Journal of Dairy Science最新文献

{"title":"Mineral profile of cow's milk and plant-based milk alternatives (PBMA).","authors":"Irene Cristina Antunes, Ricardo Bexiga, Carlos Pinto, Luísa Louro Martins, Miguel Mourato, Gonçalo Pereira, Elsa Vieira, Cristina Delerue-Matos, Mário Quaresma","doi":"10.3168/jds.2024-25752","DOIUrl":"https://doi.org/10.3168/jds.2024-25752","url":null,"abstract":"<p><p>Some consumers are replacing cow's milk by plant-based milk alternatives (PBMA), however the current knowledge regarding the mineral profile of PBMA is limited. This study aimed to characterize the mineral profile of commercial milk (n = 80) and PBMA types (n = 60; soya, rice, oat, almond, coconut, and hazelnut) by Inductively Coupled Plasma - Optical Emission Spectroscopy, along with a modification of the Sandell-Kolthoff reaction (iodine determination). A single fixed effect statistical model considering the type of beverage as an independent variable was applied. Soya PBMA presented higher contents of Ca, Mg, Cu, and Mg than commercial milk, and similar contents of K and P. On the other hand, commercial milk had higher contents of S, Zn, and Se, with the latter being below the limit of quantification (10 µg/kg) in all PBMA types. Both almond and hazelnut PBMA displayed I contents like those of commercial milk. In terms of mineral ratios, PBMA types presented a higher Ca/P compared with commercial milk, being aligned with dietary guidelines, while commercial milk and soya PBMA showing lower Na/K values, which are beneficial for cardiovascular health. Due to their variability, it is difficult to say with certainty that PBMA can reliably substitute milk as a source of minerals.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143073316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Influence of the Ionic Environment on Rheological Properties of Acidified Micellar Casein Gels.","authors":"D J Wilbanks, S R Yazdi, J A Lucey","doi":"10.3168/jds.2024-25905","DOIUrl":"https://doi.org/10.3168/jds.2024-25905","url":null,"abstract":"<p><p>Membrane filtration allows for the physical separation of milk components and can be used as a single process or in multiple steps to recombine different component streams to create cultured milk products with unique functional properties. In this study, micellar casein (MC) powder, was dispersed at 4 and 8% (wt/wt) protein in water, NaCl (10 - 100 mmol kg^-1) or ultrafiltered milk permeate (5.6%, wt/wt). MC is a dairy powder obtained by microfiltration that is mostly depleted of whey proteins and soluble salts. This study was conducted in several parts to investigate the impact of dispersant (solvent) on the pH of gelation and rheological properties of acid gels made from MC. In the initial phase, we prepared model acid gels by acidifying MC at cold temperatures (<4°C) and subsequent warming to 42°C to induce gelation. We also prepared MC gels by yogurt fermentation using commercial starter cultures incubated at 42°C. All MC samples were prepared in duplicate. Gel formation in MC samples occurred as high as pH 5.7 in the cold-acidified milk system. The pH of gelation was highly dependent on the protein level, dispersant used, and concentration of added salts. With increasing concentrations of added NaCl, a decrease in the pH of gelation was observed (from pH 5.7 to below 4.6) as well as a decrease in gel strength (from 175 to <1 Pa). Acid gelation was very dependent on the type of dispersant used to rehydrate the MC. At similar conductivities, MC dispersions with higher protein (8%) levels formed gels at higher pH values compared with lower protein (4%) dispersions. In microbially fermented yogurts, a maximum loss tangent value was observed during acidification in MC gels prepared with low-to-moderate ionic strength. This was unexpected as the concentration of denatured whey proteins should be very low in these MC systems. No maximum loss tangent value was observed for MC samples dispersed in 100 mmol kg^-1 NaCl, as they did not form a gel until pH 4.5. Gel samples with large maximum loss tangent values also exhibited a more open, porous gel microstructure, which was indicative of weak gels that can be prone to syneresis. Results from this study could help dairy manufacturers to design specialty milk powders that have unique functionality when used for acid milk gels, like yogurt.