TMR日粮不同苜蓿干草长度对奶牛生产性能的影响

探讨TMR日粮中不同长度的苜蓿干草对奶牛产奶量及其乳成分的影响。本试验选用产奶量、泌乳天数、膘情和胎次相近的健康荷斯坦泌乳奶牛40头,随机分为两组,即试验1组20头,饲喂苜蓿干草长度为2.52cm的TMR日粮,试验2组20头,饲喂苜蓿干草长度为6.46cm的TMR日粮。试验分两期完成,Ⅰ期日粮鲜重的精粗比例为20：80,Ⅱ期日粮鲜重的精粗比例为30：70。采用双因子重复方差试验设计。结果表明：在Ⅰ期和Ⅱ期两期试验中,不同长度苜蓿干草TMR日粮对奶牛的产奶量均无显著影响（P〉0.05）,但对奶牛的干物质采食量有显著影响（P〈0.05）,试验1组比试验2组奶牛的干物质采食量在Ⅰ期和Ⅱ期试验中分别显著地提高了18.36%、7.40%。在Ⅰ期试验中,试验2组乳蛋白极显著高于试验1组（P〈0.01）,较试验1组提高了11.82%;在Ⅱ期试验中,试验1组乳脂率显著高于试验2组（P〈0.05）,较试验2组提高了8.89%。     

peNDF水平对泌乳中后期奶牛产奶性能的影响

试验选择3头体况良好的泌乳中后期荷斯坦奶牛,采用3×3拉丁方设计,研究日粮不同物理有效中性洗涤纤维(peNDF)水平对奶牛产奶性能的影响。结果表明,奶牛中性洗涤纤维采食量(NDFI)、酸性洗涤纤维采食量(ADFI)、物理有效中性洗涤纤维采食量(peNDFI)、产奶量和4%FCM随peNDF水平增加呈上升趋势,对ADFI影响显著(P0.05),采食高水平peNDF日粮peNDFI1.18较采食低水平和中等水平peNDF日粮分别提高17.35%(P0.05)、8.52%(P0.01),4%FCM提高6.82%和6.59%(P0.05),差异均显著。     

TMR中苜蓿干草长度对奶牛瘤胃发酵的影响

试验旨在研究奶牛TMR中苜蓿干草长度变化对奶牛瘤胃发酵参数的影响。将3头安装永久瘤胃瘘管的中国荷斯坦奶牛采用3×3拉丁方试验研究了TMR中苜蓿干草长度变化对奶牛的瘤胃pH、NH3-N浓度及挥发性脂肪酸含量的影响。结果表明:奶牛的瘤胃pH及NH3-N含量随TMR中的苜蓿干草长度增加有所升高,但均未达显著水平(P>0.05);增加TMR中苜蓿干草长度能改变奶牛的瘤胃发酵模式,TMR苜蓿干草长度为5 cm的奶牛瘤胃中乙酸平均含量显著高于1 cm的(P<0.05),其丙酸平均含量则显著低于1 cm的(P<0.05),乙酸/丙酸的比值显著高于1 cm的(P<0.05)。奶牛瘤胃中丁酸含量和总VFA含量各处理间没有明显变化。结果提示,泌乳奶牛TMR中苜蓿干草长度增加有利于奶牛维持较高的瘤胃pH,同时能改变瘤胃的发酵模式。     

饲喂苜蓿干草对引入澳大利亚奶牛生产性能的影响

为探讨日粮中添加不同比例苜蓿干草,对引入纯种澳大利亚荷斯坦奶牛的影响,选择48头产奶量、膘情、年龄,泌乳阶段一致的引入纯种奶牛进行完全随机单位组设计,分为试验Ⅰ组(对照组)、试验Ⅱ组和试验Ⅲ组。分别饲喂苜蓿干草2.5kg/d、5kg/d、7.5kg/d,3kg精料基础料加每产4kg奶补1kg产奶料,玉米青贮自由采食。测定产奶量、干物质采食量、乳成分和试验前后奶牛体重。结果对照组、试验Ⅱ组和试验Ⅲ组干物质采食量、产奶量、乳脂率、4%标准乳日产量、乳蛋白率、乳糖率和干物质含量差异不显著(P>0.05);乳脂和乳蛋白的平均日产量均随苜蓿喂量增加而显著增加(P<0.05);试验Ⅱ组体细胞数量比对照组显著减少(P<0.05),试验Ⅲ组比对照组和试验Ⅱ组极显著减少(P<0.01)。增加苜蓿干草喂量,对提高引入澳大利亚高产荷斯坦奶牛的产奶量和奶品质有一定提高作用。     

