烟酸和胆碱对防治奶牛围产期脂肪肝和提高繁殖力的效果

经给３４头围产期奶牛口服烟酸和胆碱，试图预防和治疗脂肝病，同时监测受试牛血浆中某些相关生化指标和孕酮含量的变化。结果发现，和对照组比，试验组牛血浆中血糖浓度显著升高的同时，游离脂肪酸，谷草转氨酶和β－羟丁酸脱氢酶的含量显著降低；而白蛋白，总蛋白和镁的含量与对照组比，没有差异。烟酸和胆碱预防组牛中有３０％发生轻度到中度脂肪肝；对照组牛中有５％发生轻度到重度脂肪肝。在产后５周内，治疗组的脂肪肝患牛恢复     

投喂烟酸,胆碱和纤维素酶对患围产旨肪奶牛繁殖力的影响

给产后５天内诊断为脂肪肝的９头患牛投服烟酸，胆碱和纤维素酶。同时采血测定血浆内孕酮含量，并监测受试牛产后繁殖力指标：子宫复旧时间，产后首次排卵时间，首次发情时间，分娩至受孕的间隔时间。试验结果：试验组奶牛血浆Ｐ４值在产后２０天内与对照组奶牛无明显差异，但在２０天以后试验组明显高于对照组，而对照组在产后２０－３０天与产后１５－２０天相比无明显差异；     

烟酸胆碱和纤维素酶提高围产期脂肪肝奶牛繁殖力的研究

给产后5天内诊断为脂肪肝的9头患牛投服烟酸、胆碱和纤维素酶，同时采血测定血浆内孕酮（P4）含量，并监测受试牛产后繁殖力指标：子宫复旧时间、产后首次排卵时间、首次发情时间、分娩至受孕的间隔时间。试验结果，试验组奶牛血浆P4值在产后20天内与对照组奶牛无明显差异，20天后试验组明显高于对照组，而对照组在产后20～30天与产后15～20天相比无明显差异；子宫复旧时间和产后首次排卵时间，试验组分别比对照组平均早4．0天和4．8天，而产后首次发情时间和分娩至受孕的间隔时间，试验组比对照组平均早17天和23天。     

投喂烟酸、胆碱和纤维素酶对患围产期脂肪肝奶牛繁殖力的影响

给产后５天内诊断为脂肪肝的９头患牛投服烟酸、胆碱和纤维素酶。同时采血测定血浆内孕酮（Ｐ４）含量，并监测受试牛产后繁殖力指标：子宫复旧时间、产后首次排卵时间、首次发情时间、分娩至受孕的间隔时间。试验结果：试验组奶牛血浆Ｐ４值在产后２０天内与对照组奶牛无明显差异，但在２０天以后试验组明显高于对照组，而对照组在产后２０－３０天与产后１５－２０天相比无明显差异；子宫复旧时间和产后首次排卵时间，试验组分别比对照组平均早４０天和４８天，而产后首次发情时间和分娩至受孕的间隔时间，试验组比对照组平均早１７天和２３天。     

过瘤胃烟酸和胆碱对围产期奶牛泌乳性能和肝脂质代谢的影响

旨在研究日粮中添加过瘤胃保护烟酸(rumen-protected niacin,RPN)和过瘤胃保护胆碱(rumen-protected choline,RPC)对围产期奶牛泌乳性能和肝脂质代谢的影响,为缓解奶牛脂肪肝提供理论依据.本试验选用24头健康、胎次相近的中国荷斯坦围产期奶牛,根据2×2试验设计分为4组,每组6...     