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143073129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Milk-derived antimicrobial peptide GMp7: Disrupting protein networks for multi-target antibacterial inhibition and enhanced dairy preservation.","authors":"Jinze He, Hong Li, Yujuan Xu, Yufang Li, Tingting Yang, Xiaoyan Yu, Xue Yang, Aixiang Huang, Yuanshan Yu, Yanan Shi","doi":"10.3168/jds.2024-26090","DOIUrl":"https://doi.org/10.3168/jds.2024-26090","url":null,"abstract":"<p><p>Identification and characterization of a novel milk-derived antimicrobial peptide, GMp7 (KVLPVPQ), with potent antibacterial activity against Staphylococcus aureus and a demonstrated safety profile. Therefore, this study revealed the multi-target antibacterial mechanism of GMp7 on S. aureus DC.RB-015 by Fourier transform infrared spectroscopy, flow cytometry, scanning electron microscopy (SEM) and label-free proteomics analysis. The results showed that GMp7 has a secondary structure consisting of 17.45% α-helix, 20.10% β-corner and 37.13% β-fold, which is conducive to membrane disruption and bacterial cell death. GMp7 treatment induced a significant change in the proteome, resulting in the downregulation of 99 proteins and the upregulation of 26 proteins, indicating a multi-target effect on bacterial physiology. Notably, GMp7 forms stable bonds with the critical proteins asd and pcrA within the S. aureus protein network, which includes a larger network of 17 proteins essential for bacterial viability. The binding energies for GMp7 with asd and pcrA were determined to be -8.477 and -8.407 kcal/mol, respectively. GMp7 exerts its bacteriostatic effects through multiple pathways, including interference with peptidoglycan biosynthesis, ABC transport, the 2-component system, DNA replication and mismatch repair. The efficacy of the peptide against S. aureus in pasteurised milk suggests its potential use in the dairy industry to improve product shelf life and safety. In addition, GMp7 significantly inhibited the growth of S. aureus in milk. These findings have practical significance for the use of antimicrobial peptides to control bacterial contamination in food and improve food safety.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143073313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adjuvant-driven antibody response to use cows as biofactories of anti-SARS-CoV-2 neutralizing antibodies in colostrum.","authors":"E B Gaspar, D J B Orts, H H M Costa, P E A Souza, N T B S Honório, C R Prudêncio, L P Silva, C C Bonatto, A P A Bastos, P P Adriani, G S de Oliveira, R Domingues, E De Gaspari, A I Portilho, M F Martins, M A Machado, H M Brandão, J Diavão, M M Campos, W A Carvalho","doi":"10.3168/jds.2024-25930","DOIUrl":"https://doi.org/10.3168/jds.2024-25930","url":null,"abstract":"<p><p>Cows produce a substantial amount of immunoglobulin in the colostrum, and nutraceutical products derived from these antibodies are gaining attention for their potential role in human viral disease prevention. The objective of our study was to develop an immunization schedule for pregnant cows to produce hyperimmune colostrum with antibodies presenting high avidity and neutralizing activity against SARS-CoV-2. The recombinant spike receptor-binding domain (RBD) from SARS-CoV-2, expressed using the Expi293F system and purified via Ni-affinity chromatography, was solubilized in (1) saponin (QuilA) or (2) a suspension of potassium and aluminum hydroxide (Alum). Vaccination of pregnant cows and serum sample collection were performed 45, 30, and 15 d before the expected calving date. Serum and colostrum were also collected on the day of parturition. Anti-RBD IgG, IgG1, and IgG2 production, viral neutralization, and antibody avidity were evaluated by ELISA. Cows immunized with recombinant RBD with the QuilA adjuvant produced higher amounts of all antibody subclasses than cows in the Alum group. The viral neutralization index from serum samples was also higher in the QuilA group. Significant differences were not observed in the avidity of antibodies, except for that of IgG2, which was higher in the serum of cows receiving the Alum formulation. As the IgG1 antibody subclass and its avidity are crucial for SARS-CoV-2 neutralization, QuilA might be the optimal adjuvant for producing hyperimmune colostrum in cows. These findings support the use of cows as biofactories of neutralizing antibodies against SARS-CoV-2 or any future emerging and re-emerging viral diseases, with the possibility of simply substituting the subunit antigen in the vaccine formulation. Further tests must be done to evaluate the efficacy of using hyperimmune colostrum as a nutraceutical or purified bovine antibodies as a pharmacological approach for COVID-19 prevention.