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高产奶牛更容易发生氧化应激,氧化应激可以导致生物学大分子和生物膜系统的破坏,并可以增加炎症反应时的组织损伤:奶牛氧化应激的产生除了与机体的生理状态、健康状况和饲料成分有关外,环境因素也会引起氧化应激。目前主要通过饲喂抗氧化添加剂来预防奶牛氧化应激。 相似文献
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试验旨在揭示围产期奶牛血清代谢物和相关激素水平的动态变化规律,选取临床健康经产奶牛 20 头,分别于产前 14、7 d 及产后 0、7、14 d 采血并分离血清,检测血清葡萄糖、甘油三酯、非酯化脂肪酸、β-羟丁酸等代谢物浓度和胰岛素、生长激素、脂联素和瘦素等激素水平,并根据相应公式计算胰岛素敏感指数。结果表明:奶牛分娩当天的血糖浓度较高,而后逐步恢复至产前水平;奶牛分娩后甘油三酯浓度下降,非酯化脂肪酸和β-羟丁酸浓度升高;胰岛素浓度在产前 14 d 至产后 7 d 各时间点无显著变化;产前 7 d 时的生长激素浓度高于其他时间点(P<0.01);脂联素浓度在整个试验期无显著变化;瘦素水平在产前 7 d 和产后 0 d升高(P<0.01),但产后 7 d 时下降(P<0.01);胰岛素敏感性指数在分娩当天显著降低,随后逐步恢复。结果表明,奶牛产后体脂动员明显,可能与生长激素、瘦素等激素的调控有关。 相似文献
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本文结合笔者多年的实践经验,对奶牛泌乳早期的饲养、挤奶方法、兽医保健、繁育保健等几个方面加以总结,供广大养殖户参考。 相似文献
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通过对围产期与泌乳早期奶牛营养代谢特征及其与生产性能,繁殖率和健康关系的分析,作者提出改善能量负平衡,调整日粮营养组分,补充维生素和矿物质等营养调控手段,是降低奶牛代谢病发生率,改善繁殖性能,提高生产性能的有效策略. 相似文献
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热应激条件下日粮中添加氯化钾对奶牛生产性能和血液指标的影响 总被引:2,自引:2,他引:2
试验旨在研究热应激条件下,日粮中添加氯化钾对奶牛生产性能和血液理化指标的影响。选取45头荷斯坦泌乳牛,随机分为3组(n=15),在高温季节进行饲养试验,对照组饲喂基础日粮,试验Ⅰ、Ⅱ组分别在基础日粮中添加50、100 g/d氯化钾。试验结果表明,各组间血清游离脂肪酸(NEFA)、葡萄糖(GLU)、尿素氮(BUN)含量差异均不显著(P0.05);试验Ⅰ、Ⅱ组β-羟丁酸(BHBA)含量显著低于对照组(P0.05),但试验Ⅰ、Ⅱ组之间差异不显著(P0.05);试验Ⅰ、Ⅱ组平均日产奶量分别比对照组高1.6(P0.05)和0.7 kg(P0.05);各组间乳成分无显著变化(P0.05)。因此,夏季奶牛日粮中添加氯化钾可减缓产奶量的下降。 相似文献
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热应激对荷斯坦奶牛体温和呼吸的影响 总被引:1,自引:0,他引:1
本试验旨在研究热应激对不同泌乳阶段奶牛直肠温度、皮肤温度和呼吸频率的影响。选用不同泌乳阶段、胎次相近的荷斯坦奶牛18头,按泌乳天数分为泌乳前期、泌乳中期和泌乳后期3组,每组6个重复,根据牛舍温湿指数(THI)变化情况,进行热应激与非热应激的自身对照试验。结果表明:热应激极显著增加各泌乳阶段奶牛的直肠温度、皮肤温度和呼吸频率(P<0.01);THI与各泌乳阶段奶牛的直肠温度、皮肤温度、呼吸频率呈显著正相关(P<0.05);在同一环境下,不同泌乳阶段奶牛的直肠温度、皮肤温度及呼吸频率无显著差异(P>0.05)。热应激严重影响奶牛的直肠温度、皮肤温度和呼吸频率,与泌乳中、后期奶牛相比,热应激对泌乳前期奶牛的影响趋于较大。 相似文献
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为比较头胎奶牛与经产奶牛在围产阶段生产性能和血清生化指标的差异,本研究选取临床健康的头胎和经产奶牛各10头,在同等条件下饲喂全混合日粮,于预产期前7、4、2、1 d及产后0、1、2、4、7、14 d晨喂前尾静脉采血并分离血清,测定血糖、甘油三酯和血钙浓度,产后11~40 d记录产奶量,于产后第30天采集乳样,测定乳成分和体细胞数。结果显示,头胎奶牛与经产奶牛血清甘油三酯、乳脂、乳蛋白、乳糖和乳干物质等指标均无显著差异(P>0.05);经产牛产后日均产奶量和乳体细胞数均显著高于头胎牛(P<0.05);在分娩前第4天和分娩后第2、4天时,头胎牛血糖浓度显著高于经产牛(P<0.05),但在分娩时,头胎牛血糖浓度显著低于经产牛(P<0.05);头胎牛在产前第1、2天、分娩当天及产后第2天的血钙水平显著高于经产牛(P<0.05)。 相似文献
