Milk Somatic Cell Research Articles

Qualitative indicators of milk and fermented milk products when activated zeolite and probiotics are included in the diet of cows

Relevance. The quality of milk depends on the season of the year, the breed of animals, the state of metabolism, and the characteristics of feeding and maintenance technology. The quality of milk determines its technological properties and the quality of its processed products.Methods. The content of somatic cells in milk, the acidity of milk, cottage cheese, yogurt, and syneresis of yogurt were determined. In milk processing products, the content of the mass fraction of nitrogen and crude protein, crude ash, calcium, and phosphorus was determined.Results. When feeding cows with the yeast probiotic activated zeolite and the phytoprobiotic “Provitol”, a significant decrease in the content of somatic cells in freshly milked milk of cows was established by 13.02% (p < 0.05). Significantly lower milk acidity values were established (by 6.00% (p < 0.001) and 12.79% (p < 0.001), respectively), significantly higher yogurt acidity values (by 6.00% (p < 0.001) and 12.79% (p < 0.001), respectively, significantly lower yogurt syneresis (by 4.70% (p < 0.001) and 3.10% (p < 0.01), respectively). The use of activated zeolite and yeast probiotic “Kluver Pro” in the diets leads to a significantly higher content (compared with the control) of the mass fraction of fat in cottage cheese and yogurt — by 10.47 abs. % (p < 0.001) and 4.58 abs. % (p < 0.001).

Comprehensive proteomic analysis of buffalo milk extracellular vesicles

Extracellular vesicles are secretory vesicles involved in cell-to-cell communication via their encapsulated cargo of proteins, lipids, and nucleic acids. Bovine milk provides a rich source of extracellular vesicles (mEVs) that have been studied as therapeutics and drug delivery systems. Therefore, insight into the mEV cargo, such as its proteome, may help in understanding the molecular mechanism underlying the potential health benefits attributed to the mEVs. Hence, mEVs were isolated from healthy buffalo milk after screening the milk somatic cell count. The total proteins of mEVs were analyzed using LC-MS, and 331 proteins were found commonly present among three buffalo milk samples. These proteins were primarily derived from extracellular regions and lysosomes. The major biological roles associated with the proteins were immune response, metabolism, and cell cycle regulation. The molecular functions of the proteins were transporter activity, catalytic activity, and GTPase activity. Further, comparative analysis with the previously available bovine mEVs proteome data showed 114 proteins to be newly identified in the buffalo mEVs. The biological pathways associated with these proteins may play a major role in muscle development. These findings shed a light on the potential health benefits of buffalo mEVs as therapeutics as well as drug delivery vehicles.

Assessment of mammary stress in early lactating crossbred (Alpine × Beetal) does during heat stress in conjunction with milk somatic cells and non-invasive indicators

Milk somatic cell counts (SCC) are crucial for monitoring dairy animals' mammary health and milk quality. This study was initiated to assess the mammary health of early lactating crossbred (Alpine × Beetal) does during periods of heat stress. The udder skin surface temperature (USST), total and differential milk SCC, milk composition, milk cortisol levels and phagocytic activity (PA) of milk neutrophils and macrophages were estimated in these does. Results indicated a significant (p<0.01) increase in the milk neutrophils to macrophages (N: M) ratio and milk cortisol levels with milk somatic cell score (SCS). The PA of milk neutrophils decreased significantly (p<0.01), while that of macrophages increased significantly (p<0.01) with higher SCC. On Pearson correlation, milk SCS revealed strong positive correlation (p<0.01) with N: M ratio (r=0.90), USST (r=0.98), milk cortisol (r=0.97), milk pH (r=0.83) and conductivity (r=0.92). Conversely, milk lactose exhibited a moderate negative correlation of (r= −0.48) with SCS. These findings suggest that USST infrared thermography and milk cortisol levels are promising non-invasive methods for rapidly assessing mammary stress in early lactating does during heat stress.

Isolation of DNA from somatic milk cells: a review

Isolation of DNA from somatic milk cells: a review

The investigation of SNP in SOCS2 gene and its effect on milk yield, fat, protein, and somatic cell count in Awassi ewes.

