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1.
杨露 《中国乳业》2022,(8):15-18
优质牛奶的充足供给需要以奶牛的健康养殖为基础。益生菌在奶牛饲料中的添加对奶牛的产奶量、乳成分和瘤胃微生态区系均有正面影响,可以通过增加奶牛瘤胃中有益微生物的含量,同时竞争性抑制有害菌的生长定殖,进而提高奶牛的机体健康状况和生产性能。本文对益生菌的功能、作用机制及在奶牛养殖中的应用效果进行阐述,旨在为益生菌的广泛应用提供参考。  相似文献   

2.
奶牛日粮中脂肪(酸)是很重要的营养素之一,尤其在缓解奶牛能量负平衡和热应激等方面作用明显,此外,通过日粮添加不饱和脂肪酸还可以改变牛奶乳成分占比,为消费者提供更高质量的功能性产品。本文对2020年国内外脂肪(酸)对瘤胃代谢、牛奶成分、生产性能、氧化应激、繁殖等方面的影响进行综述。 [关键词] 2020年|奶牛|脂肪|脂肪酸  相似文献   

3.
《饲料工业》2021,(1):32-37
奶牛能够将人类难以消化利用的植物性饲料转化为人类易消化吸收的牛奶,此过程主要依赖于瘤胃微生物分解饲料产生微生物蛋白、挥发性脂肪酸和葡萄糖等牛奶的前体物。乳蛋白和乳脂肪产量是衡量牛奶品质的关键指标,文章主要综述了瘤胃微生物在牛奶形成过程中所发挥的作用及其对牛奶乳脂和乳蛋白产量的影响,为探索提升牛奶品质的方法提供参考。  相似文献   

4.
奶牛鲜乳的风味、质量在乳制品生产中占有非常重要的地位。影响鲜乳质量的因素复杂,涉及到奶牛的品质、饲养管理和奶牛的健康状况、饲料品种等。近几年来,在奶牛生产中,酒精阳性乳的发生率较高,致使大量牛奶被废弃,造成一定的经济损失。因此,对发生酒精阳性乳的原因进行了系统的分析研究,总结出了有效的防治措施,生产应用证明,成效显著,经济效益明显。  相似文献   

5.
在奶牛养殖中,亚急性瘤胃酸中毒(subacute ruminal acidosis,SARA)是一种高发的营养代谢病。随着我国奶牛养殖集约化程度的提高,为提升奶牛生产性能饲喂大量高能谷物饲料极易诱发SARA,导致瘤胃液pH值降低,瘤胃菌群发生改变,瘤胃上皮黏膜层受损,进而影响瘤胃代谢功能。分析了奶牛不同生理阶段、择食行为以及个体差异等SARA的易感因素,探讨了SARA对奶牛瘤胃菌群变化、瘤胃上皮细胞基因表达、瘤胃屏障功能的影响,以期为阐明SARA造成瘤胃功能损伤的机制、降低奶牛发生SARA的风险提供参考。  相似文献   

6.
<正>1饲料比例对牛奶成分的影响奶牛产奶量较高时,所需饲料的能量与蛋白质应适当增加。通常情况下,在奶牛日粮中添加精饲料以满足奶牛的营养需要,奶牛日粮中精、粗饲料的比例对奶牛的瘤胃功能与生产性能的影响很大。1.1精饲料的比例由于精料具有较好的适口性,因此奶牛对精料的喜爱度也较高。精料的单位体积与粗饲料相比要小一些。精饲料在瘤胃中的发酵速度与粗饲料相比也较快一些,还会导致瘤胃内含物的酸度有所提高,同时对于纤维的正常发酵会产生一  相似文献   

7.
提高饲料氮的利用率一直以来都是动物营养学家们致力于蛋白质营养研究的初衷。本文从饲料粗蛋白、非蛋白氮及瘤胃氨的利用、尿素循环、牧草中的蛋白、限制性氨基酸平衡以及牛奶尿素氮六个方面入手,对1917年美国《Journal of Dairy Science》(乳业科学)杂志创办以来奶牛营养学家们所做的探索和发现进行了概述,以期为进一步提高奶牛饲料氮的利用率提供参考。  相似文献   

8.
牛瘤胃臌气是一种较为常见的牛前胃疾病,可见于饲养牛、家庭散养户牛以及放牧牛等不同养殖方式,而散养户牛因为粗放的放牧方式和以及管理不善等原因造成的牛采食过急、采食饲料过杂、饲料较粗,早牧冰霜牧草等原因更容易引起牛瘤胃臌气。  相似文献   

