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1.
Food Chem ; 367: 130658, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34343808

RESUMO

Camel milk is rich in nutrients and its impact on human medicine and nutrition cannot be ignored. We conducted an in-depth analysis of milk proteins obtained from two camel breed (Camelus bactrianus, CB and Camelus dromedarius, CD). Label-free proteomic technology was performed to analysis the MFGM and whey proteomes of CB and CD milk. In total, 1133 MFGM proteins and 627 whey proteins were identified from camel milk. Results revealed that 216 MFGM proteins and 109 whey proteins were significantly different between them. In addition, the cellular process, cell and binding were the predominately GO annotations of milk proteins. KEGG analysis shown that most proteins were involved in metabolic pathways. Furthermore, many proteins were found to be involved in PI3K/AKT signaling pathway, which could be the possible reason for hypoglycemic effect of camel milk. These results could provide a further understanding for unique biological characteristics of camel milk proteins.


Assuntos
Camelus , Proteoma , Animais , Glicolipídeos , Glicoproteínas , Gotículas Lipídicas , Proteínas do Leite , Fosfatidilinositol 3-Quinases , Proteômica , Soro do Leite , Proteínas do Soro do Leite
2.
Food Chem ; 366: 130711, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34343947

RESUMO

Food protein and peptides are generally considered a source of dietary antioxidants. The antioxidant activity and peptide profiles of four extensive hydrolysates of milk protein concentrate (MPC) were examined using the two-step enzymatic method. The hydrolysis combinations were Alcalase-Flavourzyme (AE), Alcalase-ProteAXH (AH), Alcalase-Protamex (AX) and Alcalase-Protease A 2SD (AD). The results showed that highest degree of hydrolysis corresponded to the AE sample (20.41%). High-efficiency gel-filtration chromatography results indicated that the relative proportions of extensive hydrolysates with molecular weights < 3 kDa were 99.89%, 99.57%, 99.93%, and 99.89% for AX, AE, AD and AH, respectively. The hydrolysates of the MPC exhibited increased radical-scavenging capacity, as evidenced through an analysis with 1,1-diphenyl-2-pycryl-hydrazyl (DPPH), 2,2-azinobis (3-ethylbenzothiazo-line-6-sulfonic acid) diammonium salt (ABTS), reducing power and hydroxyl-radical scavenging activity testing. The main bioactive peptides were identified through EASY-nLC-orbitrap MS/MS and bioinformatics. The study may provide useful information regarding the antioxidant properties of extensive hydrolysates of MPC.


Assuntos
Antioxidantes , Proteínas do Leite , Hidrólise , Hidrolisados de Proteína , Proteômica , Espectrometria de Massas em Tandem
3.
Food Chem ; 368: 130820, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34416488

RESUMO

Two commercially available food grade fungal protease preparations (Fungal Protease 31,000 and Fungal Protease 60000) were found to hydrolyse bovine acid whey proteins but left the beta-lactoglobulin (ß-Lg) intact under the processing conditions used. Comparative analysis before and after hydrolysis of bovine acid whey, by 1D- and 2D-PAGE, RP-HPLC and intact-mass mass spectrometry showed that the ß-Lg remains intact and in high yield after hydrolysis by the fungal proteases. The ß-Lg could be separated from the whey protein peptide hydrolysate by ultrafiltration. Subjecting whey fraction to hydrolysis with the fungal protease preparations provides a procedure, under relatively mild conditions, to generate a highly enriched ß-Lg fraction. ß-Lg is recognised as a valued material in the food, pharmaceutical and cosmetic industries due to its properties such as gelling and foaming. The enriched ß-Lg preparation would also have application in areas such as nanoencapsulation.