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143073050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of a functional milk powder supplemented with rhizoma drynariae extracts on bone health in growing and ovariectomized rats: More effective for lumbar vertebrae?","authors":"Wenjing Wu, Mengqi Yu, Yan Liu, Xiaoya Wang, Liang Wang, Qijie Wei, Haotian Feng, Jinyao Chen","doi":"10.3168/jds.2024-25896","DOIUrl":"https://doi.org/10.3168/jds.2024-25896","url":null,"abstract":"<p><p>Bone health is vital through all life stages and has become a growing public health concern. The role of rhizoma drynariae (RD) as a traditional Chinese medicine for bone injury recovery has been widely investigated. Still, there is little research related to RD as a functional component in food to improve calcium bioavailability and bone health. Milk powder is a daily vital food source of dietary calcium. The present study aimed to investigate and compare the effects of a functional milk powder reinforced with RD extracts (RDE) or vitamin D, vitamin K2, and calcium, or both, using Sprague-Dawley rats, with both low calcium growing rat model and low calcium ovariectomized (OVX) rat model. For growing rats, RDE increased bone mineral density (BMD) and improved the microstructure of bone trabecula in the femur and lumbar vertebrae. The levels of serum bone turnover markers CTX-I, PINP, and BGP were increased with RDE supplementation. The tartrate-resistant acid phosphatase staining suggested a decrease in the number of osteoclasts in the femur. Immunohistochemistry showed that the osteoclast-related protein RANKL was downregulated, and the osteogenic-associated proteins RUNX2 and OSX significantly increased in the lumbar vertebrae. Similarly, in OVX rats, RDE improved BMD and microstructure in lumbar vertebrae, and the levels of CTX-I, PINP, and BGP were also increased. In conclusion, the novel functional milk powder supplemented with RDE facilitated osteogenesis and inhibited osteoclast in rats at both stages, especially with lumbar vertebrae in growing rats. Our findings provide new prospects and a more precise target for enhancing bone health by incorporating RDE as a functional component in milk powder.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143073254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the Link Between Cheese Consumption and Heart Failure Risk: A Mendelian Randomization Approach with Biomarker Analysis.","authors":"Yanjiang Yang, Xiaorui Wang, Wenwen Yang","doi":"10.3168/jds.2024-25892","DOIUrl":"https://doi.org/10.3168/jds.2024-25892","url":null,"abstract":"<p><p>The study investigates the association between cheese consumption and heart failure risk, employing Mendelian randomization (MR) analysis. Heart failure, influenced by various factors including diet, remains a major global health concern. Cheese, a nutrient-rich dairy product, has shown potential in reducing heart failure risk, though the mechanisms are not fully understood. This study clarifies the association by examining 45 biomarkers that could mediate this effect. This analysis revealed a significant reduction in heart failure risk with cheese consumption (OR = 0.771, P = 0.00588). Of the 45 biomarkers analyzed, 24 showed a significant relationship with cheese intake. Six biomarkers-neutrophil count (mediating effect ratio: 3.37%), apolipoprotein B (2.73%), glucose (4.16%), triglycerides (5.82%), diastolic blood pressure (14.78%), and serum uric acid (8.45%)-were identified as mediators in the cheese consumption-heart failure relationship. This study underscores the role of biomarkers in understanding heart failure mechanisms and highlights the potential of dietary interventions, like cheese consumption, to reduce heart failure risk. While these findings are promising, their generalizability may be limited, and further research across diverse populations is needed.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143073267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pre-weaning heat stress alters liver transcriptome and DNA methylation in dairy calves.","authors":"Jimena Laporta, Bethany Dado-Senn, Anne R Guadagnin, Lihe Liu, Francisco Peñagaricano","doi":"10.3168/jds.2024-25975","DOIUrl":"https://doi.org/10.3168/jds.2024-25975","url":null,"abstract":"<p><p>Prenatal hyperthermia has long-lasting impacts on dairy calf metabolism, immunity, and productivity. Yet, the effects of postnatal heat stress on neonatal calves remain unclear. As such, this study aimed to investigate the impact of heat stress on the pre-weaned dairy calf liver gene expression and DNA methylation profiles. Holstein dairy calves were exposed to summer heat stress (daily average THI >78) for 42 d postnatally (i.e., birth to weaning) with access to active fan heat abatement (postnatal cooling, post-CL; calf-height air speed 2.05 m/s, n = 12) or not (postnatal heat stress, post-HS; calf-height air speed 0.15 m/s, n = 12). All thermoregulatory responses were lower in post-CL relative to post-HS calves throughout the experimental period (-12 bpm, -2.5°C, and -0.11°C for respiratory frequency, rectal temperature, and ear skin temperature, respectively). Liver tissue was harvested via biopsy (n = 6 male calves per treatment) at 42 d of age for RNA sequencing and reduced representation bisulfite sequencing. There were 73 differentially expressed genes (DEG), of which 31 were downregulated and 42 were upregulated in post-HS relative to post-CL treatments (FDR cut-off 