Journal of Dairy Science最新文献

{"title":"Interaction of fatty acid composition and temperature cycling on melting properties of milk fat.","authors":"Carly Nelson, David M Barbano, MaryAnne Drake","doi":"10.3168/jds.2025-26576","DOIUrl":"https://doi.org/10.3168/jds.2025-26576","url":null,"abstract":"<p><p>Milk was collected and milk fat extracted from 40 individual cows that were specifically selected over time in lactation in order to produce a graduation of natural samples exhibiting a wider range of milk fatty acid composition (i.e., ratio of de novo to preformed fatty acids) than would normally be produced by changes in feeding under commercial dairy herd management conditions. The melting properties of the milk fats were determined using differential scanning calorimetry. Higher levels of de novo fatty acids (i.e., shorter chain) and higher levels of unsaturated fatty acids both caused softening of milk fat, but by different mechanisms. Unsaturation directly lowered the melting point by disrupting the 2L and 3L triglyceride crystallization process (polytypism) on first cooling, whereas differences in de novo fatty acid concentration likely caused a shift in the proportion of 2L and 3L crystal forms (polytypism) and affected polytrophic behavior. Milk fat with more de novo fatty acids was more responsive to softening by temperature cycling than milk fat with more unsaturation. The impact of de novo fatty acid concentration in milk fat and in the total milk supply should be considered in controlling the hardness of butter.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144293107","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":"Selection signatures in Gir and Holstein cattle.","authors":"Larissa G Braga, Flávio S Schenkel, Tatiane C S Chud, Julia L Rodrigues, Bacem Saada, Marco A Machado, João C C Panetto, Marcos V G B Silva, Danísio P Munari","doi":"10.3168/jds.2024-26147","DOIUrl":"https://doi.org/10.3168/jds.2024-26147","url":null,"abstract":"<p><p>Natural and artificial selection leave footprints on the genome, known as selection signatures, that can indicate regions related to adaptive and economically important traits. The recurrent use of a limited number of sires and increased selection pressure may affect genetic diversity, potentially impacting long-term breeding programs. Among dairy cattle, the Holstein breed has been intensively selected to maximize productivity, particularly in Canada and the United States. In the dairy industry, the Gir breed plays an important role in milk production in tropical regions such as India and Latin America. Gir cattle were introduced into Brazil in the 19th and 20th centuries, and since 1985, this breed has been intensively selected for milk production. This study aimed to assess the genetic diversity and characterize the selection signatures in Holstein cattle from the United States and Canada (HOL), Gir cattle from India (GIR_IN), and Dairy Gir cattle from Brazil (GIR_BR). Genetic diversity was assessed by nucleotide diversity, single nucleotide variant density analysis, minor allele frequency, observed and expected heterozygosity, and the inbreeding coefficient. Selection signatures were identified via Tajima's D, the integrated haplotype score (iHS), the fixation index, and the cross-population extended haplotype homozygosity test for autosomes. Additionally, the analysis of selection signatures using Tajima's D and iHS was conducted for the X chromosome. Lower genetic diversity was observed in the HOL population, whereas the GIR_IN and GIR_BR populations presented greater diversity. Several genes previously related to economically important traits were identified as being under selection, including DNAJC18, FSHR, HELB, HMGA2, PLAG1, GAB3, and PTEN. In conclusion, the genes identified within the selection signatures were linked to several traits, including growth, reproduction, mastitis, milk production, heat tolerance, health, and adaptation.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144293110","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":"Waste ice cream is the yeast of our problems: The valorization of waste ice cream into alcohol.","authors":"Amanda L Miller, John A Renye, David B Johnston, Jennifer Thomas, Adam M Oest, Rafael Garcia, Peggy M Tomasula","doi":"10.3168/jds.2024-25766","DOIUrl":"https://doi.org/10.3168/jds.2024-25766","url":null,"abstract":"<p><p>Valorization of food waste or food by-products into higher-value products can benefit the food industry by contributing to the food supply chain. This study aimed to investigate the potential for using waste ice cream as a fermentation substrate for production of ethanol by yeast. Results showed that 2 Saccharomyces cerevisiae