裹包青贮苜蓿替代苜蓿干草对奶牛奶产量及乳成分的影响

以裹包青贮苜蓿代替50%等量干物质的苜蓿干草,分析其对奶牛干物质采食量、产奶性能以及乳品质的影响。选取产奶量相近的中产奶牛200头,随机分为2组,每组100头,饲喂全混合日粮,试验组使用裹包青贮苜蓿代替50%等量干物质的苜蓿干草,试验期40 d,其中预试期10 d。在试验期间测定奶牛的干物质采食量、产奶量及乳品质指标。结果表明,试验组在30 d内平均干物质采食量较对照组提高了8.2%(P0.05);产奶量二者差异不显著(P0.05);试验组乳脂率和乳蛋白分别较对照组提高了7.2%和9.3%(P0.05),其他指标差异不显著(P0.05)。研究结果提示,在奶牛日粮中用裹包苜蓿青贮替代部分苜蓿干草能提高奶牛干物质采食量,并对乳品质具有改善作用。     

光照时间对奶牛泌乳和采食性能的影响

为研究光照对奶牛泌乳和采食性能的影响,分别选择处于第Ⅰ泌乳月和第Ⅳ泌乳月的90头和45头奶牛,采用人工光照的方式,使奶牛每天的光照时间分别由自然光照的9.5 h增加到15 h和18 h.试验期30 d,分析测定了产奶量、乳脂率、采食量及经济效益.结果发现当光照时间为15 h时,试验牛的产奶量和采食量均显著高于9.5 h和18 h试验牛(P＜0.05);且经济效益较好,每头奶牛每天可增收3.95元;各试验组奶牛牛奶乳脂率无显著差异(P＞0.05).综合分析表明在奶牛饲养管理中每天提供15 h光照较好.     

不同水平苜蓿干草对奶牛消化代谢及血液指标的影响

试验选用48头泌乳期荷斯坦奶牛按单因素随机设计原理分成4组,每组12头。对照组全混合日粮(TMR)不添加苜蓿,试验Ⅰ、Ⅱ、Ⅲ组分别添加10%、20%和30%左右优质苜蓿干草替代部分精料,探讨不同比例苜蓿干草对奶牛消化代谢、血液生化指标的影响。结果显示:采食量随苜蓿添加量的增加而增加,试验Ⅱ组和试验Ⅲ组达到显著程度(P0.05)。粗蛋白和酸性洗涤纤维表观消化率未受显著影响(P0.05),试验Ⅲ组中性洗涤纤维表观消化率显著高于对照组(P0.05);血浆总蛋白浓度随苜蓿添加比例的增加而增加,其中试验Ⅲ组显著高于试验Ⅰ组和对照组(P0.05),试验Ⅱ组显著高于对照组(P0.05),试验Ⅰ组和对照组间差异不显著(P0.05);血糖、血浆尿素氮、谷丙转氨酶、白蛋白及球蛋白等血液生化指标各组差异不显著(P0.05)。结果表明,TMR中添加一定比例优质苜蓿干草提高了奶牛的采食量及中性洗涤纤维的表观消化率,维持奶牛良好的健康状况,为提高产奶量奠定了基础。     