20%). Ingenuity Pathway Analysis revealed that postnatal heat stress significantly impacted 24 pathways and 60 transcription regulators, including pathway PI3K/AKT, and transcription regulators PPARGC1A, STAT5B, CREB, and X-box binding protein. A total of 14,639 differentially methylated cytosines (DMC) were found across the entire bovine genome; these DMCs mapped to 3,197 differentially methylated genes (DMG), with about 300 DMGs with DMCs located close to the transcription start site. These DMGs are closely related to metabolic pathways, such as PKA, AMPK, MAPK, and STAT3 signaling. Overall, pre-weaning exposure of dairy calves to heat stress changes hepatic methylation profiles, which in turn may impact the expression of genes with critical roles in intracellular signaling and development, metabolic, and immune-related pathways. Providing mechanical cooling via fans to dairy calves in summer seems beneficial to promoting thermoregulation and liver cellular hemostasis.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143073366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Short-term effects of Subacute ruminal acidosis on ferroptosis and iron metabolism in the livers of lactating sheep fed a high-grain diet.","authors":"Hongzhu Zhang, Huimin Shi, Shendong Zhou, Meijuan Meng, Nana Ma, Guangjun Chang, Xiangzhen Shen","doi":"10.3168/jds.2024-25557","DOIUrl":"https://doi.org/10.3168/jds.2024-25557","url":null,"abstract":"<p><p>Subacute ruminal acidosis can cause liver injury in ruminants. Ferroptosis, an iron-dependent cell death, is involved in many liver diseases. This study aimed to investigate ferroptosis in SARA-induced liver injury and explore the changes in hepatic iron metabolism. Twelve ruminally cannulated, lactating Hu sheep (parities: 2 or 3; BW: 50.6 ± 4.0 kg; 18.8 ± 3.6 d in milk; MY: 0.52 ± 0.08 kg/d; mean ± SD) were divided into 2 groups (n = 6/group) and fed a low-grain diet (LG group, grain: forage = 3: 7, 24.89% starch and 40.66% NDF) or a high-grain diet (HG group, grain: forage = 7: 3, 38.64% starch and 24.41% NDF) for 8 wk. Weekly, rumen pH was measured 10 min before feeding and 1, 2, 3, 4, 5, 6, and 8 h post-feeding. On d 57, all sheep were slaughtered after collecting the hepatic vein blood, and liver tissue was collected. The high-grain diet significantly decreased rumen pH compared with the low-grain diet; the rumen pH on d 56 in the HG group was <5.6 at 1, 2, 3, and 4 h after feeding. Plasma concentrations of LPS, MDA, IL-1β, and IL-6 at 4 h post-feeding increased, while glutathione (GSH) and glutathione peroxidase 4 (GPX4) decreased. Moreover, lipid reactive oxygen species (lipid ROS), ferrous ion, and MDA were elevated, whereas GSH was decreased in the liver of the HG group. For ferroptosis-related proteins, feeding a high-grain diet led to increased acyl-CoA synthetase long-chain family member 4 (ACSL4) and arachidonate 15-lipoxygenase (ALOX15) and decreased GPX4 and solute carrier family 7 member 11 (SLC7A11). For ferritinophagy-related proteins, high-grain diet feeding decreased ferritin heavy chain 1 (FTH1) and increased nuclear receptor coactivator 4 (NCOA4) and microtubule-associated protein 1 light chain 3 II (MAP1LC3-II). Regarding iron metabolism, increased protein expression of nuclear mothers against decapentaplegic homolog1/5/8 (SMAD1/5/8) and hepcidin, decreased protein expression of ferroportin (FPN), and iron deposits were observed in the liver of the HG group. Furthermore, feeding high-grain diets also increased inflammatory signaling-related proteins IL-6 and phospho-signal transducer and activator of transcription 3 (p-STAT3). Taken together, this study suggests that SARA induced liver injury and ferroptosis. Enhanced ferritinophagy, disordered iron metabolism, and elevated inflammatory response may mediate ferroptosis in the livers of sheep fed a high-grain diet.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143073015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Associations of serum fatty acids, serum urea nitrogen, and ruminal ammonia nitrogen with residual feed intake in lactating dairy cows.","authors":"W M Coelho, H F Monteiro, C C Figueiredo, B Mion, J E P Santos, R S Bisinotto, F Peñagaricano, P Vahmani, E S Ribeiro, F S Lima","doi":"10.3168/jds.2024-25454","DOIUrl":"https://doi.org/10.3168/jds.2024-25454","url":null,"abstract":"<p><p>Feed efficiency is critical in dairy farming, impacting production costs and environmental sustainability. The development of the trait residual feed intake (RFI) has provided an opportunity to select dairy cows that are more efficient in converting nutrients into milk. Note that RFI requires individual daily intake records, which are typically collected on a limited number of research farms. In this context, the identification of biomarkers that can be used to identify and select more feed-efficient cows