Livestock farmers face financial losses every year because milk yield and components are severely affected by udder diseases. These udder infections attract the immune response from the host and lead to the influx of neutrophils into milk to fight infection and thus the number of somatic cell count (SCC) is increased. The SCC value of milk could be used as an important indicator in detecting clinical mastitis in dairy animals. Also, the milk yield and milk quality (e.g. fat) are negatively affected by the increased SCC. The SCC is used to estimate the somatic cell score (SCS)of the milk, which is used as an indirect measure to detect subclinical mastitis. Therefore, the purpose of this study was to investigate the presence of a significant SNP rs868996547, on the suppressor of cytokine signaling 2 gene (SOCS2) which is related to milk yield and milk quality in Awassi sheep. In this study, milk production data was obtained from 210 healthy Awassi ewes with different parties and ages. The general linear model (GLM) process analysis of variance (ANOVA) was used to determine fixed effects on milk traits. The DNA extraction was done using a blood DNA extraction kit from Qiagen. To validate the presence of SNP a customized SNP detection developed by Thermofisher Scientific was used. The presence of the SNP in the SOCS2 gene was detected with genotypes (C/T, T/T, and C/C) and T being the mutated allele and it had a significant (p < 0.015) effect on the milk yield (p < 0,015;0.091), fat (p < 0,001;0,003), fat/protein ratio (p < 0.001;0,037) and log10SCC value (p < 0,006;0,015) of Awassi ewes. However, the protein, total solid, and lactose percentages in the wild type and the mutated ewes found having no significant difference (P > 0.05). Our result showed the increase in SCC or SCS of the milk significantly affected the milk yield and composition. Parity and age had significant effects on ewes' milk yield (p < 0.001). In conclusion, we investigated the presence of SOCS2 gene of Awassi ewes in the study flock and its effect on milk yield, fat, and somatic cell count, and the change in milk composition and milk yield because of SCC.

Comparative Profiling of Milk Somatic Cells Proteomes Revealed Key Players in Mammary Immune Mechanisms During Mastitis in Tropical Sahiwal (Bos indicus) Cows.

Bovine mastitis poses a significant economic burden on the dairy industry worldwide. This pioneering proteomic study conducted a comparative profiling of milk somatic cell (SC) proteins contributing to mammary immune defense during subclinical and clinical mastitis (CM) in Sahiwal (Bos indicus) cows. Based on California mastitis test (CMT) scores, milk SC counts, differential leukocyte counts (DLCs), and bacteriological culture results, quarter milk SC samples were categorized into healthy (H), subclinical mastitis (SCM), and CM groups. Comparative proteome profiling of milk SCs was done using a label-free liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) proteomic approach. The identified upregulated proteins in mastitis groups such as Vanin 2, Thioredoxin reductase-like selenoprotein T, Ceramidase, Lymphocyte antigen 75, Misshapen-like kinase 1 (MINK1), Thrombospondin 1, Macrophage scavenger receptor 1, Leupaxin, and Lipoamide acyltransferase, involved in immune responses. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed immune functions and pathways like antigen processing, complement cascades, extracellular matrix receptor interaction, efferocytosis, leukocyte migration, chemokine, peroxisome proliferator-activated receptors (PPARs), and transforming growth factor (TGF)-beta signaling. These findings provide essential information on proteomic profiling in milk SCs and contribute valuable insights into immune-related proteins regulated during mastitis in dairy cows. Further, validated proteins (Vanin 2, MINK1, and Thrombospondin 1) offer potential inflammatory biomarkers for early mastitis detection in dairy cows.

Comparative study of first lactation performance of Norwegian Red crossbred cows with traditional breeds in New Zealand dairy systems

ABSTRACT Some New Zealand dairy farmers are using semen from Norwegian Red (NR) bulls to explore the performance of this breed under local grazing conditions. The objective of this study was to compare the first lactation performance of first cross NR cattle with traditional New Zealand breeds. Data were collected from six dairy farms in Southland, New Zealand, during 2022–2023 milk production seasons. Data were collected from 1178 first lactation cows including herd test of daily yields of milk, fat and protein and somatic cell counts, and persistency. Breeds included 386 NR cross (NRX), 231 Holstein Friesian (F), 84 Holstein Friesian cross (FX), 134 Holstein Friesian x Jersey (FJ) and 58 Jersey cross (JX) cows. Findings indicate F cows produced the greatest cumulative milk yield (3,744 kg), 138.6 kg more than NRX cows. There were no significant differences among the breed groups for milk yield and milk solids yield persistency and SCS (SCS = Log2 SCC). The total lactation milk yield of NRX cows was lower than that of the other breeds, excluding JX. These results pertain specifically to first lactation cows; therefore, it is necessary to undertake further analysis to evaluate the long-term productivity and longevity of NR breeds under New Zealand conditions.

