基于高通量测序技术分析青藏高原牦牛和犏牛乳中微生物多样性的研究

为探究牦牛和犏牛生鲜乳中微生物的组成和多样性,采用高通量测序技术分析两种生鲜乳的16S rDNA V4区域,并进行生物信息学对比分析。结果显示:97%的一致性共得到5516个OTUs,微生物门水平的比较表明变形菌门（Proteobacteria）、厚壁菌门（Firmicutes）及放线菌门（Actinobacteria）为牦牛乳和犏牛乳共同的优势菌门,牦牛乳三种微生物的相对丰度分别为29.80%、35.99%及8.41%,犏牛乳为45.36%、25.79%及7.39%;在属水平上,牦牛乳的优势菌属为未分类的蓝藻细菌属（unidentified-Cyanobacteria）,相对丰度为9.32%,犏牛乳的优势菌属为慢生根瘤菌属（Bradyrhizobium）,所占比例为11.53%;在种水平上,埃尔坎尼中慢生根瘤菌种（Bradyrhizobium elkanii）和Kosakonia oryzae为牦牛乳和犏牛乳中共有的优势菌种,两种菌种在牦牛乳中分别占比2.42%、3.36%,在犏牛乳中分别占比11.53%、5.53%;Alpha多样性分析表明不同牛乳丰度估计值存在显著差异（P<0.05）,且犏牛乳的丰富度及多样性较高。     

日本香川地区荷斯坦牛乳与娟姗牛乳营养成分的比较

目的比较日本香川地区荷斯坦和娟姗牛乳中乳清蛋白的总蛋白质含量,乳过氧化物酶(LPO)和乳铁蛋白的一些基本性质。方法以荷斯坦和娟姗牛乳为对象,经酸沉淀除酪蛋白后,通过离心,SP-Sepharose离子交换层析分离纯化得到乳过氧化物酶和乳铁蛋白,利用考马斯亮蓝定量、SDS-PAGE定性、ABTS检测乳过氧化物酶活性、最后通过基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)确认分子量。结果娟姗牛乳中乳清蛋白的总蛋白质和乳过氧化物酶含量均高于荷斯坦中乳清蛋白中的总蛋白质和乳过氧化物酶含量。娟姗乳清蛋白中的乳过氧化物酶活性(0.870 5 U/ml)高于荷斯坦乳清蛋白中的乳过氧化物酶活性(0.758 9 U/ml)。娟姗乳清蛋白中的乳过氧化物酶和乳铁蛋白分子量分别为786 48.154和831 23.538 k Da,荷斯坦乳清蛋白中的乳过氧化物酶和乳铁蛋白分子量分别为777 64.841和827 65.494 k Da。结论对于乳酪行业,当考虑养殖奶牛品种生产乳酪同时又想最大限度利用需要处理的乳清蛋白和乳铁蛋白的时候,相比于荷斯坦奶牛,娟姗奶牛是更好的选择。     

基于16S rDNA高通量测序分析水牛初乳与常乳中细菌多样性

目的:利用16S rDNA高通量测序研究广西水牛研究所种畜厂三品杂水牛初乳与常乳的细菌多样性。方法:提取当天采集的生水牛乳样本的细菌总DNA,PCR扩增其16S rDNA,利用纯化后的扩增片段构建其菌群的16S rDNA文库,采用Miseq PE300平台进行高通量测序以及BLAST比对。结果:初乳组样本共得到19个门,292个属和437个种。而常乳两组样本共得到7个门,203个细菌属和330个细菌种,初乳组的细菌多样性高于常乳组。初乳组中的优势菌属为金黄杆菌属（Chryseobacterium）、不动杆菌属（Acinetobacter）、假单胞菌属（Pseusomonas）,而常乳组中的优势菌则为金黄杆菌属（Chryseobacterium）、乳球菌属（Lactococcus）、肠球菌属（Enterococcus）。样本层级聚类显示:初乳组与常乳组组间群落差异不显著。PCA与PLS-DA分析表明:两组样本组间菌群结构差异显著。结论:三品杂水牛初乳与常乳均呈现较丰富的多样性,常乳组中细菌多样性显著高于初乳组。     