is of great interest. As such, this study aimed to identify ruminal and serum biomarkers associated with RFI in mid-lactation Holstein cows. A selected subset of 24 out of 454 Holstein cows was used in this study. This subset was strategically selected to represent extremes of least feed-efficient (LFE, n = 12, RFI = 2.44) and most feed-efficient (MFE, n = 12, RFI = -2.69) cows with no difference in the 3 energy sinks, namely body weight (BW) change, metabolic BW, and energy secreted in milk. Rumen fluid and serum samples were collected between 60 and 90 d in milk (DIM). Rumen fluid samples were collected using an oresophageal tubing procedure. Serum samples were used to measure fatty acids using a 2-step assay. The fatty acid methyl ester was assessed using solid phase extraction and quantified using chromatographic peak area and internal standard-based calculations. Ruminal ammonia nitrogen was measured using a phenol-hypochlorite assay, while serum urea was measured using a commercial ELISA assay. Cows in the MFE group had higher ruminal ammonia nitrogen concentrations than cows in the LFE group. There were no differences in serum urea concentration between MFE and LFE cows. Serum fatty acids concentration differed between groups, with myristic acid (C14:0), palmitic acid (C16:0), cis-heptadecenoic acid (cis9-17:1), stearic acid (C18:0), and total saturated fatty acids (SFA) having greater concentrations in the MFE group than in the LFE group. Total polyunsaturated fatty acids (PUFA) concentration was lower in the MFE group than in the LFE group. A model incorporating C14:0, C16:0, palmitoleic acid (trans9-C16:1), ante iso heptadecanoic acid plus palmitoleic acid (C17:0+trans13-C16:1), oleic acid (cis9-C18:1), cis-vaccenic acid (cis11-C18:1), petroselinic acid (cis12-C18:1), C18:0, linoleic acid (C18:2n-6), dihomo-γ-linolenic acid (C20:3n-6), cis-monounsaturated fatty acids, omega 6 PUFA, total PUFA, total SFA, other and unknown fatty acids was used to assess goodness-of-fit for RFI and showed an adjusted R² of 0.74. When ruminal ammonia nitrogen was added to the previous model, adjusted R² improved to 0.84. Our findings provide evidence that ruminal ammonia nitrogen and serum fatty acids are associated with RFI, thus suggesting that these metabolites might be helpful in identifying more feed-efficient dairy cows.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143073124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biofilm Forming Ability of Staphylococcus aureus on Materials Commonly Found in Milking Equipment Surfaces.","authors":"C Medina, D Manriquez, B A Gonzalez-Córdova, P A Pacha, J M Vidal, R Oliva, A A Latorre","doi":"10.3168/jds.2024-25416","DOIUrl":"https://doi.org/10.3168/jds.2024-25416","url":null,"abstract":"<p><p>The presence of biofilms on milking equipment on dairy farms can be a source of bulk tank milk contamination, as well as a potential source of intramammary infections for cows. The biofilm forming ability of bacteria, including Staphylococcus aureus, may differ depending on factors such as the intrinsic ability of bacteria to form biofilms, as well as the roughness and type of material of the surfaces. We investigated the ability of S. aureus to form biofilms on coupons made of Stainless Steel, Nitrile (Buna-N) Rubber, Ethylene Propylene Diene Monomer (EPDM) Rubber, Silicone Rubber, Borosilicate Glass, Polycarbonate and Polyvinyl Chloride, which are materials commonly used to manufacture pieces of milking equipment. Three S. aureus strains isolated from biofilms naturally formed in milking equipment on dairy farms, and previously characterized as \"high,\" \"medium,\" or \"low\" adherence ability by microtiter plate assay, were analyzed to assess their ability to form in vitro biofilms using a CDC Biofilm Reactor. Bacterial counts of suspended biofilms and Scanning Electron Microscopy were performed on coupons of each material. The highest bacterial counts were observed in Buna-N surfaces for high adherence (L1-1171, mean = 4.54 Log10 cfu/mL), medium adherence (L1-030, mean = 4.18 Log10 cfu/mL), and low adherence (L1-256, mean = 3.71 Log10 cfu/mL) S. aureus. The biofilm forming ability for a same S. aureus strain, regardless their adherence abilities, was not significantly different among all tested surface materials, except of Buna-N Rubber, for which all 3 strains had an increased ability to form biofilms. In a same material, no statistically significant differences were observed among strains, except for Buna-N and EPDM Rubber in which the highly adherent S. aureus strain (L1-1171) had a greater biofilm formation as compared with other strains. Regular replacement of rubber parts of milking equipment is warranted to reduce the risk of biofilm formation.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143073127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}