strains, Lalvin EC-1118 (Lallemand Inc.) and Ethanol Red (Lesaffre), were able to ferment an aqueous by-product of waste ice cream, resulting in the production of ethanol, ~7% (wt/vol). This most likely occurred due to the utilization of free monosaccharides or sucrose, because they were unable to ferment lactose. Lactase and glucoamylase were added, to increase the availability of fermentable carbohydrates, resulting in 9.77% and 9.30% (wt/vol) ethanol produced by Lalvin EC-118 and Ethanol Red strains, respectively. Both strains were also shown to not utilize the galactose released following the hydrolysis of lactose. Maximum ethanol production, above 13% (wt/vol), was seen in samples treated with a combination of lactase and a protease, suggesting that a lack of nitrogen was stalling the fermentation. A benchtop-scale distillation was performed using a fermented vanilla ice cream treated with protease, lactase, and diammonium phosphate. The distillation was successful, and several fractions with various aromas and odors were collected. Results from this study suggest that that ethanol production is a viable valorization strategy to produce distilled beverage alcohol from waste ice cream, which is expected to be free of protein allergens.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144293123","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":"Hepatocyte necroptosis is associated with liver damage in dairy cows with ketosis.","authors":"Menglin Liu, Jingmin Gu, Chenchen Zhao, Jinxia Li, Fanrong Kong, Xinyu Du, Dandan Qi, Enzhu Li, Jie Gao, Xiliang Du, Yuxiang Song, Guowen Liu, Wenwen Gao, Xinwei Li, Lin Lei","doi":"10.3168/jds.2025-26349","DOIUrl":"https://doi.org/10.3168/jds.2025-26349","url":null,"abstract":"<p><p>Dairy cows with ketosis frequently exhibit impaired liver function and inflammation. Necroptosis, a form of programmed cell death associated with cellular lysis, releases damage-associated molecular patterns (DAMP) into injured tissues, thereby amplifying inflammatory responses and tissue damage. However, the role of necroptosis in the liver of ketotic cows remains unknown. The present study aimed to investigate whether necroptosis is associated with hepatic damage in dairy cows with ketosis. Dairy cows were selected as either the clinically healthy control group (n = 15) or a ketotic group diagnosed with ketosis, and were matched for lactation numbers (median = 3, range = 2-4) and DIM (median = 6 d, range = 3-9 d). Liver tissue samples were collected via percutaneous needle biopsy, and blood samples were obtained by coccygeal venipuncture. Primary bovine hepatocytes were isolated from the liver of 1-d-old calves. In vivo experiments showed significant increases in the activity of alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl-transferase (GGT), and glutamate dehydrogenase (GLDH) in the blood of ketotic cows. Concurrently, the mRNA abundance of IL-6 (IL-6), tumor necrosis factor-α (TNFA), and IL-1β (IL-1B) in the liver of ketotic cows also significantly increased. Histopathological examination revealed significant cytoplasmic vacuolation, lytic necrosis, and inflammatory cell infiltration in the liver of ketotic cows, along with increased CD11b immunofluorescence intensity. Furthermore, the expression levels of necroptosis-related proteins, including the ratio of phosphorylated (p) receptor-interacting protein kinase 1 (p-RIPK1)/RIPK1, phosphorylated receptor-interacting protein kinase 3 (p-RIPK3)/RIPK3, and phosphorylated mixed lineage kinase domain-like pseudokinase (p-MLKL)/MLKL significantly increased in the liver of ketotic cows. The mRNA abundance of RIPK1, RIPK3, and MLKL also significantly increased. Immunohistochemical analysis confirmed elevated p-MLKL and p-RIPK3 expression in the liver of ketotic cows. In vitro experiments showed that compared with control group, bovine hepatocytes were treated with 10 ng/mL TNF-α significantly activated necroptosis signaling, as ascertained by an increase in ratios of p-RIPK1/RIPK1, p-RIPK3/RIPK3, and p-MLKL/MLKL, and the mRNA expression of RIPK1, RIPK3, and MLKL. Moreover, TNF-α treatment significantly upregulated the mRNA abundance of inflammatory cytokines IL-1B and IL-6, as well as the activity of ALT, AST, GGT, and GLDH in the culture medium of hepatocyte. Importantly, treatment with 100 µM Nec-1 or 3 µM GSK-872 notably attenuated TNF-α-induced necroptosis signaling, inflammatory cytokine expression, and the activity of ALT, AST, GGT, and GLDH. In conclusion, these data suggest that necroptosis is associated with hepatic damage, and may be a potential therapeutic target to ameliorate liver dysfunction in dairy cows with ketosis.