9.
王成杰  周禾 《草地学报》2007,15(1):100-101
随着草原群落组成及其营养特性的变化,放牧家畜对牧草的利用率和甲烷气体排放量也随之发生变化。本研究对锡林郭勒草原的牧草种类组成和品质的变化及其对绵羊瘤胃的消化代谢以及甲烷气体排放的影响进行研究。  相似文献   

10.
过瘤胃蛋氨酸对奶牛产奶量以及乳成分的影响   总被引:5,自引:0,他引:5  
选用16头泌乳中期奶牛,每头牛饲喂过瘤胃蛋氨酸(SmartamineTM)0、8、12和16g/d,研究其对泌乳中期奶牛产奶量以及乳成分的影响。结果表明,与对照组相比,补饲12和16g/d过瘤胃蛋氨酸能提高泌乳中期奶牛产奶量,补饲8g/d过瘤胃蛋氨酸奶牛产奶量下降5.73%;12g/d组产奶量提高0.62%,但差异均不显著;16g/d组产奶量提高10.84%,差异显著。补饲过瘤胃蛋氨酸能提高乳蛋白率和乳脂率水平,但差异不显著。补饲16g/d过瘤胃蛋氨酸牛奶乳蛋白量提高11.49%,乳脂肪量提高了13.11%。  相似文献   

11.
With the development of intensive cultivation in dairy cows,the production efficiency of dairy farms has been improved.However,issues such as animal welfare,environmental protection and product quality of dairy farm have received more attention.As judging criteria in the pattern,outdoor grazing and grass intake necessary in grass-fed farming,and its products are gradually being favored by consumers in developed countries,such as Europe and the United States.The effect of grass-fed on milk and dairy products mainly depend on the quality of forage grass.The high fiber content in forage grass maintains rumen health,high unsaturated fatty acids increase the proportion of unsaturated fatty acids in milk fat,and rich degradable proteins promote milk protein synthesis.The metabolism of fatty acids,amino acids,carbohydrates and other nutrients from forage in dairy cows may affect the sensory quality of milk and dairy products.This review focused on the actual situation and standard requirements of grass-fed in some countries,and their differences compared with organic farming,and analyzed the effects of feed composition differences on rumen metabolism of dairy cows under grazing farming and total mixed diet feeding conditions,as well as resulting differences in milk fat,protein and sensory indicators.  相似文献   

12.
Background: In the last years, difficulties occurring in corn cultivation(i.e., groundwater shortages, mycotoxin contamination) have been forcing dairy farmers to consider alternative silages. Some experiments conducted on lactating cows have proven that the total replacement of corn silage with sorghum silage did not reduce milk yield.However, this kind of substitution involves supplementing sorghum-based diets with grains, to compensate for the lower starch content of sorghum silage compared to corn silage. Change of silage type and inclusion of starch sources in the diet would influence rumen fermentations, with possible effects on milk composition(i.e., fatty acid profile) and coagulation properties. A worsening of milk coagulation properties would have a negative economic impact in Italy, where most of the milk produced is processed into cheese.This study was designed to compare milk composition and quality, with emphasis on fatty acid profile and coagulation properties, in dairy cows fed two diets based on corn or sorghum silage.Results: The sorghum diet reduced milk yield(P = 0.043) but not 4% fat corrected milk(P = 0.85). Feeding sorghum silage did not influence milk contents of protein(P = 0.07) and lactose(P = 0.65), and increased fat content(P = 0.024).No differences emerged for milk concentrations of saturated(P = 0.61) and monounsaturated fatty acids(P = 0.50),whereas polyunsaturated fatty acids were lower(P 0.001) for the sorghum diet. Concentrations of n-6(P 0.001) and n-3 fatty acids(P = 0.017) were lower in milk of cows fed the sorghum diet. Milk coagulation properties did not differ between the two diets, except the "a30"(the curd firmness, expressed in mm, 30 min after rennet addition), that was lower(P = 0.042) for the sorghum diet.Conclusions: Feeding a forage sorghum silage, properly supplemented with corn meal, as total replacement of corn silage maintained milk composition and did not influence negatively milk coagulation properties, which have a great economic relevance for the Italian dairy industry. Thus, silages obtained from forage sorghums could have a potential as substitute of corn silages in dairy cow diets.  相似文献   

