Production and processing of milk from transgenic goats expressing human lysozyme in the mammary gland

The potential for applying biotechnology to benefit animal agriculture and food production has long been speculated. The addition of human milk components with intrinsic antimicrobial activity and positive charge to livestock milk by genetic engineering has the potential to benefit animal health, as well as food safety and production. We generated one line of transgenic goats as a model for the dairy cow designed to express human lysozyme in the mammary gland. Here we report the characterization of the milk from 5 transgenic females of this line expressing human lysozyme in their milk at 270 μg/mL or 68% of the level found in human milk. Milk from transgenic animals had a lower somatic cell count, but the overall component composition of the milk and milk production were not different from controls. Milk from transgenic animals had a shorter rennet clotting time and increased curd strength. Milk of such nature may be of benefit to the producer by influencing udder health and milk processing.     

Composition, physiochemical properties, nitrogen fraction distribution, and amino acid profile of donkey milk

This study investigated the changes in chemical composition, nitrogen fraction distribution, and AA profile of milk samples obtained during lactation from the Jiangyue breed of donkey in Northwest China. Results showed that donkey milk contained 9.53% total solids, 1.57% protein, 1.16% fat, 6.33% lactose, and 0.4% ash on average, which is more similar to mare and human milk than to the milk of other mammals. Throughout the lactation investigated, pH and density were constant, protein and ash content showed an apparent negative trend (an increase in lactose content during 120 d postpartum, followed by a decrease), fat content exhibited wide variability, and variations in the content and percentage of whey protein, casein, and AA were small. The casein to whey protein ratio of 52:37 was between the lower value of human milk and the higher value of cow milk. Sodium dodecyl sulfate-PAGE results demonstrated that donkey milk is rich in β-lactoglobulin and lysozyme. The percentages of 8 essential AA in protein of donkey milk were 38.2%, higher than those of mare and cow milk; donkey milk also had higher levels of serine (6.2%), glutamic acid (22.8%), arginine (4.6%), and valine (6.5%) and a lower level of cystine (0.4%).     

4 种哺乳动物乳中低聚糖的定性和定量分析研究进展

低聚糖是乳中的一类生物活性成分,具有益生元、抗病毒、抗炎及免疫调节等功能,可作为一种新型食品组分添加至特殊医学用途配方食品或功能性食品中,近年来受到了人们的广泛关注。哺乳动物乳是低聚糖的主要来源,前人围绕哺乳动物的初乳及成熟乳中的低聚糖种类及含量开展了相关研究,但是不同物种间低聚糖种类和含量的对比还鲜有报道。本文对4 种哺乳动物乳（山羊、牛、猪、骆驼）中的低聚糖种类和含量进行了总结及对比,旨在为动物乳源低聚糖的应用提供参考。     

驴乳中蛋白质组分的分离纯化与鉴定

目的：分离纯化并鉴定驴乳乳清中蛋白质组分,为进一步研究驴乳用于辅助治疗疾病,以及为作为人乳替代品提供参考。方法：采用DEAE-52 离子交换层析和Sephadex G-100 凝胶层析分离纯化驴乳乳清中蛋白质组分,并通过十二烷基硫酸钠--聚丙烯酰胺凝胶电泳法和高效凝胶渗透色谱法对所纯化蛋白质进行鉴定。结果：与牛乳乳清中蛋白组分相对比,发现驴乳乳清中存在3 种未知蛋白质,分子质量分别为32、70.1、72.2kD。结论：驴乳中除了含有与牛乳相似的营养成分外,还具有其他生物活性成分,它们可能是一些保护性蛋白,在机体的抗病机制方面起着重要作用。     

Donkey milk: An overview on functionality,technology, and future prospects

Milks from nontraditional animal species (i.e., donkey, camel, and buffalo) are recently gaining momentum mainly due to the fact that they are considered suitable to supplement the needs of special population groups (i.e., infants, the elderly). Research on donkey milk has dramatically increased over the past few years; therefore, this review aims to critically summarize the current research, offering an insight into its unique functional properties, namely, antimicrobial activity, immunomodulation, and hypoallergenicity, especially highlighting their effect on human health. The microbiological and chemical safety, the nutritional profile, and donkey milk’s technology are also discussed. Moreover, new promising research grounds are proposed to be explored in order to add to existing knowledge.     