Genome-Wide Association Study for Milk Somatic Cell Score in Holstein Friesian Cows in Slovenia.

Mastitis is a serious challenge for the dairy industry, leading to economic losses and affecting milk quality. The aim of this study is to identify genetic factors associated with mastitis resistance by conducting a genome-wide association study (GWAS) for the somatic cell score (SCS). Phenotypic records of 350 Holstein Friesian cows were obtained from the Slovenian Cattle Recording Scheme Database and consisted of around 1500 lactation data from 2012 to 2023 collected on a single farm in Slovenia. Corresponding genotypic data were also retrieved from the same database and genotyped using the Illumina BovineSNP50 BeadChip (Illumina, Inc., San Diego, CA, USA). For the association study, three SCS parameters were considered, including lactation mean somatic cell score (LM_SCS), maximum SCS value (SCSMAX), and top three mean value of SCS (TOP3). After performing a GWAS using FarmCPU and BLINK models, five significant SNPs associated with the TOP3 trait were found on BTA 14, 15, 22, and 29. The identified SNP markers were closely linked to six known candidate genes (DNASE1L3, SLC36A4, ARMC1, PDE7A, MMP13, CD44). These results indicate potential genetic markers associated with SCS in the Slovenian Holstein Friesian population.

Transcriptomic analysis reveals molecular insights into lactation dynamics in Jakhrana goat mammary gland

BackgroundGoat milk is gaining popularity as a superior alternative to bovine milk due to its closer resemblance to human milk. Understanding the molecular processes underlying lactation is crucial for improving milk quality and production in goats. However, the genetic mechanisms governing lactation in goats, particularly in indigenous breeds like the Jakhrana, remain largely unexplored.ResultsIn this study, we performed a comprehensive transcriptomic analysis of Jakhrana goat mammary glands during early and late lactation stages. We isolated milk somatic cells and conducted RNA sequencing, followed by transcript quantification and mapping against the ARS1.2 Capra hircus reference assembly. Our analysis identified differentially expressed genes (DEGs) and commonly expressed genes (CEGs) across the lactation phases. Early lactation showed enrichment of genes encoding antimicrobial peptides and lubrication proteins, while late lactation exhibited heightened expression of genes encoding major milk proteins. Additionally, DEG analysis revealed upregulation of pivotal genes, such as the ABC transporter gene MRP4, implicated in modulating milk composition and quality.ConclusionOur findings provide insights into the genetic mechanisms underlying lactation dynamics in the Jakhrana goat. Understanding these mechanisms could help in improving milk production and quality in goats, benefiting both the dairy industry and consumers.

PSIX-24 Greater glucose transporter SLC2A1 expression in milk somatic cells as a compensatory milk production strategy in young prolific Pelibuey ewes

Abstract The number of lambs per birth expressed as prolificacy is a key trait that determines productive efficiency in sheep. However, the optimal litter size depends on the production system, since the milk production of the ewe impacts the postnatal development of lambs. Milk yield, in turn, is related to the expression of the SLC2A1 gene in mammary epithelial cells. This gene encodes the solute carrier/glucose transporter 1 and is upregulated in peak/mid lactation. To assess the productive efficiency of twinning ewes in regard to SLC2A1 expression, the objective of this study was to measure the mRNA levels of SLC2A1 in milk somatic cells (MSC) of Pelibuey ewes lambing twins. Healthy ewes (n = 8), three primiparous and five multiparous, were selected to quantify and compare abundance of SLC2A1 mRNA. Management was under feedlot conditions, and the milk samples were taken between 16 and 20 d post-lambing. Total RNA was purified from MSC and SLC2A1 mRNA abundance were measured by RT-qPCR, relative to β-actin as reference gene. The total birth weight (TBW) and weaning weight of their lambs were recorded, calculating the total weight of lamb weaned (TWLW). TBW, TWLW and relative expression of SLC2A1 were analyzed with PROC GLM of SAS, whereas the Pearson correlation coefficient between TWLW and relative expression of SLC2A1 was calculated using PROC CORR of SAS. Although there was no statistical difference in TBW (P = 0.13) and TWLW (P = 0.38) between lambing groups, a numerical difference was observed both in TBW (5.7 ± 0.54 and 6.9 ± 0.42) and in TWLW (21.5 ± 3.94 and 26.2 ± 3.05) for primiparous and multiparous, respectively. The abundance of SLC2A1 mRNA were 3.1-fold change (P = 0.0005) greater in MSC of primiparous ewes than in the multiparous ones (Figure 1). In multiparous ewes a positive correlation, r = 0.96 (P = 0.01) was found between TWLW and relative expression of SLC2A1. It is concluded that greater relative expression of SLC2A1 in young prolific ewes could be a compensatory mechanism to produce more milk to feed their lambs, even with a smaller udder volume. Such findings give way for further research on the subject.