科苑采撷

用溶菌酶治疗奶牛子宫内膜炎效果好经临床１３６例治疗奶牛产后子宫内膜炎试验观察，溶菌酶对奶牛子宫内膜炎的总治愈率、治疗后各组子宫恢复的程度均较抗生素治疗组和空白对照组明显好，对子宫内膜炎的治愈率为８２．３５％～８８．２４％，明显好于金霉素的治愈率５６．２５％。溶菌酶试验组平均受胎率为７５．３８％，明显高于抗生素对照组的５６．２５％，空白对照组的１５．６３％。治愈牛产后至初配平均天数也较短。纤维素酶在蛋鸡料中的作用在蛋鸡常规饲料中添加０．１％复合纤维素酶，试验组的产蛋率比对照组提高１０．８％，蛋重提…     

纤维酶制剂对奶牛产奶量和饲料效率的影响

试验选用18头黑白花奶牛,随机地分为3组,每组6头。日粮中分别加入0、50和100g纤维素酶/头·天。结果表明,试验期间,平均每头日产4％标准奶量为18.66、20.21(比对照组提高8.30％)和18.70kg;每公斤产奶量所耗饲料量为0.90、0.81、0.93kg。另外,纤维素酶制剂对奶的营养组成无明显影响。     

烟酸和烟酸铬对热应激奶牛产奶性能、血液生理生化指标的影响

选择2~4胎次泌乳中期的荷斯坦牛15头,配对分为3组,在7~9月进行60d的饲养试验,对照组使用基础日粮,两个试验组分别在基础日粮中添加烟酸800 mg/kg和烟酸铬10 mg/kg。结果表明:在持续高温天气下奶牛处于热应激状态。烟酸铬和烟酸均使奶牛体温上升幅度相对较小;烟酸铬还可以保持其呼吸率正常。二者均使产奶量下降幅度较小;烟酸铬组奶牛的乳脂率明显高于对照组和烟酸组(P<0.05);二者也使乳中挥发性脂肪酸比对照组明显提高(P<0.05),但对其他乳成分无显著影响(P>0.05)。二者都能够维持奶牛血清T3、T4、COR、PRL水平的基本恒定;均显著降低了尿素氮和胆固醇水平(P<0.05)。烟酸铬使奶牛的血液白细胞数和淋巴细胞百分比增加;烟酸仅使血液白细胞数增加。     

灌注烟酸、核黄素对奶牛生产性能和血液参数的影响

选5头经产并装有永久性十二指肠瘘管的中国荷斯坦奶牛,采用5×5拉丁方试验设计,分为对照组(烟酸和核黄素,0 g/d)、烟酸组(烟酸,3 g/d)、核黄素组(核黄素,0.3 g/d)、烟酸+核黄素组(烟酸3 g/d+核黄素0.3 g/d)、VB混合物组(烟酸3 g/d+核黄素0.3 g/d+硫胺素0.03 g/d+泛酸0.42 g/d+吡哆醇0.03 g/d+生物素0.04 g/d+叶酸0.04 g/d),以研究十二指肠灌注烟酸、核黄素、烟酸+核黄素、VB混合物对奶牛生产性能、血液参数及牛奶风味的影响。结果表明,奶牛干物质采食量和产奶量在烟酸+核黄素组、VB混合物组中增加(P<0.05),在烟酸组、核黄素组中无显著改变(P>0.05);外周血红细胞数和血红蛋白含量在VB混合物组中增加(P<0.05),在烟酸+核黄素组中降低(P<0.05),在烟酸组中无显著变化(P>0.05),核黄素组外周血红细胞数降低(P<0.05),血红蛋白含量无显著改变(P>0.05),处理组间其余外周血红细胞参数、血小板参数及牛奶风味均无显著差异(P>0.05)。因此,泌乳奶牛十二指肠灌注烟酸+核黄素、VB混合物可以提高奶牛生产性能,且VB混合物对外周血红细胞数量和血红蛋白含量具有提高作用,经十二指肠灌注烟酸、核黄素、烟酸+核黄素、VB混合物对牛奶风味无副作用,且烟酸+核黄素、VB混合物组牛奶风味较对照组更佳。     

