Journal of Dairy Science最新文献

{"title":"The edible bird's nest hydrolysate-induced formation of drinkable yogurt.","authors":"Hui Wang, Qunyan Fan, Xiuting Hu","doi":"10.3168/jds.2025-26389","DOIUrl":"https://doi.org/10.3168/jds.2025-26389","url":null,"abstract":"<p><p>To use fragmented edible bird's nest (EBN), protease-mediated hydrolysis was employed, and these hydrolysates were subsequently incorporated into milk before fermentation for yogurt production. Notably, supplementation with specific EBN hydrolysates induced a fundamental structural transition from conventional set yogurt to a drinkable system. Thus, this study aimed to prepare such drinkable yogurt and investigate the formation mechanism. It was revealed that ≥2 h hydrolysis duration combined with 2.0% hydrolysate incorporation induced transition from set yogurt to drinkable yogurt. Below these thresholds (≤1 h hydrolysis or ≤1.0% dosage), a conventional gel network persisted. Microstructural characterization through confocal laser scanning microscopy revealed the formation of discrete protein microgels within the liquid matrix in drinkable yogurt samples, confirming macroscopic fluidity. Rheological assessments demonstrated significantly lower storage modulus and loss modulus and higher loss factor in the drinkable yogurt samples than in set yogurt. Mechanistic investigations using CN micelle suspensions showed that EBN hydrolysate addition could inhibit aggregation of CN microgels and maintain CN suspension mobility at pH 4.3. Electrophoresis analysis revealed the generation of low-molecular-weight peptides (≤11 kDa) that constituted the predominant fraction in the EBN hydrolysate. Thus, it was inferred that peptides with the molecular weight ≤11 kDa in the EBN hydrolysate inhibited aggregation of CN microgels induced by acidification into a continuous gel, thus enabling production of drinkable yogurt.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143956875","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 key quorum sensing gene luxS in Lactobacillus acidophilus CICC 6074 and Lactobacillus helveticus R0052 mediates organic acid production and promotes protein hydrolysis in yogurt","authors":"Ruitong Zhang ,&nbsp;Zihang Shi ,&nbsp;Xiankang Fan ,&nbsp;Tao Zhang ,&nbsp;Maolin Tu ,&nbsp;Zhen Wu ,&nbsp;Xiaoqun Zeng ,&nbsp;Weichen Bao ,&nbsp;Bo Chen ,&nbsp;Daodong Pan","doi":"10.3168/jds.2025-26323","DOIUrl":"10.3168/jds.2025-26323","url":null,"abstract":"<div><div>In this study, the effect of <em>luxS</em>, a key gene involved in quorum sensing, on the characteristic flavor of yogurt and its molecular mechanisms during the cofermentation of yogurt with engineered probiotics was investigated. The <em>luxS</em> gene overexpression strain was constructed by the homologous recombination technique, and its effect on the expression of population sensing signaling molecules and <em>luxS</em> gene was determined by bioluminescence and quantitative real-time PCR, and finally, headspace solid-phase micro extraction-GC-MS (HS-SPME-GC-MS) and metabolomics were used to determine the mechanism of its effect on the characteristic flavor of yogurt. The results demonstrated that the overexpression strains of <em>Lactobacillus acidophilus</em> CICC 6074-pMG36e-<em>luxS</em> and <em>Lactobacillus helveticus</em> R0052-pMG36e-<em>luxS</em> were successfully constructed. The expression of the <em>luxS</em> gene was upregulated by 2.25-fold and 3.16-fold, respectively. Compared with the wild-type strains, yogurt fermented by the overexpression strains showed a significant increase in AI-2 content, acidity, viable bacterial count, and protein hydrolysis, whereas pH, water-holding capacity, and hardness were significantly reduced. The HS-SPME-GC-MS results revealed the presence of 31 volatile flavor substances in yogurt. Among them, benzaldehyde (almond and burned sugar flavors), 2,4-dimethyl- (almond, cherry, and naphthalene flavors), dibutyl phthalate (a faint aromatic odor), and n-decanoic acid (rancid and fatty notes) were identified as the key differential flavor substances mediated by the <em>luxS</em> gene. Metabolomics results showed that the <em>luxS</em> gene mediates the production of organic acids in yogurt through arginine and proline metabolism, phenylalanine metabolism, and tryptophan metabolism. This study provides a theoretical basis for a deeper understanding of the molecular mechanisms underlying yogurt flavor formation.