驴初乳理化性质和主要成份的动态变化

对驴初乳物理性质和化学组成研究。结果表明,驴初乳的相对密度、折光度、电导率、酸度均高于常乳,而pH 值低于常乳;驴初乳中蛋白质、灰分、脂肪含量均随泌乳期延长呈下降趋势;分娩后第一次(6h)所挤初乳中乳糖含量最低,之后随泌乳期延长乳糖含量呈上升趋势;随泌乳期的延长,初乳中各项指标逐渐接近常乳。应用亲和色谱法测定驴初乳免疫球蛋白含量,结果表明,随泌乳期的延长驴初乳中IgG 含量呈下降趋势。     

河南奶山羊及其杂种羊泌乳早期乳成分动态变化

对河南奶山羊及其杂种羊泌乳早期初乳及常乳主要常规成分进行分析。结果表明:奶山羊和杂种羊乳中干物质含量分别在泌乳的第1天和第2天最高,分别达24.14g/100g和26.17g/100g,高峰后随着泌乳期的延长总体上呈下降趋势;乳糖含量在两组羊乳中随着泌乳期的延长总体上均呈上升趋势;乳脂率均在泌乳第5天和第4天时最高,分别达6.32g/100g和5.38g/100g,随着泌乳期的延长呈下降趋势。奶山羊前5d含量所泌初乳中,乳蛋白含量逐渐升高,常乳中乳蛋白含量基本稳定,杂种羊乳蛋白含量在初乳期随着泌乳期的延长呈下降趋势,常乳中含量基本稳定。乳中的灰分含量随着泌乳期的延长总体呈下降趋势,到常乳期有波动。乳中钙含量在实验期趋于稳定,磷含量在初乳期随泌乳期延长而稍有增加,常乳期平稳下降。河南奶山羊及其杂种羊乳中主要成分随着泌乳时间的变化而变化,各主要成分含量的变化与饲养管理条件和羊只营养状况等因素存在密切关系。     

山羊奶理化性状研究——Ⅱ.初乳理化性状及其变化

本文对我国三个具有代表性奶山羊初乳概略成分、比重、pH、Ca和P进行了较为系统地分析与测定。研究结果表明,三个被试品种羊初乳中总干物质、灰分,Ca、P、蛋白质、脂肪和酸度都高于正常水平,而乳糖和pH则相反。上述理化性状在产后数天内,随着泌乳期延长而发生急剧的变化,尤其是在产后3天内变化更大。一般地说,产后7天左右各种理化性状接近正常水平。     

舍饲新疆褐牛初乳产量及乳成分测定

测定10头全舍饲新疆褐牛母牛分娩后2，24，48，72，96，120h的初乳产量、常规营养成分、IgG和矿物元素含量。结果表明，母牛分娩后2h(第1次)所挤初乳产量平均为4.73kg，72h内初乳平均总产量为46．6kg，占成母牛305d平均产奶量的0．9％；120h内初乳平均总产量为85．1kg，占305d平均产奶量的1．65％。2h挤出的初乳其蛋白质、脂肪、乳糖、灰分的含量分别为12．59，6．5，2．87，1．11g／100g，是常乳的3．93，1．76，0．57，1．48倍；IgG质量浓度为60．56g／L，是常乳的108．14倍；Ca，P，Na，Mg，Fe，Zn的含量分别为186．03，167．10，89．65，23.31，0．30，2．25mg／100g，是常乳的1．66，2．01，1．81，2．05，2．14，6．43倍。随泌乳期的延长，初乳中除乳糖以外的各种成份均迅速下降，在48h以内，以蛋白质和IgG的下降幅度最大，分别达62.27％和93．40％。至第120h，除蛋白质及矿物元素的Zn以外，各种成分已和常乳相接近。新疆褐牛分娩后不同时间段初乳成分的变化规律和荷斯坦牛相似。     