Pseudomonas aeruginosa lectin PA-IIL as a powerful probe for human and bovine milk analysis

Milk composition exhibits species-specific differences depending on genetic, evolutionary, and environmental factors. In addition, commercial milk preparations are also changed by industrial manipulations, including severe heat processing. Cow milk, used as human food, provides important nutrients but lacks some essential components that are present in raw human milk. The present study, which was aimed at comparing infant breastfeeding to cow-based formula nourishment, shows major differences between the human and the commercial cow milk glycans detectable by the lectins PA-IL (galactose-binding) and PA-IIL (fucose and mannose-binding) isolated from the cells of human pathogen Pseudomonas aeruginosa. More than 40 human milk samples, several cow milks, and bovine milk-based infant formulas, were examined using these two lectins. For purposes of comparison, the plant lectins Concanavalin A (Con A), which binds mannose, and Ulex europaeus 1st lectin (UEA-I), which binds fucose, were also used. The most prominent difference was revealed using PA-IIL, which displayed a unique high sensitivity to the human milk fucosylated compounds. PA-IL and UEA-I also exhibited preferential sensitivity to the human milk but considerably lower than that of PA-IIL. Con A was inhibited by human and the other milk preparations examined to the same extent. These findings indicate the superb applicability of PA-IIL for rapid and reliable comparative investigation of milk glycans from human and cow, indicating which glycans could be added to infant formulas in order to enrich them, as well as for verification and quality control of otherwise improved bovine milk-based infant formulas.     

Short communication: Phenotypic characterization of total antioxidant activity of buffalo,goat, and sheep milk

Free radicals are reactive and unstable waste molecules produced by cells, responsible of damages and alteration on DNA, proteins, and fat. The daily intake of antioxidant compounds, acting against free radicals and their detrimental effects, is essential for human health. Milk contains several compounds with antioxidant activity, and the sum of their reducing potential blocking free radicals development is defined as total antioxidant activity (TAA). This novel trait has been described in literature both in individual and bulk cow milk, but there are no reports from other dairy species. Therefore, the present study aimed to investigate phenotypic variation of TAA in individual samples of buffalo (n = 105), goat (n = 112), and sheep (n = 198) milk. Total antioxidant activity was measured through a reference spectrophotometric method, and expressed as millimoles per liter of Trolox equivalents (TE). The greatest TAA was observed in sheep milk, averaging 7.78 mmol/L of TE and showing also the broadest phenotypic variation expressed as coefficient of variation (13.98%). Significantly lower TAA values were observed for buffalo (7.35 mmol/L of TE) and goat (6.80 mmol/L of TE) milk, with coefficients of variation of 8.18 and 8.47%, respectively. Total antioxidant activity exhibited weak correlations with milk yield and chemical composition. Phenotypic values of TAA presented in this study will be used to assess the ability of mid-infrared spectroscopy to predict this new trait and thus to collect data at the population level.     

模糊数学评价法优化驴乳奶啤稳定性的预处理参数及香气成分分析

基于模糊数学评价法对驴乳奶啤稳定性预处理参数初步优化,结合气相色谱-质谱联用（GC-MS）技术确定驴乳奶啤的最佳预处理参数,通过与牛乳奶啤香气成分差异化对比,探究驴乳奶啤的香气组成。结果表明,最佳预处理参数为单甘脂添加量0.10%、海藻酸丙二醇酯添加量0.15%、果胶添加量0.20%。在此最佳条件下,5号驴乳奶啤综合评分最高（84.20分）,稳定性系数、离心沉淀率、黏度分别为（98.23±0.17）%、（5.21±0.14）%、（37.13±0.08） mPa·s。从牛乳奶啤及5号、9号驴乳奶啤中共检测出79种香气化合物,包括醇类11种、酯类25种、醛类8种、酸类12种、酮类6种、苯类2种、烷烃类12种、萜烯类2种、其他类1种,其中醇类、酯类和酸类挥发性化合物相对含量较高,对牛乳奶啤及5号、9号驴乳奶啤共有的18种香气成分进行主成分分析,经综合评价得出5号驴乳奶啤香气品质最佳,GC-MS分析结果与综合模糊评判结果一致。     