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 5","pages":"Pages 4734-4748"},"PeriodicalIF":3.7,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143887757","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":"Productive and reproductive losses associated with abortion in specialized dairy cattle from Costa Rica","authors":"Emilia Vindas-van der Wielen ,&nbsp;Juan José Romero-Zúñiga ,&nbsp;Gustavo Monti","doi":"10.3168/jds.2024-25283","DOIUrl":"10.3168/jds.2024-25283","url":null,"abstract":"<div><div>Abortions can negatively affect a dairy farm's milk yield, reproductive efficiency, and profitability. Despite the recognized economic losses associated with abortions, the reproductive and productive detriments caused by abortion have not been estimated in dairy cattle in tropical productive conditions such as those in Costa Rica. Therefore, this study aimed to evaluate the potential productive and reproductive losses caused by abortions in dairy cattle from Costa Rica. The reproductive and productive losses caused by abortion were estimated using a dataset with 953,181 complete lactations from 322,873 cows belonging to 1,133 Costa Rican specialized dairy herds. Abortions were classified as early fetal mortality (EFM) and late fetal mortality (LFM). The number of services per conception (NSPC) and calving to effective conception interval (CECI) indicated the reproductive losses. The productive losses were indicated by the DIM per lactation and per cow, productive lifetime, 305-d milk yield per lactation (305-d MY), total milk yield per lactation (TMYPL), and total lifetime milk yield per cow (LTMY). Generalized linear mixed models were adjusted by cow breed, parity, and ecozone, using farm and cow as random effects. Cows that experienced an EFM during the lactation had NSPC increase by 1.61, CECI by 8 d, DIM per lactation by 11 d, 305-d kg by 283 kg, and TMYPL by 297 kg. Cows that experienced a LFM during the lactation had an increase of 0.22 NSPC and a reduction of 33 DIM per lactation, 201 d of productive lifetime, 1,006 kg of 305-d MY, and 1,518 kg of TMYPL. Furthermore, as the parity with abortions increased from 0 to 3 or more, the DIM per cow increased. Still, we found no significant difference in the LTMY when the number of lactations with abortions increased. These results illustrate the impact of abortions on the reproductive and productive performance of cows and, consequently, on the profitability of dairy herds from a tropical country like Costa Rica.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 5","pages":"Pages 5287-5295"},"PeriodicalIF":3.7,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143887933","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 storage time and temperature on the chemical and sensory properties of aseptic milk","authors":"Dylan C. Cadwallader ,&nbsp;Joice Pranata ,&nbsp;Yaozheng Liu ,&nbsp;David M. Barbano ,&nbsp;MaryAnne Drake","doi":"10.3168/jds.2024-25955","DOIUrl":"10.3168/jds.2024-25955","url":null,"abstract":"<div><div>Our objective was to determine the effects of storage temperature and storage time on the chemical, physical, and sensory properties of ultra-high-temperature–direct steam injection aseptic milk. Milk was collected on 2 different processing dates (2 replicates) at a commercial aseptic milk processing facility immediately as containers came off the processing line. Milk was heat treated by direct steam injection (142°C for 3 s) with a flash vacuum cooling step following the holding tube and packaged aseptically in 946-mL aseptic packages. Packages were randomly assigned to 1 of 2 treatment groups (storage temperature of 4°C or 21°C). Half of the packages of 1% aseptic milk were cooled immediately off the processing line in ice and held at 4°C, and the other half were cooled to 21°C and held at 21°C for 12 mo. An unopened package of 1% aseptic milk that had been stored at 4°C or 21°C was opened and analyzed each month (for 12 mo) by chemical and descriptive sensory analyses. Chemical analyses included volatile compounds, viscosity, furosine, and dissolved oxygen. At 2 wk, 6 mo, and 12 mo, milk samples stored at each temperature were evaluated by consumers along with commercial 1% HTST milk. By descriptive sensory analysis, sulfur-eggy flavor decreased faster and caramelized flavor increased faster in aseptic milk stored at 21°C than in that stored at 4°C. Similarly, relative abundance of sulfur volatiles was lower initially in