514 Roles of core regulatory noncoding RNAs in bovine Staphylococcus aureus subclinical mastitis

Abstract Staphylococcus aureus (S. aureus) is an opportunistic pathogen frequently associated with subclinical mastitis and accounts for a large proportion of the economic losses due to mastitis on Canadian dairy farms. Despite a plethora of investigations on the molecular mechanisms of mastitis, little information is available on the roles of regulatory noncoding RNAs (ncRNA). This study aimed to uncover the regulatory roles of microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) in the response to subclinical mastitis due to S. aureus of cows. Transcriptome sequencing (RNA-Seq and miRNA-Seq) was conducted on milk somatic cells from 13 cows with S. aureus subclinical mastitis [high somatic cell counts (SCC) of ≥350,000 cells/mL for ≥3 consecutive months and positive for S. aureus only], and 5 healthy cows (low SCC&amp;lt; 100,000 cells/mL for ≥3 consecutive months and negative for mastitis pathogens). RNASeq and smRNASeq nf-core bioinformatics pipelines were used to process the data. Results showed that 97 miRNAs (36 up-regulated and 61 down-regulated) and 1,565 lncRNAs (617 up-regulated and 948 down-regulated) were differentially expressed (DE; FDR&amp;lt; 0.05) between S. aureus subclinical mastitic cows and healthy controls. Competing endogenous networks comprising co-expressed differentially expressed mRNAs (DEGs), miRNAs (DEMs), and lncRNAs (DELs) were constructed. CytoHubba, a Cytoscape plugin, was utilized to identify the top hub regulatory ncRNAs including bta-miR-2387, bta-miR-331, bta-miR-95, bta-miR-744, bta-miR-455, bta-novel-miR-60, bta-miR-3533, bta-miR-500, bta-miR-1249 and bta-novel-miR-66). The results revealed that the main hubs (downregulated bta-miR-2387 and upregulated bta-miR-331) potentially regulate numerous DEGs during S. aureus subclinical mastitis such as NFKB1, IL10RA, IL17RA, TLR10, LOC112442665, LOC112448481 and LOC112442015, etc., and TUNAR, LOC112445429, LOC112444484 and LOC101907369, respectively. Functional analysis of bta-miR-331 target genes revealed roles in several KEGG pathways (e.g., tight junction, bacterial invasion of epithelial cells) and biological processes gene ontology (GO) terms (e.g., cell adhesion, cell locomotion and cell motility). Similarly, roles for bta-miR-2387 in KEGG pathways like JAK-STAT signaling pathway, NOD-like receptor signaling pathway and inflammatory bowel disease, and biological process GO terms such as inflammatory response, neutrophil migration, leucocyte migration and response to cytokine were revealed. MiR-331 has been found to promote cell proliferation, migration, and invasion of breast cancer. Furthermore, bta-miR-2387 has been shown to regulate several immune pathways which aid in improving the movement of spermatids across the epithelium and preleptotene spermatocytes across the blood-testis barrier during spermatogenesis. This supports our findings and suggests that bta-miR-2387 and bta-miR-331 could be pivotal regulators of immune-related genes and pathways during S. aureus subclinical mastitis. Thus, they hold potential as biomarkers for the development of therapeutic and diagnostic tools for managing subclinical mastitis.

