苜蓿鲜草部分替代苜蓿青干草对奶牛生产性能和血清生化指标的影响北大核心CSCD

本试验旨在研究苜蓿鲜草替代不同比例苜蓿青干草对奶牛生产性能、消化代谢和血清生化指标的影响。选用18头体重、胎次、产奶量相近,处于泌乳中期的健康荷斯坦奶牛,随机分成3组,每组6头。对照组饲喂基础饲粮,试验Ⅰ组和试验Ⅱ组分别饲喂以苜蓿鲜草替代基础饲粮中50%和75%苜蓿青干草的试验饲粮。预试期15 d,正试期30 d。结果表明:1)苜蓿鲜草替代不同比例苜蓿青干草对奶牛干物质采食量和产奶量均无显著影响(P>0.05),但各试验组乳体细胞数均显著低于对照组(P<0.05)。2)苜蓿鲜草替代不同比例苜蓿青干草对奶牛营养物质表观消化率无显著影响(P>0.05)。3)苜蓿鲜草替代不同比例苜蓿青干草对奶牛血清中总蛋白、白蛋白、球蛋白、胆固醇、葡萄糖、甘油三酯、高密度脂蛋白、低密度脂蛋白含量及谷丙转氨酶、谷草转氨酶、碱性磷酸酶活性均无显著影响(P>0.05)。试验Ⅰ组奶牛的血清尿素氮含量显著高于对照组和试验Ⅱ组(P<0.05),对照组和试验Ⅱ组之间无显著差异(P>0.05)。4)与对照组相比,试验Ⅰ组和试验Ⅱ组的经济效益均有所增加,其中试验Ⅱ组净增收益最高,为9.06元/(头·d)。综合得出,苜蓿鲜草可以部分替代奶牛饲粮中苜蓿青干草而不影响生产性能、消化代谢和血清生化指标,且能增加经济效益。     

青贮笋壳对奶牛生产性能及部分血清生化指标的影响

为研究青贮笋壳在奶牛生产中的应用效果，试验选用15头健康荷斯坦奶牛随机分成3组，即对照组、试验1组（6 kg青贮笋壳替代对照组日粮中1.5 kg的苜蓿干草）和试验2组（9 kg青贮笋壳替代对照组日粮中2.5 kg的苜蓿干草），进行为期60 d的饲养试验，其中预饲期10 d，正式期50 d。试验结果表明，试验1组产奶量较对照组和试验2组有所提高，但差异不显著（P＞0.05），试验1组4%标准奶产量则显著高于试验2组和对照组（P＜0.05）。试验1组乳脂率显著高于试验2组和对照组（P＜0.05），其他乳成分含量各试验组均较对照组有所改善（P＞0.05）。奶牛各项血清生化指标试验组和对照组间无显著差异，均处于正常生理范围。因此，青贮笋壳可以替代部分苜蓿干草在奶牛日粮中使用。     

饲粮中添加籽粒苋对泌乳奶牛瘤胃发酵、血液指标和生产性能的影响

本试验旨在研究饲粮中添加籽粒苋青贮和干草对泌乳奶牛瘤胃发酵、营养物质表观消化率、血液指标和生产性能的影响。选取产奶量、胎次和泌乳天数等相近的健康荷斯坦奶牛45头,随机分成3组,每组15头牛。对照组粗饲料包括全株玉米青贮、羊草和苜蓿干草,试验Ⅰ组粗饲料使用籽粒苋青贮替代30%玉米青贮,试验Ⅱ组粗饲料使用籽粒苋干草替代30%苜蓿干草。3组饲粮营养水平接近。预试期10 d,正试期60 d。结果表明:1)与对照组相比,试验Ⅰ组能显著提高粗蛋白质(CP)表观消化率、瘤胃液氨态氮(NH_3-N)和血液总氨基酸(T-AA)的含量(P0.05),对其他营养物质表观消化率、血液指标和乳成分影响不显著(P0.05)。2)与对照组相比,试验Ⅱ组的血液T-AA含量显著高于对照组(P0.05),对其他血液指标、瘤胃发酵指标、营养物质表观消化率和乳成分均无显著影响(P0.05)。综上所述,饲粮中添加适量的籽粒苋不会影响奶牛的生产性能,同时会提高牧场经济效益。     