山羊奶理化性状研究——Ⅲ 常乳主要理化性状及其变化

本文对西农萨能奶山羊(西农羊),英国萨能奶山羊(英国羊)和关中奶山羊(关中羊)常乳概略成分、比重、pH、Ca和P含量及其在各个泌乳月变化进行了系统的测定与分析。研究结果表明:三个被试品种常乳中之主要组分含量均与国外报告资料相近。pH值在各泌乳月中变化不大,酸度在泌乳后期略有上升;总干物质和脂肪含量在泌乳高峰期(第3—5泌乳月)最低;比重和蛋白质含量也有相似的变化趋势,但后期蛋白质变化更明显。灰分随泌乳期进行逐渐上升,尤其在泌乳后期,乳糖变化趋势与灰分相反,二者呈负相关。     

蒙古国戈壁红双峰驼乳化学组成及其动态变化

本实验对12峰戈壁红双峰驼驼乳的化学组成及其动态变化进行了研究。结果表明,第1次所挤初乳中总干物质为20.858%,在第2～30d间基本稳定在17.858～17.323%,第90d时降至14.488%。第1次所挤初乳中蛋白质含量为14.864%,24h后下降到8.153%,以后进一步缓慢下降。乳糖含量在泌乳第1～90d内变化较小,为4.353%～4.648%。第1次所挤初乳脂肪含量为0.278%,到24h增至4.259%,30d时为6.852%,90d又下降到5.705%。第1次所挤初乳中灰分含量为1.281%,到24h下降到0.918%,在90d泌乳期内稳定在0.861%～0.949%范围内。戈壁红驼产后第1次所挤的初乳中钙、磷含量最高,分别为216.059mg/100g和154.358mg/100g钙、磷、钠、钾及氯在2h～90d变化范围分别为156.323～216.059mg/100g、126.835～154.358mg/100g、60.067～83.025mg/100g、126.808～184.208mg/100g和85.600～193.200mg/100g;硫、镁、锌在2h～90d变化范围分别为37.108～43.208mg/100g、7.908～8.933mg/100g和0.628～0.652mg/100g。戈壁红驼90d内驼乳中VA、VC、VD、VE、VB1、VB2及VB6的平均含量分别为0.918mg/L、15.845mg/L、627IU/L、1.800mg/L、0.188mg/L、1.188mg/L和0.495mg/L。     

牦牛乳与其他哺乳动物乳常规营养成分的比较分析

通过牦牛乳与其他哺乳动物(反刍动物、马属动物、骆驼和人)乳进行产奶量、泌乳期和常规营养成分(蛋白质、脂肪、乳糖、干物质、灰分、矿物质和维生素)的比较分析,得出奶牛的泌乳期最长,产奶量最高,乳中的常规营养成分含量存在种间差异,但呈现出一定的种属特性。反刍动物乳中蛋白质、脂肪、干物质和灰分含量较高,矿物元素和维生素含量丰富;骆驼乳中常规营养成分含量介于反刍动物乳与马属动物乳之间;马属动物乳中的乳糖含量较高;人乳中除乳糖成分外其余常规营养成分普遍低于其他哺乳动物乳。     

母乳中宏量营养成分含量与新生儿相关因素的分析

实验采用队列研究的方法,收集华北地区和中南地区共四个城市乳母分娩后3~5 d、12~14 d、1月、2月、3月、4月和6月的母乳,测定中国现阶段健康乳母不同泌乳阶段母乳中脂肪、总蛋白质、乳糖、干物质、总能量和真蛋白质等宏量营养成分的动态变化,同时研究分娩方式和婴儿性别与各宏量营养成分之间的关系。母乳中宏量营养成分含量的测定采用MIRIS HMA母乳分析仪。结果表明初乳中顺产组的母乳中总蛋白质和真蛋白质含量显著高于剖宫产组的(p0.05),过渡乳中脂肪、总蛋白质、乳糖、干物质、总能量和真蛋白质等宏量营养成分含量在顺产、剖宫产两组间均无显著性差异(p0.05),成熟乳(6月时)中剖宫产组的母乳中乳糖和干物质含量显著高于顺产组的(p0.05)。此外,初乳和过渡乳中脂肪、总蛋白质、乳糖、干物质、总能量和真蛋白质等宏量营养成分含量在男孩、女孩两组间均无显著性差异(p0.05),但是成熟乳中女孩组3月时的母乳中脂肪和总能量含量,4月时的总蛋白质和真蛋白质含量显著高于男孩组的(p0.05)。不同分娩方式及婴儿性别对母乳中宏量营养成分的含量有一定影响。     