不同品种水牛乳中矿物元素的测定与分析

为阐明不同奶水牛品种的水牛乳在不同泌乳期的微量元素变化,采集了我国摩拉水牛、尼里-拉菲水牛、以及上述两种水牛加本地水牛(即三品种杂交水牛,以下简称"三杂水牛")在泌乳第15,45,150和200 d的乳样,同时采集了荷斯坦奶牛和娟姗牛的乳样,用ICP-AES法分析乳中几种常量和微量元素的质量浓度。结果表明,水牛乳中矿物元素除钾和钠外,各种矿物元素质量浓度均高于荷斯坦和娟姗牛。以平均值计,水牛乳钙、铁、锌的质量浓度分别是荷斯坦牛乳的1.7,13.0和1.7倍。泌乳期是影响水牛乳矿物元素质量浓度的主要因素,其中以早期和末期质量浓度较高。各品种水牛乳间矿物元素质量浓度无显著差异,但尼里-拉菲水牛乳总体偏低。     

南山牧场生鲜牛乳理化指标与微生物多样性对比分析

为了解南方山区牧场牛乳的特性,改善山区牧场地区原料乳的品质以及合理开发利用提供理论依据,本文比较分析了湖南南山牧场与城郊牧场生鲜牛乳的理化指标（常规成分、矿物质元素、氨基酸组成、挥发性成分）及微生物多样性。结果表明:南山牧场牛乳与城郊牧场牛乳各个常规营养成分呈明显差异,其中,南山牧场牛乳游离脂肪酸含量高达5.34 mg/kg,且铁与锌的含量分别为5.200和6.390 mg/L,明显高于城郊牧场牛乳;南山牧场牛乳中氨基酸总量为3.102 g/100 g,低于城郊牧场牛乳;城郊牧场牛乳中共检出13种挥发性物质,而南山牧场牛乳挥发性成分测定共检出11种物质,低于城郊牧场牛乳。微生物多样性测定发现两个牧场之间细菌类群的组成比例明显不同,城郊牧场两种样品细菌类群多样性丰富,组成大致相同,占优势丰度的为肠球菌,南山牧场牛乳中不动杆菌属为优势菌群。综合分析表明,同一品种的牛乳受地理环境因素影响大,不同牧场之间牛乳的常规成分、矿物质及氨基酸含量都有明显差异;微生物多样性受环境因素影响较显著。     

冬夏两季水牛乳中细菌多样性的比较分析

利用16S rDNA高通量测序研究冬夏两季水牛乳中的细菌多样性。提取当天采集的生水牛乳样本的细菌总DNA,PCR扩增其16S rDNA,采用Miseq PE300平台进行高通量测序以及BLAST比对。结果冬季组样本共得到19个细菌门,92个目,456个属和733个种。而夏季组样本共得到14个门,63个目,274个和424个菌种。冬季组中的细菌多样性显著高于夏季组。夏季组中的优势菌属为不动杆菌属(Acinetobacter)、乳球菌属(Lactococcus)、金黄杆菌属(Chryseobacterium),而冬季组的优势菌属则为芽孢杆菌属(Bacillus)、棒杆菌属(Corynebacterium)、库特氏菌属(Kurthia)、土地杆菌属(Pedobacter)。样本层级聚类显示:夏季组与冬季组组间群落差异不显著。PCA与PLS-DA分析表明:冬夏两季样本组组间菌群结构差异显著。得出结论季节因素对水牛乳中细菌多样性影响较大,在湿热的夏季,乳球菌属(Lactococcus)、金黄杆菌属(Chryseobacterium)占优势,而在低温干燥的冬季,芽孢杆菌属(Bacillus)、棒杆菌属(Corynebacterium)、库特氏菌属(Kurthia)则占优势。冬夏两季水牛乳样本整体呈现较丰富的多样性,且冬季组中的细菌多样性明显高于夏季组。     