milk stored at 21°C than in that cooled and stored at 4°C. Furosine concentration was higher in milk stored at 21°C than in milk stored at 4°C. There were differences in consumer liking between the aseptic milk samples stored at the 2 storage temperatures, but they did not translate to an advantage in flavor liking for aseptic milk. Consumers indicated higher liking scores for fresh, refrigerated HTST milk than aseptic milk stored at either temperature at all 3 storage time points. Fluid milk processors need to focus on developing technology to increase the sensory liking scores of aseptic milk to maintain and increase fluid milk consumption as consumer lifestyles increase the demand for shelf-stable beverages.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 5","pages":"Pages 4818-4838"},"PeriodicalIF":3.7,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143565597","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 between measures of network centrality and Johne's disease among dairy herds in Ontario, Canada","authors":"J. Reilly Comper ,&nbsp;Karen J. Hand ,&nbsp;Zvonimir Poljak ,&nbsp;David Kelton ,&nbsp;Amy L. Greer","doi":"10.3168/jds.2024-25643","DOIUrl":"10.3168/jds.2024-25643","url":null,"abstract":"&lt;div&gt;&lt;div&gt;&lt;em&gt;Mycobacterium avium&lt;/em&gt; ssp. &lt;em&gt;paratuberculosis&lt;/em&gt; (MAP) is the causative agent for Johne's disease (JD), a chronic, progressive enteritis in ruminants that may lead to substantial weight loss, reduction in milk yield, and eventual death. Due to the very long incubation period of MAP, many cattle are culled before presenting signs of clinical JD infection. Furthermore, poor sensitivity of diagnostic tests results in subclinically infected cattle contributing to the transmission of JD but otherwise going undetected. Therefore, one of the best control measures for JD is preventing MAP from entering the herd altogether. Numerous studies have identified associations between measurements of cattle purchases—referred to in network analysis as measures of ingoing centrality—and the presence of JD in dairy herds, suggesting that prevention of JD can be achieved by limiting cattle purchases. Between 2010 and 2013, the Ontario Johne's Education and Management Assistance Program (OJEMAP) provided JD education and bulk tank milk (BTM) testing for participating dairy producers in Ontario. Part of the OJEMAP education plan included recommendations regarding cattle purchases. These recommendations were to limit cattle purchases and, if necessary, to purchase cattle from a single, test-negative source herd. Self-reported changes in cattle purchasing behavior were included in a pre-, and post-OJEMAP risk assessment. The objectives of this study were (1) to use data provided by Lactanet Canada to create a network of between-herd dairy cow movements during the OJEMAP study period (2010–2013) and of equal timescale post-OJEMAP (2014–2017) to assess changes in movement behavior in response to program recommendations; (2) to determine whether measures of network centrality from the 2014–2017 network are associated with a positive ELISA test sampled from 2017 BTM; and (3) to use a permutation-based approach (network k-test) to determine whether the structure of the cattle movement network is “epidemiologically relevant” to the distribution of high-risk JD herds in Ontario (i.e., whether the distribution of high-risk JD herds was due to the structure of the between-herd dairy cow movement network itself). It was found that OJEMAP participants had a smaller proportion of herds that increased their cow purchases and number of source herds compared with nonparticipant herds. Furthermore, among herds that increased the number of cows purchased, nonparticipants added more cows from more source herds than OJEMAP participant herds. The results from the logistic regression analyses indicated no associations between measures of centrality, including in-degree, ingoing contact chain, and α centrality, and a positive 2017 BTM ELISA test. However, herd size, region of herd, and previous high-risk JD classification were all positively associated with being classified as high-risk for JD. Results from the network k-test suggest that the distribution of high-risk JD","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 5","pages":"Pages 5193-5208"},"PeriodicalIF":3.7,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143571610","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":"Association