不同泌乳时间内内蒙古阿拉善双峰驼驼乳化学组成变化分析

本研究对10匹内蒙古阿拉善双峰驼驼乳的化学组成进行了分析。结果表明，第1次所挤初乳中总干物质为20．16％，在2-30d内变化范围为17．42％18．22％，到90d下降为14．31％。第1次所挤初乳中蛋白质为14．23％，12h后下降到9．63％，之后进一步下降，在7、15、30及90d分别为7．40％、5．32％、4．87％和3．55％。乳糖含量在1～90d泌乳期内变化较小，为4．24％-4．44％。第1次所挤初乳脂肪含量为0．27％，到24h增加到4．18％，30d时为6．91％，90d又下降到5．65％。第1次所挤初乳中灰分含量为1．22％，到12h下降到0．99％，在90d泌乳期内稳定在0．82％～0．98％范围内。第1次所挤的初乳中，WPN占总氮58．74％，CN占总氮38．57％，NPN仅占总氮的2．69％；24h，WPN、CN及NPN分别占总氮的32．54％、65．08％及2．38％。随泌乳进行，驼乳氮分布中CN逐渐升高，WPN逐渐降低，2-90d NPN占总氮变化较小，为5．26％～7．89％。驼乳中C12：0～C18：0偶数长链饱和脂肪酸占总脂肪酸的57．54％，其中C16：0、C18：0及C12：0分别占总脂肪酸的30．12％、15．15％和11．49％，C18：1～C18：3长链多不饱和脂肪酸占总脂肪酸组成的30．25％，其中以C18：1脂肪酸为主，为26．05％。第1次所挤的初乳中钙、磷含量最高，分别为222．58mg／100g和153．74mg／100g；钙、磷、钠、钾及氯在3～90d变化范围分别在154．57～186．87、116．82～141．67、59．5～79．5、150．0～191．0和80．9～152．0mg／100g。初乳中VA、VC含量低于霄乳，VE、VB1高于常乳，VD、VB2及VB6与常乳相近。90d驼乳中VA、VE、VB1、VB2、VB6、VC和VD分别为0．97mg／L和1．45、0．124、1．24、0．54和29．60mg／L和692IU／L。     

奶牛初乳的理化性质Ⅰ热稳定性和其化学组成

本文研究了奶牛初乳的热稳定性并对其加以改进,奶牛初乳的成分分析结果表明:奶牛初乳的蛋白质、脂肪、灰分、密度均高于常乳,并随泌乳期的延长而下降逐渐接近常乳水平,pH和乳糖的变化和它们相反;初乳中Ca、Na、Mg、Cl、Fe、Zn、Cu、的含量均高于常乳几倍甚至几十倍,但K、P的含量较常乳低。奶牛初乳不允许作为原料乳应用,除牛犊食用外大部分被废弃,已有研究表明初乳在常量、微量成分、生物活性物质的含量上均有不同于常乳的性质,如初乳中的免疫球蛋白、乳铁蛋白、溶菌酶、过氧化物酶、α-乳白蛋白,β-乳球蛋白、黄嘌呤氧化酶等生物活性物质含量要高于常乳几十倍～几千倍,其分离纯化后应用于食品添加剂和医药工业潜力很大,故有必要对初乳的理化性质作系统的研究和分析,为初乳的开发和利用提供依据。     

Research on the chemical composition of Saanen goat colostrum

Changes in chemical composition in Saanen goat colostrum were studied 3, 12, 24, 48, 72, 120 and 168 h after parturition. The concentrations of dry matter, fat, ash, lactose, protein and IgG at 3 h of lactation were 21.23%, 7.73%, 1.57%, 1.93%, 10.24% and 72.01 mg/mL respectively. Saanen goat colostrum contained very high concentrations of Ca, P and Mg, and very low concentrations of Zn, Fe, Cd, As, Pb and Hg. In Saanen goat colostrum, the total concentrations of 17 amino acids and 8 essential amino acids were 5796.6 mg/100 mL and 2567.7 mg/100 mL respectively. The concentrations of saturated fatty acids were 75.21%, and medium chain saturated fatty acids (C₈⁰, C₁₀⁰) were 19.84%.     

