Seasonal changes in the mineral composition of colostrum and milk whey of cows

It is shown that in summer the level of sodium, potassium and calcium in the colostrum and milk serum of cows for the first ten days of lactation is 1.5-2.0 times higher and the content of inorganic phosphorus lower than the analogous indices for cows in winter-spring. The concentration of iron, copper, zinc and chlorides in the colostrum and milk serum of cows in different seasons is unchanged.     

Bactericidal effect of bovine normal and immune serum, colostrum and milk against Helicobacter pylori

Serum and colostrum but not post-colostral milk from non-immunized Friesian cows was found highly bactericidal for Helicobacter pylori NCTC 11637. This bactericidal activity was destroyed by heating at 56°C for 30 min and restroed by the addition of fetal calf serum as a source of complement, indicating that the bactericidal effect was probably dependent on an antibody-complement system. Systemic, serial immunization of non-lactating, pregnant cows with H. pylori resulted in high specific antibody titres in serum and colostrum. No titres were found in post-colostral milk, even after booster-immunization during lactation. Immunization did not enhance the bactericidal activity of serum and colostrum, but increased it in post-colostral milk. The bactericidal activity was not correlated with titres of specific antibody or with IgG concentrations.     

Changes of insulin concentration in colostrum and milk of women, cows and sows

The method of whey extraction in order to determine insulin concentration in colostrum and milk was worked out, checked and applied. The observation of insulin changes showed high and similar insulin concentration in whey samples of women, cows and sows colostrum on the day before and in the day of parturition. One day after delivery hormone concentration maintained high in case of women and sows but in cow colostrum it decreased to 1/12 comparing to the level on the parturition day. During the postpartum following days it was decreasing gradually in the colostrum of all three examined species; the process was very fast in cows, slower in women and the slowest in sows.     

Concentration of lactoferrin and transferrin throughout lactation in cow's colostrum and milk

The evolution of the concentration of lactoferrin and transferrin was studied in cow's colostrum and milk throughout lactation. The highest concentrations of both proteins were found in the first milking (0.83 mg/ml for lactoferrin and 1.07 mg/ml for transferrin), decreasing sharply during the first days of lactation (colostral period). Thereafter, the concentrations of these proteins decreased slowly, reaching their definitive values during the third week post-partum (0.09 mg/ml for lactoferrin and 0.02 mg/ml for transferrin). The ratio transferrin/albumin in colostrum (first milking), mature milk, milk from mastitic cows and serum was determined, and found to be four times greater in colostrum than in mature or mastitic milk, suggesting a specific transport of transferrin from blood to milk.     

Leptin in bovine colostrum and milk.

We studied leptin content in bovine colostrum, milk and plasma during the first month of lactation, and investigated relationships between selected milk components and milk leptin in five multiparous dairy cows. Colostrum/milk yield and composition were measured on days 0, 10, 20, and 30 of lactation. Leptin was assayed using a multi-species leptin RIA kit. Leptin concentration was 56 % lower in mature milk (day 10) than colostrum (13.90 vs. 6.14 microg/l; p < 0.001), but remained steady over the twenty days afterwards. Daily secretion of leptin into mature milk was 28 % lower than into colostrum (173.2 microg/d vs. 220.0 microg/d; p = 0.09) notwithstanding an 80 % increase in production. Colostrum and milk leptin levels correlated with fat (0.90; p < 0.001) and choline phospholipid (0.76; p < 0.05). Plasma and milk leptin decreased during the first month, but remained higher in milk, and highest in colostrum. Thus, leptin is present in large quantities in colostrum, less so and more variably in untreated milk, and is likely to be decreased in skimmed milk. These findings have implications for the use of untreated milk and colostrum-based (functional) food products.     

三种哺乳动物初乳乳汁氨基酸含量的比较

采用高效液相色谱法分析了人、牛、猪3种哺乳动物的初乳乳汁中氨基酸含量,结果表明:谷氨酸的含量在3种哺乳动物的初乳乳汁中是最高的,而蛋氨酸的含量最低;从3种动物比较来看,猪乳与牛乳的氨基酸含量比较接近,而人乳与其他两种动物有较大的差异.     