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In order to study the differences of productive performances and serum biochemical indices between primiparous and mulitiparous dairy cows during the perinatal period, ten primiparous and ten multiparous healthy dairy cows were selected and were fed the same total mixed ration.Blood samples were collected from the caudal vein before the morning feeding on -7, -4, -2, -1, 0, 1, 2, 4, 7 and 14 d after parturition, and serum glucose, triglyceride and calcium concentrations were determined. Milk yields were recorded every day from 11 to 40 days after parturition. Milk samples were collected from each experimental cow on 30th day after parturition and milk compositions and somatic cell counts were determined. The results indicated that no significant difference was observed in serum triglyceride, milk fat, milk protein, milk lactose and milk dry matter between primiparous and multiparous dairy cows (P>0.05). Mutiparous cows had greater daily milk yield and higher milk somatic cell count than primiparous cows (P<0.05). Primiparous cows had significant higher serum glucose level on -4, 2 and 4 d after parturition (P<0.05), but significant lower serum glucose level on calving date (P<0.05) when compared with multiparous cows. Higher serum calcium concentrations were found on -2, -1 and 2 d after parturition in primiparous cows than multiparous cows (P<0.05). 相似文献
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烟酸对热应激条件下奶牛生产性能、血清离子浓度的影响 总被引:3,自引:1,他引:2
本试验旨在研究向日粮中添加不同水平的烟酸对热应激条件下奶牛生产性能、维持行为及血清中离子浓度的影响。试验选择健康泌乳后期中国荷斯坦奶牛3头,采用3×3拉丁方设计,在基础日粮中添加0、8、 15 g/d 烟酸,试验期63 d。结果表明:①添加8、15 g/d烟酸与对照组相比热应激奶牛的产奶量提高29.9%(P<0.05)、22.0%(P<0.05),4%标准乳含量分别提高了28.5%(P<0.05)、21.5%(P<0.05),且不同添加水平间并无显著差异(P>0.05)。添加烟酸不影响奶牛的乳蛋白率、乳脂率和乳糖的水平;②添加8、15 g/d烟酸与对照组相比对热应激奶牛卧息和站立时间、排粪和排尿次数及饮水次数均无显著影响(P>0.05),但显著提高奶牛反刍时间(P<0.05),且不同添加水平间并无显著差异(P>0.05);③添加烟酸8、15 g/d与对照组相比均不同程度提高奶牛血清Ca2+、K+、Na+浓度,但两添加组间无显著差异(P>0.05);添加烟酸使奶牛血清Mg2+浓度提高,Cl-浓度降低,但未达显著水平(P>0.05)。综合分析试验奶牛生产性能、维持行为和血清离子浓度指标的变化,给热应激条件下奶牛补饲烟酸有助于缓解热应激,烟酸适宜添加量为8 g/d。 相似文献
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为了阐明日粮添加过瘤胃维生素D对围产期奶牛低钙血症的调控机制,在某集约化奶牛场选取40头奶牛,随机分为4组,对照组(C)饲喂基础日粮,试验Ⅰ、Ⅱ、Ⅲ组分别于产前10d至分娩后10d在日粮中每天添加1.5、3.0、6.0g/头过瘤胃维生素D。对4组试验奶牛围产期(分别于产前10、7、3、0d和产后3、7、10d)血清维生素D3(1,25-(OH)2D3)、钙、羟脯氨酸、甲状旁腺素和降钙素水平进行检测。结果表明,围产期奶牛血钙水平分娩时达最低,产后逐渐上升,且产前7d至产后10d对照组奶牛血钙浓度显著低于试验Ⅰ组(P<0.05);分娩当天试验Ⅰ组奶牛血浆中1,25-(OH)2D3、羟脯氨酸和降钙素水平显著高于对照组(P<0.05),甲状旁腺素水平显著低于对照组(P<0.05)。提示,日粮中每天添加1.5g/头过瘤胃维生素D能调节甲状旁腺素和降钙素等激素的分泌,促进肠道对钙的吸收,动员骨钙,从而防止奶牛产后低钙血的发生,且围产期奶牛低血钙症与机体血钙稳态调节作用密切关联。 相似文献