烟酸及胆碱对围产期奶牛营养代谢的调控

围产期是奶牛泌乳周期中十分重要的时期,奶牛要经历生理、日粮、环境和管理等一系列变化,因此,采食量下降,机体处于能量和其他营养素的负平衡状态,易诱发多种代谢性疾病,如脂肪肝和酮病等。烟酸和胆碱能够调控脂肪代谢,提高产后泌乳性能,改善奶牛健康。本文总结了烟酸和胆碱的理化性质、生理功能及其对围产期奶牛营养代谢的调控机理,为进一步研究烟酸、胆碱在奶牛围产期合理应用及保障围产期奶牛健康提供参考。     

Efficacy of sodium borate in the prevention of fatty liver in dairy cows

The effects of sodium borate (100 mg/kg body weight, p.o., 15 days) from a month before expected calving until a month after calving were evaluated in dairy cows susceptible to fatty liver. Cows received either sodium borate (n = 13) or no treatment (n = 10). All cows had mild fatty livers and increased plasma triglycerides and very low density lipoprotein (VLDL) concentrations at the beginning of the experiment. The control group of cows developed significant fatty liver after calving, and 2 of them had severe fatty liver associated with clinical and biochemical abnormalities. There were no clinicopathological signs related to sodium borate administration. Serum triglycerides and VLDL concentrations before calving decreased significantly at calving and after calving in controls, and they were within the normal range only after calving. There were significant alterations during the experiment in some hematological and chemical variables between groups, within period, but they were within the normal range. Unlike treated cows, serum triglycerides and VLDL concentrations correlated with liver fat content after calving in untreated cows. Our results document that sodium borate decreases the degree of fatty liver in dairy cows during early lactation.     

Reduced fertility associated with fatty liver in high-yielding dairy cows

In a group of 20 high-yielding dairy cows, 10 with mild and 10 with severe fatty liver one week after calving, there was an association between fatty liver and reduced fertility. The 10 cows with severe fatty liver had a significantly longer calving interval to the next lactation compared to the cows with mild fatty liver. In addition there was a significant positive correlation between the amount of fat in the liver and calving interval. The results support the concept that liver dysfunction at calving adversely affects subsequent fertility.     

Fatty acid profiles in relation to triglyceride level in the liver of dairy cows

To elucidate possible relationships between triglyceride (TG) levels and fatty acid composition in bovine liver, hepatic TG and seven individual fatty acids were measured in 23 Holstein dairy cows, of them 6 are healthy. Liver TG level was greater than 3 % in 12 cows which were ruled fatty liver. Palmitic and oleic acid proportions were significantly higher in fatty liver cows than in the healthy cows, while stearic acid was lower in fatty liver cows. With increased liver TG, stearic acid proportions decreased dramatically. Results indicate that hepatic lipidosis markedly alters the proportions of the various fatty acids in the liver of dairy cows.     

日粮添加益生菌对干乳期奶牛生长性能、瘤胃发酵及氮平衡的影响

本研究旨在评估全混合日粮添加益生菌对干乳期奶牛生长性能、瘤胃发酵及氮平衡的影响.试验将体重为(440.92±3.33)kg、平均干乳期为42?d的60头荷斯坦奶牛随机分为2组,每组5个重复,每个重复6头.对照组饲喂玉米-豆粕型全混合日粮,处理组饲喂基础全混合日粮+200?mg/kg益生菌(枯草芽孢杆菌含量:1×106?...     

