛，118种日粮的试验结果进行统计分析，评价了日粮的主要营养指标（蛋白质水平、能量水平以及氮能比）对乳尿素氮浓度的影响。结果：由于日粮营养指标间的相关关系，使一般多元回归分析中存在严重的共线性；消除共线性影响后的岭回归分析结果表明在三个营养指标中日粮蛋白质水平是对MUN影响最大的因素，其次为氮能比，但能量水平的作用不显著。     

影响奶牛繁殖性能的营养因素及其调控

本文对影响奶牛繁殖性能的营养因素及其饲养调控技术方面的研究进展进行了综合评述。结论认为奶牛营养状况与繁殖性能密切相关，随着遗传性能和饲养管理技术的改进，奶牛泌乳量得以迅速提高的同时，对营养需要量的要求也随之提高。营养需要量的提高常常导致奶牛特殊生理阶段发生能量负平衡，致使奶牛繁殖能力下降；高蛋白日粮有利于提高产奶量，却往往降低了繁殖性能；日粮中矿物质和维生素含量偏高或偏低以及比例不当都会影响奶牛的繁殖性能；奶牛营养的全过程，包括采食量及采食的营养成分水平都与奶牛的繁殖性能密切相关。     

不同蛋白质水平日粮对奶牛生产性能的影响

为了研究不同蛋白质水平日粮对奶牛生产性能的影响,试验将30头体况、年龄、胎次相近的健康荷斯坦奶牛随机分为1,2,3组,分别饲喂蛋白质水平为16.70%、18.60%、20.60%的日粮,测定生产性能指标和乳品质指标。结果表明:随着日粮蛋白质水平的提高,奶牛干物质采食量和产奶量显著增加(P<0.05);乳脂率和乳蛋白率显著降低(P<0.05),乳糖显著高于1,2组(P<0.05),乳中尿素氮3组间差异不显著(P>0.05)。说明日粮中过高的蛋白质水平可以增加奶牛产奶量,但对乳成分并没有改善作用。     

过量蛋白质对奶牛卵巢和子宫生理的影响

在奶牛生产中 ,随着日粮中蛋白质摄入量的增加 ,产奶量和干物质的采食量随之上升。但是与这种营养策略紧密相连的现象是繁殖力降低。人们已经利用血浆尿素氮或牛奶尿素氮来监控日粮蛋白质的营养状态、氮利用情况以及对卵巢和子宫生理的影响 ,PUN浓度超过19mg/dl时 ,子宫pH改变 ,繁殖性能降低。过量的RDP和RUP降低繁殖性能的机制可能是 ,过量的蛋白质使机体增加对能量消耗 ,使体内的能量平衡状态遭到破坏或进一步恶化 ;还可使体液中的尿素浓度增加 ,尿素浓度的上升促进子宫分泌前列腺F2a,前列腺F2a量的增加 ,引起黄体溶解 ,孕酮的分泌量下降 ,不利于维持妊娠状态 ;也会使奶牛的子宫分泌物的组成发生改变 ,pH降低 ,子宫的内环境发生不利于胚胎发育的变化 ,最终共同导致繁殖性能降低。     

乏情奶牛日粮营养水平和血浆生殖激素的变化

选取产后65～75天无发情表现的泌乳奶牛，经直检分为卵泡闭锁（Ⅰ）、卵巢囊肿（Ⅱ）、持久黄体（Ⅲ）和排卵延迟（Ⅳ）4组，每组10头奶牛。应用放射免疫测定法检测每头奶牛血浆FSH、LH、E2、P4的水平，同时分析该牛场此时期日粮中营养水平。结果表明：饲料中能量、蛋白质和磷的含量低于NRC（2001）水平。4个组奶牛血浆中的FSH含量均低于正常水平；Ⅰ组血浆中的E2含量低于同期正常水平；Ⅱ组血浆中的E2含量高于正常水平；Ⅲ组血浆中的E2含量低于正常水平，P4的含量高于正常水平；Ⅳ组血浆中的E2含量高于正常水平，P4和LH的含量低于正常水平。结论：日粮能量、蛋白和磷含量较低导致的泌乳奶牛生殖激素的紊乱是引起奶牛乏情的主要因素。     