Assuntos
Lactoglobulinas , Leite , Animais , Bovinos , Hidrólise , Proteínas do Leite , Peptídeo Hidrolases , Soro do Leite , Proteínas do Soro do Leite
4.
Trop Anim Health Prod ; 53(6): 524, 2021 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-34705124

RESUMO

Whole genome sequencing of bovine breeds has allowed identification of genetic variants in milk protein genes. However, functional repercussion of such variants at a molecular level has seldom been investigated. Here, the results of a multistep Bioinformatic analysis for functional characterization of recently identified genetic variants in Brazilian Gyr and Guzerat breeds is described, including predicted effects on the following: (i) evolutionary conserved nucleotide positions/regions; (ii) protein function, stability, and interactions; (iii) splicing, branching, and miRNA binding sites; (iv) promoters and transcription factor binding sites; and (v) collocation with QTL. Seventy-one genetic variants were identified in the caseins (CSN1S1, CSN2, CSN1S2, and CSN3), LALBA, LGB, and LTF genes. Eleven potentially regulatory variants and two missense mutations were identified. LALBA Ile60Val was predicted to affect protein stability and flexibility, by reducing the number the disulfide bonds established. LTF Thr546Asn is predicted to generate steric clashes, which could mildly affect iron coordination. In addition, LALBA Ile60Val and LTF Thr546Asn affect exonic splicing enhancers and silencers. Consequently, both mutations have the potential of affecting immune response at individual level, not only in the mammary gland. Although laborious, this multistep procedure for classifying variants allowed the identification of potentially functional variants for milk protein genes.


Assuntos
Caseínas , Proteínas do Leite , Animais , Bovinos/genética , Simulação por Computador , Mutação , Regiões Promotoras Genéticas
5.
Compr Rev Food Sci Food Saf ; 20(6): 5616-5640, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34622552

RESUMO

Calcium (Ca) is a key micronutrient of high relevance for human nutrition that also influences the texture and taste of dairy products and their processability. In bovine milk, Ca is presented in several speciation forms, such as complexed with other milk components or free as ionic calcium while being distributed between colloidal and serum phases of milk. Partitioning of Ca between these phases is highly dynamic and influenced by factors, such as temperature, ionic strength, pH, and milk composition. Processing steps used during the manufacture of dairy products, such as preconditioning, concentration, acidification, salting, cooling, and heating, all contribute to modify Ca speciation and partition, thereby influencing product functionality, product yield, and fouling of equipment. This review aims to provide a comprehensive understanding of the influence of Ca partition on dairy products properties to support the development of kinetics models to reduce product losses and develop added-value products with improved functionality. To achieve this objective, approaches to separate milk phases, analytical approaches to determine Ca partition and speciation, the role of Ca on protein-protein interactions, and their influence on processing of dairy products are discussed.


Assuntos
Proteínas do Leite , Oligoelementos , Animais , Cálcio na Dieta , Humanos , Micronutrientes , Leite
6.
J Dairy Sci ; 104(12): 12207-12215, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34531055

RESUMO

This study was designed to provide novel insights into milk fat globule membrane (MFGM) proteins in donkey colostrum (DC) and bovine colostrum (BC) using quantitative proteomics. In total, 179 (DC) and 195 (BC) MFGM proteins were characterized, including 71 shared, 108 DC-specific, and 124 BC-specific proteins. Fifty-one shared proteins were selected as differentially expressed MFGM proteins, including 21 upregulated and 30 downregulated proteins in DC. Gene ontology analysis showed that these proteins were mainly enriched in cellular components, including the extracellular exosome, extracellular space, and plasma membrane. Additionally, they were further involved in metabolic pathways, including cholesterol metabolism, the peroxisome proliferator-activated receptor signaling pathway, and purine metabolism. Furthermore, several key protein factors with high connectivity were identified via protein-protein interaction analysis. These results provide more comprehensive knowledge of differences in the biological properties of MFGM proteins in DC and BC as well as pave the way for future studies of the nutritional and functional requirements of these important ingredients toward the development of dairy products based on multiple milk sources.


