Relationship between haptoglobin and serum amyloid A in milk and milk quality

The objective of this study was to evaluate relationships between the presence in milk of the major bovine acute phase proteins, haptoglobin (Hp) and serum amyloid A (SAA), and milk quality parameters. Composite milk samples were collected from 89 clinically healthy dairy cows and analysed for Hp and SAA, total protein, casein, and whey protein levels, casein number, proteolysis, total fat and lactose levels, and somatic cell count (SCC). Milk samples with detectable levels of Hp showed lower total protein and casein levels, whereas milk samples with detectable levels of SAA had lower casein number and lactose level. Samples with detectable levels of acute phase proteins also showed an elevated SCC. The results suggest that the presence of Hp and SAA in milk might indicate unfavourable changes in milk composition, especially in relation to protein quality

Profiling of aminoxyTMT-labeled bovine milk oligosaccharides reveals substantial variation in oligosaccharide abundance between dairy cattle breeds.

Free milk oligosaccharides are bioactive molecules that function as prebiotics and prevent infections that commonly afflict developing infants. To date, few publications have examined the factors affecting bovine milk oligosaccharide production among cattle in the dairy industry. Here we have applied a high-throughput isobaric labeling technique to measure oligosaccharide abundances in milk collected from Danish Holstein-Friesian and Jersey dairy cattle by liquid chromatography-mass spectrometry. With a total of 634 milk samples, this collection represents the largest sample set used for milk oligosaccharide profiling in the current literature. This study is also the first to use isobaric labeling for the purpose of measuring free oligosaccharides in a real sample set. We have identified 13 oligosaccharides that vary significantly by breed, with most structures being more abundant in the milk of Jersey cattle. The abundances of several oligosaccharides were increased in second-parity cows, and correlations between the abundances of oligosaccharide pairs were identified, potentially indicating similarities in their synthetic pathways. Fucosylated oligosaccharide structures were widely identified among both breeds. Improving our understanding of oligosaccharide production will aid in developing strategies to recover these compounds from processing streams and may enable their use as a functional ingredient in foods for infants and adults

Fedtsyreprofilen i mælk fra malkekøer – Potentiale og perspektiver

Projektet SOBcows har i samarbejde med RYK gennem 16 måneder i 2015/16 analyseret for indholdet af 11 fedtsyrer/fedtsyregrupper i kontrolmælken fra alle ydelseskontrollerede køer i Danmark. Dataanalyser af godt 3,5 mio. mælkeprøver viser, at det er muligt at påvirke sammensætning af mælkefedtet gennem avl. En foreløbig beregning af arvbarheden hen over laktationen viser, at alle fedtsyrekategorier har en genetisk variation og enkeltfedtsyrerne har arvbarheder på højde med den samlede fedtydelse. Det betyder arvbarheder i intervallet 0,25-0,44 afhængig af race og paritet. De genetiske sammenhænge varierer betydeligt gennem laktationen og er påvirket af den øgede kropsmobilisering i de første måneder efter kælvning. En anvendelse af fedtstyrebestemmelserne i avlen vil derfor kræve en opdeling af laktationen i mindst to perioder. Samlet kan det konkluderes, at der er et betydeligt avlsmæssigt potentiale, og hvis der kommer et dansk marked for mælkeprodukter med særlige egenskaber, vil det være oplagt at ændre genetikken i gunstig retning og samtidigt udnytte de fodringsmæssige muligheder for at producere mælk med en sundhedsfremmende fedtsyreprofil. Datamaterialet her og fedtsyremåling af samtlige mælkeprøver i ydelseskontrollen giver en unik position i forhold til det

Comparative analysis of inflamed and non-inflamed colon biopsies reveals strong proteomic inflammation profile in patients with ulcerative colitis

<p>Abstract</p> <p>Background</p> <p>Accurate diagnostic and monitoring tools for ulcerative colitis (UC) are missing. Our aim was to describe the proteomic profile of UC and search for markers associated with disease exacerbation. Therefore, we aimed to characterize specific proteins associated with inflamed colon mucosa from patients with acute UC using mass spectrometry-based proteomic analysis.</p> <p>Methods</p> <p>Biopsies were sampled from rectum, sigmoid colon and left colonic flexure from twenty patients with active proctosigmoiditis and from four healthy controls for proteomics and histology. Proteomic profiles of whole colonic biopsies were characterized using 2D-gel electrophoresis, and peptide mass fingerprinting using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was applied for identification of differently expressed protein spots.</p> <p>Results</p> <p>A total of 597 spots were annotated by image analysis and 222 of these had a statistically different protein level between inflamed and non-inflamed tissue in the patient group. Principal component analysis clearly grouped non-inflamed samples separately from the inflamed samples indicating that the proteomic signature of colon mucosa with acute UC is strong. Totally, 43 individual protein spots were identified, including proteins involved in energy metabolism (triosephosphate isomerase, glycerol-3-phosphate-dehydrogenase, alpha enolase and L-lactate dehydrogenase B-chain) and in oxidative stress (superoxide dismutase, thioredoxins and selenium binding protein).</p> <p>Conclusions</p> <p>A distinct proteomic profile of inflamed tissue in UC patients was found. Specific proteins involved in energy metabolism and oxidative stress were identified as potential candidate markers for UC.</p