新疆疆岳驴乳理化和微生物指标分析

对50头新疆疆岳驴乳的化学成分以及微生物指标进行分析.结果表明,驴乳各项理化指标分别为:总干物质9.50%、蛋白质1.52%、脂肪1.18%、乳糖6.39%、灰分0.38%.与牛乳相比较,驴乳各项指标更接近母乳.微生物检测结果为(lg CFU/ml):细菌总数4.17、芽孢菌2.40、乳酸菌3.30、金黄色葡萄球菌2.83、肠科菌1.18.     

Bovine Milk Allergens: A Comprehensive Review

Cow milk allergy is one of the most common food allergies in early childhood and often persists through adult life, forcing an individual to a complete elimination diet. Milk proteins are present in uncounted food products, such as cheese, yogurt, or bakery item, exposing allergic persons to a constant threat. Many efforts have been made to overcome this global problem and to improve the life quality of allergic individuals. First, proper and reliable food labeling is fundamental for consumers, but the verification of its compliance is also needed, which should rely on accurate and sensitive analytical methods to detect milk allergens in processed foods. At the same time, strategies to reduce milk allergenicity, such as immunotherapy or the use of food processing techniques to modify allergen structure, have to be extensively studied. Recent research findings on the applicability of food processing, such as heat treatment, fermentation, or high pressure, have revealed great potential in reducing milk allergenicity. In this review, significant research advances on cow milk allergy are explored, focusing on prevalence, diagnosis, and therapy. Molecular characterization of cow milk allergens and cross‐reactivity with other nonbovine milk species are described, as well as the effects of processing, food matrix, and digestibility on milk allergenicity. Additionally, analytical methods for the detection of milk allergens in food are described, from immunoassays and mass spectrometry methods for protein analysis to real‐time polymerase chain reaction for DNA analysis.     

Coagulation efficiency and its determinant factors: A case study for Manchega ewe milk in the region of Castilla-La Mancha,Spain

Milk coagulation, especially in small ruminant species, is often hard to evaluate, as coagulation traits are normally considered individually and several factors related to udder health might distort yield calculation. Due to the lack of studies about these factors, our objective was to determine milk coagulation efficiency (CE) and its determinants using a deterministic technical efficiency approach, an ordinary least square regression model, and ANOVA. Milk from 300 Manchega ewes was collected and analyzed for composition, milk coagulation properties, and hygienic quality. The study results indicate that the estimated CE in Manchega ewes was 0.69, implying an important proportion of the animals produce poorly coagulating milk. The results of the ordinary least square regression model and ANOVA revealed that the main factor causing inefficiency was the initial pH of milk. Crude protein, casein and plasmin activity had moderate effects on CE, and, finally, other factors such as freezing point depression, somatic cell count, colony-forming units, and fat concentration had minor effects.     

Short communication: Monitoring nutritional quality of Amiata donkey milk: Effects of lactation and productive season

Milk nutritional characteristics are especially interesting when donkey milk is aimed at consumption by children and the elderly. The aim of this study was to monitor the nutritional quality of Amiata donkey milk during lactation and productive season to provide information on the milk characteristics and to study action plans to improve milk yield and quality. Thirty-one pluriparous jennies belonging to the same farm were selected. Individual samples of milk from the morning milking were taken once per month starting from the d 30 of lactation until d 300. Milk yield and dry matter, fat, and ash content were constant throughout the experimental period. Milk total protein content showed a progressive decrease during the first 6 mo of lactation; after this period, the protein percentages remained constant (1.50%). Caseins and lactose were lower until d 60 of lactation and remained constant thereafter. During summer and autumn, milk yield and casein and lactose contents were higher, whereas during the spring season, higher protein and ash contents were found. The percentages of fat and dry matter were stable as were most of the minerals in the milk, except for calcium, which was higher in the spring. In conclusion, Amiata donkey milk was found to be relatively stable during lactation. This is an advantage in terms of the production and trade of a food product with consistent characteristics. The different milk yield and quality during the productive seasons were probably related to better adaptability of the animals to warm and temperate periods.     

