2020年荷斯坦奶牛甲烷排放研究进展

二氧化碳、甲烷、臭氧等都是造成温室效应的主要气体,其中同等质量甲烷导致的温室效应是二氧化碳的28～35倍。甲烷不仅仅影响环境,而且还增加奶牛的能量损耗,因此,控制甲烷排放有利于保护环境和提高奶牛生产性能。本文结合国内外近年来的研究成果,从饲喂方式、饲料种类、瘤胃代谢、基因标记技术等方面进行综述,旨在为奶牛养殖过程中控制甲烷排放提供理论依据和指导。     

饲粮中添加海南霉素对奶牛瘤胃发酵及甲烷产量的影响

本试验旨在研究海南霉素对荷斯坦奶牛瘤胃发酵模式及甲烷产量的影响。试验选用3头装有永久性瘤胃瘘管、体况相近的中国荷斯坦奶牛,采用3×3拉丁方试验设计,试验分为3期,每期15 d,试验设负对照组(不添加任何添加剂)、正对照组(添加10 mg/kg莫能菌素)和海南霉素组(添加7.2 mg/kg海南霉素)。结果表明:饲粮中添加海南霉素后,除在采食后2 h显著提高奶牛瘤胃内pH(P<0.05)外,其他时间均无显著影响(P>0.05);采食后0、2、8和10 h,海南霉素组氨态氮(NH3-N)浓度均显著低于负对照组(P<0.05),而采食后6 h,海南霉素有抑制NH3-N释放的趋势(P=0.06);采食后0、2、4和6 h,海南霉素组乙酸浓度及乙酸与丙酸的比值与负对照组相比均显著降低(P<0.05),丙酸浓度显著升高(P<0.05),总挥发性脂肪酸和丁酸浓度没有显著变化(P>0.05)。海南霉素显著抑制了瘤胃甲烷的产生(P=0.02),海南霉素组的奶牛甲烷呼出量为216.50 L/d,比负对照组降低了14.03%。由此得出结论:饲粮中添加海南霉素可以改变奶牛瘤胃的发酵类型,使其更趋向于丙酸型发酵,并显著降低动物的甲烷呼出量。     

日粮不同NDF/NFC水平对周岁后荷斯坦奶牛生产性能、营养物质消化率、瘤胃发酵特征和甲烷排放的影响

本试验研究了日粮中不同中性洗涤纤维/非纤维性碳水化合物（NDF/NFC）水平对周岁后荷斯坦奶牛生产性能、营养物质消化率、瘤胃发酵特征及甲烷产量的影响，并在此基础上建立了甲烷排放预测模型，旨在获得我国生产模型下的甲烷排放规律和甲烷转化因子，为提高奶牛能量利用效率、建立国家或区域性温室气体排放清单和探索减排策略提供科学依据和支撑。将45头体况良好，平均为15月龄的荷斯坦后备奶牛随机分为3组，每组15头牛：低日粮NDF/NFC组（NDF/NFC=0.60）、中日粮NDF/NFC组（NDF/NFC=0.75）和高日粮NDF/NFC组（NDF/NFC=0.90），试验期为70 d，包括14 d的预饲期和56 d的正试期。结果表明：1）提高日粮NDF/NFC水平显著降低了奶牛的干物质采食量、有机物采食量、平均日增重、干物质和粗蛋白的表观消化率（P<0.05）；2）提高日粮NDF/NFC水平显著增加了瘤胃内总挥发性脂肪酸产量、乙酸的相对含量和乙酸/丙酸比例（P<0.05），显著降低了丙酸的相对含量（P<0.05）；3）随着日粮NDF/NFC水平的提高，瘤胃甲烷和甲烷能产量、甲烷/代谢体重、甲烷/干物质采食量、甲烷/有机物采食量、甲烷/中性洗涤纤维采食量显著提高（P<0.05）。甲烷转化因子也随着日粮NDF/NFC水平的增加而显著提高（P<0.05）；4）基于体重、采食量、营养物质含量和NDF/NFC分别建立了甲烷预测模型，其中基于干物质采食量和中性洗涤纤维采食量建立的预测模型的决定系数最高（R²=0.77）。因此，提高日粮中NDF/NFC水平可显著降低周岁后荷斯坦奶牛的生产性能、营养物质消化率和瘤胃内丙酸的相对含量，可显著提高瘤胃甲烷产量和甲烷转化因子。     