苜蓿鲜草部分替代苜蓿青干草对奶牛生产性能和血清生化指标的影响

本试验旨在研究苜蓿鲜草替代不同比例苜蓿青干草对奶牛生产性能、消化代谢和血清生化指标的影响。选用18头体重、胎次、产奶量相近,处于泌乳中期的健康荷斯坦奶牛,随机分成3组,每组6头。对照组饲喂基础饲粮,试验Ⅰ组和试验Ⅱ组分别饲喂以苜蓿鲜草替代基础饲粮中50%和75%苜蓿青干草的试验饲粮。预试期15 d,正试期30 d。结果表明:1)苜蓿鲜草替代不同比例苜蓿青干草对奶牛干物质采食量和产奶量均无显著影响(P0.05),但各试验组乳体细胞数均显著低于对照组(P0.05)。2)苜蓿鲜草替代不同比例苜蓿青干草对奶牛营养物质表观消化率无显著影响(P0.05)。3)苜蓿鲜草替代不同比例苜蓿青干草对奶牛血清中总蛋白、白蛋白、球蛋白、胆固醇、葡萄糖、甘油三酯、高密度脂蛋白、低密度脂蛋白含量及谷丙转氨酶、谷草转氨酶、碱性磷酸酶活性均无显著影响(P0.05)。试验Ⅰ组奶牛的血清尿素氮含量显著高于对照组和试验Ⅱ组(P0.05),对照组和试验Ⅱ组之间无显著差异(P0.05)。4)与对照组相比,试验Ⅰ组和试验Ⅱ组的经济效益均有所增加,其中试验Ⅱ组净增收益最高,为9.06元/(头·d)。综合得出,苜蓿鲜草可以部分替代奶牛饲粮中苜蓿青干草而不影响生产性能、消化代谢和血清生化指标,且能增加经济效益。     

饲粮中添加禾王草对泌乳奶牛瘤胃发酵和生产性能的影响

为提高牧场养殖经济效益,本文研究了饲粮中添加禾王草青贮或干草对泌乳奶牛瘤胃发酵、营养物质消化率和生产性能的影响。选取45头健康荷斯坦奶牛,按产奶量、胎次和泌乳天数等相近原则随机分成3组。对照组饲粮粗饲料由全株玉米青贮、羊草和苜蓿干草构成,试验Ⅰ组粗饲料由禾王草青贮、全株玉米青贮、羊草和苜蓿干草构成,试验Ⅱ组粗饲料由禾王草干草、全株玉米青贮和苜蓿干草构成,3组饲粮营养水平相近。预试期10 d,正试期60 d。结果表明:1)与对照组相比,试验Ⅰ组能显著提高瘤胃液氨态氮含量和乙酸含量、乳蛋白率(P0.05),对其他乳成分、干物质采食量(DMI)、产奶量和营养物质消化率影响不显著(P0.05),每头牛每天多盈利1.19元。2)与对照组相比,试验Ⅱ组能显著降低瘤胃液氨态氮含量(P0.05),对乳成分和营养物质消化率没有显著影响(P0.05),能提高奶牛的DMI和产奶量,差异不显著(P0.05),每头牛每天多盈利2.07元。由此可知,用禾王草青贮代替适量全株玉米青贮或用禾王草干草代替部分苜蓿干草不会影响奶牛的生产性能,同时会提高牧场奶牛养殖经济效益。     

苜蓿青贮饲用价值及经济效益分析

为规模化牧场苜蓿青贮的应用和推广提供科学依据。日粮中以苜蓿青贮替代部分苜蓿干草、玉米青贮及羊草,进行饲喂效果及饲喂成本对比,探讨苜蓿青贮对产奶量、乳品质及饲喂成本的影响。结果表明:奶牛日粮中添加苜蓿青贮,试验组奶牛日均产奶量、乳脂率、乳蛋白率和干物质含量均高于对照组,但两组差异不显著(P0.05)。试验组日粮成本降低4.96元/头,明显提高养殖经济效益。     