13.
为比较研究对亚急性瘤胃酸中毒(SARA)耐受性不同的奶牛血浆和乳中代谢组的差异,试验选用12头装有永久性瘤胃瘘管的泌乳中期荷斯坦奶牛[泌乳天数=(114±22) d],饲喂精粗比为4∶6的全混合日粮。在试验期第20和21天晨饲后0、2、4、6、8和12 h监测瘤胃pH值,在早晚饲喂前收集奶样,晨饲6 h后采集颈静脉血,用于测定脂肪酸及代谢物组成。基于奶牛瘤胃平均pH值高低,将奶牛分为SARA易感组(SUS,瘤胃pH=5.76,n=4)和SARA耐受组(TOL,瘤胃pH=6.10,n=4)。脂肪酸测定结果分析显示,与TOL组相比,SUS组奶牛血液及乳中的碳链长度≤C16的脂肪酸含量显著增高(P<0.05),而>C16的脂肪酸的含量显著降低(P<0.05),乳中饱和脂肪酸及单不饱和脂肪酸含量均显著降低(P<0.05)。血浆代谢组结果显示, SUS组奶牛血浆中L-苯丙酮酸水平显著降低(P<0.05),而MG(18:0/0:0/0:0)、9-HODE、12(13) Ep-9-KODE、烟酰胺、异戊基肉碱、磷酸肌酸和L-谷氨酸水平显著升高(P<0.05)。乳代谢组分析结果显示,与TOL组比较,SUS组奶牛乳中的1-硬脂酰磷酸甘油丝氨酸和鞘氨醇水平显著升高(P<0.05),而甘油磷酰基乙醇胺、3-磷酸甘油和乳清酸等其他14个差异代谢物水平显著降低(P<0.05),这些差异代谢物主要涉及甘油磷脂代谢、甘油脂代谢及泛酸与辅酶A代谢等代谢途径。综上所述,SARA耐受性不同的奶牛的血浆和乳中脂肪酸及代谢物组成存在较大差异,SUS组奶牛血浆中氨基酸代谢活动增加,乳腺的乳脂从头合成能力较强,而从血液中摄取长链脂肪酸能力减弱,与此同时,易感奶牛乳中磷脂、乳清酸等营养物质水平下降,乳品质下降。  相似文献   

14.
为研究牧草物候期对其脂肪酸组成和放牧牦牛乳中共轭亚油酸(CLA)含量的影响及其相关关系,本研究在甘肃省甘南牧区选取平均体重为(234.9±10.5) kg的10头带犊甘南牦牛作为研究对象(自然放牧),分别于牧草返青期、盛草期、枯草期采集试验牦牛采食牧草、乳和瘤胃液,分别测定瘤胃液、牧草中脂肪酸及乳脂中共轭亚油酸组成,并分析其相关关系,以期探明牧草物候期对牦牛瘤胃液和牧草中脂肪酸组成与放牧牦牛乳中共轭亚油酸含量的影响及其变化规律。结果表明:物候期显著影响了牧草中月桂酸、肉豆蔻酸、棕榈酸、硬脂酸、亚油酸、亚麻酸、总脂肪酸、多不饱和脂肪酸、多不饱和脂肪酸/总脂肪酸(P<0.05),盛草期牧草中月桂酸、肉豆蔻酸、棕榈酸、亚油酸、亚麻酸、总脂肪酸、多不饱和脂肪酸、多不饱和脂肪酸含量/总脂肪酸均显著高于返青期和枯草期(P<0.05);物候期显著影响了牦牛乳中共轭亚油酸异构体c9t11、共轭亚油酸异构体t10c12和共轭亚油酸总含量(P<0.05),盛草期放牧牦牛乳中共轭亚油酸异构体c9t11、共轭亚油酸异构体t10c12和共轭亚油酸总含量显著高于返青期和枯草期(P<0.05);物候期显著影响了牦牛瘤胃pH值、乙酸、丙酸、乙酸/丙酸、异丁酸、丁酸、异戊酸、戊酸、总挥发酸和反式11-油酸含量(P<0.05),盛草期牦牛瘤胃乙酸、丙酸、丁酸、戊酸总挥发酸和反式11-油酸含量显著高于返青期和枯黄期(P<0.05);牧草粗蛋白、粗脂肪、无氮浸出物、单宁酸、总脂肪酸和瘤胃液pH值与放牧牦牛乳中CLA含量显著正相关(P<0.05),粗纤维和粗灰分与放牧牦牛乳中CLA含量显著负相关(P<0.05),多不饱和脂肪酸(PUFAs)和瘤胃总挥发酸(TVFA)与放牧牦牛乳中CLA含量无显著相关关系(P>0.05)。  相似文献   