不同饲喂方式对南方奶牛产奶性能、养分消化和代谢的影响

研究了具有南方奶牛日粮类型特征的相同精粗比日粮的不同饲喂方式对奶牛的采食行为、产奶性能、全肠道养分表观消化率和血清代谢产物的影响。选用体重相近的12头荷斯坦奶牛,采用单因子设计,根据产奶量、胎次及泌乳天数随机分为2组（n=6）,分别为精粗分饲组（SI）和全混合日粮组（TMR）,精饲料：粗饲料均为50：50。试验结果表明：奶牛采食量无差异,在相同精粗比日粮下,TMR饲养技术极显著减少了奶牛的采食时间（P〈0.01）,显著增加了反刍时间（P〈0.05）,TMR组奶牛的乳脂率、4%标准奶产量、乳脂产量、乳糖产量和乳固形物产量分别比SI组显著提高11.20%、11.60%、17.50%、13.21%和9.86%（P〈0.05）,但对奶牛咀嚼行为、全肠道养分表观消化率和血清代谢产物影响不显著（P〉0.05）。在南方奶牛典型日粮采用TMR饲养技术时,与精粗分饲相比,可提高奶牛的产奶性能,但对奶牛的采食量、咀嚼行为、全肠道养分表观消化率和血清代谢产物没有显著影响。     

不同饲喂方式对南方奶牛产奶性能、养分消化和代谢的影响

研究了具有南方奶牛日粮类型特征的相同精粗比日粮的不同饲喂方式对奶牛的采食行为、产奶性能、全肠道养分表观消化率和血清代谢产物的影响.选用体重相近的12头荷斯坦奶牛,采用单因子设计,根据产奶量、胎次及泌乳天数随机分为2组(n=6),分别为精粗分饲组(SI)和全混合日粮组(TMR),精饲料:粗饲料均为50:50.试验结果表明:奶牛采食量无差异,在相同精粗比日粮下,TMR饲养技术极显著减少了奶牛的采食时间(P<0.01),显著增加了反刍时间(P<0.05),TMR组奶牛的乳脂率、4%标准奶产量、乳脂产量、乳糖产量和乳固形物产量分别比SI组显著提高11.20%、11.60%、17.50%、13.21%和9.86%(P<0.05),但对奶牛咀嚼行为、全肠道养分表观消化率和血清代谢产物影响不显著(P>0.05).在南方奶牛典型日粮采用TMR饲养技术时,与精粗分饲相比,可提高奶牛的产奶性能,但对奶牛的采食量、咀嚼行为、全肠道养分表观消化率和血清代谢产物没有显著影响.     

光照时间对奶牛泌乳和采食性能的影响

为研究光照对奶牛泌乳和采食性能的影响,分别选择处于第Ⅰ泌乳月和第Ⅳ泌乳月的90头和45头奶牛,采用人工光照的方式,使奶牛每天的光照时间分别由自然光照的9.5h增加到15 h和18 h。试验期30 d,分析测定了产奶量、乳脂率、采食量及经济效益。结果发现当光照时间为15 h时,试验牛的产奶量和采食量均显著高于9.5 h和18 h试验牛(P<0.05);且经济效益较好,每头奶牛每天可增收3.95元;各试验组奶牛牛奶乳脂率无显著差异(P>0.05)。综合分析表明在奶牛饲养管理中每天提供15 h光照较好。     

TMR中物理有效中性洗涤纤维对奶牛产奶性能的影响

本文旨在研究不同物理有效中性洗涤纤维水平的TMR日粮对奶牛瘤胃消化性能的影响。选取3头体重为（650±10）kg的荷斯坦奶牛,采用3×3拉丁方试验设计,三种试验日粮精料补充料完全相同,粗饲料由长度不同的玉米青贮和羊草配制而成的三种peNDF水平的日粮,即I组（长度为5cm-7cm）、II组（长度为3cm-5cm）、III组（长度为1cm-2cm）。试验分三期,每期试验共17天。试验结果表明：随着物理有效中性洗涤纤维含量的增加,I组、Ⅱ组、Ⅲ组的产奶量差异不显著,I组、Ⅱ组的乳脂率与4％标准乳显著高于Ⅲ组,I组与Ⅱ组之间差异不显著。结果显示,荷斯坦奶牛TMR日粮中不同物理有效中性洗涤纤维的含量对奶牛的产奶量影响不大,但是会影响到奶牛的乳脂率及4％标准乳的含量,综合本试验结果建议奶牛TMR日粮中粗饲料的长度在3cm-5cm较为适宜。     