Assuntos
Proteômica , Espectrometria de Massas em Tandem , Animais , Bovinos , Cromatografia Líquida de Alta Pressão/veterinária , Colostro , Equidae , Feminino , Glicolipídeos , Glicoproteínas , Gotículas Lipídicas , Proteínas de Membrana , Proteínas do Leite , Gravidez , Espectrometria de Massas em Tandem/veterinária
7.
J Dairy Sci ; 104(12): 12249-12262, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34538486

RESUMO

Dairy-derived lipids such as phospholipids (PL) have been gaining interest due to their functional and nutritional properties. Our research goal was to develop a separation process (nonsolvent based) to produce an enriched dairy lipid fraction from whey protein phospholipid concentrate (WPPC). Various chemical pretreatments (i.e., adjustment of pH, calcium, or temperature) were applied to rehydrated commercial WPPC solutions. These treatments were done on a bench-top scale to aid in the precipitation of proteins or PL. The chemically treated solutions were centrifuged and fractionated into the following 3 layers: (1) top fat layer, (2) supernatant in the middle zone, and (3) sediment at the bottom of the centrifuge tubes. The thickness and size of the layers varied with the treatment parameters. Compositional analysis of each layer showed that the proteins, fat, and PL always appeared to fractionate in similar proportions. The proteins in each layer were characterized using sodium dodecyl sulfate-PAGE under reducing and nonreducing conditions. Different proteins including whey proteins, caseins, and milk fat globule membrane proteins and lipoproteins were identified, and no specific type of protein had an affinity for either the top or bottom layer. All types of proteins were present in each of the layers after centrifugation, and there were no major differences in fractionation of the proteins between layers with respect to the chemical treatment applied. The microstructure of protein and fat in WPPC was investigated using confocal laser scanning microscopy. Dual staining of the rehydrated WPPC solution with Fast Green FCF (proteins) and Nile Red (lipids) showed the presence of very large protein aggregates that varied in size from 20 to 150 µm, with fat trapped within these aggregates. The confocal laser scanning microscopy images of liquid WPPC revealed fine strands of a weak protein network surrounding the fat globules. This indicated that there were specific interactions between the proteins, as well as between the fat and proteins in WPPC. Sodium dodecyl sulfate treatment was performed to understand the nature of the interactions between protein and fat. We found that about 35% of the fat present in WPPC was in the form of free fat, which was only physically entrapped within the protein aggregates. The remaining fat had some form of association with the proteins in WPPC. Other fractionation techniques would be needed to obtain an enriched dairy lipid fraction.


Assuntos
Caseínas , Fosfolipídeos , Animais , Eletroforese em Gel de Poliacrilamida/veterinária , Proteínas do Leite , Temperatura , Proteínas do Soro do Leite
8.
Theriogenology ; 175: 95-99, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34521031

RESUMO

So far, no study has been conducted on the effect of milk protein concentrations (MP%) in different time periods of lactation on subsequent calving intervals (CI). The purpose of this study was to evaluate the association between MP% at different stages of the first to fourth lactations and subsequent calving intervals in primiparous and multiparous Holstein dairy cows. Test day records (3X milking frequency) of milk yield measured on primiparous (n = 503793) and multiparous (n = 389237, 257347, 156035 and 87750 for parity 2, 3 and 4, and 5 respectively) Holstein dairy cows collected during 1984-2019 were obtained from Animal Breeding Center of Iran. To investigate the relationship between MP% at different time intervals of lactation and subsequent calving intervals (up to fifth parity), each lactation was divided into four time periods (≤50d, 50 < d ≤ 100, 100 < d ≤ 200 and 200 < d ≤ 305). At each period, protein concentrations were also divided into three classes: 1-3%, 3-5%, 5-7%. There was a negative relationship between MP% in the first 50 days of first lactation in primiparous and multiparous dairy cows and subsequent calving intervals in a way that calving intervals decreased as MP% increased and the shortest calving intervals were observed for the third class of milk protein concentrations. After the first 50 days of first lactation, the shortest subsequent calving intervals were detected for the second class of MP% and the CI increased non-significantly when MP% increased to 5-7. In general, due to the significant relationship between MP% and subsequent CI, this relationship can be further considered in breeding programs in dairy cattle.


