Dairy Research Bulletin: Selected Articles from November 2025

Environmental Management and Sustainability

Impacts of dairy manure and synthetic fertilizers on greenhouse gas emissions and crop yields: A global meta-analytical comparison. Brar JS, Baath GS, Wyatt BM, et al. Sci Total Environ. 2025 Nov 20;1005:180836.

Dairy manure (DM) is commonly used as an organic nutrient source to improve soil fertility. However, concerns remain about its potential to increase greenhouse gas emissions and reduce crop yields compared to synthetic fertilizers (SF).
This global meta-analysis evaluated and compared the effects of DM and SF applications on greenhouse gas emissions and crop yields, considering different soil properties (texture, pH), nitrogen application rates, crop types, water managements, and climate zones. Additionally, the influence of different DM types and placement methods were examined.
Results showed no significant differences in methane emissions and grain yield between DM and SF across most conditions. However, fine-textured soils exhibited higher soil carbon dioxide emissions with DM application. Elevated soil carbon dioxide emissions were also observed with DM in alkaline soils (pH 7.4-7.6), while slightly acidic soils (pH 5-6.5) favored higher crop yields.
Lower DM application rates (≤200 kg N ha^-1) reduced crop biomass and increased soil carbon dioxide emissions, though grain yields remained comparable to SF. Crop-specific effects included higher nitrous oxide emissions from barley (Hordeum vulgare L.) and lower corn (Zea mays L.) yields under DM than SF.
Higher soil carbon dioxide emissions were associated with DM in cooler climates and under irrigation.
Among DM types, liquid DM increased nitrous oxide emissions, whereas composted DM enhanced crop yields. Sub-surface DM application mitigated nitrous oxide emissions while maintaining yields.
Findings suggest that DM can be effectively utilized without increasing greenhouse gas emissions or compromising crop yields compared to SF, provided that site-specific factors and trade-offs are carefully managed.

Waste concrete stabilization of soluble phosphorus in dairy cattle manure to reduce runoff risk and maintain fertilizer value in a greenhouse pot test. Zhao T, Omelon S. Sci Total Environ. 2025 Nov 11;1006:180818.

A modern agricultural challenge is large and localized mass production of manure due to agricultural intensification. While manure is an effective fertilizer, its soluble inorganic orthophosphate (o-Pi) content can increase phosphorus (P) runoff risk and contribute to excessive P soil concentrations if its land application is not restricted.
Stabilization of soluble o-Pi in manure as calcium phosphate solids could mitigate the P runoff risk without reducing its nutrient value.
Waste concrete powder was investigated as a source of calcium ions and alkalinity to form calcium phosphate solids in manure. Ground and sieved waste concrete powder from a local overpass demolition site was mixed with dairy cattle manure and water in a range of ratios.
The inorganic apatite-type P fraction increased in the waste-concrete-manure mixtures, suggesting the formation of Ca-P solids.
The P fertilizer potential of two optimized 30 ppm TP waste-concrete-manure mixtures was compared to 30 ppm TP manure, a synthetic o-Pi ladder (0, 15, and 30 mg P/kg soil), and 15 ppm synthetic P mixed with excessive waste concrete in synthetic soils. Spring wheat sprouts were grown for eight weeks in a greenhouse.
Mehlich-3 extractable o-Pi of the 30 ppm TP waste-concrete-manure synthetic soil was significantly lower than for 30 ppm TP manure, and 15 or 30 ppm synthetic P. The sprout tip P uptakes were highest for the 30 ppm synthetic P soil, and were similar for the soils with 15 ppm synthetic P, and 30 ppm TP manure and waste-concrete-manure mixtures.
This indicates the potential to lower the o-Pi runoff risk associated with excessive manure land application while not reducing P availability.

Valorising Whey: From Environmental Burden to Bio-Based Production of Value-Added Compounds and Food Ingredients. Selmi H, Presutto E, Spano G, Capozzi V, Fragasso M. Foods. 2025 Oct 25;14(21):3646.

Cheese manufacturing generates large volumes of whey with high biochemical and chemical oxygen demand, historically treated as waste. Yet, whey is rich in lactose, proteins, and minerals that can be fractionated and upgraded into foods and bio-based products.
During cheese production, 80% to 90% of the total volume is discarded as whey, which can cause severe pollution. However, milk by-products can be a natural source of high-value-added compounds and a cost-effective substrate for microbial growth and metabolites production.
The current review focuses on cheese whey as a key milk by-product, highlighting its generation and composition, the challenges associated with its production, methods for fractionating whey to recover bioactive compounds, its applications in functional food development, the barriers to its broader use in the food sector, and its potential as a substrate for producing value-added compounds.
Particularly, the focus was on the recent solutions to use cheese whey as a primary material for microbial fermentation and enzymatic processes, producing a diverse range of chemicals and products for applications in the pharmaceutical, food, and biotechnology industries.
This review contributes to defining a framework for reducing the environmental impacts of whey through its application in designing foods and generating biomaterials.

Potential of silage inoculants to mitigate methane production from the rumen: A systematic review. Afonso RB, Adivi LN, Stanton C, et al. J Dairy Sci. 2025 Nov 7:S0022-0302(25)00906-3.