Studies on milk yield and composition of the West African dwarf goat in Nigeria

Six adult West African dwarf does, about 2 1/2 years old and weighing from 24 to 29 kg, were kept for 18 weeks/lactation, and for 2 lactation periods in all. During these periods the does were hand-milked twice daily and the daily samples were bulked for each animal for subsequent analysis. Milk yields for the period were low. Colostrum was characterized by a high content of total solids of 19-2%, fat 8-3%, total protein 5-1% and a gross energy of 517 kJ/100 g milk, but a low lactose content of 4-9%. The composition tended to approach that of mature goat milk between the second and third d after parturition. The mature goat's milk contained higher mean percentages of fat (6-9) and lactose (6-3) than any temperate breeds of goats and indigenous dairy cattle, but their protein (3-9%) and total ash (0-8%) contents were comparable with any temperate breeds of goats. The percentage protein, lactose, fat and total solids declined slightly with advance in lactation and there was a steady fall in milk yield which was statistically significant (P less than 0-01).     

Changes in chemical composition of Alxa bactrian camel milk during lactation

Changes in chemical composition of Alxa bactrian camels reared in Inner Mongolia (China) during lactation were investigated. Colostrum and milk samples from 10 nomadic female camels in their first season of lactation were collected periodically from parturition until 90 d postpartum (PP). The average contents of gross composition were 14.23% protein, 4.44% lactose, 0.27% fat, 0.77% ash, and 20.16% total solids in colostrum at 2 h PP, and the respective mean values were 3.55, 4.24, 5.65, 0.87, and 14.31% for regular milk on d 90. A 15-fold increase was shown in fat content during the first 24 h, whereas a sharp decrease was shown during the first 12 h of lactation in protein, ash, and total solids contents. Variation in lactose content was small (4.24 to 4.71%) throughout the study period. Total N, nonprotein N, casein N, and whey protein N were found to be 2.23, 0.06, 0.86, and 1.31 g/100 mL for the colostrum at 2 h PP; and 0.56, 0.04, 0.45, and 0.07 g/100 mL for the milk at 90 d PP. Percentages of caseins increased steadily, whereas whey proteins declined gradually until 3 mo of lactation. Gas liquid chromatography analysis of milk fat showed that the content of even-numbered saturated fatty acids (C_12:0-C_18:0) in camel colostrum (2 h to 7 d PP) was lower than that of regular milk (15 to 90 d PP). The predominant saturated fatty acids were C_14:0, C_16:0, and C_18:0, regardless of the stage of lactation. There was a considerable level of polyunsaturated fatty acids (mainly C_18:1) in Alxa camel's milk fat. The levels of Ca, P, Na, K, and Cl were 222.58, 153.74, 65.0, 136.5, and 141.1 mg/100 g, respectively, at 2 h PP; the values of the minerals were 154.57, 116.82, 72.0, 191.0, and 152.0 mg/100 g, respectively, for the regular milk on d 90. The levels of vitamins A, C, E, B₁, B₂, B₆, and D were 0.97, 29.60, 1.45, 0.12, 1.24, 0.54 mg/L, and 640 IU/L, respectively, in Alxa camel milk at 90 d PP. Vitamin A and C contents were higher and vitamins E and B₁ were lower than those in colostrum. Sodium dodecyl sulfate-PAGE and densitometry results demonstrated that Alxa camel colostrum is rich in immunoglobulins, serum albumin, and 2 unknown fractions, which are reduced in amount (%) within 2 d of lactation. It seems that there is lack of β-lactoglobulin in Alxa camel milk, whereas casein and α-lactalbumin start at a low level and increase gradually until they reach their regular levels in the milk.     