Effects of Diseases on Reproductive Performance in Dairy Cattle Ⅲ: Nutritional Metabolic Diseases

Under the modern large-scale and intensive dairy farming production mode,the continuous supply of feed with high nutrition level is the material basis for maintaining the rapid growth and development of reserve cows and the high lactation performance of lactating cows.However,after the genetic quality reaches the "bottleneck period",although the milk yield of dairy cow can continue to maintain a certain high level with the continuous improvement of the nutrient concentration of feed and the increase of dry matter intake (DMI),the incidence of nutritional metabolic diseases of high-yield dairy cows also shows a rapid growth trend,especially ketosis caused by the negative energy balance in perinatal period,acidosis caused by high-precision diet and the increase of blood urea nitrogen caused by high-protein diet,negatively regulate the reproductive performance of dairy cows,resulting in inconspicuous postpartum estrus,decreased mating rate and conception rate of dairy cows,which directly affect the update speed of dairy cows production groups,the normal performance of high-quality cattle and the economic benefits of dairy farming.In this paper,the author introduced in detail the relevant research on the current situation and its mechanism influence of different nutritional metabolic diseases on the reproductive performance of dairy cows in recent years,and focused on analyzing the molecular mechanism of nutritional and metabolic diseases with high perinatal incidence such as ketosis,low blood calcium and moderate gastric acid,and put forward the prospect and thinking on the future research direction of nutritional and metabolic diseases and reproductive performance of high-yielding dairy cows,in order to provide some reference and theoretical basis for improving the reproductive efficiency of high-yielding dairy cows in large-scale pastures in China and the perinatal nutrition management level of dairy cows.     

某奶牛场全混合日粮技术饲喂效果

全混合日粮(TMR)是现代标准化、规模化奶牛场普遍采用的饲喂技术。该技术是依据奶牛各阶段的营养需要,一次性供给奶牛精粗比合适、适口性较好、各部分营养浓度相同的日粮。[目的]为了定量分析TMR技术效果。[方法]采用全混合日粮技术饲喂奶牛。[结果]产奶牛奶量提高了10.8%,干物质、蛋白质、脂肪含量分别提高了1.6%,3.9%和4.6%,每头产奶牛日均增加效益10.7元。[结论]应用全混合日粮饲养技术可以提高产奶量、乳品质以及经济效益。     

Effects of a short-term increase in the nutritional plane before the mating period on metabolic and endocrine parameters, hepatic gene expression and reproduction in primiparous beef cows on grazing conditions

Sixty-four spring-calved primiparous crossbred cows paired by calving date and body condition score (BCS) at calving were used to study the effect of a short-term increase in the nutritional plane before the mating period on cow and calf performance, changes in metabolic and endocrine parameters and hepatic gene expression. At 48 ± 10 days post-partum (onset of nutritional treatment = day 0), cows were assigned to two treatments during 23 days: control (grazing of native pastures; NP; n = 31) and increased nutritional plane (NP improved with Lotus subbiflorous cv Rincon; IP; n = 33). Cow body weight (BW), BCS and total protein and albumin concentrations increased while urea and non-esterified fatty acids levels decreased from the beginning of the nutritional treatment in both groups, indicating the animal positive energy balance as forage growth and availability of pastures increased during spring. In addition, cow BW and BCS, as well as calf average daily gain and BW, were greater in IP than in NP cows groups. Insulin concentrations were less in IP than in NP (1.37 vs. 2.25 ± 0.26 μU/ml) because insulin increased owing to nutritional treatment only in NP cows. Hepatic insulin receptor mRNA at day 23 tended to be 1.5-fold greater, while insulin growth factor binding protein-3 mRNA expression was 1.7-fold greater in NP than in IP cows. Reproductive responses were not affected by nutritional treatment, but days to initiation of ovarian ciclicity (108 ± 10 days) were positively correlated with insulin concentrations. Grazing of improved NP for 23 days before the mating period did not improve cow reproductive performance but modified metabolic, endocrine and gene expression parameters, in agreement with greater nutrient and energy partitioning towards milk production, reflected in better calf performance.     