Methane (CH₄) emissions from enteric fermentation in ruminants represent the largest source of anthropogenic agricultural emissions, contributing significantly to global CH₄ Enteric CH₄mitigation strategies have been intensively investigated to address the detrimental effects on climate change and ruminant production characteristics.
This systematic review investigated whether microbial silage inoculants could reduce CH₄formation in the rumen microbiome, both ex vivo and in vivo, based on available literature.
Among the 10 selected studies, 9 measured CH₄production using in vitro assays, whereas one reported an in vivo trial. The majority of the experiments (70%) were conducted using cattle rumen samples, including the in vivo study involving cattle, the remainder of the experiments used rumen samples obtained from sheep.
Ten bacterial species were used as inoculants across the selected studies. Lactobacillus buchneri, used in combination with additives, achieved the highest CH₄reduction at 83%. Lactobacillus plantarum also showed a significant reduction in CH₄ output, achieving a 48% decrease.
Overall, 80% of the reviewed studies reported a reduction in CH₄production by ruminant microorganisms following the application of silage microbial inoculants. These findings suggest that silage microbial inoculants hold promise as a strategy to mitigate CH₄ emissions in livestock.
The limited number of studies highlights the need for further research to confirm these results and explore wider applications.

Resilience and Robustness in the Service of Longevity and Sustainable Efficiency in Dairy Production. Ithurbide M, Bouquet A, Friggens NC, et al. Annu Rev Anim Biosci. 2025 Nov 10.

Dairy cattle industries navigating increasingly frequent climate disruptions and volatile input costs must maintain productivity while simultaneously minimizing environmental impacts.
This article examines how resilience (ability to recover from short-term disturbances) and robustness (capacity for long-term adaptation to challenging environments) contribute to longevity and lifetime efficiency in farm animals.
Resilience reduces aging costs by enhancing recovery from environmental perturbations, e.g., health challenges, whereas robustness involves resource allocation strategies that facilitate survival in constraining environments.
Both traits exhibit moderate heritability, offering opportunities for genetic improvement. However, their expression varies significantly across environments, necessitating context-specific selection approaches.
Simulation studies, using models that incorporate robustness and resilience mechanisms, demonstrate that genotype-by-environment interactions strongly influence the economic and environmental benefits of selecting for these traits.
In conclusion, incorporating resilience and robustness into breeding objectives can improve lifetime efficiency, particularly in challenging environments, but their economic value must be evaluated carefully in relation to specific production systems and anticipated future conditions.

Animal Health and Food Safety

Effect of water quality on performance and health of dairy calves. Carvalho NI, Oliveira ICR, Bittar CMM, et al. J Dairy Sci. 2025 Nov 7:S0022-0302(25)00899-9.

Water quality plays a crucial role in calf health and performance, mainly when it is used to dilute milk replacers, which can affect the incidence of diarrhea.
This study assessed the effects of municipal tap water (TW) compared with purified water (PW) on calf performance and health.
Thirty Holstein calves were randomly assigned to 2 treatment groups in a randomized block design. Calves received 6 L/d of milk replacer (14% solids) diluted with the respective water treatment until gradual weaning (49-53 d).
A pelleted starter was offered from birth, and chopped hay was provided ad libitum from 49 to 70 d. Dry matter intake, water intake, and health scores were recorded daily. Average daily gain was measured weekly, whereas body measurements and blood samples were collected biweekly.
The PW tended to improve feed efficiency and increased ADG in the third week of life, but the final BW did not differ between treatments. Calves that received PW consumed more hay and tended to have greater water intake.
Moreover, PW reduced day with diarrhea and the number of antibiotic treatments. Blood metabolites varied primarily with age, except for higher albumin concentrations in TW calves at wk 10.
In summary, the PW tended to enhance performance during preweaning, particularly after diarrhea episodes. These findings highlight the importance of water quality during early life, but further studies are needed to determine the effect on dairy calf health.

A good start: early-life risk factors associated with dairy cow longevity. Thomsen PT. J Dairy Res. 2025 Nov 7:1-6.

Dairy cow longevity affects production economy, climate footprint, and cow welfare.
Based on data from the Danish Cattle Database, this research paper evaluates the relationship between early-life risk factors associated with the period before first calving and cow longevity, including data from all Danish dairy cows culled in 2019-2023.
Explanatory variables for linear mixed models included calf size, twinning, and age at first calving. Information about the length of productive life (LPL) (mean: 1,074 days) and lifetime milk yield (mean: 32,088 kg energy-corrected milk) was available for 767,305 and 716,120 cows, respectively.
Milk yield per day of life increased from 7 kg in cows culled during the first lactation to more than 20 kg in cows culled in their fifth or later lactations. For cows born as singletons, LPL was one month longer for cows born as large calves than for medium-sized calves, and 2 months longer than for small calves.
Cows born as twins had 2 to 3 months shorter productive lives compared to cows born as singletons. For singletons, lifetime milk yield was 1,200 kg higher for large calves than for medium-sized calves, and 2,100 kg higher than for small calves. Lifetime milk yield was 1,500 to 3,500 kg lower in cows born as twins.
Cows being among the third quartile of age at first calving had an estimated productive life 2.5 months longer, and a lifetime milk yield more than 2,600 kg higher than cows calving among the first quartile of age.
The results from this study clearly demonstrate the importance of ‘a good start’.