Effects of animal selection on milk composition and processability

One goal of animal breeding is to increase the economic output through increased production, improved milk quality, and cow health. The objective of this study was to evaluate genetic progress in relation to milk composition, processability, and yield as a correlated response to selection for the Swedish breeding objective. Dairy cows with high genetic merit, classified as elite dairy cows, of the Swedish Red and Swedish Holstein breeds were used. Milk samples were collected on the farm level in winter and summer from a research herd at Nötcenter Viken, a bovine research farm in Sweden. Comparisons were made with milk from a Swedish Red herd, a Swedish Holstein herd, and a Swedish dairy processor in the same geographical area. Protein, lipid, and carbohydrate profiles as well as minerals were analyzed, and technological properties, including rennet-induced gelation characteristics, lipid oxidation, total antioxidant capacity, and fat globule size, were determined. Higher yields were found for elite cows for components of the protein, lipid, and carbohydrate profiles as well as for minerals, implying genetic progress in relation to milk yield; however, the content of some milk components (e.g., lipid and whey protein contents) had decreased on average. Milk from the elite cows had good gelation characteristics, but was more susceptible to lipid autooxidation and had a lower total antioxidant capacity. These results demonstrate that milk composition and processing characteristics could be used to adjust breeding practices to optimize the quality and stability of milk and dairy products.     

蛋白质组学技术在不同物种乳掺假检测中的应用

乳品是人类重要的营养源，然而乳品掺假现象时常发生，近年来尤以向乳品中掺假动、植物蛋白，向特色畜乳中掺假牛乳等方式为主，这不仅损害了消费者的利益，甚至会危害消费者的健康。该研究总结了目前常见的掺假行为及相关检测方法，并介绍了蛋白质组学技术——一种通过确立特定生物标记物来区别不同物种乳的技术。作者查询了国内外近十年来牛乳和特色乳掺假方面的研究报道，关键词设置为“蛋白质组学”、“乳品”、“真实性”、“生物标记物”等，按照奶畜乳类别将所得文献进行分类。分别对奶牛乳、羊乳、驼乳、水牛乳、牦牛乳、驴乳的掺假物、潜在标记物和检出限等方面进行了总结和分析，以期为乳品真实性鉴定和保障乳品质量安全提供有效的工作思路。     

Composition of milk from minor dairy animals and buffalo breeds: a biodiversity perspective

A comprehensive review is presented of the nutrient composition for buffalo, mare, and dromedary camel milks at the level of breed, and species‐level data for yak, mithun, musk ox, donkey, Bactrian camel, llama, alpaca, reindeer and moose milks. Average values of nutrients were calculated and compared. Interspecies values (g 100 g^?1) were 0.7–16.1 for total fat, 1.6–10.5 for protein, 2.6–6.6 for lactose, and 67.9–90.8 for water. Reindeer and moose milks had the highest fat and protein concentrations and the lowest lactose contents. Mare and donkey milks had the lowest protein and fat contents, in addition to showing the most appropriate fatty acid profile for human nutrition. Dromedary camel milk was most similar to cow milk in proximate composition. Moose milk was the richest in minerals, having values as high as 358 mg 100 g^?1 for calcium, 158 mg 100 g^?1 for sodium and 150 mg 100 g^?1 for phosphorus. Interbreed differences of 4 g 100 g^?1 were observed in total fat in buffalo, yak, mare and dromedary camel milks. Large interbreed differences were also present in the mineral contents in mare, buffalo and dromedary camel milks. By bringing together these compositional data, we hope to usefully widen the biodiversity knowledge base, which may contribute to the conservation and sustainable use of milk from underutilized dairy breeds and species, and to improved food and nutrition security, particularly in developing countries. Copyright © 2011 Society of Chemical Industry     