15.
Feeding unsaturated oils to lactating dairy cows impair ruminal biohydrogenation (BH) of unsaturated fatty acids (USFA) and increase ruminal outflow of BH intermediates such as trans‐10, cis‐12 CLA that are considered to be potent inhibitors of milk fat synthesis. Supplementing lactating dairy cow’s rations containing plant origin oils with monensin and/or vitamin E may minimise the formation of trans‐10 isomers in the rumen, thereby preventing milk fat depression. Therefore, this study was conducted to evaluate the effects of monensin and vitamin E supplementation in the diets of lactating dairy cows containing whole cottonseed, as the main source of FA on feed intake, milk production and composition, milk fatty acid profile, efficiency of nitrogen (N) utilisation, efficiency of net energy (NE) utilisation and nutrients digestibilities. Four multiparous Holstein lactating dairy cows (86 ± 41 days in milk) were assigned to a balanced 4 × 4 Latin square design. Each experimental period lasted 21 days with a 14 days of treatment adaptation and a 7 days of data collection. The control diet was a total mixed ration (TMR) consisted of 430 g/kg forage and 570 g/kg of a concentrate mixture on dry matter (DM) basis. Cows were randomly assigned to one of the four dietary treatments including control diet (C), control diet supplemented with 150 mg of vitamin E/kg of DM (E), control diet supplemented with 24 mg of monensin/kg of DM (M) and control diet supplemented with 150 mg of vitamin E and 24 mg of monensin/kg of DM (EM). Dry matter intake (DMI) ranged from 19.1 to 19.5 kg/d and was similar among the dietary treatments. Dietary supplementation with vitamin E or monensin had no effect on milk production, milk fat, protein and lactose concentrations, efficiency of utilisation of nitrogen and net energy for lactation (NEL). Digestibility of DM, organic matter (OM), crude protein (CP) and ether extract (EE) was not affected by the dietary treatments. Digestibility of neutral detergent fibre (NDF) was higher in cows fed with the M and EM diets in relation to those fed the C and E diets. The concentrations of C4:0, C6:0, C8:0, C10:0, C12:0, C14:0, C15:0, trans‐10‐16:1, cis‐9‐16:1, 17:0, 18:0, trans‐11‐18:1, cis‐9‐18:1, cis‐9, trans‐11 conjugated linoleic acid (CLA), trans‐10, cis‐12 CLA, and 18:3n‐3 FA in milk fat were not affected by the dietary supplementations. While feeding the M diet tended to decrease milk fat concentration of C16:0, the milk fat concentration of C18:2n‐6 FA tended to be increased. Dietary supplementation with vitamin E or monensin had no effect on milk fat concentrations of saturated, unsaturated, monounsaturated, polyunsaturated, short chain and long chain FA, but feeding the M diet numerically decreased milk fat concentration of medium chain fatty acids (MCFA). The results showed that vitamin E and/or monensin supplementations did not improve milk fat content and did not minimise the formation of trans‐10 FA isomers in the rumen when whole cottonseed was included in the diet as the main source of fatty acids.  相似文献   