CDRF-Funded Research – Replacement of cottonseed with an extruded flaxseed-based supplement alters milk fatty acid profile without affecting yield or methane emissions in Holstein dairy cows. Akter A, Li X, Grey E, Wang SC, Kebreab E. J Dairy Sci. 2025 Nov 27:S0022-0302(25)00969-5.

Fats are considered effective in reducing enteric methane (CH₄) emissions in ruminants, but limited research exists on the use of flaxseed fatty acids for this purpose in Holstein dairy cows.
Therefore, researchers evaluated the effects of an extruded flaxseed-based supplement that included a mix of flaxseed, peas, and alfalfa hay (LinPRO-R) on enteric CH₄emissions and milk quality.
Holstein cows (n = 24, 113 ± 31 DIM) were arranged in a 3 × 3 Latin square design and assigned to one of the 3 treatments: control (CON), ration containing 4.5% LinPRO (4.5% LinPRO-R), or ration containing 9% LinPRO (9% LinPRO-R) on a DM basis.
In the 9% LinPRO-R group, cottonseed was replaced with the flaxseed supplement; therefore, the fatty acid profile was altered, and the forage NDF increased with higher inclusion. However, the total fat content of different diets remained similar.
After 2 weeks of adaptation, each of the experimental periods lasted for 28 days. Milk yield and enteric emissions were captured daily. Weekly milk samples were analyzed for milk fat, protein, lactose, SNF, MUN, and SCC. All data were analyzed using a mixed model ANOVA in the GLIMMIX procedure in SAS (SAS Institute Inc.).
Body weight change, DMI, and milk yield did not differ among the different LinPRO-R treatments. Milk fat percentage was lower in LinPRO-R supplemented cows compared with the CON group (CON: 4.67 ± 0.14%, 4.5% LinPRO-R: 4.47 ± 0.14%, and 9% LinPRO-R: 4.51 ± 0.14%), but milk protein, lactose, SNF, MUN, and SCC were unaffected.
Methane and CO₂emissions did not differ among treatments, whereas H₂ production was lower in CON than in 9% LinPRO-R (CON: 4.42 ± 0.14 g/d, 4.5% LinPRO-R: 4.66 ± 0.14 g/d, and 9% LinPRO-R: 4.88 ± 0.14 g/d).
The percentage of cis-9 C18:1 in milk fat was higher in the 9% LinPRO-R group compared with the CON and 4.5% LinPRO-R groups. The percentage of C18:3n-3 was greater in LinPRO-R-supplemented cows (CON: 0.52 ± 0.03%, 4.5% LinPRO-R: 1.05 ± 0.03%, and 9% LinPRO-R: 1.46 ± 0.03%).
Therefore, supplementation of Holstein cow diets with 4.5% and 9% LinPRO-R did not affect milk yield or enteric CH₄emissions, likely due to alterations in forage NDF content and the dietary fatty acid profile.

UC Davis Research – Daily Milk Losses Associated with Dairy Cow Bunching, Cattle’s Protective Behavior Against Stable Flies (Stomoxys calcitrans) in California. ElAshmawy WR, Ferreira FC, Williams DR, Gerry AC, Aly SS.Vet Sci. 2025;12(11):1035.

Cow bunching is a behavioral phenomenon where cattle aggregate in tight groups to protect themselves from biting by stable flies (Stomoxys calcitrans). The incidence of bunching varies between dairies and even among pens within the same dairy, as it is associated with the location-specific biting intensity of stable flies, which largely varies with dairy management and local environmental factors.
Bunching may be associated with decreased feeding and laying times, as well as heat stress due to cattle aggregation. Thus, bunching may affect dairy cows’ milk production by reducing dry matter intake and rumination. To our knowledge, there are no previous studies specifically addressing the effect of cow bunching on milk production in lactating dairy cows.
The objectives of our study were to estimate the economic impact of cow bunching against stable flies on milk production on a commercial California dairy and to estimate the economic losses associated with cow bunching and stable fly biting per cow per year.
A longitudinal study was conducted from 1 May 2017 through 31 July 2017 on a 5000-cow Holstein herd housed in free stall pens in Tulare County, California.
Pen-level cow bunching in four lactating cow pens was recorded weekly for 12 weeks. Bunching observations each day were matched to daily milk records for the study dairy. Two-piece spline linear mixed models were used to estimate the impact of cow bunching and stable fly counts on milk production.
Cows in pens where bunching occurred experienced a significant milk reduction of 0.45 kg ± 0.104 (SE) per cow (p< 0.01) on the day of bunching in comparison to cows in pens without bunching. There was a significant reduction of 0.6 kg/cow/day in milk production associated with each increase in one stable fly per cow leg (standard metric for recording stable fly biting activity) after adjusting for parity, temperature humidity index (THI), and days in milk (DIM).
Based on the economic analysis conducted on weekly bunching and fly counts, modeled milk production losses were reported as weekly loss in milk revenue per cow. The estimated economic loss associated with cow bunching and stable fly counts was highest during the last week of May (USD 0.34/cow/week and USD 1.86/cow/week, respectively) and was lowest during the last week of July (USD 0.03/cow/week and USD 0.29/cow/week, respectively).
To mitigate the most substantial economic loss, dairy producers should focus their efforts on controlling stable flies during the early stable fly season, when stable fly abundance tends to be highest.