of phenotypic traits and fertility in Holstein heifers: Body condition score, body weight, antral follicle count, anti-Müllerian hormone, and anogenital distance","authors":"Andréia Ferreira Machado ,&nbsp;Leticia P. Sanglard ,&nbsp;Santiago Andres Paez Hurtado ,&nbsp;João Victor Chaves ,&nbsp;Muhammad Awais Ajmal ,&nbsp;José Domingos Guimarães ,&nbsp;Jeffrey S. Stevenson ,&nbsp;Simone E.F. Guimarães ,&nbsp;Victor E. Gomez-Leon","doi":"10.3168/jds.2024-25923","DOIUrl":"10.3168/jds.2024-25923","url":null,"abstract":"<div><div>The aim of this cross-sectional observational study was to assess whether nulliparous Holstein heifer fertility is associated with (1) energy reserve-related traits, such as BCS and BW; (2) ovarian reserve-related traits, such as anti-Müllerian hormone (AMH) and antral follicle count (AFC); and (3) development-related traits, such as anogenital distance (AGD) and vulval length (VUL). From August 2022 through July 2023, we used a prospective approach in which the phenotypic traits (BCS, AMH, AFC, AGD, BW, and VUL) of 698 Holstein heifers were measured once at approximately 12 mo of age (at the beginning of the breeding program). All heifers were submitted to the herd reproductive management from 367 ± 3 d of age and 297 kg of BW until 570 d of age, or 5 breedings. Fertility outcomes (age at first service, pregnancy per artificial insemination [P/AI] at first service, age at conception, and number of services per conception) were retrieved from software records. Pearson correlations were performed among phenotypic traits collected. The strongest correlations (r &gt;0.5) observed were for AGD with VUL and AMH with AFC. Associations of phenotypic traits with fertility outcomes were determined using generalized linear models. Body condition score was the phenotypic trait most associated with fertility outcomes. Associations of AMH, AFC, AGD, BW, and VUL with fertility were not observed or were very weak. Furthermore, we divided the data into BCS tertiles and performed association analyses by category. The top BCS tertile was associated with greater BW (365.7 ± 1.8 vs. 356.0 ± 1.5 kg), greater P/AI at first service (65.0% ± 4.0% vs. 52.0% ± 4.0%), and fewer number of services per conception (1.5 ± 0.10 vs. 1.8 ± 0.09) compared with the bottom tertile. Moreover, AGD was greater in the top and bottom tertiles compared with the middle tertile. Finally, BCS was associated with time to conception based on the Cox proportional hazards survival analysis, indicating that heifers with greater BCS became pregnant earlier. Based on the results observed in the current study, we would expect benefits for fertility by improving management practices that result in heifers with greater BCS at first service, but ovarian reserve-related traits (AMH, AFC) and developmental traits (AGD, VUL) were not associated with fertility outcomes in our study.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 5","pages":"Pages 5372-5381"},"PeriodicalIF":3.7,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143584111","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 Jr. ,&nbsp;H.F. Monteiro ,&nbsp;C.C. Figueiredo ,&nbsp;B. Mion ,&nbsp;J.E.P. Santos ,&nbsp;R.S. Bisinotto ,&nbsp;F. Peñagaricano ,&nbsp;P. Vahmani ,&nbsp;E.S. Ribeiro ,&nbsp;F.S. Lima","doi":"10.3168/jds.2024-25454","DOIUrl":"10.3168/jds.2024-25454","url":null,"abstract":"<div><div>Feed efficiency is critical in dairy farming, affecting 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 BW change, metabolic BW, and energy secreted in milk. Rumen fluid and serum samples were collected between 60 and 90 DIM. Rumen fluid samples were collected using an oro-esophageal 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 the chromatographic peak area and internal standard-based calculations. Ruminal ammonia nitrogen was measured using a phenol-hypochlorite assay, and serum urea was measured using a commercial ELISA kit. 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 acid concentrations differed between groups, with myristic acid (C14:0), palmitic acid (C16:0), <em>cis</em>-heptadecenoic acid (<em>cis</em>-9–17:1), stearic acid (C18:0), and total SFA having greater concentrations in the MFE group than in the LFE group. The total PUFA concentration was lower in the MFE group than in the LFE group. A model incorporating C14:0, C16:0, palmitoleic acid (<em>trans</em>-9-C16:1), <em>anteiso</em>-heptadecanoic acid plus palmitoleic acid (C17:0+<em>trans</em>-13-C16:1), oleic acid (<em>cis</em>-9-C18:1), <em>cis</em>-vaccenic acid (<em>cis</em>-11-C18:1), petroselinic acid (<em>cis</em>-12-C18:1), C18:0, linoleic acid (C18:2n-6), dihomo-γ-linolenic acid (C20:3n-6), <em>cis</em>-MUFA, n-6 PUFA, total PUFA, total SFA, and other or 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, the 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.