豆渣混贮对青年期奶牛生长性能、营养物质表观消化率、瘤胃发酵及甲烷排放的影响

本试验以豆渣、麦麸和玉米粉为原料,按鲜重基础8∶1∶1的比例进行混合发酵（混合后水分含量65%）,获得豆渣混贮,并用该混贮替代青年期奶牛基础饲粮中的豆粕、麦麸和玉米,探究豆渣混贮对奶牛生长性能、营养物质表观消化率、饲养成本、血清生化指标、瘤胃发酵和甲烷（CH4）排放的影响。采用单因素随机试验设计,选取体重[（311.0±29.8） kg]相近的青年期荷斯坦奶牛24头,随机分为对照组和豆渣混贮组,每组12头。结果表明：豆渣混贮具有良好的发酵品质,主要表现为低pH和高乳酸含量。与对照组相比,豆渣混贮组干物质（DM）和有机物（OM）采食量没有显著变化（P>0.05）,酸性洗涤纤维（ADF）采食量则显著升高（P<0.05）,粗蛋白质（CP）采食量有升高的趋势（P=0.06）;豆渣混贮组OM和中性洗涤纤维（NDF）表观消化率显著降低（P<0.05）,DM表观消化率呈降低趋势（P=0.07）;豆渣混贮组的平均日增重（ADG）显著升高（P<0.05）,而饲料费用显著降低（P<0.05）;豆渣混贮显著提高了血清中总胆固醇（TC）、甘油三酯（TG）、血氨（BA）和补体4(C...     

发芽玉米对荷斯坦奶牛瘤胃发酵、产奶性能及乳品质的影响

试验旨在研究发芽玉米对荷斯坦奶牛瘤胃发酵、血液成分、产奶性能及乳品质的影响。选取胎次、分娩日龄、产奶量相近的荷斯坦泌乳奶牛15头,试验分为3组,每组5头。对照组饲喂基础日粮(TMR和苜蓿干草),T1、T2组分别在基础日粮中添加20%发芽玉米和20%发酵发芽玉米。结果表明,添加发芽玉米及发酵发芽玉米均能降低瘤胃pH的变化幅度,提高挥发性脂肪酸和氨态氮浓度,但差异均不显著(P＞0.05);与对照组相比,T1、T2组4%乳脂校正乳极显著提高(P＜0.01),并可显著提高T2组的饲料效率(P＜0.05),显著降低乳中体细胞数(P＜0.05);T1、T2组具有降低乳中胆固醇含量的趋势,并对血液成分无显著影响。因此,饲料中添加发芽玉米可改善瘤胃内环境,显著提高产奶量与饲料效率,显著降低乳中体细胞数,且乳中胆固醇含量有降低的趋势。     

喷浆玉米皮替代玉米粉对山羊营养物质采食和消化、瘤胃发酵、甲烷排放和瘤胃微生物数量的影响

本试验旨在研究喷浆玉米皮替代玉米粉对山羊营养物质采食和消化、瘤胃发酵、甲烷排放和瘤胃微生物数量的影响。采用单因素试验设计,选用24只体况良好、体重相近的湘东黑山羊,随机分为2组,每组12只。玉米粉组饲喂基础饲粮,喷浆玉米皮组饲喂以喷浆玉米皮替代玉米粉的试验饲粮。试验期47 d,预试期10 d,正试期37 d。结果表明：与玉米粉相比,喷浆玉米皮可以显著提高山羊粗蛋白质、中性洗涤纤维和酸性洗涤纤维采食量和消化率（P<0.05）;显著降低山羊甲烷的每天排放量、采食每千克干物质排放量和采食每千克可消化干物质排放量（P<0.05）;显著增加山羊瘤胃pH、溶解态硫化氢和氨态氮浓度以及丙酸比例（P<0.05）,显著降低溶解态氢、溶解态甲烷浓度和乙酸/丙酸以及氢的生成效率（P<0.05）;显著增加山羊瘤胃真菌数量（P<0.05）,显著降低瘤胃嗜淀粉瘤胃球菌数量（P<0.05）。由此可见,喷浆玉米皮替代玉米粉可以增加山羊纤维摄入量,降低淀粉摄入量,有助于瘤胃真菌的增殖,抑制瘤胃嗜淀粉瘤胃球菌的增殖,增加瘤胃溶解态硫化氢的产生,促进瘤胃发酵模式向丙酸型转变,降低山羊甲烷...     