LACTIC ACID BACTERIA AS INGREDIENTS OF PROBIOTIC PREPARATIONS

Lactic acid bacteria have a long and extensive application record as probiotic strains. Lately, due to wide-spread use of molecular-genetic, transcirptomic, proteomic, metabolomic etc. studies and the massive accumulation of data on the structure and functions of symbiotic intestinal microbiota, the interest in probiotic microorganisms tends to expand year-by-year. Lactic acid bacteria were the first used probiotic species, are still of sharp market demand and have been recognized as the most thoroughly studied microbes among functional relatives. However, characteristics inherent to probiotic bacteria are strain-specific, as a rule, and for preparations with defined purpose it is essential to select special strains showing a complex of appropriate properties. It accentuates the top relevance of research aimed at selection of lactic acid bacterial strains suitable for diverse probiotic preparations. For several decades we curried out investigations to isolate strains of lactic acid bacteria from various natural sources, to characterize their properties and to derive technologies of producing pro- and prebiotic preparations for farm stock, poultry, veterinary practice, food processing, cosmetic formulas, etc. Enrichment, in addition to bifidobacteria, of probiotic product Poultrybac with lactic acid bacteria showing high antagonistic activity toward pathogen Salmonella typhimurium and producing enzymes capable to hydrolyze feed oligo- and polysaccharides, promotes prevention of salmonellosis cases, normalizes gut microbiocenosis, contributes to assimilation of fodder, accelerates growth of broilers. Bacteria of genera Lacticaseibacillus, Limosilactobacillus, Lactococcus constitute bacterial preparation Bilametrit designed for prophylaxis and complex therapy of endometrites in cows, actively suppress growth of pathogenic microorganisms of the genera Staphylococcus, Streptococcus, Pseudomonas, Salmonella, Escherichia, including isolates from uterus exudate from animals with post-partum endometritis. Owing to the pronounced adhesive ability to protein ligands the selected lactic acid bacteria recover microbiocenosis in reproductive system, especially after antibiotic therapy, facilitate regeneration of endometrium, produce organic acids, antimicrobial peptides, amino acids, enzymes of carbohydrate and protein metabolism. Inclusion, in addition to bifidobacteria, of microorganisms of genus Lactiplantibacillus with a high antagonistic activity against pathogenic and opportunistic microorganisms responsible for inflammation of the mammary gland in animals as component of dry probiotic preparation Bactomast shifts the bias of the mammary gland biocenosis towards lactic acid bacteria, curtails general insemination level 2.4–4.8 times, provides a shield protecting from penetration of pathogenic agents, decreases the ratio of somatic cells in milk. The constituent bacterial strains raise non-specific macro host resistance, display tolerance to a series of antimicrobial compounds (antibiotics of aminoglycoside and cephalosporin groups), allowing to recommend it for comprehensive therapy of mastites in cows. Bactomast is not inferior to veterinary drug iodomastin in therapeutic efficacy (83.3%). A crucial characteristic of the above-mentioned preparations, as well as probiotics Lactimet, Bilavet (liquid form), Bilavet-C (dry product), complex probiotic Synvet, probiotic ingredient Lyobact in whole milk substitutes, dry bacterial concentrate IM-pro fortifying dairy products with probiotics is that they are safe and eco-friendly, i.e. they will not cause adverse effects on the body and reproductive functions of humans, animals, poultry, are not accompanied by health complications, do not deteriorate quality of milk and meat products. Farm products may be consumed without restraints following treatment with biopreparations.

Social interactions of dairy cows and their association with milk yield and somatic cell count

The social environment experienced by livestock can have implications for their health, welfare, and subsequently, their productivity. Changes in the dairy industry have led to larger herd sizes and altered management of cows, which has impacted their social environment. Studies have shown that mixing of animals can lead to social instability of groups and expansion of herds can lead to high stocking densities resulting in social stress and negative effects on production. Yet few studies have assessed the putative impact of positive cow-cow interactions, such as proximity to preferred herd mates and engaging in grooming, on milk production and udder health. To address this, we used cattle proximity as a proxy for affiliative interactions between cows in three dairy herds in south-west England over one week study periods. We created proximity networks of dairy cows and measured cow-cow associations according to milk yield, somatic cell count (SCC; an indicator of mastitis), parity (number of lactations in the cow’s lifetime), and lactation stage (grouped by days in milk for current lactation). We then assessed associations between social factors and production and health measures (milk yield and SCC). In all three herds, cows interacted more with cows in the same parity, suggesting early social bonding may be evident later in life and that grouping animals in terms of parity might encourage affiliative interactions. Cows did not associate according to milk yield, SCC, or lactation stage. There was no significant association between milk production or SCC and the total time spent in social contact with other cows, the mean time spent with the four closest herd mates, or the number of closest herd mates of the same parity. We suggest that further research on positive social environments for dairy cattle is warranted in the interests of improving welfare and enabling a more robust assessment of the putative effects on production and health parameters

The Effect of the Season on the Time Dependent Changes in Colostrum Lactoferrin Level in Murciano-Granadina Goats in Intensive System Farming.

