A proteomics study of colostrum and milk from the two major small ruminant dairy breeds from the Canary Islands: a bovine milk comparison perspective.

Colostrum and milk feeding are key factors for the newborn ruminant survival, affecting the future performance of the animal. Nowadays, there is an increasing interest in the potential of feeding newborn ruminants (mainly goat kids and lambs) with colostrum and milk from other more productive ruminant species (mainly cows). Although some studies regarding differences between colostrum and milk from these three species have been performed, herein we conduct for the first time a comparison using a proteomics 2-Dimensional Electrophoresis gel-based approach between these three ruminant species. In this study colostrum and milk samples from six Holstein cows, six Canarian sheep and six Majorera goats were used to determine the chemical composition, immunoglobulin G (IgG) and M (IgM) concentrations and proteomics profiles. Results showed that in general sheep colostrum and milk contained higher fat, protein and lactose percentages compared to bovine and goat samples. Additionally, no differences in the IgG or IgM concentrations were found among any of the three studied species, with the exception of sheep colostrum that showed the highest IgM concentration. With reference to the proteomics-based approach, some high abundant proteins such as serum albumin precursor, beta-caseins or different immunoglobulins components were found in colostrum, milk or even both. Nevertheless, differences in other proteins with immune function such as serotransferrin or lactoperoxidase were detected. This study shows that despite the similar immunoglobulin concentrations in colostrum and milk from the three studied species, differences in several immune components can be detected when these samples are studied using a proteomics approach. Finally, this study also provides a base for future investigation in colostrum and milk proteomics and metabolomics.

Set-up and application of an analytical approach for the quality control of purified colostrum as food supplement.

A validated analytical procedure is here described for the quality control of the protein fraction of purified bovine colostrum used in food supplements. The proposed procedure starts with 1D and 2D-gel electrophoresis. The sample is then separated into two fractions by protein G affinity chromatography: the IgG enriched and the IgG depleted fraction (IgG-d). A size exclusion chromatography coupled to UV is then applied to the IgG and IgG-d fractions for the quantitative analysis of IgG and IgM, respectively. The IgG-d fraction is then analysed by HPLC-MS analysis for the quantitative analysis of ß-lactoglobulins and α-lactoalbumin. The next step is to quantitatively measure a set of bioactive proteins selected from the bovine colostrum data bank on the basis of their claimed health benefits. The enzymatic activities of lactoperoxidase and xanthine dehydrogenase/oxidase are then tested as an index of protein functionality.

Lingual antimicrobial peptide and lactoferrin concentrations and lactoperoxidase activity in bovine colostrum are associated with subsequent somatic cell count.

The present study was undertaken to examine whether potential levels of innate immune factors (lingual antimicrobial peptide (LAP), lactoferrin (LF) and lactoperoxidase (LPO)) in colostrum are associated with subsequent milk somatic cell count (SCC) in dairy cows. Quarter milk samples were collected daily for 1 week postpartum to measure LAP and LF concentrations and LPO activity. SCC in milk was determined weekly for 2 months postpartum and its correlations to concentrations of LAP and LF and LPO activity were examined. Only small variations of all immune factors were found among four udders in each individual cow, whereas there were great differences in these factors among cows. Negative correlation was detected only between LPO activity and mean and maximum SCC, whereas its relationship was not significant. LAP and LF concentrations were significantly correlated positively to mean, maximum and minimum SCC. These results suggest that the great difference in innate immune factors among animals and high LAP and LF concentrations in colostrum may be associated with subsequent high incidence of SCC increase.

The impact of iron on the bleaching efficacy of hydrogen peroxide in liquid whey systems.

UNLABELLED: Whey is a value-added product that is utilized in many food and beverage applications for its nutritional and functional properties. Whey and whey products are generally utilized in dried ingredient applications. One of the primary sources of whey is from colored Cheddar cheese manufacture that contains the pigment annatto resulting in a characteristic yellow colored Cheddar cheese. The colorant is also present in the liquid cheese whey and must be bleached so that it can be used in ingredient applications without imparting a color. Hydrogen peroxide and benzoyl peroxide are 2 commercially approved chemical bleaching agents for liquid whey. Concerns regarding bleaching efficacy, off-flavor development, and functionality changes have been previously reported for whey bleached with hydrogen peroxide and benzoyl peroxide. It is very important for the dairy industry to understand how bleaching can impact flavor and functionality of dried ingredients. Currently, the precise mechanisms of off-flavor development and functionality changes are not entirely understood. Iron reactions in a bleached liquid whey system may play a key role. Reactions between iron and hydrogen peroxide have been widely studied since the reaction between these 2 relatively stable species can cause great destruction in biological and chemical systems. The actual mechanism of the reaction of iron with hydrogen peroxide has been a controversy in the chemistry and biological community. The precise mechanism for a given reaction can vary greatly based upon the concentration of reactants, temperature, pH, and addition of biological material. In this review, some hypotheses for the mechanisms of iron reactions that may occur in fluid whey that may impact bleaching efficacy, off-flavor development, and changes in functionality are presented. PRACTICAL APPLICATION: Cheese whey is bleached to remove residual carotenoid cheese colorant. Concerns regarding bleaching efficacy, off-flavor development, and functionality changes have been reported for whey proteins bleached with hydrogen peroxide and benzoyl peroxide. It is very important for the dairy industry to understand how whey bleaching can impact flavor and functionality of dried ingredients. Proposed mechanisms of off-flavor development and functionality changes are discussed in this hypothesis paper.