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144293103","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":"Screening of potential probiotic Bifidobacteria from intestinal tract and its application in fermented milk.","authors":"Y Li, Q Fan, H Dong, S Chang, W Liu","doi":"10.3168/jds.2024-25960","DOIUrl":"https://doi.org/10.3168/jds.2024-25960","url":null,"abstract":"<p><p>Bifidobacteria, a significant component of human gut microbiota, play a crucial role in maintaining human health. Studies have shown that the composition of gut microbiome is closely related to the geographical environment, ethnicity, and dietary structure of the host. Currently, most of the mainstream probiotics on the market are based on the gut microbiota characteristics of Western populations, which may not be completely suitable for the gut environment of Chinese people. Therefore, the isolation and screening of Bifidobacteria with probiotic functions in the intestinal tract is critically important to meet the demands of the Chinese market. In the present study, 216 Bifidobacterial strains were isolated and identified from 35 fecal samples collected from the city of Hohhot, Inner Mongolia, China. Further investigations were conducted to determine the probiotic potential of these strains. Among the screened strains, Bifidobacterium longum ssp. longum IMAU12449 was identified as the most promising probiotic strain. The survival rate of strain IMAU12449 was highest in the simulated artificial gastrointestinal fluid. The survival rate of strain IMAU12449 in artificial gastric fluid for 3 h was 62.38%, and the survival rate was 40.30% in the artificial intestinal fluid for 8 h. Furthermore, the strain exhibited excellent cell autoaggregation (72.79%) and surface hydrophobicity (45.66%). Strain IMAU12449 also exhibited a strong inhibitory effect on common pathogens. Safety evaluation revealed that the strain possessed 2 potential antibiotic resistance genes and no virulence factors. This strain exhibited γ-hemolysis in vitro. The advantages of a stable viable count, moderate acidity, and absence of whey precipitation were observed in fermented cow and soy milk processed by strain IMAU12449 combined with commercial starters. After storage at 4°C for 21 d, the viable cell count remained above 10⁷ cfu/mL. In conclusion, a Bifidobacterial strain, IMAU12449, with favorable probiotic properties was identified in this study. This strain has demonstrated significant potential for application in fermented milk, and further research should be conducted to elucidate its role in promoting health.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144293109","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":"Advancing dairy farm simulations: A two-step approach for tailored lactation curve estimation and its systemic impacts.","authors":"Y Gong, H Hu, K F Reed, V E Cabrera","doi":"10.3168/jds.2025-26334","DOIUrl":"https://doi.org/10.3168/jds.2025-26334","url":null,"abstract":"<p><p>Lactation curve models are a foundational component of dairy farm simulation models because they support prediction of individual animal milk production over time. For farm simulation models to be applicable as decision-support tools, the predicted baseline milk production should match farm reported production as accurately as possible. However, individual animal lactation curve parameters are not easily accessible farm data. This study introduces a straightforward and effective calibration method for determining the parameters of Wood's lactation curve, leveraging a previously published database of parameters and 3 additional data inputs readily available on farms: annual herd milk production (AHMP), number of milking cows, and herd parity composition. Our method involves (1) adjusting curve parameters based on previously reported national estimates and farm contextual metadata (i.e., temporal, geographic, and management factors) and (2) further optimizing the scale parameter for each parity to match the 305-d milk yield derived from observed AHMP, number of milking cows, and herd parity composition. The Ruminant Farm Systems (RuFaS) model, a comprehensive dairy farm simulation platform, was employed to evaluate this method on 10 commercial Holstein dairy farms in New York (n = 3), Texas (n = 3), and Wisconsin (n = 4). By using lactation curve parameters estimated by this calibration method, we achieved greater accuracy in estimating AHMP with RuFaS for these case study farms, reducing the root mean square percentage error from 40.6% to 2.22%. To evaluate the downstream effects of lactation curve estimation methods within a farm systems context, we used the RuFaS Animal Module to simulate key performance and environmental metrics, including dry matter intake, enteric methane production, and manure excretion. We calculated gross feed efficiency and associated feed and manure emissions using emission factors derived from established literature. The results underscore the critical role of lactation curve modeling in dairy farm system simulation models and its substantial effects on environmental footprint predictions. In conclusion, this study demonstrates the effectiveness of our lactation curve parameter calibration method. With this method, farm system simulation models such as RuFaS can greatly increase their reliability in generating farm-specific predictions without requiring extensive farm data collection.