Detection of H5N1 highly pathogenic avian influenza virus RNA in filth flies collected from California farms in 2024. Nayduch D, Scroggs SLP, Shults P, Brendel LA, Reister-Hendricks LM, Taylor C, Bird E, Lopez B, Marshall ES. Sci Rep. 2025 Nov 28.

The emergence of highly pathogenic avian influenza (HPAI) H5N1 clade 2.3.4.4b in U.S. dairy cattle highlights the urgent need to understand transmission dynamics within and among farms.
House flies (Musca domestica) and blow flies (Calliphoridae), ubiquitous in agricultural settings, are suspected mechanical vectors of numerous pathogens, including viruses. We investigated the presence of H5N1 viral RNA in filth flies collected opportunistically from four H5N1-positive farms (three dairy and one poultry) in California during the 2024 outbreak.
H5N1 RNA was detected via qRT-PCR in fly pools from all four locations, with the lowest Ct values (highest viral RNA) in house flies collected near milking parlors and dead animals. Whole-genome sequencing confirmed H5N1 viral genomes in flies from dairy farms, demonstrating high similarity (99.92–99.95%) to the B3.13 lineage circulating in the region and grouping closely with farm-associated viral sequences from milk.
Although infectious virus was not detected in this study, our findings suggest that filth flies acquire HPAI H5N1 RNA from their environment, supporting their potential role as sentinels and/or mechanical vectors.
These results underscore the critical importance of fly control, targeted surveillance, and integrated pest management strategies in agricultural settings to enhance biosecurity and potentially mitigate HPAI H5N1 transmission.

The effect of different levels of heat stress on the behavior of cows at different stage of lactation. Baccouri W, Wanjala G, Tóth V, Komlósi I, Mikó E. J Therm Biol. 2025 Nov 14;134:104334.

Rising temperatures and humidity increasingly challenge the welfare and productivity of dairy cows worldwide. Behavioral changes are among the earliest responses to heat stress, reflecting animals’ efforts to reduce heat load.
This study investigated how heat stress and lactation stage interact to influence the behavior of Holstein Friesian cows.
Data were collected from 60 cows between 20 June and July 20, 2024, with 1680 records of eating, ruminating, and inactivity times. Cows were grouped by lactation stage: early (days in milk, (DIM) ≤ 60), mid (DIM 61-180), and late (DIM >180). Behavior was assessed under moderate (temperature-humidity index, (THI) 72-76) and severe heat stress (THI ≥77).
A significant interaction was observed between the level of heat stress and lactation stage. Under severe heat stress, eating time declined significantly across all lactation groups, with the largest reduction observed in late-lactation cows. Ruminating time decreased significantly only in late-lactation cows, while remaining relatively stable in early and mid-lactation.
Conversely, inactivity time increased in all groups, with the duration of inactivity rising as lactation advanced. These results suggest that behavioral responses to heat stress intensify with advancing lactation.
In conclusion, late-lactation cows are more susceptible to heat stress than those in earlier stages, indicating a need for targeted mitigation strategies to support cow welfare and productivity.

Modeling the Influence of Macronutrients on the Heat Resistance of Salmonella in Milk Powder. Wei X, Lian Y, Liu S. Foods. 2025 Nov 1;14(21):3757.

Multiple Salmonellaoutbreaks linked to milk powders call for the need for effective pasteurization processes. Understanding the thermal inactivation kinetics of Salmonella in milk powder is crucial; however, the influence of macronutrient content (protein, fat, and carbohydrate) on these kinetics remains unclear.
This study investigated the effects of common reconstitution temperature (45, 70, and 99 °C) on Salmonellasurvival in infant milk powder to raise public awareness about contamination risks.
Seven milk powders with varying macronutrient compositions were used as model systems. After equilibrating to a uniform water activity (a_w= 0.2), the thermal resistance of Salmonella was determined at 75, 80, and 85 °C. The goodness-of-fit of two primary models (log-linear and Weibull) was compared, and secondary response surface models were developed to predict the combined effects of temperature and macronutrient composition on Salmonella
Results showed that Salmonellacould proliferate or be resuscitated when contaminated milk powder was reconstituted at conventional preparation temperatures (45 °C and 70 °C).
Across the seven formulations, Salmonellathermal resistance (D-value) increased with protein content (10.44-90.18%) and decreased with carbohydrate content (0.35-63.24%). A significant protein-temperature interaction was observed, whereby the effect of protein content on the Salmonella D-value decreased as temperature increased from 75 to 85 °C. Fat content did not significantly affect thermal inactivation (p > 0.05).
Overall, this research quantifies how macronutrient composition impacts Salmonellathermal resistance and offers predictive models to improve pasteurization strategies for milk powder.

Nutrition and Health

Consumption of Dairy Products and Abdominal Obesity in Adults: A Systematic Review and Dose-Response Meta-Analysis of Epidemiologic Studies With GRADE Assessment. Rouhani P, Mokhtari E, Soltani S, Saneei P. Nutr Rev. 2025 Nov 9:nuaf189.