玉米秸秆饲粮条件下阴外动脉灌注氨基酸混合物对奶牛乳腺内短链脂肪酸摄取规律的影响

本试验采用动静脉血插管技术,以泌乳中期荷斯坦奶牛为研究对象,研究玉米秸秆饲粮条件下阴外动脉灌注氨基酸(AA)混合物对奶牛产奶性能、尾动脉血和乳静脉血中短链脂肪酸(SCFA)浓度及其比例以及乳腺内SCFA摄取规律的影响。采用2×2交叉试验设计,将体况良好、体重相近、日乳产量为(20.17±1.28)kg的8头经产(2~3胎)荷斯坦奶牛随机分为采食不同饲粮的2组[苜蓿组(MF组)和玉米秸秆组(CS组)],每组4头。2组奶牛饲喂的饲粮精粗比均为45∶55,精饲料组成相同,粗饲料组成不同,MF组粗饲料由苜蓿干草、玉米青贮和羊草组成,CS组以单一的玉米秸秆全部替代MF组饲粮中的粗饲料。试验分为2个阶段,每个阶段20 d,均分为饲粮适应期(预试期)14 d,载体灌注期3 d,正式灌注期3 d。在第1阶段,在载体灌注期,MF组奶牛接受载体灌注(阳性对照组1),CS组奶牛也接受载体灌注(对照组);在正式灌注期,MF组奶牛继续接受载体灌注(阳性对照组2),CS组奶牛接受AA混合物灌注;在第2阶段,将2组动物互换后处理方法同第1阶段。每个正式灌注期的最后2 d采集乳样和血样。结果显示:CS组奶牛阴外动脉灌注AA混合物可显著提高乳蛋白率(P0.05),对乳产量、4%乳脂校正乳(FCM)产量、乳脂率、乳脂产量、乳蛋白产量有一定促进效果,但部分指标仍然显著低于MF组(P0.05)。CS组奶牛阴外动脉灌注AA混合物可趋于显著地提高乳静脉血中乙酸的浓度(P=0.09),显著降低乳腺内乙酸的动静脉差(P0.05),缩小CS组与MF组奶牛在乳腺对乙酸的摄取量和摄取效率方面存在的差距。CS组奶牛阴外动脉灌注AA混合物对提高尾动脉血中乙酸/丙酸、(乙酸+丁酸)/丙酸有一定的促进效果(P0.05)。由此得出,以玉米秸秆为粗饲料的奶牛阴外动脉灌注AA混合物可显著提高乳蛋白率,增加乳静脉血中的乙酸浓度,同时缩小与以苜蓿干草、玉米青贮和羊草为粗饲料的奶牛在乳腺对乙酸的摄取量和摄取效率方面存在的差距。     

围产期奶牛脂肪肝生物标志物受试者工作特征曲线分析

[目的] 通过受试者工作特征（receiver operating characteristic，ROC）曲线筛选诊断脂肪肝生物标志物的最佳临界值。[方法] 随机采集77头产后7 d中国荷斯坦奶牛血清，测定生理生化指标。根据Reid方程计算的Y值将奶牛分为正常组（Y>1）和脂肪肝组（Y<1），比较两组奶牛血清指标的差异，并与Y值进行相关性分析，筛选组间差异与相关性显著的指标作为生物标志物，用ROC曲线评估生物标志物的AUC值、诊断敏感性与特异性和最佳临界值。将Reid方程诊断脂肪肝的准确率作为标准，用非酯化脂肪酸（NEFA）、谷草转氨酶（AST）的最佳临界值检测461头奶牛患脂肪肝的情况。[结果] 生理生化检测结果表明NEFA、葡萄糖（Glu）、AST、谷丙转氨酶（ALT）在2组间差异极显著（P<0.01），总蛋白（TP）组间差异显著（P<0.05），其他指标两组间无显著差异（P>0.05）；NEFA、Glu、AST、ALT、TP、甘油三酯（TG）、低密度脂蛋白胆固醇（LDL-C）、胰岛素（Ins）、胰高血糖素（Gln）与Y值显著相关（P<0.05），可作为生物标志物；NEFA、AST、ALT和Gln的AUC值>0.5能准确诊断脂肪肝，诊断敏感性分别为81.8%、72.7%、63.6%和54.5%，特异性分别为92.8%、89.4%、84.8%和69.7%，最佳临界值分别为471.74 μmol/L、95.50 U/L、46.50 U/L和64.60 ng/mL。用NEFA、AST和NEFA+AST最佳临界值诊断脂肪肝的准确率分别高达89.96%、73.49%和69.08%。Y值诊断发病率为54.01%，NEFA、AST、NEFA+AST诊断出的发病率分别为48.59%、39.70%和37.31%。[结论] NEFA、AST、ALT和Gln可用于快速、准确地诊断脂肪肝。     