Assuntos
Lactação , Proteínas do Leite , Animais , Bovinos , Feminino , Irã (Geográfico) , Leite , Paridade , Gravidez
9.
Trop Anim Health Prod ; 53(5): 463, 2021 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-34545452

RESUMO

Lactation curves are a valuable tool for improving flock production efficiency, adjusting flock sizes, and improving farmers' income in grazing-based livestock production. Therefore, we used natural cubic splines to estimate (a) a general flock production pattern throughout a year, (b) an average lactation curve, and (c) patterns of milk chemical components in dual-purpose goats grazing in arid plant communities in the Sierra de San Francisco, Baja California Peninsula, during years of abundant precipitation. Also, milk chemical composition was compared between flocks. Annual flock milk production showed a wiggly pattern with two greater waves in summer and spring. The average individual lactation curve (kg/doe/day) and production curves of fat, protein, lactose, and ashes (g/doe/day) showed a decreasing and wiggly pattern across 35-week lactation; the greatest average daily production was in week 2. Milk, protein, lactose, and ash production curves had similar persistency values that were greater than those of the fat production curve. Milk production had a high-positive correlation with fat production and very high-positive correlations with protein, lactose, and ash production. Density (g/ml) and fat, protein, lactose, and ash contents (%) showed a ditch-shaped pattern across lactation, with greater values at the end. Goat flocks grazing across plant communities produced different quality milk. Thus, native plant communities are a valuable resource that favors a great fat content and moderate protein content in local goat milk. Also, breeding programs must pay attention that an increment in individual milk production could decrease fat and protein production, which are valuable for cheesemaking.


Assuntos
Cabras , Leite , Animais , Feminino , Lactação , Lactose , México , Proteínas do Leite
10.
Sci Rep ; 11(1): 18623, 2021 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-34545177

RESUMO

While enzymatic hydrolysis is an effective method for lowering the antigenicity of cow milk (CM), research regarding the antigenicity and nutritional traits of CM hydrolysate is limited. Here, we evaluated the protein content, amino acid composition, sensory traits, color, flow behavior, and antigenicity of CM following enzymatic hydrolysis. The results showed that enzymatic hydrolysis increased the degree of hydrolysis, destroyed allergenic proteins, including casein, ß-lactoglobulin, and ɑ-lactalbumin, and significantly increased the content of free amino acids and nutritional quality. In particular, the antigenicity of CM was significantly reduced from 44.05 to 86.55% (P < 0.5). Simultaneously, the taste, color, and flow behavior of CM were altered, the sweetness and richness intensity decreased significantly (P < 0.5), and astringency and bitterness were produced. A slightly darker and more yellow color was observed in CM hydrolysate. In addition, apparent viscosity decreased and shear stress significantly increased with increasing shear rate intensity. The results will provide a solid theoretical foundation for the development of high-quality hypoallergenic dairy products.


Assuntos
Aminoácidos/análise , Proteínas do Leite/análise , Leite/química , Valor Nutritivo , Animais , Hidrólise , Leite/metabolismo
11.
Nutrients ; 13(9)2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34578905

RESUMO

The purpose of this study was to evaluate the diagnosis and management of infants presenting with symptoms attributable to cow's milk allergy (CMA) in a real life setting and to test how the Cow's Milk-related Symptom Score (CoMiSS®) can be used to support the awareness to diagnose cow's milk protein allergy in primary care practice. The CoMiSS is an awareness tool based on various symptoms such as crying, gastrointestinal symptoms, dermatological and respiratory symptoms. The study was conducted on 268 infants from four countries (Belgium, Czech Republic, Germany, UK) aged 0 to 18 months consulting for CMA related symptoms. The analysis was based on two visits of these subjects. The results show an average CoMiSS of 11 at the first visit. After a therapeutic dietary intervention, the score at the second visit, which happened 3 weeks ± 5 days after the first one, dropped to an average value of 4. A satisfaction questionnaire completed by the primary care practitioners suggested an overall high level of satisfaction with the application of the CoMiSS tool in routine practice. These data highlight a huge discrepancy in the diagnosis and management of infants suspected of CMA in the different countries. The findings suggest that the CoMISS questionnaire is an effective tool in aiding awareness of CMPA in primary health care.