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144293027","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":"Astral-data-independent acquisition depicts the dynamic landscape of milk fat globule membrane proteins in yak colostrum, transitional milk, and mature milk.","authors":"Yunduan Wang, Daoliang Lan, Shunyang Liu, Shaohui Beng, Kechao Chen, Xueer Mu, Yueyue Li, Jian Li, Wei Fu","doi":"10.3168/jds.2025-26661","DOIUrl":"https://doi.org/10.3168/jds.2025-26661","url":null,"abstract":"<p><p>The MFGM proteins are crucial for neonatal growth, immune regulation, and metabolic balance throughout mammalian life cycle. However, the composition and dynamic changes of MFGM proteins in yak colostrum (MC), transitional milk (MT), and mature milk (MM) remain poorly understood. This study applied Astral-data-independent acquisition proteomics to profile yak MFGM proteins, identifying 5,437 proteins. Specifically, 2,310 MFGM proteins were significantly differentially expressed between MC and MM, 2,351 between MC and MT, and 846 between MT and MM. In MC, proteins involved in immune modulation, antioxidants, and cell protection were highly expressed. As lactation progressed, lipid metabolism proteins increased, particularly in MT, which demonstrated activation of metabolic pathways related to triglyceride synthesis and fatty acid desaturation. Our findings reveal that MFGM proteins support passive immunity in MC, activate metabolism in MT, and ensure sustained nutrient delivery in MM. These insights are valuable for developing yak milk-based dairy products.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144293095","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 feeding beets and ensiled beets on rumen volatile fatty acid and ethanol metabolism in dairy cows.","authors":"E M V Hvas, M Hanigan, M R Weisbjerg, M Larsen","doi":"10.3168/jds.2024-26194","DOIUrl":"https://doi.org/10.3168/jds.2024-26194","url":null,"abstract":"<p><p>Ensiling beets allows for year-round feeding, and the high sugar content results in the production of ethanol-rich silage. This study aimed to investigate the effects of feeding sugar- and ethanol-rich beet diets to dairy cows on rumen ethanol metabolism and absorption. Beets were washed, crushed, and stored in daily portions either frozen at -20°C or ensiled in barrels. Four rumen-cannulated Danish Holstein cows were used in a partially replicated 3 × 3 Latin square design with 21-d periods. The control diet (CON) was based on grass/clover silage, corn silage, barley, soybean meal, dried beet pulp, urea, and minerals. For the sugar-rich (SUG) and ethanol-rich (ETH) diets, 20% of DM from CON was replaced with either beets or ensiled beets. To assess the transfer of carbon between ethanol and VFA, including acetate, propionate, butyrate, isobutyrate, and isovalerate, [¹³C]-labeled isotopes of these compounds were individually infused into the rumen for 5 h each. A dynamic 6-pool rumen model was fit to measured isotopic enrichments to estimate synthesis, absorption, and interconversions for ethanol and VFA. The basal ethanol synthesis level for CON was 325 mmol/h. Feeding ETH maintained this level, whereas SUG resulted in a slight decrease in ruminal ethanol synthesis. From the total influx (intake + production) of ethanol, 63.1% was metabolized to acetate and 22.2% was absorbed for CON, 57.2% was metabolized to acetate and 37.5% was absorbed for SUG, and 43.7% was metabolized to acetate and 45.5% was absorbed for ETH. Furthermore, 85.3% of the additional ethanol from the beet silage diet was absorbed. Especially due to the high basal ethanol synthesis, the addition of the rumen pools of ethanol, isobutyrate, and isovalerate influenced model estimates for acetate, propionate, and butyrate. For CON, excluding these pools led to overestimations of synthesis for the included pools by 7.8%, 10.4%, and 12.8%, respectively.