Journal of Dairy Research最新文献

{"title":"Economic modeling and selection for longevity traits in dairy cattle.","authors":"Farzaneh Shokri-Sangari, Ali Sadeghi-Sefidmazgi, Saeid Ansari-Mahyari, Hadi Atashi","doi":"10.1017/S0022029926102192","DOIUrl":"https://doi.org/10.1017/S0022029926102192","url":null,"abstract":"<p><p>Different definitions have been proposed for longevity, making it challenging to compare methods for estimating the economic significance of survival traits. Simple profit functions often fail to capture biological complexity, whereas bioeconomic models, though comprehensive, can be difficult to apply. This study aimed to develop a versatile framework for estimating the economic value (EV) of longevity traits and designing optimal selection indices. The approach can accommodate various definitions of longevity (e.g., herd life, productive life, number of lactations, stayability or survival across lactations) and be applied across production systems. The economic model is founded on a stable herd age structure at equilibrium, where changes in survival rates influence profitability and age distribution. Average survival rates between parities determine the distribution of cows across parities and the number of replacements needed to maintain a steady-state herd structure. Iranian production and economic data were used for parameterization, and EVs were estimated accordingly. Seven selection indices were developed, incorporating production, reproduction, somatic cell score (SCS), longevity and type traits. The estimated economic weights were $0.12/kg for milk yield, $5.56/kg for fat yield, $5.50/kg for protein yield, $2.73/month for productive life, $22.6/year for herd life, $0.18/percentage point for survival, $37.59/lactation for number of lactations, $-3.84/day for days open and $-122.87/unit for SCC. Excluding longevity from the breeding goal led to the lowest observed genetic gain, demonstrating that including longevity traits positively influences overall genetic improvement. The greatest genetic progress was achieved by indices enhancing productive life through indirect selection on fore udder conformation. This study demonstrates that (1) the flexible approach enables estimation of EVs under multiple longevity definitions and (2) selection for productive life, particularly via indirect selection on fore udder traits, improves longevity, enhances production and reduces SCC.</p>","PeriodicalId":15615,"journal":{"name":"Journal of Dairy Research","volume":" ","pages":"1-10"},"PeriodicalIF":1.2,"publicationDate":"2026-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147816206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research communication: comparison of calf faeces and rumen digesta as inoculum to measure <i>in vitro</i> digestibility using the gas production technique.","authors":"Stefan Yerby, James Huntington, Nicholas N Jonsson, Helen Warren","doi":"10.1017/S0022029926102337","DOIUrl":"https://doi.org/10.1017/S0022029926102337","url":null,"abstract":"<p><p>This Research Communication addresses the hypothesis that calf faeces can be used as a microbial inoculum in the <i>in vitro</i> gas production (GP) technique to model rumen digestibility in calves. <i>In vitro</i> GP is a valuable method of screening dietary interventions in ruminants. However, the technique requires a microbial inoculum, typically obtained from the rumens of fistulated animals. Using faecal inocula that can be collected non-invasively would be ethically and economically preferable, if it provided equivalent results. The aim of this pilot study was to compare <i>in vitro</i> GP from faecal and ruminal inocula obtained from dairy calves that were killed either pre-weaning or post-weaning. Ruminal content and faeces were collected from calves aged 4, 7 and 13 weeks old, and incubated with calf starter concentrates in the ANKOM^RF system. A weak relationship between inocula was seen for all modelled GP kinetic parameters (R² < 0.53), although modelling indicated that incubations using faecal and rumen inocula from pre-weaned calves had similar lag times and rates of degradation. In weaned calves, aged 13 weeks, faecal incubations produced less gas, lag times were longer, and the rate of degradation of the slowly degradable fraction of calf starter was slower, compared to rumen incubations. Weak relationships, and kinetic differences, between rumen and faecal inocula would likely hinder the use of faeces to model calf rumen fermentation.</p>","PeriodicalId":15615,"journal":{"name":"Journal of Dairy Research","volume":" ","pages":"1-5"},"PeriodicalIF":1.2,"publicationDate":"2026-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147816159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Editorial: <i>Journal of Dairy Research</i> instructions for peer reviewers.","authors":"Nicholas N Jonsson","doi":"10.1017/S0022029926102386","DOIUrl":"https://doi.org/10.1017/S0022029926102386","url":null,"abstract":"","PeriodicalId":15615,"journal":{"name":"Journal of Dairy Research","volume":" ","pages":"1-4"},"PeriodicalIF":1.2,"publicationDate":"2026-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147816187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Is dairy food loss early in food supply chains an issue? Insights from a New Zealand farm and processor