油脂对反刍动物瘤胃发酵、甲烷产量及生产性能影响的研究进展

油脂具有调控反刍动物瘤胃发酵模式、减少甲烷排放和提高动物生产性能等功能,被认为是一种可以替代抗生素药物的天然饲料添加剂。越来越多的研究致力于探讨各种来源的油脂对瘤胃发酵和瘤胃甲烷排放的影响。该文综述了油脂对反刍动物瘤胃发酵、甲烷排放和生产性能的影响,旨在为今后油脂在反刍动物健康养殖应用上提供科学的理论参考依据。     

保护性赖氨酸对荷斯坦奶牛瘤胃发酵参数的影响

选用3头装有永久性瘤胃瘘管和十二指肠瘘管的荷斯坦奶牛,试验分4个阶段。每个阶段分别饲喂日粮I[基础日粮+保护性赖氨酸Ⅰ30g(/头·d)]、日粮Ⅱ[基础日粮+保护性赖氨酸Ⅱ30g/(头·d)]、日粮Ⅲ[基础日粮+保护性赖氨酸Ⅲ30g(/头·d)]和日粮Ⅳ(基础日粮),研究脂肪包被赖氨酸对瘤胃发酵参数的影响。结果表明,日粮中添加保护性赖氨酸对瘤胃pH值和NH3-N浓度影响不显著(P>0.05)。     

茶皂素对甲烷产量和瘤胃发酵影响的研究进展

茶皂素是从茶籽中提取的一种五环三萜类糖苷化合物,近年来研究发现,茶皂素可以调控反刍动物瘤胃发酵模式,减少甲烷排放的功能,因此,茶皂素可望成为反刍动物的新型瘤胃发酵调控剂.论文主要综述茶皂素的结构,以及茶皂素对甲烷产量和瘤胃发酵的影响.     

饲喂甘草茎叶对奶牛瘤胃发酵参数及瘤胃微生物的影响

研究奶牛饲喂甘草茎叶后对瘤胃发酵参数和瘤胃微生物的影响。试验选取20头健康的泌乳后期(258±12)d的荷斯坦奶牛,根据产奶量、分娩时间和胎次进行配对试验设计,分为对照组(苜蓿添加组)和试验组(甘草茎叶添加组),每组10个重复。试验期28 d。结果显示,试验组的瘤胃乙酸、丙酸、戊酸浓度均极显著高于对照组(P<0.01),丁酸浓度显著高于对照组(P<0.05),乙酸/丙酸的比值显著低于对照组(P<0.05)。试验组的白色瘤胃球菌、总瘤胃球菌和溶纤维丁酸弧菌的数量均显著低于对照组(P<0.05),黄色瘤胃球菌的数量极显著低于对照组(P<0.01)。研究表明,采用甘草茎叶替代苜蓿饲喂奶牛,对瘤胃液中的纤维分解菌白色瘤胃球菌、黄色瘤胃球菌、溶纤维丁酸弧菌和总瘤胃球菌具有抑制作用,能够改善奶牛瘤胃参数,有利于提高饲料的利用效率。     

Effect of feeding Bacillus subtilis natto fermentation product on milk production and composition, blood metabolites and rumen fermentation in early lactation dairy cows

This experiment was conducted to determine the effect of Bacillus subtilis natto fermentation product supplementation on blood metabolites, rumen fermentation and milk production and composition in early lactation dairy cows. Thirty-six multiparous Holstein cows (DIM = 29 ± 6 days, parity = 2.8 ± 1.1) were blocked by DIM and parity and then randomly assigned to three treatments (12 per treatment) in a 9-week trial. Cows in control, DFM1 and DFM2 were fed TMR diets supplemented with 0, 6 and 12 g of B. subtilis natto solid-state fermentation product per day per cow respectively. Plasma non-esterified fatty acids were lower (p = 0.03) in DFM1 and DFM2 compared with control cows (633 and 639 vs. 685 μm). Ruminal propionate increased (23.9 vs. 26.3 and 26.9/100 mol, control vs. DFM1 and DFM2 respectively) and acetate decreased (64.2 vs. 62.7 and 62.1/100 mol, control vs. DFM1 and DFM2 respectively) with increasing B. subtilis natto fermentation product supplementation. DMI of the cows in three treatments was not affected by B. subtilis natto fermentation product supplementation, but milk yield was 3.1 and 3.2 kg/day higher for DFM1 and DFM2 than that for control cows on average across the 9-week trial, and significant differences were observed during weeks 5-9 of the trial, which resulted in 9.5% and 11.7% increase in feed efficiency. B. subtilis natto fermentation product supplementation did not affect milk fat percentage and protein yield but increased (p < 0.05) milk fat yield and lactose percentage (p < 0.01) and tended to decrease protein percentage (p = 0.06). The findings show that B. subtilis natto fermentation product was effective in increasing lactation performance of early lactation dairy cows possibly by altering the rumen fermentation pattern without any negative effects on blood metabolites.     