Fluorimetric study of the selenium course in the dam-calf relationship

This study was conducted in a southeast region of Romania, known to be selenium (Se) deficient. The fluorimetric method for the determination of Se in biological samples was used in a study on the serum Se content in time in a group of 10 cows with a high milk yield and in their calves. The same cows were sampled antepartum (late pregnancy) and postpartum (1, 7, 21, 30, and 60 d), and the calves were sampled on d 1 of life and 7, 21, 30, and 60 d postcalving. Colostrum and milk samples were also collected and analyzed at the same times. Throughout the study, the serum Se content in both the cows and the calves was below the reference values (0.040–0.100 μg/mL), except the control conducted 7 d postpartum, for which it was 0.044±0.017 and 0.023±0.007 μg/mL in cows and calves, respectively. The most significant drops were recorded 21 (p<0.01) and 60 d postpartum (p<0.05). The colostrum Se was higher (0.036±0.022 μg/mL), decreasing progressively throughout the study to the normal low limit (0.005 μg/mL). The milk Se concentration was lower by approx 78% than the colostrum one on d 1 postcalving. These data demonstrate the course of hyposelenosis both in the cows and their calves. The maternal body proved to “mobilize,” even in case of deficiency, important Se amounts in the colostrum, during the first days in particular.     

牛初乳的开发利用及研究进展

牛初乳是指健康奶牛分娩后1周内所分泌的乳汁,它不仅含有丰富的营养物质,还含有多种免疫因子和生长因子等活性成分,具有强化机体免疫力、调节肠道菌群、改善胃肠道功能、促进生长发育、增强智力、调节血糖、改善糖尿病症状等多种保健功能。牛初乳作为功能性食品的重要原料,具有广阔的开发利用前景。     

Bovine Milk Proteome in the First 9 Days: Protein Interactions in Maturation of the Immune and Digestive System of the Newborn

In order to better understand the milk proteome and its changes from colostrum to mature milk, samples taken at seven time points in the first 9 days from 4 individual cows were analyzed using proteomic techniques. Both the similarity in changes from day 0 to day 9 in the quantitative milk proteome, and the differences in specific protein abundance, were observed among four cows. One third of the quantified proteins showed a significant decrease in concentration over the first 9 days after calving, especially in the immune proteins (as much as 40 fold). Three relative high abundant enzymes (XDH, LPL, and RNASE1) and cell division and proliferation protein (CREG1) may be involved in the maturation of the gastro-intestinal tract. In addition, high correlations between proteins involved in complement and blood coagulation cascades illustrates the complex nature of biological interrelationships between milk proteins. The linear decrease of protease inhibitors and proteins involved in innate and adaptive immune system implies a protective role for protease inhibitor against degradation. In conclusion, the results found in this study not only improve our understanding of the role of colostrum in both host defense and development of the newborn calf but also provides guidance for the improvement of infant formula through better understanding of the complex interactions between milk proteins.     

Human and bovine lactoferrins in the milk of recombinant human lactoferrin-transgenic dairy cows during lactation

Seven Friesian human lactoferrin (hLf)-transgenic primiparous dairy cows expressing recombinant hLf (rhLf) in their milk were included in the study. After calving, concentrations of rhLf and bovine LF (bLf) in the milk, somatic cell count and milk yield were determined. The concentration of rhLf was found to be constant, about 2.9 mg/mL, throughout the early lactation period of 3 months. The concentration of bLf in colostrum was higher after calving, but decreased rapidly during the first days of lactation. The mean concentration of bLf was 0.15 mg/mL, but concentrations varied between cows from 0.07 mg/mL to 0.26 mg/mL. Based on that, it may be possible to improve the non-specific host defence mechanism in the mammary gland of dairy cows by enhancing the content of rhLf in the milk.     

Compositional analysis of dairy products derived from clones and cloned transgenic cattle

Cloning technology is an emerging biotechnological tool that could provide commercial opportunities for livestock agriculture. However, the process is very inefficient and the molecular events underlying the technology are poorly understood. The resulting uncertainties are causing concerns regarding the safety of food products derived from cloned livestock. There are similar concerns for livestock produced by biotechnologies which enable the purposeful introduction of genetic modifications. To increase the knowledge about food products from animals generated by these modern biotechnologies, we assessed compositional differences associated with milk and cheese derived from cloned and transgenic cows. Based on gross composition, fatty acid and amino acid profiles and mineral and vitamin contents, milk produced by clones and conventional cattle were essentially similar and consistent with reference values from dairy cows farmed in the same region under similar conditions. Whereas colostrum produced by transgenic cows with additional casein genes had similar IgG secretion levels and kinetics to control cows, milk from the transgenic cows had a distinct yellow appearance, in contrast to the white color of milk from control cows. Processing of milk into cheese resulted in differences in the gross composition and amino acid profiles; 'transgenic' cheese had lower fat and higher salt contents and small but characteristic differences in the amino acid profile compared to control cheese.     