Assuntos
Hipersensibilidade a Leite/diagnóstico , Atenção Primária à Saúde/métodos , Alérgenos/imunologia , Animais , Bélgica , República Tcheca , Feminino , Alemanha , Humanos , Lactente , Recém-Nascido , Masculino , Leite/imunologia , Hipersensibilidade a Leite/terapia , Proteínas do Leite/imunologia , Estudos Prospectivos , Inquéritos e Questionários , Reino Unido
12.
Nutrients ; 13(9)2021 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-34578889

RESUMO

Human clinical trials have shown that a specific partially hydrolyzed 100% whey-based infant formula (pHF-W) reduces AD risk in the first yeast of life. Meta-analyses with a specific pHF-W (pHF-W1) confirm a protective effect while other meta-analyses pooling different pHF-W show conflicting results. Here we investigated the molecular composition and functional properties of the specific pHF-W1 as well as the stability of its manufacturing process over time. This specific pHF-W1 was compared with other pHF-Ws. We used size exclusion chromatography to characterize the peptide molecular weight (MW), a rat basophil degranulation assay to assess the relative level of beta-lactoglobulin (BLG) allergenicity and a preclinical model of oral tolerance induction to test prevention of allergic sensitization. To analyze the exact peptide sequences before and after an HLA binding assay, a mass cytometry approach was used. Peptide size allergenicity and oral tolerance induction were conserved across pHF-W1 batches of production and time. The median MW of the 37 samples of pHF-W1 tested was 800 ± 400 Da. Further oral tolerance induction was observed using 10 different batches of the pHF-W1 with a mean reduction of BLG-specific IgE levels of 0.76 log (95% CI = -0.95; -0.57). When comparing pHF-W1 with three other formulas (pHF-W2 3 and 4), peptide size was not necessarily associated with allergenicity reduction in vitro nor oral tolerance induction in vivo as measured by specific IgE level (p < 0.05 for pHF-W1 and 2 and p = 0.271 and p = 0.189 for pHF-W3 and 4 respectively). Peptide composition showed a limited overlap between the formulas tested ranging from 11.7% to 24.2%. Furthermore nine regions in the BLG sequence were identified as binding HLA-DR. In conclusion, not all pHF-Ws tested have the same peptide size distribution decreased allergenicity and ability to induce oral tolerance. Specific peptides are released during the different processes used by different infant formula producers.


Assuntos
Alérgenos , Fórmulas Infantis/análise , Lactoglobulinas , Hipersensibilidade a Leite , Peptídeos , Proteínas do Soro do Leite , Alérgenos/imunologia , Animais , Cromatografia , Dermatite Atópica , Indústria Alimentícia , Alimentos Formulados , Humanos , Hidrólise , Imunoglobulina E , Lactente , Lactoglobulinas/análise , Lactoglobulinas/imunologia , Hipersensibilidade a Leite/prevenção & controle , Proteínas do Leite , Peso Molecular , Peptídeos/análise , Peptídeos/imunologia , Hidrolisados de Proteína/análise , Hidrolisados de Proteína/imunologia , Ratos Sprague-Dawley , Soro do Leite , Proteínas do Soro do Leite/análise , Proteínas do Soro do Leite/imunologia
13.
Compr Rev Food Sci Food Saf ; 20(6): 6057-6088, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34494713

RESUMO

The popularity of fat-free fermented concentrated milk products, such as fresh cheeses and high-protein yogurt, has increased over the recent years, attributed to greater availability and improvements in taste and texture. These improvements have been achieved through modifications and new developments in processing technologies, for example, higher heat treatment intensities and incorporating different membrane filtration technologies. Though numerous processing parameters are discussed in the literature, as well as reasons behind the developments, detailed examinations of how process modifications affect the final textural attributes of these products are lacking. To draw links between processing parameters and texture, we review the literature on fat-free fermented concentrated milk products from the perspective of fermented milk protein-based microgel particles as the basic structural unit. At each main processing step, relationships between process parameters, micro- and macrostructural and sensory (textural) properties are discussed.An overview of particle characteristics that drive structural changes at each processing step is developed in relation to textural characteristics. Using this approach of assessing relationships between structural characteristics of concentrated dispersions of fat-free fermented milk protein-based microgel particles and processing parameters provides a basic context for the selection of optimal parameters to achieve a desired texture.