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 5","pages":"Pages 4839-4850"},"PeriodicalIF":3.7,"publicationDate":"2025-05-01","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":"Enrichment of pasteurized skim milk with grape seed oil multilayer emulsions: Investigating the effect of emulsion layers on physicochemical, microbial, and sensory characteristics","authors":"Marziyeh Sepeidnameh ,&nbsp;Ali Fazlara ,&nbsp;Seyed Mohammad Hashem Hosseini ,&nbsp;Mahdi Pourmahdi Borujeni","doi":"10.3168/jds.2024-25789","DOIUrl":"10.3168/jds.2024-25789","url":null,"abstract":"<div><div>Cow milk is a nutritionally valuable food, although it lacks essential UFA. Enriching milk with these fatty acids can reduce risks associated with cholesterol and saturated fats while meeting consumers' dietary needs. Grape seed oil (GSO), which is rich in n-6 and n-9 fatty acids, is one potential additive to replace milk fat and increase the unsaturated fat content. However, these essential UFA are hydrophobic, making them difficult to dissolve in water, and are prone to oxidation, which can negatively affect the aroma and flavor of the milk. The layer-by-layer emulsion method is a promising approach to mitigate these challenges. This study investigated the enrichment of pasteurized skim milk with optimized multilayer emulsions of GSO and evaluated the physicochemical, microbial, and sensory characteristics of the milk over a storage period of 7 d at 4°C. Results indicated that single- and triple-layer emulsions remained stable within the milk matrix, but the 2-layer emulsion became unstable by d 3 of storage. During storage, acidity increased in all samples (from 0.16 to 0.44, 0.24 to 0.48, and 0.2 to 0.36 for single-, double-, and triple-layer emulsions, respectively), as did viscosity (from 1.53 to 1.9, 1.55 to 2.2, and 1.46 to 1.78 mPa·s, respectively), total microorganism count, peroxide value (from 5.52 to 17.6, 4.7 to 19.38, and 3.09 to 10.3 mEq/kg oil, respectively), and thiobarbituric acid index (from 0.43 to 0.52, 0.44 to 0.63, and 0.39 to 0.47 mg malondialdehyde/kg of oil, respectively). The pH values decreased slightly across all samples (from 6.6 to 6.5). No mold, yeast, or coliforms were detected in any sample throughout the study. Overall, the use of bioactive compounds such as essential fatty acids through milk enrichment can greatly enhance the quality of widely consumed dairy products.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 5","pages":"Pages 4604-4613"},"PeriodicalIF":3.7,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143475998","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":"Investigating the epidemiology of hyperketonemia in grazing dairy cows in early lactation: Incidence, prevalence, and time to resolution of hyperketonemia","authors":"S.J. Hendriks ,&nbsp;J.R. Roche ,&nbsp;J.A.A. McArt ,&nbsp;T.M. Grala ,&nbsp;S-A. Turner ,&nbsp;C.R. Burke ,&nbsp;B. Kuhn-Sherlock ,&nbsp;C.V.C. Phyn","doi":"10.3168/jds.2024-25205","DOIUrl":"10.3168/jds.2024-25205","url":null,"abstract":"<div><div>Most cows experience a degree of negative energy balance due to an energy deficit during early lactation, which leads to the mobilization of body tissue to support milk production and results in the production of ketone bodies. Elevated ketones have been associated with an increased risk of clinical ketosis and reduced cow performance and health. The objectives of this study were to (1) characterize the incidence and prevalence of hyperketonemia (HYK) and severe HYK (Sev-HYK) in 3 seasonal calving herds of grazing dairy cows in early lactation, and (2) characterize the time to resolution of HYK based on the timing and degree of HYK. Grazing cows from 3 dairy farms were tested 15 times (mean ± SD; 14.9 ± 0.4 tests) for HYK between 1 and 35 DIM using a hand-held meter. Hyperketonemia was defined as blood BHB ≥1.2 to 2.9 mmol/L and Sev-HYK was defined as blood BHB ≥3.0 mmol/L. Associations between time to resolution of HYK and factors influencing this (farm, timing