牛奶替代品致敏性的识别

为找到牛奶替代资源,以牛奶过敏患者血清为探针,识别牛奶及其制品过敏原,并鉴别山羊奶、水牛奶、驴奶蛋白与牛奶过敏患者血清交叉反应性。结果表明,β - 乳球蛋白和a- 酪蛋白为牛奶主要过敏原,山羊奶、驴奶总蛋白IgE 结合能力低于牛奶,二者可以作为牛奶替代资源。     

Short communication: Performance of lactating dairy cows fed pearl millet grain

Fifteen multiparous Holstein cows were used in a 3 × 3 Latin square experiment to determine the effects of feeding pearl millet grain on feed intake, milk yield, and milk composition of lactating dairy cows. Three isonitrogenous diets with a 57:43 forage:concentrate ratio were formulated. Diets contained 30% corn, 30% pearl millet, or 31% corn and pearl millet mixed 1:1 (wt/wt). Three lactating Holstein cows fitted with ruminal cannulas were used to determine the effects of dietary treatments on ruminal fermentation parameters. Dry matter intake and energy-corrected milk were similar for all dietary treatments and averaged 23.8 and 33.5 kg/d, respectively. Dry matter intake (% of BW) was unaffected by dietary treatments and averaged 3.40%. Milk fat, protein, lactose, and total solids concentrations were not influenced by grain type. Ruminal NH₃-N concentration was unaffected by dietary treatments. However, ruminal pH tended to be lower for cows fed pearl millet than those fed corn and pearl millet mix. It was concluded that pearl millet grain can replace corn in dairy cow diets up to 30% of the diet DM with no adverse effects on milk yield or milk composition.     

不同乳源动物成分鉴别技术研究进展

随着我国经济的发展,人民生活水平不断提高,乳制品成为日常饮食的重要组成部分。乳制品含有促进人体生长发育及维持健康必需的营养成分,驴乳、驼乳、牦牛乳等特种乳因其良好的营养价值而越来越受到人们欢迎。由于特种乳具有良好市场前景且其产量较低,目前市场中特种乳价格普遍高于牛乳,受经济利益驱动的影响,乳源掺假问题日益凸显,掺假鉴别成为近年来研究的热点。针对乳制品中乳源掺假问题,国内外研究学者已经建立了多种鉴别的方法,本文从基于核酸、蛋白、化合物的方法和智能无损检测四个方面对乳及乳制品乳源鉴别方法现状进行了概述,并对4种方法做出总结和比较,对未来需要解决的问题进行了探讨。     

Production and health of pasture-fed dairy cattle following oral treatment with the ionophore lasalocid

The aim of the study was to evaluate the effect of feeding the ionophore lasalocid on the productivity and health of seasonally calving, pasture-fed dairy cows. Dairy cows (n = 1020) from 4 herds were enrolled in a split-herd, prospective intervention study. Cows were blocked by breed and age, ranked on previous production, and then assigned to 2 treatment groups. Treatment cows were each exposed to 300 to 350 mg of lasalocid/d commencing 3 wk before and ending 18 wk after the start of the seasonal calving period. Milk production was determined on 3 occasions for each cow at approximately monthly intervals (herd tests 1 to 3), body condition score was determined fortnightly, and all disease occurrences were recorded. Lasalocid treatment increased milk volume milk protein and milk fat production by approximately 2%, without altering milk composition. Fewer lasalocid-treated cows than control cows (7.3 vs. 11.6%, respectively) were diagnosed with clinical mastitis. Lasalocid treatment of pasture-fed dairy cows resulted in reduced mastitis incidence and increased milk production without changes in body condition or negative effects on metabolic processes as monitored by metabolite concentrations.