study.","authors":"Jessica O'Connor, Miranda Mirosa, Gina Lucci, Sheila Skeaff, Phil Bremer","doi":"10.1017/S0022029926102362","DOIUrl":"https://doi.org/10.1017/S0022029926102362","url":null,"abstract":"<p><p>Despite the significant contribution of the dairy sector to global food systems, data on food loss during dairy farming and processing are scarce. This research aimed to quantify and understand the drivers, and strategies that prevent food loss and waste. Using a mixed-method approach combining quantitative (processor quantities and farmer estimates) and qualitative (interview) data, two New Zealand case studies (dairy farmers and staff who worked for a dairy processor) were assessed to estimate the quantity of milk solids lost, identify dairy disposal practices and examine drivers that incentivised waste disposal or prevention/recycling approaches. From this study, dairy food loss is not a sizable issue given the percentage of losses occurring (1.8% per farm, and 5.5% at the processor). However, when extrapolated to national milk production: a 1.8% loss of New Zealand dairy production is the equivalent annual production of 350,000 cows. Qualitative analysis associated four key drivers with the level of food loss: perceptions of food loss inevitability, economic pressures, strong inter-stakeholder relationships and risk mitigation strategies. Prevention and recycling decisions were enabled by the industry's cooperative structure and the high value of milk solids, for example, surplus milk was traded to other processors rather than put onto farmers to dispose of/use. However, this study found that participants were very limited in their recycling and disposal destination options. This exposed farmers and the processor to serious reputational (e.g. odour, wasteful perceptions) and biohazardous (e.g. animal disease, antibiotic resistance) risks. These findings highlight how supporting more equitable market power between farmers and processors prevents dairy food loss, and that farmers and processors require support to diversify end-of-pipe recycling options, and ultimately improve the sustainability of dairy supply chains.</p>","PeriodicalId":15615,"journal":{"name":"Journal of Dairy Research","volume":" ","pages":"1-16"},"PeriodicalIF":1.2,"publicationDate":"2026-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147816189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular characterisation and epidemiology of <i>Streptococcus uberis</i>, isolated in a longitudinal study from the milk of a large commercial South African dairy herd.","authors":"Grant Kevin van Lelyveld, Inge-Marié Petzer, Christiaan Labuschagne, Joanne Karzis","doi":"10.1017/S0022029926102350","DOIUrl":"https://doi.org/10.1017/S0022029926102350","url":null,"abstract":"<p><p><i>Streptococcus uberis</i> is currently the most notable emerging mastitis pathogen in South Africa. Multilocus sequence typing (MLST) was used to investigate the sequence types (STs) of <i>S. uberis</i> isolated from bovine milk and their epidemiological patterns of occurrence. This retrospective, longitudinal study was conducted on a pasture-based herd of 1005 lactating cows, on which slurry-spreading had been recently introduced. Composite cow milk samples were collected quarterly during routine whole herd sampling and from clinical mastitis cases (monthly) during 2021. <i>Streptococcus uberis</i> isolates obtained from two routine samplings and clinical mastitis cases were stored at -80°C. In 2024, seven <i>S. uberis</i> isolates were added; these were from the same cows in consecutive samplings. The prevalence of <i>S. uberis</i> intramammary infection (IMI) was 7.44%, while 21.26% of clinical mastitis cases were caused by <i>S. uberis.</i> Based on conventional microbiology, 31.4% of <i>S. uberis</i> IMIs were recurring in consecutive samplings. A total of 42 <i>S. uberis</i> STs were identified from 70 isolates; 41 were novel and only 1 (ST 1613) had been previously reported in the PubMLST/GenBank database. Of the <i>S. uberis</i> isolates examined, 35.7% had known clonal complexes (CCs); of these, 60% were CC ST-5. Owing to the high heterogeneity, no predominant STs were observed; ST 1613 was isolated six times but did not cause clinical cases. When <i>S. uberis</i> was isolated from a cow more than once, only 50% of the isolates had similar STs. Where cows had multiple infections in an udder, quarters infected had different STs. In summary, this herd showed significant heterogeneity in <i>S. uberis</i>, with all but one ST being novel variants. Results indicate that <i>S. uberis</i> IMI in this herd was transient, possibly of environmental origin rather than persistent udder infections, making a point-source of infection less likely.