甘草茎叶对绵羊生长性能和血液生理生化指标的影响

试验研究甘草茎叶替代苜蓿干草对绵羊生长性能和血液生理生化指标的影响。对照组、试验Ⅰ组、试验Ⅱ组绵羊分别用0%、25%、50%甘草茎叶替代饲粮中苜蓿干草。结果表明:对照组平均日增重显著高于试验Ⅰ组(P0.05),极显著高于试验Ⅱ组(P0.01),且随着甘草茎叶的替代苜蓿水平的增加,绵羊的日增重反而呈现出降低的趋势。试验第55 d,试验Ⅰ、Ⅱ组绵羊血清中白细胞、红细胞、平均血红蛋白量、平均血红蛋白浓度与对照组相比差异均不显著(P0.05),但试验Ⅱ组绵羊血液血红蛋白水平显著高于对照组(P0.05)。试验Ⅰ组血清中谷草转氨酶水平显著低于对照组(P0.05),试验Ⅰ、Ⅱ组血清中总蛋白、白蛋白水平显著高于对照组(P0.05),试验Ⅰ组血清中磷水平显著高于对照组(P0.05);试验Ⅰ、Ⅱ组绵羊血清中谷丙转氨酶、球蛋白、碱性磷酸酶、葡萄糖、甘油三酯、总胆固醇、低密度脂蛋白、尿素氮、肌酐、钙水平与对照组相比差异均不显著(P0.05)。甘草茎叶替代苜蓿干草的比例应低于25%,甘草茎叶能在一定程度上提高动物的免疫功能。     

燕麦青贮替代燕麦干草和羊草对奶牛生产性能及血清生化指标的影响

试验旨在分析燕麦青贮替代日粮中燕麦干草和羊草对奶牛生产性能和血清生化指标的影响。选取平均胎次、体重、产奶量差异均不显著的荷斯坦泌乳奶牛32头，随机分为4组，每组8个重复，每个重复1头奶牛。对照组奶牛饲喂基础日粮，试验组分别使用等干物质含量的燕麦青贮替代基础日粮中的100%燕麦干草（Ⅰ组）、50%燕麦干草（Ⅱ组）和100%羊草（Ⅲ组）。预试期14 d，正式试验期35 d。结果显示，燕麦青贮的干物质（DM）、酸性洗涤纤维（ADF）、中性洗涤纤维（NDF）含量均低于燕麦干草和羊草（P<0.05）,Ca含量显著高于燕麦干草和羊草（P<0.05）。与对照组相比，Ⅰ组、Ⅱ组奶牛的乳脂率显著提高（P<0.05），Ⅱ组乳脂量显著提高（P<0.05），试验Ⅱ组、Ⅲ组的乳蛋白率显著提高（P<0.05）。试验Ⅱ组奶牛的养殖利润高于其他组。研究表明，使用燕麦青贮替代燕麦干草和羊草对奶牛生产性能和机体健康无不良影响，且使用燕麦青贮替代50%燕麦干草可提高奶牛的产奶量和乳品质，经济效益较好。     