Milking hygiene: new issues and opportunities from automatic milking

Automatic milking offers the opportunity of in-line measurements of milk components, check of milking and cleaning procedures,and surveillance through the management program. These advantages may directly benefit the milk quality.Diversion of abnormal milk at time of milking is critical to the milk quality. It is proposed to define abnormal milk as milkbeing visibly changed in homogeneity or colour from that of normal milk. Several enzymes and other milk componentsmay be involved in the formation of clots in the milk. Based on reported changes in primarily the milk protein fraction asa response to infection of the mammary gland, different explanations for the generation of precipitates in mastitis milkare discussed. Automatic milking systems (AMS) should have sensors to monitor and divert abnormal milk. The managementsystem of AMS provides an excellent opportunity to introduce Hazard Analyses Critical Control Points (HACCP)systems for surveying the milk quality. HACCP-based proposals are given for avoiding contamination of the bulk milk withmilk from cows with clinical mastitis and for ensuring a low bulk milk bacterial count

Digestibility of Bovine Serum Albumin and Peptidomics of the Digests: Effect of Glycation Derived from α-Dicarbonyl Compounds

α-Dicarbonyl compounds, which are widely generated during sugar fragmentation and oil oxidation, are important precursors of advanced glycation end products (AGEs). In this study, the effect of glycation derived from glyoxal (GO), methylglyoxal (MGO) and diacetyl (DA) on the in vitro digestibility of bovine serum albumin (BSA) was investigated. Glycation from α-dicarbonyl compounds reduced digestibility of BSA in both gastric and intestinal stage of digestion according to measurement of degree of hydrolysis. Changes in peptide composition of digests induced by glycation were displayed, showing absence of peptides, occurrence of new peptides and formation of peptide-AGEs, based on the results obtained using liquid chromatography electron-spray-ionization tandem mass spectrometry (LC-ESI-MS/MS). Crosslinked glycation structures derived from DA largely reduced the sensitivity of glycated BSA towards digestive proteases based on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) results. Network structures were found to remain in the digests of glycated samples by transmission electron microscope (TEM), thus the impact of AGEs in unabsorbed digests on the gut flora should be an interest for further studies

Mineral and fatty acid composition of milk from native Jutland and Danish Red 1970 cattle breeds

Mineral and fatty acid composition in milk from two minor native dairy breeds in Denmark; Danish Red 1970 (RDM-1970) and Jutland cows were analyzed. Results showed that for most compositional traits breed only played a minor role, whereas management and feeding played a significant role. Biodynamic management and very low milk yield resulted in a very characteristic fatty acid composition and a strongly elevated n-3/n-6 ratio (ratio 0.9 compared to 0.3). For milk minerals, RDM-1970 had significantly higher contents of P, Mg, Mn, whereas milk from Jutland cows had significantly higher K content

Different proteomic profiles of sweet whey and rennet casein obtained after preparation from raw versus heat-treated skimmed milk

Proteomic profiles of sweet whey and rennet casein fractions prepared from raw or pasteurised (72 °C for 15 s), skimmed milk were studied by proteomics coupled with the detection of protein spots by MALDI TOF mass spectrometry. Proteins were analysed by a modification of the traditional, two-dimensional gel electrophoresis (2-DGE) method under non-reducing running conditions, which potentially permits the visualisation of disulphide-linked protein complexes formed in response to pasteurisation. Separated proteins were stained with Coomassie blue. The relative spot volumes obtained after 2-DGE of fractions from raw or pasteurised milk were compared. A number of different spots in the rennet casein and sweet whey fractions were found to vary in response to pasteurisation. Some of these represented higher molecular mass complexes that increased in the chymosin-precipitated casein fraction, and they were identified by mass spectrometry to contain αS1-casein. Certain fragments of αS1-casein, probably generated as a result of chymosin cleavage, increased in the whey after pasteurisation. The whey content of proteose peptone component 3 (PP3) or lactophorin decreased after pasteurisation, which could indicate increased association of PP3 with for example the milk fat globule membrane after pasteurisation. This shows that gel-based proteome analysis can be used in the characterisation of subtle variations in protein composition of milk fractions that occur as a consequence of pasteurisation

Variation in casein distribution and mineralisation in the milk from Holstein-Friesian cows

In this study, protein and salt distributions in the milk of 48 Holstein-Friesian cows were studied. Gross composition of milk samples and variation between individual cows was in line with expectation. However, the mineralisation of the casein fraction, expressed in mmol protein-associated calcium per 10 g casein, differed >2-fold between the milk samples. Reasons for this variation are unknown and could not be correlated to casein composition and/or genetic variants of caseins. Furthermore, notable differences (>5-fold) in non-sedimentable (100,000×g for 60 min) casein were observed. Percentages of non-sedimentable caseins differed for κ-casein genetic variants (BB > AB > AA) and increased with increasing degree of glycosylation. Higher levels of non-sedimentable caseins with increasing degree of glycosylated κ-casein could be attributable to increased repulsion between the micelles, leading to the formation of a less cohesive sediment on centrifugation.</p