山西老陈醋和怀仁醋酒精发酵阶段细菌菌群多样性分析

为了探明山西老陈醋酿造工艺和怀仁醋酿造工艺对细菌菌群的影响,该研究利用高通量测序技术对两种工艺酒精发酵阶段样品（分别编号为S和X）的细菌菌群多样性进行分析。结果表明,S样品的细菌菌群多样性更高。两种工艺酒精发酵阶段样品的细菌菌群组成差别较大,与S样品相比,X样品中相对丰度较高的乳杆菌属（Lactobacillus）、魏斯氏菌属（Weissella）、乳球菌属（Lactococcus）均增多,片球菌属（Pediococcus）、明串珠菌属（Leuconostoc）、泛菌属（Pantoea）、链霉菌属（Streptomyces）、短状杆菌属（Brachybacterium）、肠杆菌属（Enterobacter）和非培养细菌（uncultured bacterium）均减少。导致两种工艺酒精发酵阶段样品有显著差异的细菌在S样品中为片球菌属、明串珠菌属、链霉菌属和泛菌属,在X样品中则为乳杆菌属、魏斯氏菌属和乳球菌属。相关性分析结果表明,乳杆菌属、泛菌属、魏斯氏菌属和片球菌属与其他物种联系紧密。     

汉中地区浆水发酵过程中微生物群落演替及其功能预测

该研究利用Illumina MiSeq测序技术，对发酵不同阶段的汉中浆水进行细菌与真菌多样性检测分析。结果表明，随着发酵的进行，细菌群落的丰度和多样性较为稳定，真菌群落的丰度和多样性先增加后趋于稳定。3个发酵时期中优势细菌门均为厚壁菌门（Firmicutes），优势细菌属为乳植杆菌属（Lactiplantibacillus）、腐败乳杆菌属（Loigolactobacillus）、魏斯氏菌属（Weissella）、寡碳乳杆菌属（Paucilactobacillus）、明串珠菌属（Leuconostoc）等；优势真菌门为担子菌门（Basidiomycota）和子囊菌门（Ascomycota），优势真菌属主要有双胞菌属（Cystofilobasidium）、白冬孢酵母属（Leucosporidium）、镰刀菌属（Fusarium）、德巴利酵母属（Debaryomyces）、Holtermanniella等。整个发酵过程中优势菌属相对含量有明显波动，参与发酵的真菌种类多于细菌。微生物功能预测结果显示，细菌中涉及代谢、遗传信息处理和环境信息处理的通路比例分别为（74.11±0.11）%、（12....     

荷斯坦牛乳蛋白多态性与乳成分的关联分析

乳蛋白多态性影响牛乳的营养成分,通过分析乳蛋白多态性对乳成分的影响,可指导企业选育优质基因型的奶牛进行生产,提高经济效益。本文使用反相高效液相色谱法对牛乳蛋白的多态性进行研究,发现在广西地区的55头荷斯坦牛乳蛋白中,除了αs2-酪蛋白、α-乳白蛋白没有多态性外,其他的蛋白皆存在多态性。通过分析荷斯坦乳蛋白多态性与乳成分的关系,发现其乳蛋白多态性对乳成分的组成有影响。     

黄豆发酵与牛乳发酵酸奶的细菌多样性分析

为探究植物蛋白与动物蛋白发酵乳品中细菌多样性之间的关系,运用16S rRNA高通量测序技术,对纯黄豆、纯牛乳发酵酸奶中细菌多样性进行分析,并探究植物代糖对其细菌多样性差异形成的影响,预测酸奶中微生物群落功能的组成。α多样性分析结果表明,黄豆样本细菌多样性高于牛乳样本;Adonis及主坐标分析显示,黄豆样本与牛乳样本组间群落组成差异极其显著;多级物种层级分析及组间差异分析表明,黄豆、牛乳样本菌群中优势门均为厚壁菌门(Firmicutes),优势属均为链球菌属(Streptococcus),黄豆样本显著富集芽孢杆菌目(Bacillales),牛乳样本大量富集乳杆菌目(Lactobacillales);样本层级聚类分析显示,添加代糖对黄豆发酵酸奶样本群落组成具有一定的影响。功能预测发现,细胞运动、癌症(特定类型)、排泄系统、物质依赖功能在黄豆发酵酸奶样本中丰度值远大于牛乳样本。黄豆发酵酸奶细菌多样性显著高于牛乳发酵酸奶,这为开发利用植物蛋白中的微生物资源提供了理论支持。     

A comparison of the environmental impact of Jersey compared with Holstein milk for cheese production