全株水稻青贮替代全株玉米青贮对泌乳奶牛生产性能、血清生化指标、抗氧化能力和免疫能力的影响

为研究全株水稻青贮替代全株玉米青贮对泌乳后期奶牛生产性能、血清生化指标、抗氧化能力和免疫功能的影响,试验选用健康状况良好、胎次相近（2 ~ 4胎）、平均泌乳量（16.63±4.22） kg/d、泌乳天数和体重相近的荷斯坦泌乳后期奶牛45头,随机分成3个组,每组15头牛。对照组饲喂全混合饲粮,其中粗饲料由全株玉米青贮、全株燕麦干草和苜蓿干草组成,试验Ⅰ组和试验Ⅱ组分别用全株水稻青贮替代对照组饲粮中35%和70%的全株玉米青贮（干物质基础）,其他原料不变,预试期10 d,正试期30 d。结果表明：（1）对照组的干物质采食量显著高于试验I组和试验II组（P < 0.01）,且试验I组显著高于试验II组（P < 0.01）,其他指标无显著差异（P ＞ 0.05）。（2）试验Ⅱ组血清总蛋白含量显著低于对照组和试验Ⅰ组（P < 0.01）|试验Ⅰ组和试验Ⅱ组血清尿素氮含量显著高于对照组（P < 0.01）|各组之间其他各项血清生化指标差异均不显著（P > 0.05）。（3）试验Ⅰ组血清硫氧还蛋白还原酶含量显著低于对照组和试验Ⅱ组（P < 0.05）,各组之间其他各项血清抗氧化指标差异不显著（P > 0.05）。（4）试验Ⅰ组血清中免疫球蛋白A和免疫球蛋白M含量显著高于对照组和试验Ⅱ组（P < 0.05）。各组之间血清免疫球蛋白G差异不显著（P > 0.05）。综上所述,全株水稻青贮替代饲粮中35%的全株玉米青贮降低了奶牛干物质采食量,并且能提高泌乳后期奶牛的免疫能力。在生产中,使用全株水稻青贮部分替代全株玉米青贮,有利于降低泌乳奶牛饲养成本,提高免疫能力,为提高全株水稻青贮在畜牧业中的应用提供数据支持。 [关键词] 泌乳奶牛|全株水稻青贮|全株玉米青贮|血清生化指标|抗氧化能力|免疫能力     

杞柳条熟皮替代苜蓿对奶牛泌乳性能的影响

为了测定杞柳条熟皮的饲用价值以及替代苜蓿饲喂奶牛的效果,探讨其适宜的饲喂量,试验采用单因素完全随机分组设计方法,将24头体重、胎次、泌乳日龄、产奶量基本一致的健康荷斯坦奶牛随机分为4组,每组6头,对照组饲喂基础日粮,试验1组用2 kg杞柳条熟皮替代0.5 kg苜蓿干草,试验2组用4 kg杞柳条熟皮替代1.5 kg苜蓿干草,试验3组用8 kg杞柳条熟皮替代3.5 kg苜蓿干草,测定了杞柳条熟皮的营养成分以及奶牛泌乳性能,并进行了经济效益分析。结果表明:1)杞柳条熟皮具有较高的饲用价值,完全可以替代青贮玉米和羊草或部分替代苜蓿作为反刍家畜的粗饲料,具有很大的开发利用价值。2)与对照组比较,试验1,2组泌乳量无显著变化(P0.05),试验3组泌乳量显著下降(P0.05);各试验组乳脂率显著上升(P0.05),其他乳成分无显著变化(P0.05);每生产1 kg 4%标准乳,试验1,2,3组分别节约成本0.03元、0.12元和0.28元,每头奶牛日净收入试验1,2组分别增加1.14元和0.68元,试验3组减少0.49元。说明2 kg杞柳条熟皮替代0.5 kg苜蓿干草饲喂奶牛最适宜,但4 kg杞柳条熟皮替代1.5 kg苜蓿干草也能取得较好的经济效益。     