The aim of this research was to evaluate the effects of postpartum day and parity season on the lactoferrin (LF), immunoglobulin G (IgG), and chemical composition of Murciano-Granadina goat colostrum during the first 96 h after kidding, and the use of the Brix refractometer to estimate IgG content. A herd of 3500 intensively managed Murciano-Granadina dairy goats (45-50 kg body weight) was used. Colostrum samples were collected from days 1 to 4 postpartum in the winter, spring, summer, and autumn. The colostrum composition was assessed using an automated infrared method; the LF and IgG concentrations were measured using an ELISA, and for the Brix percentage, we used a digital refractometer. Colostrum taken on the first postpartum day showed the highest concentrations of LF, IgG, proteins and non-fat solids (NFSs). As the postpartum days progressed, a rapid decrease in the LF, IgG, protein, and NFS contents and the Brix value was observed. In contrast, the lactose content increased steadily until the fourth postpartum day (p < 0.001). The season influenced milk yield, LF, IgG, protein, fat, and somatic cell content (p < 0.05). LF contents were significantly higher in the spring season, IgG contents were higher in autumn colostrum, and fat components were higher in the winter season. The colostrum Brix value showed a positive correlation with the ELISA colostrum LF (r = 0.716, p < 0.001) and IgG (r = 0.894, p < 0.001) determination; a 20 mg IgG/mL colostrum concentration corresponded to 18 °Brix. Our results corroborate the importance of feeding colostrum to newborns on the first day after birth, not only because of its high level of IgG but also because of its greater presence of the other bioactive protein compounds such as lactoferrin.

An Automated Sprinkler Cooling System Effectively Alleviates Heat Stress in Dairy Cows.

(1) Background: Heat stress detrimentally restricted economic growth in dairy production. In particular, the cooling mechanism of the spraying system effectively reduced both environmental and shell temperatures. This study was designed to investigate the underlying modulatory mechanism of an automatic cooling system in alleviating heat-stressed dairy cows. (2) Methods: A total of 1208 multiparous dairy cows was randomly allocated into six barns, three of which were equipped with automatic sprinklers (SPs), while the other three were considered the controls (CONs). Each barn was considered a replicate. (3) Results: Body temperatures and milk somatic cell counts significantly decreased, while DMI, milk yield, and milk fat content significantly increased under SP treatment. Rumen fermentability was enhanced, embodied by the increased levels of total VFA, acetate, propionate, and butyrate after SP treatment. The rumen microbiota results showed the relative abundances of fiber-degrading bacteria, including the Fibrobacters, Saccharofermentans, Lachnospira, Pseudobutyrivibrio, Selenomonas, and Succinivibrio, which significantly increased after receiving the SP treatment. (4) Conclusions: This study demonstrated that SP effectively alleviated heat stress and improved production performances and milk quality through modulating the rumen microbiota composition and fermentation function of dairy cows.

Unraveling Dynamic Transcriptomic Changes in Sheep's Lactating Mammary Gland Following Escherichia coli Lipopolysaccharide Exposure