and magnitude of the first positive HYK test) were investigated by survival analysis using Cox regression. A total of 749 (76%) of 980 eligible cows were classified with HYK or Sev-HYK at least once within 35 DIM. Cumulative incidence of HYK was 64% within 14 DIM and varied across farm A (40%), farm B (76%), and farm C (74%). Cumulative incidence of Sev-HYK was 11% within 35 DIM and varied across farm A (12%), farm B (18%), and farm C (6%). Peak incidence of HYK occurred at 3 DIM, when 34% of cows had their first positive HYK test; however, peak HYK incidence and timing of peak incidence varied widely between the 3 herds (20% at 7 DIM on farm A, 38% at 4 DIM on farm B, and 58% at 3 DIM on farm C). Median time from the first positive HYK test (1.2 to 2.9 mmol/L) to a negative test (&lt;1.2 mmol/L) was 3.3 d. In multivariable models, blood BHB concentration (≥1.2 to &lt;2.0 mmol/L vs. 2.0 to 2.9 mmol/L) and timing (≤4 DIM vs. &gt;4 DIM) of the first positive HYK test were associated with the time taken to resolve HYK (blood BHB &lt;1.2 mmol/L) within 35 DIM. Cows with blood BHB 1.2 to &lt;2.0 mmol/L at their first positive HYK test were 43% more likely to resolve HYK than cows that tested 2.0 to 2.9 mmol/L at their first positive test within 35 DIM. Further, cows that first tested positive after 4 DIM were 62% more likely to resolve HYK than cows that first tested positive within the first 4 DIM. Our results indicate substantial variation in the incidence and prevalence of HYK across 3 case study herds in seasonal calving, pasture-based systems. The time of HYK onset relative to calving and BHB concentration at the first HYK-positive test can influence the time taken to resolve HYK.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 5","pages":"Pages 5257-5270"},"PeriodicalIF":3.7,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143727147","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":"Effect of proportion of pasture in the cow diet and seasonality on the milk metabolome as determined by 1H-NMR","authors":"Paula Rojas-Gómez ,&nbsp;Raghunath Pariyani ,&nbsp;Lorraine M. Bateman ,&nbsp;Denis Lynch ,&nbsp;Mark Timlin ,&nbsp;Michael Dineen ,&nbsp;Noel A. McCarthy ,&nbsp;André Brodkorb ,&nbsp;Anita R. Maguire ,&nbsp;Michael O'Donovan ,&nbsp;Deirdre Hennessy ,&nbsp;Thomas Brendan Murphy ,&nbsp;James A. O'Mahony ,&nbsp;Tom F. O'Callaghan","doi":"10.3168/jds.2024-26168","DOIUrl":"10.3168/jds.2024-26168","url":null,"abstract":"<div><div>This study investigates the effect of varying proportions of pasture (high, medium, no-pasture) in the diet of cows and seasonality on the milk metabolome throughout lactation using proton nuclear magnetic resonance (¹H-NMR) spectroscopy. This study explored the potential to differentiate milks from varying levels of pasture in the cow's diet and highlight potential biomarkers for authentication. A total of 54 spring calving cows were assigned to the 3 diet treatments for the duration of lactation. Weekly bulk milk samples were collected from each herd. Over 37 wk (March–November 2020), 43 metabolites representing diverse chemical classes, including AA and nitrogenous compounds, carbohydrates, VFA, organic acids, and alcohols were quantified. Significant dietary and seasonal influences on the milk metabolome were characterized, with signature differences attributed to the proportion of pasture in the cow's diet and the season of milk production. Receiver operating characteristic analysis of the milk from different feeding systems across lactation highlighted the potential of the milk metabolome to distinguish pasture from nonpasture-derived milks, with a series of metabolites demonstrated as excellent biomarkers, including hippurate. Multivariate analysis also highlighted dimethyl sulfone as a key metabolite for the distinction between different diet regimens. These findings highlight the diversity and complexity of the composition of milk as affected by seasonality, and signature characteristics that are associated with pasture-based feedings systems. As “grass-fed” dairy products become more prominent on the market, the analysis of the milk metabolome using ¹H-NMR shows significant promise for utilization as a tool for authentication purposes.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 5","pages":"Pages 4659-4673"},"PeriodicalIF":3.7,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143727242","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}