</p>","PeriodicalId":15615,"journal":{"name":"Journal of Dairy Research","volume":" ","pages":"1-8"},"PeriodicalIF":1.2,"publicationDate":"2026-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147816209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 yellow-fleshed sweet potato powder on the quality and stability of yoghurt during storage.","authors":"Po-Hsien Lu, Yin-Yen Huang, Yung-Chang Lai, Fatma Laili Khoirunnida, Ying-Chen Lu","doi":"10.1017/S0022029926102283","DOIUrl":"https://doi.org/10.1017/S0022029926102283","url":null,"abstract":"<p><p>This research paper addresses the hypothesis that the incorporation of yellow-fleshed sweet potato powder (SPP) into yoghurt can enhance its physicochemical, microbial and textural properties while improving storage stability. This study aimed to develop a yoghurt product incorporating yellow-fleshed SPP and to evaluate its effects on physicochemical, microbial and textural properties during fermentation and a 28-day storage period. SPP was added at concentrations of 0%, 5%, 10%, 15% and 20% (w/v) to milk prior to fermentation. Parameters including pH, titratable acidity (TA), syneresis, viscosity, hardness, adhesiveness, colour attributes and microbial viability were measured. The addition of SPP positively influenced the fermentation process, significantly increasing total plate count, TA, viscosity and adhesiveness, while reducing pH, syneresis and hardness. Colour analysis showed that supplementation decreased <i>L</i>* values and whiteness index while increasing <i>a</i>*, <i>b</i>*, yellowness index and Δ<i>E</i>*, depending on the amount added. During storage, yoghurts with 5-10% SPP maintained superior textural stability, lower syneresis, minimal colour changes and preserved microbial viability compared to the control and higher concentration treatments. Otherwise, 15-20% additions resulted in reduced bacterial counts and destabilised gel structure. These results suggest that yellow-fleshed SPP acts as a natural stabiliser and prebiotic, enhancing yoghurt quality and storage stability. An optimal addition of 5-10% is recommended to maximise functional and sensory benefits without compromising product integrity, offering promising potential for the development of value-added, health-oriented dairy products targeting modern consumers.</p>","PeriodicalId":15615,"journal":{"name":"Journal of Dairy Research","volume":" ","pages":"1-9"},"PeriodicalIF":1.2,"publicationDate":"2026-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147816139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sources of variation in milk osmolality in dairy cows.","authors":"Birgitta Staaf Larsson, Anna Jansson, Kristina Dahlborn","doi":"10.1017/S0022029926102295","DOIUrl":"https://doi.org/10.1017/S0022029926102295","url":null,"abstract":"<p><p>This is a descriptive longitudinal pilot study aimed at investigating the individual variation in milk osmolality, within and between cows, both diurnally and over one lactation. Milk samples from 21 Swedish Holstein (<i>n</i> = 9) and Swedish Red Breed (<i>n</i> = 12) dairy cows on one farm were collected 5-44 days after calving, then monthly for 12 months. During the first month, samples were also obtained every second hour (during the day) for 4 days. Milk samples were collected by hand milking in 10 ml tubes and analysed in a Fiske osmometer. The sample collection time was measured, and individual variation in milk osmolality was investigated within both days and months. In addition, bulk-tank milk samples (including milk from additional 230 cows) were collected at the end of each sampling day, with osmolality varying between 286 and 305 mOsm/kg among days. Individual osmolality ranged from 279 to 317 mOsm/kg, and there were significant variations in the mean milk osmolality between cows (2% variation). The individual osmolality varied significantly within days (up to 8%) and over months (up to a 13% variation). Swedish Red Breed cows had higher (1%, <i>P</i> = 0.02) osmolality (301 ± 1 mOsm/kg) than Swedish Holstein cows (299 ± 1 mOsm/kg). The observed differences range from 1% to 9% with variations between breeds being the smallest and those between months/lactation stages and individuals being the largest. It is concluded that there are variations in milk osmolality between individuals, days and breeds that exceed what can be interpreted as thirst-stimulating (+1-2%). Since the variation among clinically healthy animals and over time is considerable, there is potentially a challenge to the practical use of milk osmolality as an indicator of hydration state to be of practical use. Further studies are needed to understand the variations in milk osmolality when cows are water deprived.</p>","PeriodicalId":15615,"journal":{"name":"Journal of Dairy Research","volume":" ","pages":"1-7"},"PeriodicalIF":1.2,"publicationDate":"2026-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147772982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extending the shelf life of pasteurized milk through microfiltration and implementation of a comprehensive safety and quality management system: case study at the farm and dairy plant.","authors":"Sana Gammoh, Muhammad H Alu'datt, Mohammad N Alhamad, Carole C Tranchant, Taha Rababah, Mohammad Alrosan, Bayan Obeidat, Haya Alzoubi, Ala'a Al-Tawaha","doi":"10.1017/S0022029926102234","DOIUrl":"https://doi.org/10.1017/S0022029926102234","url":null,"abstract":"<p><p>This study aimed to implement good hygienic practices and good manufacturing practices programmes, together with the hazard analysis critical control points (HACCP) system, to produce extended shelf-life (ESL) pasteurized milk using crossflow microfiltration. The microbiological quality of raw milk was markedly improved upon implementation of hygienic prerequisites and HACCP, resulting in a reduction of total colony count (TCC), <i>Staphylococcus aureus</i>, psychrotrophs, yeasts