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144293098","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":"Impact of decreasing undigested neutral detergent fiber concentration in corn silage-based diets for dairy cows: Nutrient digestibility, ruminal fermentation, feeding behavior, and performance.","authors":"Daniel J C Vieira, Nathália T S Grigoletto, Guilherme Poletti, Rodrigo G Chesini, Evan C Diepersloot, Caio S Takiya, Luiz F Ferraretto, Francisco P Rennó","doi":"10.3168/jds.2025-26388","DOIUrl":"https://doi.org/10.3168/jds.2025-26388","url":null,"abstract":"<p><p>The objective of this study was to evaluate the effects of decreasing concentrations of undigested NDF after 288 h of incubation (uNDF288) in corn silage-based diets for dairy cows on nutrient intake and digestibility, feed sorting index, ingestive behavior, ruminal fermentation, milk yield, and milk composition. Twenty-four Holstein cows were used, including 8 primiparous and 16 multiparous cows, in a replicated 4 × 4 Latin square experiment. Cows were blocked based on milk yield (37.1 ± 4.28 kg/d), DIM (110 ± 60.0 d), and BW (669 ± 74.2 kg). Each period lasted 21 d, with the last 7 d designated for data collection. Treatments consisted of dietary uNDF at 11.1%, 10.4%, 9.7%, and 9.0% diet DM. The dietary uNDF concentration was manipulated by ensiling corn plants cut at 40 cm and 65 cm above the ground, provided in different proportions in the diet. Increasing the cutting height of corn silage from 40 to 65 cm resulted in a reduction in the uNDF288 concentration from 21.2% to 16.8% DM, and increased estimated in vitro ruminal NDF digestibility and total-tract NDF digestibility for silage with a cutting height of 65 cm. Results showed that reducing dietary uNDF concentration linearly increased intake and apparent total-tract digestibility of DM, OM, CP, and NDF. Cows fed diets with greater uNDF concentration rejected larger particles, whereas lower uNDF diets tended to decrease ruminal ammonia concentration. Milk yield and FCM yield increased linearly with decreasing diet uNDF. A 1 unit increase in uNDF was negatively associated with -0.59 kg/d in DMI and -0.48 kg/DIM yield and -0.75 kg/d in FCM yield, as well as decreases of 1.79% in DM digestibility and 1.73% in amylase-treated NDF digestibility. In conclusion, reducing the dietary uNDF concentration from 11.1% to 9.0% improved performance due to increased nutrient intake and digestibility, as well as altering the ruminal fermentation.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144293104","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":"Staphylococcus lugdunensis and Staphylococcus simulans super shedders in dairy goats.","authors":"Y de Geus, R A Blok, M P Spaninks, J A Stegeman, L Benedictus, L Portengen, L A M Smit, G Koop","doi":"10.3168/jds.2025-26465","DOIUrl":"https://doi.org/10.3168/jds.2025-26465","url":null,"abstract":"<p><p>The bulk milk total bacterial count (BMTBC) is a key milk quality indicator because bacterial byproducts reduce the shelf life of milk and dairy products and increase the risk of bacterial overgrowth before consumption. Exceeding BMTBC limits results in milk price penalties, motivating farmers to keep it under control. Factors influencing BMTBC include milking hygiene and milking technique, but also goats with IMI can shed bacteria into the milk. How many bacteria are shed during IMI, and to what extent individual goats can contribute to BMTBC is not known yet. From January to October 2023, a Dutch dairy goat farm experienced persistently high geometric mean BMTBC and bulk milk somatic cell count (BMSCC). In a cross-sectional study of 98 goats on this farm, we evaluated whether goats with mastitis could significantly affect the BMTBC and BMSCC. Also, the relation between mastitis pathogens in individual goat milk and udder health parameters such as clinical mastitis and asymmetry were investigated. Milk was cultured on blood agar plates and bacteria were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Additionally, the numbers of bacteria in the milk samples were determined using both flow cytometry and conventional culture methods (total blood agar plate count with track dilution). We found that goats with IMI caused by Staphylococcus lugdunensis or S. simulans shed extremely high numbers of bacteria into the milk with a maximum of approximately 700 million cfu/mL. Moreover, presence of S. lugdunensis or S. simulans was associated with having a clinical mastitis and an asymmetric udder, a clinical sign often observed in goats with a history of mastitis. Research into host-specific reactions and which virulence factors of S. lugdunensis and S. simulans contribute to this high bacterial shedding could help in developing preventive measures.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144293111","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}