Abdominal obesity is a risk factor for cardiometabolic diseases, and dietary factors such as dairy products may play a role. However, findings on the association between dairy product consumption and abdominal obesity remain inconsistent.
The purpose of this study was to investigatethe association between types of dairy product consumption and abdominal obesity in adults.
The researchers conducted a systematic search for observational studies. This review comprised 28 observational studies (n = 6 cohort and 22 cross-sectional) that assessed the relationship between total dairy and/or milk, yogurt, or cheese consumption as exposures and abdominal obesity in adults as the outcome.
The results revealed that the highest (vs lowest) amount of total dairy consumption was significantly related to a 16% reduced odds of abdominal obesity in adults. Dose-response analysis showed that each 160 g d-1 increment in total dairy consumption was linearly related to a significant 8% reduced odds of abdominal obesity.
A U-shaped significant association in nonlinear dose-response analysis was found between total dairy consumption and abdominal obesity. Pooling effect sizes from 9 eligible studies with 47,778 participants showed that higher amounts of yogurt consumption was related to a 21% reduction in abdominal obesity.
Stratified analysis based on dairy fat showed significant inverse relations between whole-fat dairy (OR = 0.73) and yogurt (OR = 0.79) and central obesity.
The results of this meta-analysis suggest dairy consumption, even whole-fat products, was associated with lower odds of abdominal obesity in adults.

Dairy products intake and its association with cognitive function in older adults: A systematic review and dose-response meta-analysis. Gao T, Li Y, Xu X, et al. Clin Nutr. 2025;55:24-41.

Emerging evidence suggests a possible association between dairy product intake and cognitive function in older adults; however, previous findings remain inconsistent.
This study aimed to systematically evaluate the association between dairy intake and cognitive outcomes in older adults, and explore potential dose-response relationships and regional differences.
Researchers searched PubMed, MEDLINE, Embase, Cochrane Library, Scopus, and CINAHL from their inception to 31 December 2024. Dose-response analysis was performed for cohort studies to assess the impact of different types and quantities of dairy intake on cognitive subdomains.
A total of 38 studies were included, comprising 21 cohort studies, 15 cross-sectional studies, and 2 randomized controlled trials. The researchers stratified dairy products intake levels, and found that higher total dairy intake was associated with a reduced risk of cognitive decline and improved global cognitive function (Cohort: medium vs low, RR: 0.92; high vs low, RR: 0.85; Cross-sectional: high vs low, OR: 0.64).
Fermented dairy products were associated with improved verbal memory and executive function, whereas higher milk intake showed a potential association with poorer verbal memory in certain instances.
Evidence showed nonlinear associations, with the lowest risk of cognitive decline associated with a daily intake of 150 g of dairy products (RR: 0.86), and 30 g/day of whole-fat dairy (RR: 0.83).
Regional differences were observed, with cognitive outcomes varying between European and Asian populations, possibly reflecting dietary habits and cultural contexts.
In conclusion, dairy intake, especially fermented products and moderate total intake, may support cognitive health in older adults, though associations vary by region and dairy type. More high-quality studies are needed to clarify these relationships and guide dietary recommendations.

Cheese Consumption and Incidence of Dementia in Community-Dwelling Older Japanese Adults: The JAGES 2019-2022 Cohort Study. Jeong S, Suzuki T, Kondo K, et al. Nutrients. 2025;17(21):3363.

Dementia is a growing public health concern in rapidly aging Japan. Dietary factors, including dairy products, have been proposed as modifiable influences on cognitive health, although findings across studies remain inconsistent.
This study aimed to examine the association between habitual cheese consumption and incident dementia in a large, population-based cohort of older Japanese adults, and to provide epidemiological evidence regarding its potential preventive role in populations with low baseline dairy intake.
Researchers analyzed data from the Japan Gerontological Evaluation Study (JAGES) 2019-2022 cohort, linking survey responses to long-term care insurance (LTCI) certification records. Cheese consumption was assessed at baseline and categorized as ≥1 time/week vs. non-consumers. Propensity score matching (PSM) was applied on sociodemographic and health-related covariates.
After PSM, 7914 participants were analyzed (3957 consumers; 3957 non-consumers). Baseline covariates were well-balanced. Over 3 years, 134 consumers (3.4%) and 176 non-consumers (4.5%) developed dementia, corresponding to an absolute risk difference of 1.06 percentage points.
Cheese consumption was associated with a lower hazard of dementia (HR = 0.76).
In conclusion, habitual cheese consumption (≥1 time/week) was modestly associated with a reduced 3-year incidence of dementia in older Japanese adults. While the absolute risk reduction was small, these findings are consistent with prior observational evidence linking dairy intake to cognitive health.