The objective of this study was to compare the environmental impact of Jersey or Holstein milk production sufficient to yield 500,000 t of cheese (equivalent cheese yield) both with and without recombinant bovine somatotropin use. The deterministic model used 2009 DairyMetrics (Dairy Records Management Systems, Raleigh, NC) population data for milk yield and composition (Jersey: 20.9 kg/d, 4.8% fat, 3.7% protein; Holstein: 29.1 kg/d, 3.8% fat, 3.1% protein), age at first calving, calving interval, and culling rate. Each population contained lactating and dry cows, bulls, and herd replacements for which rations were formulated according to DairyPro (Agricultural Modeling and Training Systems, Cornell, Ithaca, NY) at breed-appropriate body weights (BW), with mature cows weighing 454 kg (Jersey) or 680 kg (Holstein). Resource inputs included feedstuffs, water, land, fertilizers, and fossil fuels. Waste outputs included manure and greenhouse gas emissions. Cheese yield (kg) was calculated according to the Van Slyke equation. A yield of 500,000 t of cheese required 4.94 billion kg of Holstein milk compared with 3.99 billion kg of Jersey milk-a direct consequence of differences in milk nutrient density (fat and protein contents) between the 2 populations. The reduced daily milk yield of Jersey cows increased the population size required to supply sufficient milk for the required cheese yield, but the differential in BW between the Jersey and Holstein breeds reduced the body mass of the Jersey population by 125×10(3) t. Consequently, the population energy requirement was reduced by 7,177×10(6) MJ, water use by 252×10(9) L, and cropland use by 97.5×10(3) ha per 500,000 t of cheese yield. Nitrogen and phosphorus excretion were reduced by 17,234 and 1,492 t, respectively, through the use of Jersey milk to yield 500,000 t of Cheddar cheese. The carbon footprint was reduced by 1,662×10(3) t of CO(2)-equivalents per 500,000 t of cheese in Jersey cows compared with Holsteins. Use of recombinant bovine somatotropin reduced resource use and waste output in supplemented populations, with decreases in carbon footprint equivalent to 10.0% (Jersey) and 7.5% (Holstein) compared with nonsupplemented populations. The interaction between milk nutrient density and BW demonstrated by the Jersey population overcame the reduced daily milk yield, thus reducing resource use and environmental impact. This reduction was achieved through 2 mechanisms: diluting population maintenance overhead through improved milk nutrient density and reducing maintenance overhead through a reduction in productive and nonproductive body mass within the population.     

Comparative feed efficiency of Holstein and Jersey cows

Feed efficiency measures, gross energy (solids-corrected milk/estimated energy intake), N (milk N/N intake) utilization, and apparent digestibilities of ration dry matter and N were calculated for 34 daughters of 21 Holstein and 29 daughters of 18 Jersey sires in first and second trimesters of lactation. Cows were studied in N balance trials and were fed ad libitum corn silage-based, complete rations formulated to meet average nutrient requirements. The objective was to determine whether these breeds differ in rates of converting dietary protein or energy to milk protein or milk energy. Holstein and Jersey did not differ for digestibility of ration dry matter in either trimester of lactation. They also converted dietary protein to milk protein at similar rates. Energy efficiencies of Holstein and Jersey did not differ in first trimester, but Holstein exceeded Jersey in second trimester. Because intake of dry matter by Jersey increased about 4% from first to second trimester (opposite of Holstein) and N balance was higher than for Holstein, Jersey cows may have been repleting more adipose tissue. We suggest no comparative advantage for Jersey in spite of higher ratios of milk to body weight and feed intake less than Holstein.     