Development of a sandwich ELISA assay for measuring bovine soluble type II IL-1 receptor (IL1R2) concentration in serum and milk

The IL1R is composed of two kinds of molecule, type I (IL1R I) and type II (IL1R2). IL1R1 contributes to IL-1 signaling, whereas the IL1R2 has no signaling property and acts as a decoy for IL-1. In this study, we developed a bovine IL1R2-specific sandwich ELISA to examine the sIL1R2 concentration in serum and milk from dairy cows. The concentration of colostral IL-1beta was examined to estimate the correlation to sIL1R2. The results showed that the sIL1R2 concentration in sera and milk changes with the stages of lactation. The serum sIL1R2 concentrations were 5.56+/-0.69 ng/ml (colostrum), 3.14+/-0.72 ng/ml (the early stage of lactation) and 5.76+/-1.25 ng/ml (the late stage of lactation). The milk sIL1R2 concentrations were 1.83+/-0.47 ng/ml (colostrum), 0.73+/-0.22 ng/ml (the early stage of lactation) and 2.92+/-0.56 ng/ml (the late stage of lactation). The concentrations of IL1R2 in sera and milk were significantly higher at the late stage of lactation and colostrum than that of the early stage of lactation. The reduction rates of sIL1R2 levels from the colostrum to the early stage of lactation were 43.6% (serum) and 61% (whey). IL-1beta was detected in all the colostrum (995.9+/-346.6 ng/ml). Significant correlation was observed between the levels of colostral IL-1beta and IL1R2 (r=0.75).     

IgG1 variations in the colostrum of Holstein dairy cows

High-immune quality colostrum (IgG1 concentration ⩾50 g/l) is crucial for the health and development of the young calf. Studies on colostrum quality tend to focus on external factors such as breed, parity or dry period length, but few have focused on within-cow variations. Here we ran experiments to gain a deeper insight into within-cow variation in IgG1 concentrations in dairy cow colostrum. Trials were performed in an experimental farm, located in the Western part of France. Colostrum from each quarter and a composite sample (mix of four quarters) were concomitantly collected on 77 Holstein dairy cows just after calving to assess the influence of sample type on IgG1 concentrations. Variation in IgG1 concentrations during the first milking was studied on samples from nine cows collected every minute from the start of milking. Repeatability of colostral IgG1 concentration was estimated from 2009 and 2010 data on 16 healthy cows. IgG1 concentrations were tested using a radial immunodiffusion method. Sensitivity and specificity were similar regardless of sample type tested (individual quarter or composite milk). Mean average IgG1 concentration was 54.1 g/l in composite colostrum, and was significantly higher in hind quarter teats (56.2 g/l) than front quarter teats (53.1 g/l). Average IgG1 concentration did not change significantly during colostrum milking, and the variations observed (15% or less) were likely due to the laboratory method (CV 15%). IgG1 concentrations in dam colostrum increased slightly from 2009 to 2010 due to BW and parity effects. In 56% of cases, colostrum quality could have been assessed on either individual or composite colostrum samples collected at any time during the first milking without affecting the reliability of the measurement. However, in other cases, differences were significant enough to mean that estimates of average IgG1 concentration in colostrum from any one quarter would not be reliable. It is concluded that colostrum quality, from an IgG1 concentration point of view, could be assessed with a composite sample taken at any time during the first milking.     