香蕉茎叶对母牛繁殖性能影响的研究

[目的]为研究香蕉茎叶对母牛繁殖性能的影响,[方法]采用比较法,对饲喂香蕉茎叶和玉米秸秆青贮能繁母牛间的繁殖性能及犊牛的生长发育的差异进行了对比。[结果]研究结果表明,在相同的饲养管理条件下两组母牛的繁殖性能和犊牛的生长发育情况无明显差异。[结论]与肉牛常规饲料——玉米秸秆青贮相比,长期饲喂香蕉茎叶青贮饲料对能繁母牛繁殖性能、对胎儿和犊牛的生长发育不会产生不良影响,可以部分或完全替代玉米秸秆饲料,来降低母牛的生产成本,提高母牛的养殖效益。     

日粮能量水平对奶牛繁殖性能、血浆代谢产物和生殖激素的影响

为了解日粮能量水平对泌乳奶牛生殖机能的影响,选取年龄、体重、胎次、泌乳量相近的健康泌乳奶牛40头,按添加过瘤胃脂肪量分为高（H,400g/d/头）、中（M,300g/d/头）、低（L,200g/d/头）和对照组（不添加过瘤胃脂肪）四组,每组10头,试验期为产后30d至70d。产后30d、45d、60d、70d以及发情时记录试验奶牛采食量、体况分,记录繁殖性能,检测奶牛血浆GLU、BUN、ALB、TP、LH、FSH、E2、P4和PG浓度,结果显示：1）试验奶牛繁殖性能高低依次为H组、M组、L组和对照组。2）血浆GLU水平H组〉M组〉L组〉对照组;BUN水平L组〉M组〉H组;ALB和TP各组间无差异。3）血浆LH、FSH、E2水平随能量摄入增加而升高。这些结果提示：高能量摄入能缓解奶牛能量负平衡,促进卵泡正常性周期活动,从而提高奶牛繁殖性能。     

Indications and implications for testing of milk urea in dairy cattle: A quantitative review. Part 2. Effect of dietary protein on reproductive performance

dDietary protein and dairy cow fertility. Feeding more dietary protein has been negatively associated with dairy cow fertility in some but not all studies. We used meta-analysis to examine the relationship between dietary crude protein and conception rate. While a higher intake of dietary crude protein significantly lowered conception rate, the potential for feeding less degradable dietary protein to modify this relationship was not demonstrated.

dMilk urea concentrations and dairy cow fertility. The use of milk urea as an indicator of dietary energy and protein intake and as an indictor of reproductive performance has been questioned. We found that changes in urea concentration in body fluids explained only 25% (p = 0.08) of the variance in conception rate after conducting a meta-analysis of available studies.

dInterpretation of milk urea concentrations. High intakes of dietary protein may induce adaptations in urea metabolism, and the negative relationship identified between high intakes of dietary protein and fertility for Northern Hemisphere dairy herds may not necessarily apply in Australasian dairy herds. Because of the potential for cows to adapt to high protein diets, the use of a single milk urea determination on a herd will have limited value as an indicator of nutritional status and little value as a predictor of fertility.     

奶牛常见繁殖障碍疾病及防治措施

繁殖障碍是奶牛饲养过程中一类常见的疾病,可导致奶牛繁殖性能降低。子宫内膜炎、胎衣不下、卵巢囊肿等疾病是引发奶牛繁殖障碍的主要原因。此外,遗传、营养、环境等因素也可造成奶牛繁殖障碍,严重影响奶牛的正常生产,对我国奶牛养殖业造成巨大的经济损失。本文对引起奶牛繁殖障碍的疾病原因、临床症状、治疗方法和预防措施进行论述,提高奶牛场对该病的认识。     

日粮蛋白质水平对奶牛产后卵巢机能恢复及生殖激素的影响

[目的]本试验旨在探讨不同蛋白质水平日粮对奶牛产后卵巢机能恢复及生殖激素的影响,以确定奶牛日粮适宜蛋白质水平.[方法]采用单因素对比实验设计,根据生理状况和泌乳性能相近原则将72头中国荷斯坦牛,随机分成3组,每组24头,分别在围产期和泌乳盛期饲喂9.8%(A1)和13.8%(A2)、12.6%(B1)和16.2%(B2...