and moulds, spore-forming bacteria, <i>Salmonella</i>, coliforms and <i>Escherichia coli</i>. All the milk samples tested negative for antibiotics and aflatoxin <i>M</i>₁. Pasteurized and homogenized milk was microfiltered through a 0.8 or 0.45 μm pore-size membrane to produce ESL whole milk and ESL partly skimmed (2%) milk, respectively, resulting in further improvement of refrigerated shelf life to about 2 weeks and 3 weeks, respectively. ESL 2% milk showed a significantly lower TCC compared to ESL whole milk, and the latter also had a lower TCC than pasteurized whole milk. Both ESL milk products showed negligible denaturation of α-lactalbumin and β-lactoglobulin. The results demonstrate the effectiveness of combining microfiltration with on-farm and in-plant safety management systems for ensuring the safety and quality of ESL pasteurized milk.</p>","PeriodicalId":15615,"journal":{"name":"Journal of Dairy Research","volume":" ","pages":"1-15"},"PeriodicalIF":1.2,"publicationDate":"2026-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147729095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Circular food resources as feed in South Asia: practices, gaps and implications for livestock systems - a systematic review with a focus on dairy production.","authors":"Shahin Alam, Thomas Hartinger, Md Elias Uddin, Jenia Mukherjee, Timothy J Krupnik, Eva Schlecht, Christoph Dittrich","doi":"10.1017/S0022029926102246","DOIUrl":"https://doi.org/10.1017/S0022029926102246","url":null,"abstract":"<p><p>This review explores the potential of circular food resources (CFRs) as animal feed in South Asian countries, with particular attention to dairy production systems. The review examines how CFRs are produced and supplied, identifying barriers to adoption, and evaluating existing governance and management frameworks to enable their integration into dairy feeding systems. A total of 24 research articles published in English between 2000 and 2025 met the selection criteria. Studies were included if they addressed CFRs in relation to feed types, processing methods, revalorization, life cycle assessments, circular economy models, relevant legislation, incentives and barriers to adoption. A thematic analysis was conducted to identify key patterns, trends and gaps in literature using MAXQDA. The review highlights that a large share of organic CFRs comes from private households, supermarkets, the hospitality sector and food industries. However, CFR management is still dominated by uncontrolled dumping and open burning, and only limited quantities are reused as feed, even though they could serve as a potential feed resource for dairy animals. Urban and peri-urban dairy farmers face adoption barriers such as contamination with inorganic materials, lack of regulation, insufficient nutritional, hygienic and safety data, and low awareness of impacts on animal performance. At conceptual level, the lack of integrated frameworks and stakeholder engagement limits the development of circular practices. At governance level, weak regulations and coordination hinder policy support. At management level, insufficient data on nutrition, safety, hygiene and regional availability highlight the need for context-specific evidence. Building on the synthesized findings, the review proposes a Strengths, Weaknesses, Opportunities, and Threats (SWOT) framework to evaluate the opportunities and risks of integrating CFRs into feeding systems. Transitioning from fragmented efforts to systemic change in CFRs-to-feed will require an interdisciplinary and multi-stakeholder approach, to build resilient and sustainable circular food systems in South Asian countries and beyond.</p>","PeriodicalId":15615,"journal":{"name":"Journal of Dairy Research","volume":" ","pages":"1-13"},"PeriodicalIF":1.2,"publicationDate":"2026-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147698999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of water adulteration in camel milk by freezing point.","authors":"Gaukhar Konuspayeva, Moldir Nurseitova, Elizaveta Chuvashova, Zauresh Bilal, Farida Amutova, Bernard Faye","doi":"10.1017/S002202992610212X","DOIUrl":"https://doi.org/10.1017/S002202992610212X","url":null,"abstract":"<p><p>This Research Communication aimed to establish reference freezing point (FP) values for raw Bactrian and dromedary camel milk and to evaluate the detectability of water dilution up to 30% using the cryoscopy method. A total of 38 milk samples from healthy camels in Kazakhstan were analysed. Pure Bactrian camel milk exhibited FP values between -0.542°C and -0.799°C, while dromedary milk ranged from -0.527°C to -0.655°C. Progressive dilution caused a significant linear increase in FP in both species (<i>p</i> < 0.0001). Although a 10% water addition resulted in measurable changes, natural variability may mask slight adulteration. FP showed weak correlations with protein and pH, with species-specific differences. These results provide reliable reference values for the FP and confirm the possibility of detecting adulteration of camel milk.</p>","PeriodicalId":15615,"journal":{"name":"Journal of Dairy Research","volume":" ","pages":"1-4"},"PeriodicalIF":1.2,"publicationDate":"2026-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147627874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}