Lipid composition and vitamin E content in human colostrum and mature milk

Lipidic components, as well as fatty acid composition and vitamin E content were determined in colostrum (days 3-5 of postpartum) and mature milk (day 21) in 8 women from Murcia (Spain). Triglycerides concentration was higher and cholesterol and esterified cholesterol were lower in mature milk than in colostrum, whereas phospholipid content was similar. These differences indicate that the diameter of milk fat globules increases in mature milk. The percentage of medium-chain fatty acids (12:0 and 14:0) increased in mature milk as compared to colostrum, reflecting de novo synthesis of fatty acids. With the only exception of stearic acid which was lower in mature milk than in colostrum, the remaining long-chain fatty acids was similar. The proportion of both linoleic (18:2) and eicosapentaenoic (20:5) acids found in mature milk and colostrum is higher than in studies from other countries and may reflect the intake of high proportions of polyunsaturated fat from vegetable oils and fish in the studied women. Both vitamin E content and vitamin E/linoleic acid ratio in mature milk are lower than in colostrum, evidencing the efficient mechanism of mammary gland vitamin E uptake around parturition.     

A genetic association between bovine serum and colostrum lysozyme levels

Serum and colostrum lysozyme activity was determined in primiparous cows employing a lysoplate method described elsewhere. Samples from 336 animals were collected over a 5-year period from a research station. The animals were sired by 20 elite bulls, one of which (1893) is probably heterozygous for a dominant high lysozyme level gene. The resulting two-population split of high and low level offspring from 1893 is also consistent for the present cow material both in serum and colostrum. A highly significant overall correlation (P less than 0.01) between serum and colostrum lysozyme was estimated. Positive correlation was also found within families and this was particularly high for 1893. No association between serum and colostrum lysozyme activity could be detected when high level animals were excluded. This means that the genetic association between lysozyme activity in the two body fluids is solely dependent upon the major gene described. Consequently, selection of bulls for serum lysozyme activity will influence the colostrum or milk lysozyme activity in the cow population, provided that the major gene is present in the population.     

Soluble form of ICAM-1, VCAM-1, E- and L-selectin in human milk

In breast milk and paired serum from 70 lactating women and 40 of their term, infection-free neonates, on the 2nd and 5th day postpartum slCAM-1, sVCAM-1, sE- and sL-selectin were measured by ELISA and compared with those in 26 healthy adults (controls). Seven infant formulas and fresh milk from five cows were also analyzed. Human colostrum values of slCAM-1, sVCAM-1 (similar to those in maternal and control serum), sE-selectin and sL-selectin (-10 and -100 times lower than in maternal and control serum) were significantly higher than those in milk, while they varied widely. None of the adhesion molecules was detected in fresh cow's milk or infant formulas. Exclusively breast-fed infants showed significantly higher values of slCAM-1 and sL-selectin on the 2nd day of life than those supplemented also with formula. Only slCAM-1 values correlated positively between colostrum and time-matched maternal serum. These findings show in human milk important amounts of slCAM-1 and sVCAM-1 but minimal amounts of sE- and sL-selectin, which could affect the immune system of the neonate.     

研究: 奶牛与水牛初乳中乳寡糖组分比较研究

乳寡糖是由乳汁中含量丰富的固体物质组成．研究结果表明,乳寡糖有提高免疫、益生元及抗感染等作用,已发现与婴儿肠道发育、神经智力发育等多方面关系密切．水牛奶是除牛奶外的第二大奶源,国际上公认其为营养含量高、口感好的优质乳制品,但目前针对水牛乳寡糖的研究多以美洲水牛为研究对象,尚无中国水牛的相关研究．本研究利用固相萃取对已脱脂和除去蛋白质的广西水牛初乳乳汁样品进行纯化,并采用苯胺 (aniline,Bn)衍生化试剂对其进行衍生化处理,通过UPLC-ESI-Q-TOF-MS液相质谱进行优化后,对水牛初乳中的寡糖组分进行测定并与牛乳进行了对比,最终测得奶牛初乳中19种及水牛初乳中的9种乳寡糖组分,并对二者的种类及含量进行比较,发现在两种初乳的乳寡糖中,中性糖二糖m/z 385.15和中性糖三糖m/z 547.21以及酸性糖m/z 635.23均为其主要寡糖成分,与其他乳寡糖相比含量相对较高．总体而言水牛初乳中的中性寡糖占比比奶牛初乳高,二者中性糖占乳寡糖总量的比例分别为88.88%和63.16%．     

The serum-free growth of cultured cells in bovine colostrum and in milk obtained later in the lactation period