Mammary gland infections constitute a significant challenge in dairy sheep, impacting productivity and welfare. Temporal RNA-Seq provide a valuable approach to evaluate the evolution of the host defensive molecular mechanisms triggered by mastitis caused by external agents or events. This study aimed to characterize the transcriptomic response of sheep mammary glands to an intramammary inflammation induced with an Escherichia coli lipopolysaccharide (LPS) inoculation based on RNA-Seq samples generated from milk somatic cells collected at 3 time points: pre-inoculation (0 h), and 6 h and 24 h post-LPS inoculation. The differential expression analyses between the analyzed time points were performed using 2 statistical approaches: one parametric (DESeq2) and one non-parametric (Wilcoxon rank sum test). The differentially expressed genes (DEGs) commonly identified by both approaches encompass 5,872 for the 0 h versus 6 h comparison, 4,063 for the 0 h versus 24 h comparison, and 1,034 for the 6 h versus 24 h comparison. At both 6 h and 24 h, transcriptomic data highlighted a significant decrease in the expression of genes linked to metabolic processes crucial for milk protein and lipid synthesis within the mammary gland. Concurrently, increased expression of genes related to the neutrophil attraction was observed for 6 and 24 h, with differences in gene expression between DEGs with the highest expression at 6 h, related to T cell activation, type I interferon-mediated signaling pathway, and 24 h, related to cell-cell neutrophil adhesion extravasation or epithelial cell proliferation. In summary, this study reveals how the sheep mammary gland transcriptome responds dynamically to an LPS inoculation, providing a comprehensive understanding of how gene expression patterns evolve over time and shedding light on the molecular mechanisms driving the initial defensive response of the mammary gland against potential inflammatory challenges.

Differences in Lactation Performance, Rumen Microbiome, and Metabolome between Montbéliarde × Holstein and Holstein Cows under Heat Stress.

Heat stress negatively affects lactation performance and rumen microbiota of dairy cows, with different breeds showing varying levels of heat tolerance. This study aimed to compare the lactation performance of Montbéliarde × Holstein (MH, n = 13) and Holstein (H, n = 13) cows under heat stress, and 16S rRNA sequencing and liquid chromatography-mass spectrometry (LC-MS) were used to determine the rumen microbiome and metabolome in experimental cows. The results indicated that during heat stress, milk yield (p = 0.101), milk fat yield, milk protein yield, milk protein, and milk lactose (p < 0.05) in Montbéliarde × Holstein cows were higher than those in Holstein cows, whereas milk yield variation and somatic cell counts (p < 0.05) were lower than those in Holstein cows. The sequencing results indicated that the rumen of Montbéliarde × Holstein cows was significantly enriched with beneficial bacteria, such as Rikenellaceae, Allobaculum, and YRC22 (p < 0.05). In addition, correlations were observed between specific ruminal bacteria and lactation performance. Ruminal metabolites related to antioxidant and anti-inflammatory properties were significantly higher (p < 0.05) in Montbéliarde × Holstein cows than in Holstein cows. Overall, Montbéliarde × Holstein cows showed higher production efficiency under heat stress, which may be related to the different rumen mechanisms of crossbred and Holstein cows in adapting to heat stress.

Продуктивные особенности коров голштинской породы разных генетических линий

Abstract. The purpose of the study is to investigate the productive features of Holstein cows of different genetic lines. Methods. The research was carried out in two breeding enterprises of the Sverdlovsk region on the livestock of Holstein cows. Groups of animals were formed by the method of pairs of analogues, taking into account the age of animals in lactation, physiological condition, live weight, lines of breeding bulls. The coefficient of milk content was estimated by the calculation method. The lactose, fat and protein content in milk was determined using a “Bentley 150” device. Somatic cells were determined on the “Somatos-M” device. Bacterial contamination was studied using a reductase assay. Prolactin was determined by enzyme immunoassay, cortisol by immunochemiluminescent method. Results. In terms of milk yield for 305 days of lactation and protein content in milk, Montwick Chieftain cows had an advantage with a significant difference between the groups (P &lt; 0.05). The animals of the Reflection Sovering line were the best in terms of fat content, the difference between the groups was insignificant. The lowest content of somatic cells in milk and bacterial contamination was found in animals of the Reflection Sovering and Vis Back Idial lines. The best indicators of the leukocyte profile were determined in animals of the Vis Back Idial and Montwick Chieftain lines. In terms of glucose and total protein content in the blood, cows of the Montwick Chieftain line had an advantage, in terms of the amount of urea, animals of the Montwick Chieftain and Vis Back Idial line affiliation. The highest level of total lipids in the blood is typical for cows of the Reflection Sovering line. Scientific novelty. The research results indicate the relationship of biological characteristics and milk productivity with different lines of breeding bulls. The leukocyte profile of this herd of cows of different genetic lines in breeding enterprises of the Sverdlovsk region was studied for the first time. Practical significance. The results of the research can be used in breeding enterprises in order to increase the milk productivity of cows.