Emerging insights into dairy products and Alzheimer’s disease: exploring the potential neuroprotective effects. Basha S, Ks P, Chattopadhyay A, Ramakrishna Pai A, Kishore Mahato K. Crit Rev Food Sci Nutr. 2025 Nov 17:1-28

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by cognitive decline, synaptic dysfunction, and chronic neuroinflammation. While genetic and environmental factors are well-established contributors, emerging evidence suggests that diet, particularly dairy intake, may modulate AD risk.
This review critically evaluates epidemiological and clinical findings on the neuroprotective potential of dairy products.
Bioactive components, including milk-derived peptides, milk fat globule membrane (MFGM), and fermentation-derived metabolites, exhibit antioxidant and neurotrophic properties that support mitochondrial function and synaptic plasticity. Fermented dairy products may further influence cognition through modulation of the gut-brain axis and production of neuroactive microbial metabolites.
Observational studies often indicate a positive association between dairy consumption and cognitive health, yet findings remain inconsistent, with neutral or contradictory outcomes reported. Clinical investigations are limited by small cohorts, heterogeneous methodologies, and population variability.
Overall, dairy represents an accessible source of bioactive compounds with potential to promote cognitive resilience, though robust longitudinal and interventional studies are required to establish causality and inform dietary guidelines.

Examining the causal link between cheese intake and susceptibility to type 2 diabetes through metabolic traits: Insights from Mendelian randomization. Yang Y, Wang X, Yang W. J Dairy Sci. 2025 Nov 20:S0022-0302(25)00878-1.

Type 2 diabetes (T2D) is a global metabolic disorder influenced by diet. While cheese consumption has been suggested to protect against T2D, the mediating metabolic pathways remain unclear.
Using Mendelian randomization (MR), researchers analyzed genetic variants associated with cheese intake (UK Biobank) and their effects on T2D risk (FinnGen) via 249 metabolites.
Instrumental variables were selected under stringent criteria. Causal estimates were derived via inverse-variance weighted method, with sensitivity analyses (MR-Egger method) and mediation testing.
Cheese intake was inversely associated with T2D risk (odds ratio [OR] = 0.616). Of 249 metabolites, 26 mediated this relationship, including triglycerides (e.g., total triglycerides levels, 3.55% mediation), free cholesterol (e.g., free cholesterol levels in high-density lipoprotein, 5.84%), glucose (3.43%), and albumin (2.69%).
Among the 66 metabolites identified as T2D-associated, notable examples included: AA (Phe OR = 1.14, Leu OR = 1.22, Val OR = 1.13), ketone bodies (acetoacetate OR = 1.62, 3-hydroxybutyrate OR = 1.36), and protective factors (albumin OR = 0.871, apolipoprotein A1 OR = 0.871).
Cheese consumption may lower T2D risk primarily by modulating lipid metabolites (triglycerides, cholesterol esters) and albumin. These findings highlight novel metabolic pathways for dietary prevention of T2D and underscore the need for research on cheese-specific components (e.g., fermentation byproducts).

Effects of whey protein isolate on the human gut microbiota and intestinal function in older adults. Rackerby B, Kim E, Bobe G, Dallas DC, Park SH. J Dairy Sci. 2025 Nov 27:S0022-0302(25)00975-0.

Whey protein is commonly used to prevent sarcopenia in older adults due to its high digestibility and amino acid content. Its bioactive components may also influence the gut microbiota, which plays a growing role in healthy aging as microbial composition shifts with age.
This study investigated whether daily supplementation with whey protein isolate (WPI) improves gut microbiota diversity and composition in older adults. Sixteen participants consumed 59 g of WPI (35 g of protein) daily for 3 wk.
Whey protein isolate significantly increased Simpson diversity in individuals with low baseline diversity, with effects appearing by d 3 and persisting after intervention. Taxonomic analysis revealed increases in beneficial taxa (e.g., Ruminococcaceae, Faecalibacterium, and Christensenella) and reductions in potentially harmful groups (e.g., Proteobacteria, Streptococcaceae, and Colidextribacter), particularly in the low diversity group.
ANCOM-BC analysis based on absolute abundance confirmed increases in probiotic genera including Lactobacillus, Lactococcus, and Christensenella. Despite these microbial shifts, no significant changes were observed in gastrointestinal symptoms or stool consistency.
These findings highlight the potential of WPI supplementation as a dietary strategy to promote a healthier gut microbiome in older adults, particularly in those with low baseline diversity.

Bioactive compounds in milk/dairy foods and their value to health at key life stages: Functionality beyond nutrient supply. Givens DI. Proc Nutr Soc. 2025 Nov 24:1-34.

This review aims to highlight some of the key bioactive functionalities that a range of components in milk can potentially make to reduce risks to health at key life stages. Such functionalities cannot be adequately explained by traditional estimates of nutrient supply.
The benefits of gangliosides from the milk fat globule membrane (MFGM) for neonatal neurodevelopment are examined along with milk proteins for growth stimulation of children via the proteins’ ability to stimulate insulin-like growth factor-1 (IGF-1).
Exosomes in bovine milk and their miRNA are bioavailable, with an animal study indicating that placenta development and embryo survival were both enhanced.
Concerning bone health, the unique characteristics of the casein micelle for supplying Ca, P and Mg to the GI tract were considered.
The so-called dairy food matrix and the hypotensive effect of some peptides from milk proteins may be compensatory factors for SFA regarding CVD risk.
The recent rise in use of glucagon-like peptide-1 (GLP-1) receptor agonists for adiposity reduction and improving glycemic control is noted alongside evidence that milk proteins can stimulate GLP-1 synthesis potentially reducing GLP-1 receptor agonist need in high milk protein consumers.
Other functionality included the ability of whey proteins to stimulate synthesis of skeletal muscle protein, crucial for bone protection and glycemic control and the role of milk/Ca for reducing colorectal cancer risk.
Perhaps the most exciting functionality is that of polar phospholipids in the MFGM potentially improving cognition and reducing the risk of dementia in the elderly. Clearly more human studies are needed.