Assuntos
Queijo , Produtos Fermentados do Leite , Microgéis , Proteínas do Leite , Iogurte
14.
J Dairy Sci ; 104(10): 10950-10969, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34364638

RESUMO

The protein profile of milk includes several caseins, whey proteins, and nonprotein nitrogen compounds, which influence milk's value for human nutrition and its cheesemaking properties for the dairy industry. To fill in the gap in current knowledge of the patterns of these individual nitrogenous compounds throughout lactation, we tested the ability of a parametric nonlinear lactation model to describe the pattern of each N compound expressed qualitatively (as % of total milk N), quantitatively (in g/L milk), and as daily yield (in g/d). The lactation model was tested on a data set of detailed milk nitrogenous compound profiles (15 fractions-12 protein traits and 3 nonproteins-for each expression mode: 45 traits) obtained from 1,342 cows reared in 41 multibreed herds. Our model was a modified version of Wilmink's model, often used for describing milk yield during lactation because of its reliability and ease of parameter interpretation from a biological point of view. We allowed the sign of the persistency coefficient (parameter c) that explained the variation in the long-term milk component (parameter a) to be positive or negative. We also allowed the short-term milk component (parameter b) to be positive or negative, and we estimated a specific speed of adaptation parameter (parameter k) for each trait rather than assumed a value a priori, as in the original model (k = 0.05). These 4 parameters were included in a nonlinear mixed model with cow breed and parity order as fixed effects, and herd-date as random. Combinations of the positive and negative signs of the b and c parameters allowed us to identify 4 differently shaped lactation curves, all found among the patterns exhibited by the nitrogenous fractions as follows: the "zenith" curve (with a maximum peak; for milk yield and 10 other N traits), the "nadir" curve (with a minimum point; for 20 traits, including almost all those expressed in g/L of milk), the "downward" curve (continuously decreasing; for 14 traits, including almost all those in g/d), and the "upward" curve (continuously increasing; only for κ-casein, in % N). Direct estimation of the k parameters specific to each trait showed the large variability in the adaptation speed of fresh cows and greatly increased the model's flexibility. The results indicated that nonlinear parametric mathematical models can effectively describe the different and complex patterns exhibited by individual nitrogenous fractions during lactation; therefore, they could be useful tools for interpreting milk composition variations during lactation.


Assuntos
Lactação , Proteínas do Leite , Animais , Bovinos , Indústria de Laticínios , Feminino , Leite , Gravidez , Reprodutibilidade dos Testes
15.
J Dairy Sci ; 104(10): 10513-10527, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34419278

RESUMO

Whey proteins of Saanen goat milk samples from 3 provinces in China (Guangdong, GD; Inner Mongolia, IM; Shaanxi, SX) were characterized and compared using data-independent acquisition quantitative proteomics technique. A total of 550 proteins were quantified in all 3 samples. There were 44, 44, and 33 differentially expressed proteins (DEP) for GD versus IM, GD versus SX, and IM versus SX, respectively. Gene ontology annotation analysis showed that the largest number of DEP for the 3 comparisons were as follows: for biological processes: response to progesterone, glyceraldehyde-3-phosphate metabolic process, and negative regulation of megakaryocyte differentiation; for molecular functions: antioxidant activity, binding, and peroxiredoxin activity; and for cellular components: the same category of extracellular regions for the 3 comparisons, respectively. Pathways for the DEP of 3 comparisons were (1) disease; (2) synthesis and metabolism; and (3) synthesis, degradation, and metabolism. Protein-protein interaction network analysis showed that DEP for GD versus SX had the most interactions.


Assuntos
Leite , Proteômica , Animais , Ontologia Genética , Cabras , Proteínas do Leite , Proteínas do Soro do Leite
16.
J Dairy Res ; 88(3): 326-329, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34382922