Effects of physically effective fiber in diets based on rice straw and cassava pulp on chewing activity,ruminal fermentation,milk production,and digestibility in dairy cows

The objective of this study was to evaluate the effects of physically effective neutral detergent fiber (peNDF) in rice straw and cassava pulp diets on the chewing activity, ruminal fermentation, milk production, and digestibility in low‐producing dairy cows. Eight lactating Holstein crossbred cows were randomly divided into two groups in a crossover design with two dietary treatments over two 21‐day periods. The difference in peNDF contents was achieved by balancing the ratio of rice straw, cassava pulp, and concentrate. The high cassava pulp diet had 15.5% peNDF and the low cassava pulp diet had 20.2% peNDF. The results showed that feeding the low cassava pulp diet increased the concentrations of milk protein, milk fat, solids‐not‐fat, and total solids in the milk. In contrast, the dry matter intake, milk yield, lactose content, chewing activity, nutrient digestibility, ruminal fermentation, and pH were not affected by treatments.     

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.     

Effect of Dietary Monensin on Production Performance and Nutrient Digestion of Lactating Dairy Cows

Twelve lactating Holstein dairy cows were selected via a replicated 4 × 4 latin square design to determine the effect of feeding different levels of monensin on the production performance and nutrient digestion of lactating dairy cows.The test was divided into 4 period and each period was 28 d (7 d for preliminary feeding and 21 d for formal feeding).The cows in control group were fed with the basal diet (TMR,group A),and the diets of the three experimental groups were added with different levels of monensin (300 mg/d,group B;400 mg/d,group C;500 mg/d,group D) on the basis of the TMR diet,respectively.The results showed that the diets containing monensin increased the milk yield and lactose percentage,and reduced milk fat percentage.Compared with control group,the milk yield of group C and D were significantly increased by 4.08% and 4.57% (P < 0.05) respectively,the lactose of group D was significantly increased by 1.99% (P < 0.05),and milk fat of group D was significantly reduced by 7.45% (P < 0.05).However,adding monensin had no effect on 4% fat corrected milk (FCM),solids-non-fat (SNF) and milk protein (P > 0.05).In addition,adding monensin also significantly increased body weight gain (BWG),digestibility of crude protein (CP),neutral detergent fiber (NDF) and acid detergent fiber (ADF) in diet.The BWG of group D was significantly increased by 34.62% (P < 0.05),and the digestibility of CP in three experimental groups were respectively increased by 3.73%,4.35%,5.35% (P < 0.01),and the digestibility of NDF and ADF in group D was respectively increased by 7.24% (P < 0.05)and 9.08% (P < 0.05) compared to the control group.Moreover,the dry matter intake (DMI) and the digestibility of ether extract (EE),calcium (Ca) and phosphorus (P) were not significantly changed by monension (P > 0.05).The results suggested that supplementing 400 to 500 mg/d monensin with diet per cow was optimal for production performance,nutrient digestion and economic benefit of lactating dairy cows.     

Effect of replacing corn with brown rice grain in a total mixed ration silage on milk production,ruminal fermentation and nitrogen balance in lactating dairy cows

Nine multiparous Holstein cows were used in a replicated 3 × 3 Latin square design to determine the effects of substituting corn grain with brown rice (BR) grain in total mixed ration (TMR) silage on milk yield, ruminal fermentation and nitrogen (N) balance. The TMR silages were made from the ensiling of TMR containing (dry matter basis) 50.1% forage in rice silage and corn silage combination, and 49.9% concentrate. The grain portion of the diets contained 31.2% steam‐flaked corn, 31.2% steam‐flaked BR or an equal mixture of corn and BR. Dietary treatments did not affect dry matter intake, milk yield and milk fat, protein and lactose yields. The ruminal pH and total volatile fatty acid concentrations were not affected by dietary treatment. The urinary N excretion decreased linearly (P < 0.01) in response to increased levels of BR, with no dietary effect on N intake, N secretion in milk and fecal N excretion. Our results indicate that steam‐flaked BR is a suitable replacement for steam‐flaked corn in dairy cow diets, and that it can be included in rations to a level of at least 31.2% of dry matter without adverse effects on milk production, when cows were fed rice silage and corn silage‐based diets.     