不同能量物质对泌乳奶牛产奶性能的影响

本文探讨了不同能量补充物质对泌乳奶牛生产的影响。,以麸皮作对照,用全棉籽、膨化全脂大豆和脂肪酸钙作为能量补充物质,35d试验结果显示,奶牛产奶量分别提高了6．7％、14．4％和18．2％．．乳脂肪分别提高19．（／9％、11．82％和11．21％、经济效益分别比对照组提高4．20、5．36和8．72．＇L／（头·d）!试验表明,全棉籽、膨化全脂大豆和脂肪酸钙作为能量补充物质,可减轻夏季热应激,提高牛奶产量和牛奶品质,尤以脂肪酸钙效果最佳。     

Total serum bile acid concentrations in dairy cows with fatty liver and liver failure

In forty-five Holstein Frisian dairy cows (1-6 weeks post partum; mean age: 5.1 +/- 1.2 years) the serum total bile acid concentrations (SBA) were measured enzymatically. In all cows a left sided abomasal displacement was corrected surgically by right side laparotomy and omentopexy three days before investigation. The liver fat content was determined in all cows histologically. Liver failure was assumed if typical clinical signs (ataxia, general depression, recumbency or coma), an increased venous plasma ammonia level (> 35 mumol/l) and a decreased plasma amino acid index (< 4.0) were found. Cows without liver failure (N = 29) were grouped according to the liver fat content as cows with mild (N = 5), moderate (N = 19) or severe hepatosteatosis (N = 5). Histological examination of liver biopsies in cows with liver failure (N = 16) revealed in twelve cases a severe fatty liver and in four cases a hydropic degeneration of the liver tissue. Although in cows without liver failure mean SBA concentrations were higher in the group with moderate (47.3 +/- 30.9 mumol/l) or severe fatty liver (32.9 +/- 21.7 mumol/l) than in that with mild lipidosis (18.0 (16.8 mumol/l), differences were not significant. The mean SBA concentration in cows with liver failure (70.5 +/- 49.5 mumol/l) was only significantly (p < 0.05) increased compared to cows with uncomplicated mild hepatic lipidosis. In conclusion, the determination of SBA concentrations is of little value in the recognition of fatty liver or even liver failure due to the considerable variance of SBA concentrations in dairy cows.     

归芪益母复方制剂对产后奶牛瘤胃微生物和短链脂肪酸的调节

本试验旨在探究归芪益母复方制剂对产后奶牛瘤胃微生物和短链脂肪酸的调节作用。将19头待产的健康荷斯坦奶牛随机分为两组,对照组10头,试验组9头。试验组奶牛产后每天灌服归芪益母复方制剂500 mL,对照组奶牛每天灌服等体积饮用水,连续6 d。产后第7天晨饲前采集瘤胃液,采用16S rRNA高通量测序和GC-MS/MS靶向代谢组学技术对两组奶牛瘤胃菌群的丰度和短链脂肪酸的含量进行了测定。结果表明,与对照组相比,试验组奶牛瘤胃变形菌门(Proteobacteria)、Escherichia-Shigella属和拟杆菌属(Bacteroides)的菌群丰度极显著升高(P<0.01),乳杆菌属(Lactobacillus)和Subdoligranulum属菌群丰度显著升高(P<0.05)。试验组奶牛瘤胃丙酸(P<0.05)和异丁酸(P<0.01)含量明显升高。本研究从瘤胃微生物菌群及短链脂肪酸角度揭示了归芪益母方对产后奶牛的保健机制。