A comparison between Holstein-Friesian and Jersey dairy cows and their F1 hybrid on milk fatty acid composition under grazing conditions

The objective of this study was to investigate the effect of 2 breeds, Holstein and Jersey, and their F₁ hybrid (Jersey × Holstein) on milk fatty acid (FA) concentrations under grazing conditions, especially conjugated linoleic acid (CLA) and n-3 polyunsaturated fatty acids because of their importance to human health. Eighty-one cows (27 per breed grouping) were allocated a predominantly perennial ryegrass pasture. Samples were collected over 2 periods (June and July). Breed affected dry matter intake and milk production and composition. Holstein cows had the highest dry matter intake (18.4 ± 0.40 kg of DM/d) and milk production (21.1 ± 0.53 kg of DM/d). Holstein and Jersey × Holstein cows had similar 4% fat corrected milk, fat yield, and protein yield; with the exception of fat yield, these were all higher than for Jersey cows. Milk fat concentration was highest for Jersey cows and lowest for Holstein cows, with the hybrid cows intermediate. Total FA and linolenic acid intake (1.09 ± 0.023 and 0.58 ± 0.012 kg/d, respectively) were highest for Holstein cows. In terms of milk FA, Holstein cows had higher contents of C14:1, cis-9 C18:1 and linoleic acid. In turn, Jersey and Jersey × Holstein cows had higher content of C16:0. Milk concentrations of neither the cis-9,trans-11 isomer of CLA nor its precursor, vaccenic acid, were affected by breed. Nevertheless, large variation between individual animals within breed grouping was observed for CLA and estimated Δ⁹-desaturase activity. There was some evidence for a negative heterotic effect on milk concentration of CLA, with the F₁ hybrid cows having lower concentrations compared with the mid parent average. Plasma FA profile did not accurately reflect differences in milk FA composition. In conclusion, there was little evidence for either breed or beneficial heterotic effects on milk FA content with human health-promoting potential, though significant within-breed, interanimal variation was observed.     

中国主要牧区特色干制发酵乳制品细菌多样性和游离氨基酸及脂肪酸特征性分析

为研究我国主要牧区特色干制发酵乳制品中细菌、游离氨基酸、脂肪酸组成及其相关性,通过高通量测序技术对新疆酸奶疙瘩、西藏曲拉、内蒙古奶渣子和云南乳扇中细菌16S rDNA V4-V5区测序,利用气相色谱-质谱联用技术和液相色谱技术分别测定脂肪酸和游离氨基酸含量,最后再利用冗余分析研究细菌群落与α多样性、脂肪酸和游离氨基酸的相关性。高通量测序结果表明,干制发酵乳制品样本共获得2 421 338条reads,其中clean reads为1 871 524条,云南乳扇中细菌Chao1指数和Shannon指数均明显高于其他3个地区的干制乳制品样品。细菌群落组成分析发现,不同干制乳制品样品的菌群组成差异较大,4个地区的干制乳制品中的菌群均以Firmicutes为主,其中新疆酸奶疙瘩的Firmicutes相对最高,西藏曲拉的Proteobacteria相对于其他地区的干制乳制品占比最高。在属水平上,不同地区的干制乳品主要以Lactococcus或Lactobacillus为主。脂肪酸分析发现,云南乳扇中的16种脂肪酸均高于其他3个地区。对游离氨基酸进行分析,共检出24种游离氨基酸,其中新疆酸奶疙瘩的游...     

不同品种原料乳理化特性分析

主要分析荷斯坦牛、牦牛、娟珊牛、摩拉水牛、尼里-拉菲水牛、Ⅰ代杂交水牛、高代杂交水牛等7个品种的原料乳的常规营养成分,并对原料乳中蛋白质和氨基酸组成及牛乳缓冲能力进行测定。结果显示：摩拉水牛、尼里-拉菲水牛、Ⅰ代杂交水牛和高代杂交水牛的乳脂肪含量分别为6.86%、7.99%、8.34%、8.69%,蛋白质含量分别为5.75%、5.14%、5.78%、5.58%,干物质含量分别为17.07%、18.79%、19.73%、19.88%,显著高于其他3种牛乳;牦牛和娟珊牛乳中乳糖含量分别为5.09%、5.17%,显著高于其他5种牛乳。SDS-PAGE显示：水牛乳中除含有牛乳血清蛋白(BSA)、α-酪蛋白(α-CN)、β-酪蛋白(β-CN)、κ-酪蛋白(κ-CN)、β-乳球蛋白(β-Lg)和α-乳白蛋白(α-La)主要蛋白外,还含有一些未定性蛋白;且水牛乳具有最好的缓冲性能,其次是牦牛乳和娟珊牛乳,荷斯坦牛乳缓冲性能最差。     