Innovation, Social Science, and Dairy Alternatives

Effect of High-Pressure Processing Operating Parameters on Microbial Inactivation and Bioactive Protein Preservation in Bovine Milk: A Systematic Review. Sykora R, Mark C, Dallas DC, et al. Compr Rev Food Sci Food Saf. 2026 Jan;25(1):e70324.

In the U.S., bovine milk is processed using thermal pasteurization to ensure microbial safety. However, this process alters the structure of heat-sensitive bioactive proteins associated with the functional benefits of raw milk, including antimicrobial, immunomodulatory, and antioxidant proteins.
Given the risks associated with raw milk consumption and the negative effects of thermal processing on protein functionality, there is a growing interest in high-pressure processing (HPP), an alternative treatment that may better preserve milk’s functional qualities. HPP is widely used in other food sectors but is not yet approved for milk in the U.S. Most studies have investigated either the microbial safety or the preservation of bioactive protein structure in HPP-treated milk, rarely considering both outcomes together.
Therefore, optimization of HPP treatments for dairy remains incomplete. The goal of this systematic review was to identify optimal HPP operating parameters for simultaneously achieving microbial inactivation and preserving bioactive proteins in bovine milk.
Eighty-nine articles met inclusion criteria from Web of Science, Medline, EMBASE, and PubMed based on a specified search strategy. Pressures ≥600 MPa achieved >5-log average reductions in Listeria monocytogenes, Salmonella enterica, and Staphylococcus aureus, yet often caused considerable denaturation of proteins such as β-lactoglobulin and immunoglobulin G and lesser denaturation of lactoferrin and alkaline phosphatase.
Future research on HPP and bovine milk should evaluate both microbial reductions and impacts on nutrients within the same manuscript to facilitate regulatory evaluation and possible commercial adoption.

Exploring the potential of microwave processing for improved microbial safety and nutritional quality of liquid milk. Huang Y, Tao Y, Fan D, et al. Food Res Int. 2025 Nov;219:116786.

This study systematically compared the effects of microwave (MW) and conventional thermal (CT) processing on microbial inactivation, enzyme activity, protein retention, and nutritional characteristics of bovine milk under pasteurization (70 °C for 20 s) and ultra-high temperature (UHT) sterilization conditions.
Both technologies achieved effective microbial reduction (>4 log CFU/mL) for Escherichia coli, Staphylococcus aureus, and Salmonella spp., complying with EU and FDA safety standards.
Enzymatic analysis demonstrated MW treatment preserved 12.9 % higher lactoperoxidase (LPO) activities than CT processing at 80 °C for 15 s, suggesting enhanced preservation of native enzyme systems.
It is noteworthy that MW treatment improved the retention of whey proteins compared to the CT method, particularly lactoferrin (LF), which has a lower thermal denaturation temperature than the sterilization temperature. Specifically, LF retention increased by approximately 12 % when MW treatment was applied within the pasteurization safety range.
Furthermore, MW processing enhanced protein digestibility, as shown by accelerated β-lactoglobulin (β-Lg) degradation during gastric digestion, which might mitigate allergic reactions associated with whey protein ingestion.
The study also explored the bioactive peptide release during digestion and its subsequent antioxidant activity, finding no significant difference between MW and CT processing. Finally, cell viability assays confirmed that MW-processed milk digestion products maintained high intestinal epithelial cell viability, suggesting that MW transient heating could serve as an effective alternative to conventional methods while preserving both safety and nutritional value.
The findings underscored the potential of MW processing for improving milk safety, protein retention, and functional properties in liquid milk production.

Public Risk Perceptions and Policy Attitudes Toward Highly Pathogenic Avian Influenza (HPAI). Motta M, Lunz Trujillo K, Walter D, et al. J Health Polit Policy Law. 2025 Nov 19:12317977.

Attention to the potential impact of highly pathogenic avian influenza (H5N1, or “bird flu”) on human health increased following documentation of mammalian transmission in Spring 2024, and the prevalence of H5N1 in the commercial dairy supply.
This paper’s aim was to quantify (a) the prevalence and (b) socio-political correlates of public concern about H5N1, as well as support for policy action aimed at reducing its potential health risks.
In a nationally representative survey of N = 831 US adults, researchers asked respondents to answer questions about their levels of concern about H5N1 transmission, beliefs about the safety of consuming unpasteurized milk products, and support for policy interventions.
Few Americans express high levels of concern about the H5N1 health risks. People who express lower levels of concern about H5N1 and those who hold inaccurate or uncertain views toward raw milk safety are in turn less supportive of policies aimed at mitigating the spread of H5N1; as is both anti-intellectual attitude endorsement and partisan identification with the Republican Party.
In conclusion, moderate levels of concern about H5N1 risks could undermine pandemic preparedness. Lacking strong signals from the public, policymakers may be reluctant to pursue policies that reduce avian influenza’s pandemic potential.