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为探究体况评分(Body Condition Score,BCS)和步态评分(Locomotion Score,LS)对奶牛泌乳性能的影响,本试验在2016年7月至8月通过对北京地区7个奶牛场近5 000头泌乳牛进行体况和步态评分并收集相关的DHI数据,采用固定模型分析BCS和LS的影响因素及场、胎次、泌乳阶段、LS和BCS对日产奶量、体细胞数及乳成分的影响。结果表明:BCS和LS对日产奶量均有极显著影响(P0.01),BCS对乳蛋白率有显著影响(P0.05);胎次对LS有极显著影响(P0.01),而对BCS无显著影响,场-测量人、泌乳阶段对BCS和LS均有极显著影响(P0.01);LS与BCS之间回归关系显著,LS较高的个体BCS较低。在生产上可以综合运用BCS和LS加强管理,提升产奶量,改善乳品质量,使牛场获得更大的经济利益。 相似文献
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This study aimed to assess the effect of ketone body status early postpartum on time empty in 74 multiparous dairy cows under field conditions. Animals were equally distributed across eight farms and were controlled by the same herd‐fertility‐monitoring programme. Cows were visited twice antepartum and six times postpartum at weekly intervals between 0530 and 0830 a.m. On these occasions, body condition scores and milk yields were measured, blood and milk samples were taken, cows were gynaecologically examined, and parameters of reproduction were recorded. Cows with a time empty of less or more than 80 days were classified as early and late conceiving cows (EC and LC, respectively). A time empty of 80 days results in calving‐to‐calving intervals of 1 year and classification based on this threshold value resulted in groups of equal size and equal distribution of EC and LC within farms. Ketone bodies measured were β‐hydroxybutyrate in blood and acetoacetate and acetone in blood and milk. Blood and milk ketone body concentrations, as well as the ratios of acetoacetate and acetone to β‐hydroxybutyrate, over the first 6 weeks postpartum were higher in LC than in EC, whereas plasma glucose and non‐esterified fatty acids and milk fat, protein and urea concentrations did not exhibit clear differences between groups. Ketone body concentrations were as good predictors of time empty as ketone body ratios and might have practical impact in herd‐fertility‐monitoring programmes. 相似文献
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