Growth, reproduction, and lactation in somatic cell cloned cows with short telomeres

We previously showed that telomere lengths of 10 somatic cell cloned cows were significantly shorter than normal. In this study, we investigated growth, reproduction, and lactation in these animals to determine if shortened telomeres have any effect on these characteristics. Six Holstein and 4 Jersey cloned cows, derived from oviduct cells, were reared under general group feeding. Body weights were recorded from birth to 48 mo of age. A number of reproductive characteristics were screened during the prepubertal, postpubertal, and postpartum periods. After parturition, milk yields were recorded daily and percentages of milk fat, proteins, and solids-not-fat were measured at monthly intervals. These data were used to estimate production of milk components over a 305-d period. Overall, the cloned heifers exceeded standard growth rates for each breed. The cows were inseminated at the first estrus after they reached 450 d of age, and delivered normal calves except for one stillbirth in the Holstein group. They were inseminated at postpartum estrus to provide second and third parturitions and, again, these pregnancies were normal. Gestational periods and birth weights of the calves were both within the normal range. The average total milk yield per cow in Holstein group clones was less than that of the original cow, whereas Jersey group clones showed a higher average milk yield than the original cow. In both groups of cloned cows, inter-individual variation in milk production was relatively large; however, the coefficient of variation was less than 10%. Our results suggest that the cloned cows have normal growth, reproductive, and lactation characteristics, and thus normal productivity, despite having reduced telomere lengths.     

The effect of blending Jersey and Holstein–Friesian milk on composition and coagulation properties

The impact of blending on milk composition and properties is subject to controversy on whether the effect is additional or not. The effects of blending Jersey and Holstein–Friesian milk on composition and coagulation properties were investigated. Milk from herds of Jersey and Holstein–Friesian cattle was collected and blended (0–100% Jersey milk at 10% intervals) (n = 55).Including Jersey milk resulted in a positive non‐additive effect in fat globule volume mean diameter D(4.3) and a negative non‐additive effect in casein micelle size. Coagulation time decreased quadratically when Jersey milk was added and curd firmness and firming rate increased quadratically.     

水分活度对贮藏脱水香葱的风味和菌群的影响

为研究水分活度(water activity,aw)对脱水香葱贮藏过程中风味和菌群的影响,本实验测定了脱水香葱在不同aw条件下贮藏50d后的挥发性成分和细菌群落组成,并探讨两者之间的相关性.结果 表明,在不同aw条件下贮藏50d后,脱水香葱的细菌多样性相比贮藏前显著升高(P＜0.05),脱水香葱样品的细菌群落结构与贮藏...     

Responses of milk fat composition to dietary fat or nonstructural carbohydrates in Holstein and Jersey cows

Milk fat from Jersey cows contains less oleic acid (cis-C18:1) and more short- and medium-chain fatty acids than does milk fat from Holstein cows. The objective of this experiment was to determine responses in milk fat composition when Jersey and Holstein cows were fed diets either high (37% of dry matter) or low (27% of dry matter) in content of nonstructural carbohydrates (NSC) and supplemented with either 0 or 2.5% (of dry matter) of a mostly saturated fat source. Four Holstein cows and four Jersey cows were used in a Latin square design with 28-d periods; diets were in a 2 x 2 factorial arrangement. Fat supplementation decreased contents of fatty acids synthesized de novo within the mammary gland and increased contents of C18:0 and cis-C18:1. Low-NSC diets tended to increase C16:0 and to decrease C18:0, cis-C18:1, and C18:3. Despite the differences in fatty acid composition between breeds, both breeds generally responded similarly to dietary treatments. An interaction of breed and fat indicated that the content of cis-C18:1 in milk fat was increased more by supplemental fat in Holsteins than in Jerseys. Interactions of breed x fat and breed x carbohydrate type showed that the ratio of cis-C18:1 to C18:0 decreased when Jerseys were supplemented with fat but increased for Holsteins, and decreased when Jerseys were fed the low-NSC diet but increased when Holsteins were fed low NSC. The data are consistent with the hypothesis (Beaulieu and Palmquist, 1995, J. Dairy Sci. 78:1336-1344) that mammary activity of stearoyl-coenzyme A desaturase is lower in Jerseys than in Holsteins.