苜蓿青贮料替代苜蓿青干草对奶牛生产性能及乳品质的影响

试验旨在探讨苜蓿青贮料替代不同比例苜蓿青干草对奶牛生产性能、乳品质、营养物质表观消化率、血液生化指标及经济效益的影响。选取体重、产奶量、胎次相近的健康泌乳中期中高产中国荷斯坦奶牛15头,随机分为3组,每组5个重复,每个重复1头牛。对照组饲喂4.0 kg苜蓿青干草,试验A、B组分别用4.4,8.8 kg苜蓿青贮料代替2.0和4.0 kg等干物质的苜蓿青干草,正试期64 d。结果表明,1)各组间干物质采食量差异不显著(P>0.05),B组产奶量显著低于对照组(P<0.05),A组与对照组、B组间差异不显著(P>0.05); 2)用50%,100%的苜蓿青贮料替代等干物质的苜蓿青干草,其乳蛋白、乳脂率、乳糖均有所改善,但只有B组的乳脂率显著高于对照组(P<0.05),其余指标各组间差异均不显著(P>0.05);3)A、B组与对照组的中性洗涤纤维表观消化率、钙表观消化率无显著性差异(P>0.05),A、B组间粗蛋白和磷表观消化率差异不显著(P>0.05),但是粗蛋白表观消化率均显著低于对照组、磷表观消化率均显著高于对照组(P<0.05);4)苜蓿青贮料替代苜蓿青干草其血清总蛋白、白蛋白、血尿素氮、血糖、二氧化碳结合力等指标没有显著性改变(P>0.05);5)试验A、B组经济效益均有所增加,其中A组的净增收益最高,为0.61元/(头·d)。综上,用4.4 kg苜蓿青贮料代替2.0 kg苜蓿青干草对中高产奶牛是适宜的,能提高其生产性能,改善乳品质,增加收益。     

热应激条件下粗饲料组合对奶牛氮素利用的影响

为了研究粗饲料组合对热应激奶牛氮素利用的影响,试验选取20头胎次和泌乳天数相似的健康荷斯坦奶牛,随机分成2组,每组10头,分别饲喂2种粗饲料组合饲粮:玉米青贮+苜蓿(0.92∶1.00,AF组)和玉米秸秆(CS组)。2组饲粮精料相同,精粗比均为63.7∶36.3。预试期1周,正试期8周。结果表明:1)与CS组相比,AF组奶牛产奶量及能量校正乳、4%脂肪校正乳、乳蛋白和乳糖产量显著或极显著升高(P0.01或P0.05)。2)奶牛对AF组饲粮粗蛋白质表观消化率极显著高于CS组(P0.01)。3)与CS组相比,AF组瘤胃微生物蛋白产量显著升高(P0.05),而尿液和血液尿素氮浓度极显著降低(P0.01)。4)与CS组相比,AF组氮摄入量和乳中氮产量极显著升高(P0.01),但氮转化效率显著降低(P0.05)。结果提示,与玉米秸秆相比,玉米青贮+苜蓿的组合能提高饲粮粗蛋白质水平,增加热应激奶牛粗蛋白质表观消化率,促进瘤胃微生物蛋白和乳蛋白的合成,但氮的转化效率有待提高。     

Substitution of fresh forage ramie for alfalfa hay in diets affects production performance,milk composition,and serum parameters of dairy cows

We hypothesized that ramie, Boehmeria nivea (a nettle native to Asia), can be used as a high-quality forage to replace alfalfa hay in diets of dairy cows. Accordingly, we aimed to examine the effects of substituting fresh forage ramie for alfalfa (Medicago sativa) hay on production performance, milk composition, and serum parameters of dairy cows. Thirty-two Holstein cows (body weight (BW)?=?590?±?50.6 kg) were randomly divided into four groups of eight cows. The experimental period lasted 10 weeks. The dietary treatments consisted of four proportions of fresh forage ramie (0, 33, 67, and 100%) as a substitute for alfalfa hay (designated as CON, FR33, FR67, and FR100, respectively). On days 69 and 70 of the experimental period, milk and blood samples were collected for analysis. We found no significant differences in the milk yield and milk quality (milk protein percentage, milk fat percentage, and milk lactose percentage) between the treatments. We did find that forage ramie significantly reduced dry matter intake (DMI) and 4% fat-corrected milk (FCM) yield. Meanwhile, no significant differences were detected in serum parameters between the treatments, with the exception of triglyceride (TG) and alanine aminotransferase (ALT). In conclusion, our data indicate that alfalfa hay can be replaced with forage ramie in the diet of Holstein cows in the milk lactation stage, with no negative effects on milk quality and blood parameters.