The composition of milk of the friesian cattle imported into Nigeria

Here the results of analyses of milk of Friesian cows imported into the University Teaching and Research Farm from Western Germany are reported. Twenty-five of the cows were milked from the first day after parturition for a lactation of 305 days (average yield 3000 ± 88kg). The colostrum contained higher percentages of total solids (TS), crude protein (CP), fats and ash but lower lactose than the mature milk. Concentration of major minerals in the colostrum were higher than the corresponding values in the mature milk. The composition of the colostrum approached normal values on the seventh day after parturition. Contents of TS, CP, lactose and fats in milk were highest in the first month of lactation and then decreased with advance in lactation. The trends were highly significant (P<0.01). On the other hand, the concentration of the minerals increased except for potassium which decreased with advance in lactation with the trends being highly significant (P < 0.01). The values obtained for the gross composition of milk (except total ash) were higher than those reported for the Friesian cow's milk in temperate countries.     

Dietary fat and nitrogen composition of milk from lactating cows

Effects of dietary fat on milk composition, particularly milk N, were evaluated in lactating dairy cows at two stages of lactation. Complete mixed diets containing 0, 3.5, or 7% of the diet DM as animal fat were fed to 12 cows in a 3 X 3 Latin square. Cows were divided into two status categories based on stage of lactation resulting in two squares of early and two of late lactation cows. Percentages of fat, solids, lactose, and protein were decreased and ash increased in the milk of cows fed the 7% fat diet. Percent of casein N was elevated while nonprotein N was depressed by fat fed in diet. Percentage of solids and protein was higher and lactose lower for cows in late lactation than for those in early lactation. Dietary fat reduced the proportion of short-chain fatty acids in milk fat and increased C18:0 and C18:1 fatty acids. Digestibility of DM, energy, and fiber was not significantly affected by dietary fat, but estimates decreased with increased dietary fat. Cows in late lactation had a higher digestibility of dietary fractions than early lactation cows even though intakes of DM were similar.     

Immunoglobulin G content and colostrum composition of different goat and sheep breeds in Switzerland and Germany

Colostrum represents the sole source to acquire humoral immunity and is an important energy source for newborn lambs and goat kids. However, colostrum composition (i.e., the contents of IgG, fat, protein, and lactose) is affected by various factors such as parity and litter size and, potentially, by breed. In the present study, we examined the colostrum composition of different goat and sheep breeds raised for milk and meat production in Switzerland and Germany. Ten goat breeds (Anglo-Nubian, Appenzell, Boer, Bunte Deutsche Edelziege, Chamois-colored, Grisons Striped, Peacock, Saanen, Toggenburg, and Valais Blackneck) and 10 sheep breeds (Brown-Headed Meat, East Friesian Milk, German Blackheaded Mutton, Gray Horned Heath, Lacaune Dairy, Merino Land, Swiss Black-Brown Mountain, Swiss Charollais, Swiss White Alpine, and Valais Blacknose) were involved in this study. First colostrum samples were obtained from ewes (n = 100) and goats (n = 116) between 10 and 390 min after parturition and analyzed for total IgG, fat, protein, and lactose contents. Colostral IgG concentrations varied between 4.8 and 75.0 mg/mL in goats, and between 6.2 and 65.4 mg/mL in ewes, and the time interval between milking and parturition did not affect colostral IgG concentrations. In goats, the highest IgG concentrations were found in Boer (meat-type; 61.0 ± 10.3 mg/mL; mean ± SD) and the lowest concentrations were observed in Bunte Deutsche Edelziege (milk-type; 26.5 ± 12.5 mg/mL). In sheep, East Friesian Milk and Lacaune Dairy showed the lowest colostral IgG concentrations (17.9 ± 7.3 and 20.2 ± 8.0 mg/mL, respectively), and the highest values were observed in the Merino Land breed (44.2 ± 15.7 mg/mL). The lowest fat and protein concentrations and concomitantly highest lactose concentrations were observed in colostrum of East Friesian Milk and Lacaune Dairy sheep. Parity number did not affect colostrum composition in sheep or goats. In contrast, colostral fat content was higher in ewes bearing twins and triplets than in those carrying singletons. Increasing litter size tended to be associated with higher protein and lower lactose concentrations in ovine (i.e., singletons vs. twins vs. triplets) and caprine colostrum (i.e., singletons vs. twins), whereas colostral IgG concentrations were not affected by litter size. In conclusion, IgG and concentrations of other colostrum constituents showed a wide range in goats and ewes and were mainly affected by the type of breed.     