Effect of brewer's grain on rumen fermentation, milk production and milk composition in lactating dairy cows

Six lactating Holstein cows were divided into two groups (n = 3) and used in a double reversal trial with three periods of 14 days each to evaluate the rumen fermentation, milk production and milk composition of cows fed brewer's grain (BG). The control diets contained 14% chopped Sudangrass hay, 24% corn silage, 18% alfalfa hay cube, 34% concentrate mixture‐1 and 10% concentrate mixture‐2 (wheat bran, soybean meal and cottonseed). In the experimental diet, wet BG replaced the concentrate mixture‐2. The protozoal population, concentration of ammonia‐N and volatile fatty acids in the ruminal fluid did not differ between the control and BG diets. The molar percentage of acetic acid was significantly higher (P < 0.05) with the BG diet at 5 h after feeding. The milk yield, the percentage of protein, lactose, solids not‐fat and somatic cell counts of milk did not differ between the two diets. The percentage of milk fat tended to increase with the BG diet. The BG diet significantly increased the proportions of C18:0 and C18:1 in milk fat (P < 0.01, P < 0.05, respectively) and tended to increase that of conjugated linoleic acid.     

Theoretical turnover rate of the rumen liquid fraction in dairy cows and its relationship to feed intake,rumen fermentation,and milk production

Ruminant animals are able to convert plant materials (grain and the human‐indigestible portion of carbohydrates) to milk and meat. In this conversion, most of the plant materials are digested by rumen fermentation and are changed to short‐chain fatty acids, microbial cells, and methane, which is released into the atmosphere. The relationships among feed, rumen fermentation, and milk production are poorly understood. Here we report a novel indicator of characteristics of rumen fermentation, theoretical turnover rate (TTOR) of the rumen liquid fraction. The TTOR was calculated from the presumed rumen volume (PRV) which is estimated by dividing the methane yield by the methane concentration of rumen fluid. The formula for the TTOR is: TTOR = PRV/body weight^0.75. Our present analyses confirm that the TTOR as an indicator is capable of connecting feed, rumen fermentation, and milk production, because dry matter intake/TTOR showed a strong correlation with milk yield/TTOR. In addition, the TTOR may be related to ruminal pH, as we observed that the ruminal pH decreased as the TTOR increased. We propose that the TTOR is a factor characterizing rumen fermentation and a good indicator of the productivity of ruminants and dysbiosis of the rumen microbiome.     

The effects of high levels of rumen degradable protein on rumen pH and histamine concentrations in dairy cows

An experiment was conducted to test the hypothesis that the supplementation of crude protein (CP) results in rumen acidosis and increased histamine concentrations in dairy cows. Six ruminally fistulated, non-pregnant dry cows were fed three experimental rations in a replicated 3 × 3 Latin square design. The CP contents in the low-CP, the high rumen undegradable protein (high-RUP) and the high rumen degradable protein (high-RDP) rations were 112, 259 and 266 g/kg dry matter (DM) respectively. The cows were fed 7.7 kg DM of the concentrates and 2.7 kg DM of rice straw. High levels of RDP in the ration significantly increased the ammonia, total volatile fatty acid (VFA) and histamine concentrations in the rumen fluid. However, supplemental CP, whether degradable or undegradable, did not significantly affect the pH of rumen fluid. Plasma urea nitrogen concentration was higher in both high-RDP and high-RUP in relation to cows fed the low-CP ration. The rise in ruminal histamine concentrations was physiologically non-relevant, most likely because rumen pH was not affected by supplemental CP at the installed level of DM intake. Therefore, it can be concluded that the issue of supplemental CP, rumen pH and ruminal histamine concentrations has not yet been settled. Further research is warranted to understand these relationships.     

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?...     

植物精油对泌乳期奶牛生产性能养分消化、瘤胃发酵及氮平衡的影响

本研究以泌乳期奶牛为研究对象,研究全混合日粮中补充植物精油对其养分摄入量、表观消化率、瘤胃发酵及氮和能量平衡的影响.试验将泌乳性能一致的16头荷斯坦奶牛随机分为2组,每组8个重复,每个重复1头牛.对照组饲喂基础全混合日粮,处理组饲喂基础全混合日粮+150 mg/kg植物精油,试验为期7周.结果:植物精油组奶牛干物质、有...     