     

苜蓿青干草替代部分精料对奶牛生产性能及经济效益的影响

本研究的目的在于探讨苜蓿青干草替代部分精料后对奶牛生产性能、牛奶品质和经济效益的影响,为在奶牛饲粮中合理利用苜蓿青干草和精料提供依据。选取体重、产奶量、胎次相近处于泌乳中期的中高产荷斯坦奶牛24头,随机分为4组。对照组日粮组成为全株玉米青贮料、花生秧和混合精料,精粗比为52∶48,试验A、B、C组分别用3 kg 苜蓿青干草替代1.5,2.0,3.0 kg精料,饲养期70 d。结果表明,试验A组、B组、C组产奶量极显著高于对照组(P<0.01),试验A组显著高于B组、C组(P<0.05),试验B组、C组差异不显著(P>0.05);试验A组、B组、C组的乳蛋白含量显著高于对照组(P<0.05),试验B组和C组显著高于A组(P<0.05);试验组的乳脂率极显著(P<0.01)和乳糖、干物质显著(P<0.05)高于对照组,各试验组之间差异不显著(P>0.05)。试验A组、B组干物质采食量显著高于对照组和C组(P<0.05),C组与对照组差异不显著(P>0.05),A组干物质采食量最高。试验组与对照组体细胞数差异不显著(P>0.05),但均较对照组低。试验B组、C组的粗蛋白表观消化率显著(P<0.05)和中性洗涤纤维表观消化率极显著(P<0.01)高于对照组,试验A组与对照组差异均不显著(P>0.05)。试验A组的纯增收益最高,为7.92元/d。由以上结果可知,用苜蓿青干草替代适量的精料补充料可以提高奶牛的生产性能,改善乳品质,增加收益,其中用3.0 kg苜蓿青干草替代1.5 kg精料组效果最好。     

奶牛常用蛋白质饲料和粗饲料的瘤胃降解特性研究

本研究旨在评定不同蛋白质饲料(豆粕、双低菜籽粕、膨化大豆、玉米蛋白粉、棉籽粕)和粗饲料(苜蓿干草、全株玉米青贮、燕麦草、苜蓿青贮、羊草)的营养价值,并研究其奶牛瘤胃降解特性.选择5头安装永久性瘤胃瘘管的健康荷斯坦牛,采用尼龙袋评定法评定饲料瘤胃有效降解率和动态降解率.结果表明:1)各蛋白质饲料干物质(DM)含量差异不显...     

Effects of Moringa oleifera silage on milk yield,nutrient digestibility and serum biochemical indexes of lactating dairy cows

This study investigated the effects of Moringa oleifera (MO) as a partial substitute of alfalfa hay on milk yield, nutrient apparent digestibility and serum biochemical indexes of dairy cows. MO was harvested at 120 days post‐seeding. Fresh MO was cut, mixed with chopped oat hay (425:575 on a DM basis), ensiled and stored for 60 days. Sixty healthy Holstein dairy cows were allocated to one of three groups: NM (no MO or control), LM (low MO; 25% alfalfa hay and 50% maize silage were replaced by MO silage) or HM (high MO; 50% alfalfa hay and 100% maize silage were replaced by MO silage). The feeding trial lasted 35 days. The LM and HM diets did not affect dry matter (DM) intake, milk yield or milk composition (lactose, milk fat, milk protein and somatic cell count). The apparent digestibility of DM and NDF was lower for HM group than NM group. Additionally, there were no significant differences in serum biochemical indexes between the LM and NM groups. The HM group had lower serum concentrations of total cholesterol, high‐density lipoprotein cholesterol, and low‐density lipoprotein cholesterol and higher serum concentrations of urea than the NM group. The partial replacement of alfalfa hay (≤50%) and maize silage with MO silage had no negative effects on milk yield, in vivo nutrient apparent digestibility or serum biochemical indexes of lactating cows.     