Seven established cell lines, including both epithelial cells and fibroblasts (MDCK, Vero, CV-1, NRK, 3T3, F2408, and NIL8) and four early passage cell strains (bovine articular chondrocytes, bovine smooth muscle cells, human foreskin fibroblasts, and rat embryo cells) were cultured in serum-free medium supplemented with milk obtained 1 day after birth (colostrum) or 80 days after birth (older milk). MDCK, Vero, CV-1, NRK, and 3T3 grew readily in colostrum and attained saturation densities ranging from 22% to 63% of that in serum. There was no growth of F2408, NIL8, or the early passage strains in bovine colostrum. None of the 11 cell cultures grew in older milk. The temporal dependence of growth in milk was examined in detail using MDCK cells. Growth equivalent to that in serum occurred in 3% colostrum and in 15% milk obtained 2 days after birth. Milk obtained 3 days and 10 days after birth was not effective as a growth supplement for MDCK cells at any concentration. Those cells, unable to grow in colostrum or in older milk, could be induced to grow if culture dishes were precoated with fibronectin. In addition to fibronectin, it was necessary in some cultures to supplement colostrum or older milk with insulin and/or transferrin in order to achieve growth. In the presence of fibronectin and appropriate factors, the final saturation density attained in colostrum or older milk ranged from 25% to 100% of that in serum. The fibronectin contents of bovine colostrum and milk were determined. The fibronectin level of colostrum was found to be approximately 5% of bovine serum. There was no detectable fibronectin in the 80-day-old milk.     

Glucocorticoid effects on zinc transport into colostrum and milk of lactating cows

Colostrum Zn concentrations were measured in eight randomly selected Holstein dairy cows. Overall mean Zn concentrations were highest within 12 h postpartum (257 +/- 14 microM, mean +/- SEM), fell to 141 +/- 8 microM by 24 h, and then declined at a linear rate of 30 microM/d during the following 48 h. Zn concentrations at 3 d (82 +/- 5 microM) were not different from 150-d milk samples (72 +/- microM). In a second experiment, 32 early-gestation cows were blocked by stage of lactation into four groups in a randomized block design and injected with 0, 15, 30, or 45 mg of dexamethasone. Milk and blood samples were collected at 0, 12, and 24 h after injection and analyzed for Zn, and for fat, protein, and lactose in milk. Cows administered 0 and 15 mg of dexamethasone showed no difference in milk Zn concentrations compared to pretreatment measurements; however, milk Zn concentrations in cows administered 30- and 45-mg doses increased significantly. Plasma cortisol decreased in the dexamethasone-treated cows. Plasma Zn and milk fat, protein, and lactose did not change. These data indicate that glucocorticoids can mediate Zn uptake and transport by the mammary glands of lactating cows and suggest that the high Zn concentration in colostrum could be a result of the preparturient surge of cortisol.     

Serum immunoglobulin type G concentrations in calves produced by IVF and delivered by elective cesarean section

Colostrum ingestion by neonatal calves is widely recognized to provide passive transfer of immunity. In this study immunoglobulin absorption from colostrum was evaluated in 54 IVF-produced calves. The IVF calves were delivered by Cesarean section on Days 275 to 277 of gestation, 24 h after the dams had been administered 30 mg dexamethasone. The calves suckled bottles or were force-fed 6 L of colostrum in the first 12 h of life. Colostrum was obtained from the first post-calving milking of recipient dams or from frozen storage reserves if dam secretion was not adequate. Immunoglobulin type G (IgG) content of both sources of colostrum was determined. Serum samples from the calves were collected at 0, 12 and 24 h of age and analyzed for IgG. Twenty dairy calves born vaginally served as the controls and were subjected to the same colostrum management protocol except that the colostrum was obtained only from frozen post-calving milk of dairy cows from the same farm. The control calves were also subjected to the same sampling protocol. The IVF group of calves ingested more IgG (P < 0.0001) and absorbed more IgG by 24 h of age (P < 0.0001) than their control group counterparts. Absorption of IgG was analyzed by comparing the g/kg body weight of IgG with serum IgG values at corresponding times after birth. Colostrum absorption efficiency was the same for both IVF and control groups of calves at 12 and 24 h of age. There was a maximum IgG dose above which additional increases in serum IgG were not realized. The slightly premature, Cesarean delivered IVF calves absorbed IgG from colostrum similarly to control calves delivered vaginally.