玉米青秸青贮为粗饲料的奶牛日粮采食量预测模型研究

本研究试验 1测定了 2 2头荷斯坦产奶牛以玉米青秸青贮为粗饲料常规饲喂时的个体干物质采食量 ,体重 ,产奶量和乳脂率等。试验 2将 2 2头牛随机分成两组 ,按产奶量添加不同水平的精料 ,测定相关数据。结果表明 ,精料水平影响粗饲料的采食量和精料转化率。综合两个阶段试验数据 ,通过多元回归分析建立了利用奶牛体重 (W)、标准乳产量 (FCM)、和精料补充量 (C)预测奶牛总干物质采食量 (TD MI)的预测模型 :TDMI=0 .0 6 5W0 .75+0 .1 36FCM +0 .6 2 6C ,n =4 4,r=0 .91 53(P <0 .0 1 )。粗饲料玉米青秸青贮采食量 (RDMI)与日粮NDF %、ADF %回归关系为 :RDMI=1 1 .4 2 8-0 .834NDF % +1 .72 7ADF %n =4 4,r=0 .850 4 (P <0 .0 1 )     

日粮中添加莫能菌素对泌乳期奶牛生产性能及养分消化率的影响

本试验旨在研究日粮中添加不同水平莫能菌素对泌乳期奶牛生产性能和养分消化率的影响。选取泌乳期荷斯坦奶牛12头,采用重复4×4拉丁方试验设计,随机分成4组,每组3个重复,对照组饲喂基础日粮(A组),试验组分别在基础日粮的基础上添加300 (B组)、400 (C组)、500 (D组)mg/(头·d)莫能菌素。试验分为4期,每期28 d (7 d预饲期,21 d正饲期)。结果表明,日粮中添加莫能菌素可以提高泌乳期奶牛产奶量和乳糖率,降低乳脂率,其中C组和D组的平均日产奶量分别较对照组提高4.08%和4.57%(P < 0.05),D组的乳糖率较对照组提高1.99% (P < 0.05),D组的乳脂率较对照组降低7.45% (P < 0.05),但对4%乳脂校正乳(FCM)、乳中非脂固型物(SNF)比例和乳蛋白率的影响不显著(P > 0.05)。莫能菌素会提高奶牛的体增重(BWG)及粗蛋白质(CP)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)的表观消化率,其中D组的BWG较对照组提高34.62% (P < 0.05),3个试验组的CP消化率分别较对照组提高3.73%、4.35%和5.35% (P < 0.01),D组的NDF和ADF消化率分别较对照组提高7.24%和9.08% (P < 0.05),另外,莫能菌素对泌乳期奶牛的粗脂肪(EE)、钙(Ca)和磷(P)的消化率及干物质采食量(DMI)影响不显著(P > 0.05)。综上所述,在泌乳期奶牛日粮中添加莫能菌素可以促进奶牛机体代谢,提高奶牛养分消化率和经济效益,其适宜添加量为400~500 mg/(头·d)。     

苜蓿干草添加量对奶牛生产性能及经济效益的影响

选取沧州奶牛养殖小区体重、产奶量、胎次、泌乳期相近的荷斯坦奶牛40头,随机分为4组,对照组日粮组成为秸秆加精料,试验组添加不同水平苜蓿干草,分析对奶牛生产性能及经济效益的影响。结果表明,试验组与对照组干物质采食量差异显著（P＜0.05）,试验组产奶量显著提高,差异极显著（P＜0.01）;乳脂率有所降低,差异不显著（P＞0.05）;乳蛋白、非脂乳固形物极显著提高（P＜0.01）;体细胞数显著下降（P＜0.05）。添加苜蓿使牛奶品质得到明显改善。经济效益分析结果表明,日粮中添加苜蓿能显著提高奶牛养殖业的整体效益。