The Rumen Degradation Characteristics of Whole Sugarcane for Dairy Cows and Its Application in Substituting Alfalfa,Oat Hay and Concentrate in Dairy Cows' Diets

The purpose of this experiment was to investigate the rumen degradation characteristics of whole sugarcane of dairy cows and its effects of using it replacing alfalfa, oat hay and concentrates in dairy cows' diet on the rumen fermentation, nutrient apparent digestibility, blood biochemical indexes and production performance of dairy cows, in order to open up new ways to replace the increasing prices feedstuff such as alfalfa, oat hay and concentrate in dairy cows' diets with whole sugarcane. In experiment one, the in-situ test, namely the rumen nylon bag test was used to investigate the rumen degradation characteristics of various nutrients of whole sugarcane, leymus chinensis and alfalfa. Experiment two was in vivo test,repeat 3 ⅹ 3 Latin square design was conducted and Holstein dairy cows with similar body weight, parities and milk yield and permanent rumen fistula were chosen to investigate the effect of using whole sugarcane replacing 25% or 50% of imported alfalfa from the Unites States in dairy cows' diet on nutrient digestibility, rumen fermentation characteristics and blood biochemical indexes of dairy cows. In experiment three, 60 Holstein dairy cows with similar parity, milk yield and milk in lactation were selected to perform production test, which aimed to explore the effects of using whole sugarcane replacing 30% alfalfa hay, 50% oat hay or 10% concentrate on the production performance, blood biochemical indexes of dairy cows and the economic benefits of dairy farms. The results showed that：1) The effective degradation rates of dry matter (DM) and acid detergent fiber (ADF) of whole sugarcane were significantly higher than leymus chinensis (P<0.05), and the effective degradation rates of neutral detergent fiber (NDF) and organic matter (OM) were significantly higher than leymus chinensis and alfalfa (P<0.05). 2) There was no significant effect on rumen pH, NH₃-N (except 25% group at the 4 h time point) and volatile fatty acid (VFA) concentrations of dairy cows when using 25% and 50% whole sugarcane to replace imported alfalfa from the Unites States in the diet. There was also no significant effect on DMI and digestibility of DM, CP, OM and ADF, while the digestibility of NDF in the 50% group was significantly increased (P<0.05). In 50% group, the content of serum urea nitrogen in 2 and 8 h was significantly lower than 25% group and control group (P<0.05) and there was no significant difference in the blood content of β-hydroxybutyric acid, rumen VFA and total VFA in each group at different time points. 3) After using 50%, 30% and 10% of whole sugarcane to replace oat hay, alfalfa hay and concentrate, respectively, no significant difference was detected in blood glucose, urea nitrogen, β-hydroxybutyric acid, the esterification of fatty acid (NEFA), and milk yield. Besides, combined with milk yield and feed cost, the economic benefits of each cow in the substitution groups increased by 3.28, 7.48 and 1.62 yuan per day. respectively, compared with control group. It can be seen that the whole sugarcane is a kind of high-quality roughage that can be used by dairy cows with high digestibility, and using it to replace 25% or 50% of imported alfalfa from the Unites States in dairy cows' diet does not affect the rumen fermentation characteristics and rumen apparent digestibility of nutrients of dairy cows. And using whole sugarcane replacing 30% alfalfa hay, 50% oat hay or 10% concentrate will not affect the blood biochemical indicators and production performance of dairy cows, and will also increase the economic benefits of the dairy farm.     