Rumen-protected methionine supplementation during the transition period under artificially induced heat stress: Effects on cow-calf performance

This study aimed to evaluate the effects of rumen-protected Met on lactation performance, inflammation and immune response, and liver glutathione of lactating dairy cows during a subclinical mastitis challenge (SMC). Thirty-two Holstein cows (145 ± 51 DIM) were enrolled in a randomized complete block design. At -21 d relative to the SMC, cows were assigned to dietary treatments, and data were collected before and during the SMC. Cows were blocked according to parity, DIM, and milk yield and received a basal diet (17.4% CP; Lys 7.01% MP and Met 2.14% MP) plus 100 g/d of ground corn (CON; n = 16) or a basal diet plus 100 g/d of ground corn and rumen-protected Met (SM, Smartamine M at 0.09% of dietary DM; n = 16), fed as a top-dress. At 0 d, the mammary gland's rear right quarter was infused with 100,000 cfu of Streptococcus uberis (O140J). Milk yield was recorded twice daily from 0 until 3 d relative to SMC. Milk samples were collected during each milking from 0 to 3 d relative to SMC, blood samples were collected at 0, 6, 12, 24, 48, and 72 h relative to SMC. The mTOR pathway activation was assessed in immune cells in blood and milk samples by measuring quantity and phosphorylation status of mTOR-related proteins, including AKT, S6RP, and 4EBP1. For the ratio of phosphorylated to total AKT, S6RP, and 4EBP1, blood samples were collected at 0, 12, and 24 h, and milk samples at 24 h relative to SMC. Liver biopsies were performed at -10 d and 24 h relative to SMC for measurement of glutathione. Linear mixed models with repeated measures were used to analyze the results. There was a trend for greater milk yield per milking (+ 0.8 kg) and per day (+1.7 kg) after SMC in SM cows compared with CON. The DMI was not affected by dietary treatments. Reactive oxygen metabolites (ROM) were lower in SM cows than in CON. Milk somatic cell linear score was not affected by dietary treatments, and a score >4 at 24 h confirmed subclinical mastitis. The SM cows had greater milk fat percentage at 24 and 36 h post SMC, resulting in overall greater milk fat. Milk protein tended to be greater in SM cows than in CON. We observed greater liver glutathione in SM cows than in CON. Among inflammation biomarkers, ceruloplasmin was lower for SM cows compared with CON. In milk, greater pAKT:AKT and pS6RP:S6RP ratios were observed in immune cell populations from SM cows compared with CON. Blood neutrophils had a greater p4EBP1:4EBP1 ratio in SM cows compared with CON. Overall, our results show that Met supplementation during an SMC positively affected milk performance, lowered the risk of oxidative stress, and attenuated inflammation partially by increasing liver glutathione and immune cells' protein synthesis via mTOR signaling.

Dielectric relaxation parameters combing raw milk compositions to improve the prediction performance of milk somatic cell count.

Milk somatic cell count (SCC) is an international standard for identifying mastitis in dairy cows and measuring raw milk quality. Milk SCC can be predicted based on dielectric relaxation parameters (DRPs). We noted a high correlation between DRPs and the milk composition content (MCC), and so we hypothesized that combining DRPs with MCC could improve the prediction accuracy of milk SCC. The present study aimed to analyze the relationship between milk SCC, DRPs and MCC, as well as to investigate the potential of combining DRPs with MCC to improve the prediction accuracy of milk SCC. The dielectric spectra (20-4500 MHz) of 276 milk samples were measured, and their DRPs (εl, εh, Δε, τ and σ) were solved by the modified Debye equation. The SCC prediction models were developed using dielectric full spectra, DRPs and DRPs combined with MCC. The results showed the correlations between DRPs (εl, εh, Δε and σ) and MCC (fat, protein, lactose and total solids) were high, and SCC exhibited a non-linear relationship with DRPs and MCC. The 5DRPs + MCC-generalized regression neural network model had the best prediction, with a standard error of prediction for prediction of 0.143 log SCC mL-1 and residual of the prediction bias of 2.870, which was superior to the models based on full spectra, DRPs and near-infrared or visible/near-infrared. The present study has improved the prediction accuracy of milk SCC based on the DRPs combing MCC and provides a new method for dairy farming and milk quality assessment. © 2024 Society of Chemical Industry.