不同淀粉水平日粮中添加酵母培养物对奶牛干物质采食量和瘤胃发酵功能的影响

文章旨在研究不同淀粉水平日粮中添加酵母培养物对奶牛生产性能和瘤胃发酵功能的影响。试验选择16头荷斯坦奶牛,随机分为4组,每组4个重复,每个重复1头牛。试验日粮采用2×2多因素方差设计,两个淀粉水平(23%和29%),两个酵母培养物水平(0和25 g/d),试验共进行28 d。结果显示:日粮添加酵母培养物后显著提高了产奶量、3.5%标准乳、能量校正奶(P <0.05)。无论是在低或高淀粉水平日粮中添加酵母培养物均显著提高乳脂含量(P <0.05)。高淀粉水平日粮或添加酵母培养物显著提高了乳蛋白含量(P <0.05)。高淀粉水平日粮中添加酵母培养物较对照组显著降低了血浆结合珠蛋白的含量(P <0.05)。高淀粉水平日粮中添加酵母培养无较对照组显著降低了淀粉表观消化率(P <0.05),低淀粉水平日粮组显著提高了乙酸含量(P <0.05)。高淀粉水平日粮组显著提高了瘤胃乳酸含量(P <0.05)。高淀粉水平日粮组较低淀粉水平组显著降低了氮沉积量(P <0.05),添加酵母培养物使氮沉积量显著升高(P <0.05)。高淀粉水平日粮中添加酵母培养物组氮摄入量和乳氮含量最高(P <0.05)。结论 :在本试验条件下,高淀粉水平日粮中添加15 g/d酵母培养物可以降低奶牛代谢紊乱症的发生,提高纤维消化率及微生物蛋白的产量,进而改善泌乳性能。     

Effect of water‐soluble carbohydrate content in orchardgrass pasture on grazing time and rumen fermentation in dairy cows

Two experiments were conducted to clarify the effect of water‐soluble carbohydrate (WSC) content in orchardgrass pasture on the diurnal distribution of grazing time. Six ruminally cannulated, non‐lactating dairy cows were grazed on either of two pastures with different orchardgrass cultivars containing low WSC (LWSC; cultivar: ‘Hokkai 28’) or high WSC (HWSC; cultivar: ‘Harunemidori’). The cows were grazed in morning and evening sessions in experiment 1, whereas the cows were grazed throughout the day in experiment 2. In experiment 1, grazing time of the cows on HWSC was longer than that of the cows on LWSC (P < 0.01). This difference was larger in the morning session than in the evening session (pasture × grazing session: P < 0.05). Effects on herbage intake were similar to those on grazing time. In experiment 2, daily total grazing time was longer for the cows on HWSC than for those on LWSC (P < 0.05). The cows on HWSC spent a longer time grazing than those on LWSC in the morning between 03.00 and 09.00 hours (P < 0.01). The results indicated that prolonged grazing time in the period between dawn and early morning could increase daily herbage intake in cows grazed on pastures of orchardgrass cultivars with high‐WSC content.     

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.     

高温高湿条件下添加功能性油脂对奶牛生产性能、瘤胃发酵和生理状态的影响

文章旨在评估功能性油脂替代莫能菌素对高温高湿环境下奶牛生产性能、瘤胃发酵和生理状态的影响。试验选择产奶期(200±50)d,平均体重(600±75)kg的荷斯坦奶牛36头,将其随机分为3组,每组12个重复,每个重复1头牛,进行为期6周的试验(1周适应期,5周试验期),试验共设计3种日粮,对照组饲喂基础日粮,处理1组在基础日粮添加20mg/kg莫能菌素,处理2组在基础日粮添加0.05%功能性油脂。试验期间环境温度、湿度和温湿度指数分别是(25±0.55)℃、(82.0±1.20)%和74.5±0.30,表明奶牛处于高温高湿环境。结果:处理1组较对照组和处理2组显著降低了干物质和有机物的摄入量(P<0.05),较对照组显著降低了粗蛋白质摄入量(P<0.05)。试验时间显著影响有机物、蛋白质摄入量及养分表观消化率(P<0.05),同时显著影响瘤胃pH、氨氮和挥发性脂肪酸含量(P<0.05)。对照组较处理2组显著降低了血清尿素含量(P<0.05),处理和时间对血清尿素含量的影响具有显著交互效应(P<0.05)。处理1组较处理2组显著降低了脂肪产量和乳脂肪含量(P<0.05)。试验时间显著影响乳成分含量及产量(P<0.05)。结论:在本试验条件下,功能性油脂增加了乳脂产量,并且可以代替莫能菌素而不影响奶牛在高温高湿环境下的采食量、养分消化率、瘤胃发酵和生理状态。