全株甘蔗的奶牛瘤胃降解特性及其替代奶牛饲粮苜蓿、燕麦草及精料的应用研究

本试验旨在探究全株甘蔗的奶牛瘤胃降解特性及其替代奶牛饲粮中苜蓿、燕麦草及精料对奶牛瘤胃发酵、营养物质表观消化率、血液生化指标及生产性能的影响,为其替代奶牛饲粮中价格日益攀升的苜蓿和精饲料,并用作奶牛粗饲料资源开辟新途径。试验一采用半体内试验即瘤胃尼龙袋技术,探究了全株甘蔗、国产羊草与国产苜蓿各营养成分的瘤胃降解特性;试验二采用重复3×3拉丁方试验设计,选择体重、胎次、泌乳天数和产奶量相近并装有永久瘤胃瘘管的荷斯坦奶牛进行消化试验,探究全株甘蔗替代饲粮25%或50%的美国进口苜蓿对奶牛营养物质消化率、瘤胃发酵特性和血液生化指标的影响;试验三选取60头胎次、产奶量和泌乳天数相近的荷斯坦奶牛进行生产试验,探究了全株甘蔗分别替代饲粮30%苜蓿干草、50%燕麦草或10%精料对奶牛生产性能、血液生化指标和牧场经济效益的影响。结果发现：1）全株甘蔗干物质（DM）和酸性洗涤纤维（ADF）的有效降解率显著高于国产羊草（P<0.05）,中性洗涤纤维（NDF）和有机物（OM）的有效降解率显著高于国产羊草和国产苜蓿（P<0.05）。2）用全株甘蔗替代饲粮25%或50%美国进口苜蓿对奶牛瘤胃pH、氨态氮（NH₃-N）（除25%组4 h外）和挥发性脂肪酸（VFA）含量无显著影响;对奶牛干物质采食量（DMI）及饲粮DM、粗蛋白质（CP）、OM和ADF消化率无显著影响,而全株甘蔗替代饲粮50%美国进口苜蓿组的NDF消化率显著升高（P<0.05）;全株甘蔗替代饲粮中50%美国进口苜蓿组2和8 h血清尿素氮含量显著低于25%组和对照组（P<0.05）,且各处理组不同时间点血液β-羟丁酸含量、瘤胃各VFA和总VFA含量均无显著差异。3）用全株甘蔗替代高产奶牛饲粮中50%燕麦草、30%苜蓿干草或10%精料对奶牛血液中的葡萄糖、尿素氮、β-羟丁酸和非酯化脂肪酸（NEFA）等含量及产奶量均无显著影响,且综合产奶量和饲料成本两方面的因素,各替代组分别比对照组每头奶牛的经济效益增加3.28、7.48和1.62元·d^-1。由此可知,全株甘蔗是一种可供奶牛食用的消化率较高的优质粗饲料,且用其替代饲粮中的25%或50%美国进口苜蓿不影响奶牛的瘤胃发酵特性和营养物质表观消化率;用其替代30%苜蓿干草、50%燕麦草或10%精料不会影响奶牛的血液生化指标及生产性能,还会提高牧场的经济效益。     

Effects of Replacing the Corn Silage with Puelia sinese Roxb Silage on Production Performance,Composition of Milk and Economic Benefits in Dairy Cows

This experiment was conducted to study the effects of replacing the corn silage with Puelia sinese Roxb silage on the production performance, composition of milk and economic benefic in dairy cows.90 healthy Holstein cows in middle or late lactation were chosen and randomly divided into 3 groups (control group,groups Ⅰ and Ⅱ). The control group was fed with diet based on corn silage,groups Ⅰ and Ⅱ were fed diets with Puelia sinese Roxb silage instead of 50% and 100% corn silage, respectively. The experiment lasted for 8 weeks,including 2 weeks pre-trail period and 6 weeks formal period.The results showed that:The ether extract,neutral detergent fiber,acid detergent fiber,Ash and nitrogen-free extract of Puelia sinese Roxb silage were 192.3%,45.9%,34.1%,128.6% and 194.3% higher than corn silage respectively (P<0.05),and the crude protein of Puelia sinese Roxb silage was 15.3% lower than that of corn silage (P>0.05).The milk yield of group Ⅰ was significantly increased (2.38 kg/d higher) compared with control group (P<0.05),while that in group Ⅱ was decreased (0.87 kg/d lower)(P>0.05).With the increase of Puelia sinese Roxb silage,the butter-fat percentage, lactoprotein and lactose contents were increased (P>0.05).More profits (7.64 yuan/d) could get in group Ⅰcompared with control group. It was concluded that Puelia sinese Roxb silage had a high feeding value,which could be used to fulfill the requirement of dairy cows in high feeding value silage,and the effect of 50% substitution group was the best.