广西水牛原料乳微生物和理化指标分析

按不同种群从广西取80个水牛原料乳样品，通过理化和微生物指标检测，对水牛乳营养价值和安全性进行了分析比较．主要理化检测结果如下：脂肪7．32％，蛋白质4．71％，乳糖4．67％。固形物18．42％，灰分0．84％（均为质量分数），pH值为652，密度1.030g／mL。纯种河流型水牛摩拉和尼里-拉菲的脂肪、蛋白质、固形物、灰分舍量显著低于（P〈0.05）河流-沼泽型杂交水牛。微生物检测结果如下（对数值）：细菌总数5．69mL^-1，茅孢菌3．03mL^-1，乳酸菌4．79mL^-1，真菌1．80mL^-1，大肠菌群2．48mL^-1，大肠杆菌1．83mL^-1，金黄色葡萄球菌1.80mL^-1，所有样品中李斯特氏苗均未检出。地区间微生物指标差异较大。微生物含量均在可接受范围之内，但是致病菌的出现说明需要建立相关的卫生质量标准.     

Characteristics of Milk,Cheddar-Like and White Cheese Obtained from Three Goat Phenotypes during Three Lactation Periods

Goat's milk from three phenotypes: Shami, Local, and Mixed was collected during three lactation periods in 2002. The milk was analyzed for moisture, protein, fat, ash, and lactose content. Also milk was examined for yeast, mold and bacterial content. Cheddar and white cheese were manufactured from goat's bulk milk and examined for chemical composition and evaluated for color, taste and flavor, appearance, and texture and aroma. Results showed that the chemical composition of goat's milk varied significantly during the whole year and also among the three goat phenotypes. Local goats produced milk at the first lactation period with highest (44.6%) fat content: the lowest fat content was 29.8% for the Mixed color phenotype at the end of the year. Protein showed the same trend. Shami goat produced milk lower in lactose and ash content than the mixed color breed, whereas the Local (black) produced milk having intermediate content of lactose and ash. Cheddar and white cheese were highly acceptable. Their composition varied—cheddar cheese was higher in protein and NSF but slightly lower in fat content. White cheese retained more lactose. Goat's milk of Shami, Local (black) and Mixed color phenotypes were found to be highly contaminated with bacteria and mold due to lack of hygiene. Milk contained low number of pathogenic bacteria. Using a pasteurization temperature at 73°C for 16 seconds was found to eliminate them.     

山羊初乳成分及其免疫球蛋白构成变化的研究

动物初乳对其后代健康的作用已经得到了广泛的证实,其对人类健康的影响也受到了越来越多的重视.本研究探讨了阿尔卑斯山羊产后一周内乳成分和其中免疫球蛋白(Ig)含量的变化.结果表明:产后48h内山羊奶的蛋白质、总固形物和免疫球蛋白含量均快速下降;脂肪含量在前三次的初乳中逐渐升高,随后又缓慢下降;乳糖含量保持相对稳定于4%～5%;经产山羊前三次初乳的蛋白含量分别达到了16.5%、10.7%和6.8%,显著地高于初产山羊前三次初乳的蛋白含量(7.0%、4.8%和4.1%);经产山羊前两次初乳的IgG含量达到了59.9mg/ml和34.7mg/ml,IgM含量达到了6.14mg/ml和2.37mg/ml,显著地高于初产山羊前两次初乳的IgG含量(18.1mg/ml和13.9mg/ml)和IgM含量(1.95mg/ml和0.98mg/m1);经产和初产山羊初乳的IgA含量无显著差异.