RESUMO

Our objective was to evaluate relationships between milk components (acute phase proteins, enzymes, metabolic parameters and oxidative indices) and the spontaneous cure outcome of Staphylococcus aureus subclinical mastitis in dairy cows. The values of haptoglobin, serum amyloid A (SAA), malondialdehyde (MDA), total antioxidant capacity, milk urea nitrogen (MUN), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), electrolytes (Cl and K), total protein, albumin, α-lactalbumin, ß-lactoglobulin, and immunoglobulin were measured in milk samples of S. aureus subclinical mastitis cows with spontaneous cure (n = 23), S. aureus subclinical mastitis cows without spontaneous cure (n = 29) and healthy cows (n = 23). The comparison of measured parameters revealed that subclinical mastitis cows with spontaneous cure had lower ALP and haptoglobin concentrations both at diagnosis and after cure (P < 0.05). In contrast, total antioxidant capacity and MDA concentration in subclinical mastitis cows without spontaneous cure significantly increased with time (P < 0.05). We can suggest that elevated haptoglobin concentration and higher ALP activity indicative of enhanced oxidative stress could potentially serve as early diagnostic indicators of chronic disease and the persistence of S. aureus subclinical mastitis in dairy cows.


Assuntos
Mastite Bovina/diagnóstico , Leite/química , Infecções Estafilocócicas/veterinária , Staphylococcus aureus , Fosfatase Alcalina/análise , Animais , Antioxidantes/análise , Bovinos , Doença Crônica/veterinária , Feminino , Haptoglobinas/análise , Malondialdeído/análise , Mastite Bovina/metabolismo , Mastite Bovina/microbiologia , Proteínas do Leite/análise , Estresse Oxidativo , Remissão Espontânea , Proteína Amiloide A Sérica/análise
17.
J Dairy Res ; 88(3): 307-313, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34392841

RESUMO

Dairy goat farming is an important sector of the agricultural industry in Greece, with an annual total milk production exceeding 450 000 l and accounting for over 25% of all goat milk produced in the European Union; this milk is used mainly for cheese production. Despite the importance of goat milk for the agricultural sector in Greece, no systematic countrywide investigations in the bulk-tank milk of goats in Greece have been reported. Objectives were to investigate somatic cell counts (SCC) and total bacterial counts (TBC) in raw bulk-tank milk of goat herds in Greece, study factors influencing SCC and TBC therein and evaluate their possible associations with milk content. Throughout Greece, 119 dairy goat herds were visited for milk sampling for somatic cell counting, microbiological examination and composition measurement. Geometric mean SCC and TBC were 0.838 × 106 cells ml-1 and 581 × 103 cfu ml-1, respectively. Multivariable analyses revealed annual frequency of check-ups of milking system and total milk quantity per goat (among 53 variables) to be significant for increased SCC; no factor emerged (among 58 variables) to be significant for increased TBC. Negative correlation of SCC with total protein was found; mean total protein content in the bulk-tank milk in herds with SCC >0.75 × 106 cells ml-1 was 5.1% lower and in herds with SCC >1.5 × 106 cells ml-1, it was 7.8% lower.


Assuntos
Carga Bacteriana/veterinária , Contagem de Células/veterinária , Cabras , Leite/citologia , Leite/microbiologia , Animais , Composição Corporal , Indústria de Laticínios/métodos , Feminino , Grécia , Leite/química , Proteínas do Leite/análise , Staphylococcus/isolamento & purificação
18.
J Dairy Sci ; 104(11): 12139-12152, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34419281