16.
旨在研究泌乳早期奶牛瘤胃微生物与牛奶脂肪酸组成的变化。本试验选取江苏省某奶牛场胎次、泌乳天数及产奶量相近的50头荷斯坦奶牛,收集泌乳7和30 d的奶样和瘤胃液样品,测定采食量、产奶量、乳成分及乳脂肪酸含量,同时采用16S rRNA测序技术分析瘤胃微生物的组成。结果表明,泌乳7 d的干物质采食量(15.79 kg·d-1)和产奶量(26.81 kg)均极显著低于泌乳30 d的干物质采食量(18.87 kg·d-1)和产奶量(37.47 kg)(P<0.01),而泌乳7 d的乳脂率、乳蛋白率和体细胞评分均极显著高于泌乳30 d (P<0.01);泌乳7 d乳中的C6:0、C8:0、C10:0、C12:0、C14:0、C14:1trans9、C14:1cis9、C15:1trans10、中链脂肪酸(MCFA)和饱和脂肪酸(SFA)的含量显著低于泌乳30 d (P<0.05),相反地,C17:0、C17:1cis10、C18:1trans6、C18:1trans11、C18:1cis9、C18:1cis11、C19:1trans10、C22:5cis4,7,10,13,16、长链脂肪酸(LCFA)、单不饱和脂肪酸(MUFA)和反式脂肪酸(TRANS)的比例显著高于泌乳30 d (P<0.05)。16S rRNA测序结果表明,泌乳7和30 d奶牛瘤胃细菌的丰富度与多样性未发生显著变化(P>0.05)。在属水平上,泌乳7 d奶牛瘤胃内的瘤胃梭菌属(Ruminiclostridium_1)、瘤胃球菌属(Ruminococcaceae_UCG_014和Ruminococcaceae_UCG_005)、梭菌属(Clostridium_sensu_stricto_1)、小杆菌属(Dialister)丰度显著低于泌乳30 d (P<0.05),而球藻菌属(Sphaerochaeta)、弯曲菌属(Campylobacter)和真细菌(Eubacterium_saphenum_group)属的丰度显著高于泌乳30 d (P<0.05)。此外,牛奶脂肪酸与瘤胃微生物组数据关联分析显示,瘤胃微生物对乳中MCFA含量影响较小,纤维素降解细菌(Ruminiclostridium_1、Ruminococcaceae_UCG_005)与乳中C17:0、C18:1trans6、C18:1trans11和C19:1trans10的含量显著负相关(P<0.05)。综上所述,奶牛泌乳早期在生理和采食量上发生了变化,导致瘤胃微生物组成发生改变,进而引起微生物代谢产物和代谢路径发生变化,最终引起产奶量和乳成分的变化,本研究为解析瘤胃微生物调控乳脂代谢机制提供了科学依据,也为产后奶牛营养调控和提高原料乳品质提供了理论基础。  相似文献   

17.
It is argued that in view of the many new methods in dairy farming an economic model of the dairy farm should be available to improve advisory work. Some quantitative data concerning the dairy cow needed for such a model are given. They deal with a net energy feeding value of grass, hay, silage, artificially dried grass and concentrates estimated with a feed evaluation system based on results obtained with lactating cows. Also data on the requirements for net energy and for long forage dry matter are given, again obtained with such cows. Finally information is given on voluntary intake of forage dry matter at pasture, from fresh grass fed indoors, from various preserved forages including forage pellets, as influenced by milk yield and condition of the cow and by kind of forage and level of concentrates fed. Special attention has been paid to the precision of the information. These data are used to predict both the maximal and minimal amounts of long forage which can be fed in the stall period without loss of production, and the additional quantities of concentrates needed. For the grazing cow the problem of the adjustment of voluntary intake of grass to milk yield and amount of concentrates fed is studied. It is concluded that the information is sufficient to develop an economic model of a dairy farm. For its development grassland research should supply data on pasture yield in terms of digestible organic matter when the forage is fed to sheep at the maintenance level, and the economists should add data on costs of food and labour.  相似文献   

18.
This experiment was designed to evaluate the effects of different concentrate crude protein (CP) concentration on performance, metabolism and efficiency of N utilization (ENU) on early-lactation dairy cows grazing intensively managed tropical grass. Thirty cows were used in a ten replicated 3 × 3 Latin square design. The treatments consisted of three levels of concentrate CP: 7.9%, 15.4%, and 20.5% offered at a rate of 1 kg (as-fed basis)/3 kg of milk. The cows fed low and medium CP had negative balance of rumen degradable protein and metabolizable protein. Increasing CP tended to linearly increase DMI, 3.5% FCM and milk casein, and linearly increased the yields of milk fat and protein. Increasing CP linearly increased the intake of N, the concentration of rumen NH3–N, and the losses of N in milk, urine, and feces. Increasing dietary CP linearly increased the molar proportion of butyrate but had no effect on the other rumen VFAs and no effect on microbial yield. In conclusion, feeding a concentrate with 20.5% of CP to early-lactation dairy cows grazing tropical grasses, leading to a 17.8% CP diet, tended to increase DMI, increased the yield of 3.5% FCM and the milk N excretion, and decreased ENU by 32%.  相似文献   

19.
Milk fatty acid composition is determined by several factors including diet. The milk fatty acid profile of dairy cows is low in polyunsaturated fatty acids, especially those of the n-3 series. Efforts to change and influence fatty acid profile with longer chain polyunsaturated fatty acids have proven challenging. Several barriers prevent easy transfer of dietary polyunsaturated fatty acids to milk fat including rumen biohydrogenation and fatty acid esterification. The potential for cellular uptake and differences in fatty acid incorporation into milk fat might also have an effect, though this has received less research effort. Given physiological impediments to enriching milk fat with polyunsaturated fatty acids, manipulating the genome of the cow might provide a greater increase than diet alone, but this too may be challenged by the physiology of the cow.  相似文献   

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