Antioxidants in colostrum and milk of sows and cows.

On account of the oxidative stress conditions that may appear during parturition, colostrum should provide with not only nutritional and immunological components but also antioxidative protection of newborn. There is evidence that apart from well-known antioxidative enzymes like glutathione peroxidase, superoxide dismutase, catalase or low molecular antioxidants, proteins like lactoperoxidase (LPO), lactoferrin (LF) and ceruloplasmin (CP) may exert antioxidative properties in colostrum. The aim of present study was to determine and to evaluate LPO, LF and CP activities in colostrum and milk of sows and cows. Samples were collected from 16 healthy cows five times: immediately after parturition, 12, 24 and 48 h, and 7 days postpartum as well as from 14 healthy sows five times: immediately after parturition, 6, 12, 24 and 36 h later. Examined parameters were determined spectrophotometrically at 412, 560 and 540 nm respectively. LPO activity was higher in sows as in cows and increased significantly within examined time. LF ability to inhibit superoxide radical generation was higher in sows as in cows and increased significantly within examined time. CP oxidase activity was higher in cows as in sows and decreased significantly during experimental period. In conclusion, antioxidative defence system in colostrum shows dynamic changes that allow for providing with necessary protection from oxidative stress conditions, which may appear after parturition.

Determination of minor proteins of bovine milk and colostrum by optical biosensor analysis.

Automated, rapid, sensitive, and label-free biosensor-based immunoassays for immunoglobulin G (IgG), folate binding protein, lactoferrin, and lactoperoxidase in bovine milk using surface plasmon resonance optical detection with direct binding assay format are described. Samples are prepared for analysis by direct dilution into buffer. Analysis conditions, including ligand immobilization, flow rate, contact time, and regeneration are defined and nonspecific binding considerations evaluated. The technique has been applied to the measurement of these proteins in consumer milks, colostrum, milk products, and infant formulas, and their temporal change during early bovine lactation followed.

Influence of whey and purified whey proteins on neutrophil functions in sheep.

The effects of ruminant whey and its purified fractions on neutrophil chemotaxis and superoxide production in sheep were studied. Both colostral whey and milk whey were found to inhibit chemotaxis regardless of whether they were autologous or homologous, but the inhibitory effects were abolished by washing neutrophils with culture medium before their use in the chemotaxis assay. Colostral whey and milk whey also inhibited the chemotactic activity of zymosan-activated serum. Whey fractions of various degrees of purity such as lactoferrin, lactoperoxidase, lactoferrin-lactoperoxidase, alpha-lactalbumin, bovine serum albumin and whey protein concentrate were then studied. While none of these proteins showed any effects on chemotaxis, lactoferrin-lactoperoxidase and whey protein concentrate were found to have an enhancing effect on superoxide production in a dose-dependent manner. Our results provide information on the modulatory role of ruminant milk proteins in inflammatory responses and warrant future investigation.

Nonspecific antibacterial factors in milk from cows immunized with human oral bacterial pathogens.

Both the immunoglobulins and non-specific antibacterial factors in milk from cows immunized with pathogenic oral bacteria have the potential to influence the oral microflora during passive immunization studies. The first six milks after calving were collected from 2 cows immunized with adjuvant and from 14 cows immunized with adjuvant and heat-killed strains of periodontopathic Actinomyces, Porphyromonas, Prevotella, and Fusobacterium. Analysis of the products from the first to the sixth milks revealed that the protein and lysozyme content decreased approximately 66 and 72%, respectively; the mean specific activity of the enzyme remained relatively constant. In contrast, the mean lactoperoxidase activity increased 2.3-fold in the second milking and increased further in the fourth and sixth milkings. The mean iron-binding activity increased 1.2-fold from the first to the second milkings and then decreased 3.6-fold through the sixth milking. Cows immunized with adjuvant alone showed similar responses. Per unit volume, the milk contained approximately 150 times less lysozyme than whole human saliva obtained from six subjects but higher concentrations of lactoperoxidase and iron-binding components. Purified bovine nonspecific factors prevented the growth of the bacteria used for immunization when bacteria were tested at concentrations similar to those found in saliva and milk. Because bovine nonspecific antibacterial factors could influence both the pathogenic target bacteria and the indigenous microflora in oral passive immunization studies with bovine immunoglobulins, the presence of these proteins should be considered.

Lactoperoxidase activity in human milk and in saliva of newborn infants.

Human milk and saliva from newborn infants were analyzed for their content of lactoperoxidase and thiocyanate. The activity of lactoperoxidase in infant saliva was variable but generally higher than that found in calf saliva. In contrast, the activity in human colostrum was low ( approximately 5%) compared with that found in cow's milk. The enzyme was resistant to gastric juice. Thiocyanate was demonstrated in infant saliva in concentrations about one-third of that in adult saliva. The amounts of lactoperoxidase and thiocyanate in infant saliva are quite sufficient to inhibit bacterial growth in in vitro systems. The importance of this system in vivo has not yet been demonstrated. The availability of this system to both newborn calves and humans (in calves provided largely by colostrum and in human babies by saliva) might be indirect evidence of its importance.