RESUMO

Cooling can alleviate the negative consequences of heat stress on multiple milk production metrics in dairy cows. However, it is still controversial whether cooling can increase milk protein content compared with heat-stressed cows. The objective of the present study was to evaluate the relief effect of cooling on the decrease in milk protein concentration during heat stress and elucidate the potential metabolic mechanisms. Thirty lactating multiparous Holstein cows (days in milk = 175 ± 25 d, milk yield = 27.5 ± 2.5 kg/d; mean ± SD) were assigned to 1 of 3 treatments: heat stress (HS; n = 10), cooling (CL; n = 10), and cooling with pair-feeding (PFCL; n = 10). The barns for PFCL and CL cows were equipped with sprinklers and fans, whereas the barn for HS cows were not. The average temperature-humidity index during the experiment ranged from 74 to 83. The spraying was activated automatically 2 times per day (1130-1330 h and 1500-1600 h) with 3 min on and 6 min off during the first 2 wk, and 1.5 min on and 3 min off during the last 2 wk, whereas the fans operated 24 h/d. The experiment lasted for 4 wk in total. Milk, urine, feces, total mixed ration, blood, and rumen fluid samples were collected weekly. Compared with HS, feed efficiency (1.24 and 1.49), milk protein yield (0.82 and 0.94 kg/d), and milk fat yield (0.98 and 1.26 kg/d) were increased in PFCL, whereas the differences between CL and HS were not significant. Compared with HS cows, PFCL and CL cows had a lower respiratory rate (70.6, 59.1, and 60.3 breaths per minute, respectively), rectal temperature (38.95, 38.61, and 38.51°C), and shoulder skin temperature (33.95, 33.25, 33.40°C), and had greater milk protein content (3.41, 3.72, and 3.69%) and milk fat percent (4.08, 4.97, 4.65%). Both the blood activity of catalase (increased by 12.8 and 41.0%) and glutathione peroxidase (12.6 and 40.4%) of PFCL and CL cows were greater than the HS cows. Compared with HS, cooling increased the blood content of glucose, methionine, threonine, and cystathionine by 10.7% and 10.3%, 19.0% and 9.5%, 15.8% and 12.0%, and 9.5% and 23.8% in PFCL and CL, respectively. In conclusion, the results indicated that cooling partially rescued milk protein synthesis induced by heat stress, and the potential mechanism may have been due to increased antioxidant ability, blood glucose, and key AA. Consequently, in addition to modifying the environment, nutritional and physiological strategies designed to influence carbohydrate, AA, and oxidative homeostasis may be an opportunity to maintain or correct low milk protein content during the warm summer months.


Assuntos
Lactação , Proteínas do Leite , Animais , Benchmarking , Bovinos , Feminino , Resposta ao Choque Térmico , Temperatura Alta , Proteínas do Leite/análise
19.
J Dairy Sci ; 104(11): 11499-11508, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34454765

RESUMO

Cow milk protein is one of the leading food allergens. This study aimed to develop an effective method for reducing milk sensitization by evaluating antigenicity of fermented skim milk protein using Lactobacillus helveticus KLDS 1.8701, Lactobacillus plantarum KLDS 1.0386, and a combination of both strains. The proteolytic systems of strains in terms of genotype and phenotype are characterized by complete genome sequence, and evaluation the antigenicity of skim milk proteins was determined by ELISA and liquid chromatography with tandem mass spectrometry. Our results showed that the genomes encoded a variety of peptidase genes. For fermented skim milk, the degree of hydrolysis of the combined strains was higher than that of individual strain. Electrophoresis showed that the band color density of α-casein (α-CN) by fermentation of the combined strains was reduced when compared with control group. The fermentation process of the combined strains inhibited α-CN, ß-lactoglobulin, and α-lactalbumin antigenicity by 69.13, 36.10, and 20.92, respectively. Major allergic epitopes of α-CN and ß-lactoglobulin were cleaved by abundant proteases of combined strains. In all, this study showed that the fermentation process involving both L. helveticus and L. plantarum strains could reduce cow milk protein allergenicity through the combination of cell-envelope proteinase and peptidase on α-CN.


Assuntos
Lactobacillus helveticus , Lactobacillus plantarum , Alérgenos , Animais , Bovinos , Feminino , Fermentação , Proteínas do Leite
20.
J Dairy Sci ; 104(11): 11413-11421, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34454769

RESUMO

The value of milk hinges on its physicochemical functionality under processing conditions. We examined composition-functionality relationships with individual milks from 24 New Zealand dairy cows, sampled at 3 times over the season. Milks were classified into type A or B, according to the shape of 3-point heat coagulation time versus pH profiles. Milk type changed over the season for half of the cows in the study. Best subsets regression suggested that different factors controlled heat stability in the 2 milk types. Urea concentration was key for both types, but for type A milks, osmotic pressure and milk solids were the most important predictors of heat stability, whereas casein micelle size and ionic calcium predicted heat stability for type B milks. This study revealed that milk type is prone to change over the season, and the findings suggest that optimizing heat stability could be achieved by different means for type A versus type B milks.


Assuntos
Temperatura Alta , Leite , Animais , Caseínas , Bovinos , Feminino , Micelas , Leite/química , Proteínas do Leite/análise , Estações do Ano
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