Preserving edible biodiversity through indigenous dairy emulsions: valorization of traditional milk systems for a resilient future. Kumar A, Yadav M, Alsanie SA, et al. Front Nutr. 2025 Oct 23;12:1693995.

Traditional dairy emulsions such as ghee, laban, reyab, and fermented camel milk are produced using locally adapted livestock breeds and unique microbial consortia, reflecting centuries of ecological adaptation.
These products are increasingly positioned as functional foods that integrate traditional practices with modern nutritional needs, thereby enhancing dietary diversity and sustainability.
These systems are structurally complex and nutritionally dense, containing bioactive compounds, natural emulsifiers, and probiotics. They contribute to regional food resilience and edible biodiversity through bioactive compounds, natural emulsifiers, and probiotics.
This paper explores the dynamic role of these emulsions in dairy food systems, their biochemical makeup, socio-cultural relevance, and technological avenues for their valorization. Advances in nano and micro emulsion methods, ultrafiltration, and spray drying are investigated for their potential to improve bioavailability, stability, and application while maintaining traditional values.
Recent research has shown that when used correctly, these technologies can preserve or even enhance their health-promoting properties, allowing them to be incorporated into modern diets and treatment formulations. However, their value must be based on ethical considerations for local producers, the preservation of microbiological and cultural variety, and a governmental framework that encourages small-scale, decentralised innovations.
When treated with cultural sensitivity and scientific precision, these technological interventions for the valorisation of traditional dairy systems can increase their nutritional and functional value while conserving their essential identity. These emulsions have the potential to bridge the gap between tradition and innovation, facilitating for the development of diversified, robust, and culturally grounded nutritional practices.

Association between nutritional quality and the degree of naturalness in animal-based and plant-based food products. Guillemette D, Labonté MÈ, Provencher V, et al. J Nutr Sci. 2025 Nov 26;14:e83.

Consumers tend to perceive certain foods as more natural and in turn as more nutritious.
Thus, this study aimed to evaluate the nutritional quality, the degree of naturalness, and their association with animal-based and plant-based food products.
A total of 1275 food products were collected by the Food Quality Observatory in Québec (Canada) between 2018 and 2022. These products were divided into five categories: sliced processed meats (n= 477), yogurts and dairy desserts (n = 344), sausages (n = 266), processed cheese products (n = 96) and plant-based alternatives (n = 92) within these four categories.
The overall nutritional quality was evaluated using the Nutri-Score and the front-of-package (FOP) nutrition symbol recently implemented in Canada, while the degree of naturalness was measured using the Food Naturalness Index (FNI).
Yogurts and dairy desserts as well as plant-based alternatives had lower Nutri-Score and thus, higher nutritional quality compared to other food categories. The FOP symbol for foods high in saturated fat or sodium was more common in sliced processed meats and sausages. FNI scores were higher in processed cheese products than in other categories, indicating a greater degree of naturalness.
Correlations between nutritional quality and food naturalness varied depending on the food category and the nutrient profiling model, with Spearman coefficients being positive or negative and ranging from weak to moderate.
This study supports the idea that food naturalness and nutritional quality offer complementary information depending on the food category. Further research in other food categories would help to better understand the associations between the two concepts.

Hybrid plant-dairy cheese: Effects of lactic acid bacteria and plant proteins on composition, proteolysis, and flavor profile. Luo H, Akkermans S, Wells-Bennik MHJ, et al. Food Chem. 2025;496(Pt 3):146804.

In the search to improve the sustainability of the food supply chain, the market for plant-based cheese analogs is growing. However, sensory defects, particularly related to flavor, remain a challenge.
Here researchers developed a hybrid plant-dairy cheese that balances flavor with sustainability. Out of 44 lactic acid bacteria (LAB) strains that were screened for their acidification and flavor-improving abilities, four were chosen for further testing in a newly developed hybrid MicroCheese system.
Hybrid cheeses could be produced by enriching bovine milk with either rice or pea protein slurry (18 % w/v) in a ratio of 9:1. GC-MS analysis showed that fermentation allowed for reduction of plant protein derived off-flavors but also for production of volatiles that are desired cheese flavors.
Machine learning provided a data-driven understanding of how LAB and plant protein shape hybrid cheese flavor, identifying marker volatiles and enabling differentiation of these cheese types.

The addition of plant protein to yogurt reduces the bioaccessibility of essential elements. Costa-Santos AC, Baptista DP, Gigante ML, et al. Food Res Int. 2025;222(Pt 1):117719.

There is a growing interest in replacing dairy proteins in yogurts with plant ingredients, driven by factors such as population growth, environmental concerns, sustainability, and animal welfare.
Among plant sources, nut proteins have been explored as promising alternatives, as nut-enriched yogurts may provide additional benefits from fibers, polyphenols, and minerals. However, understanding the bioaccessibility of these minerals post-ingestion is crucial for assessing their nutritional impact.
This study evaluated the effect of partial replacement of dairy proteins by almond proteins on total and bioaccessible concentrations of essential minerals (Ca, Mg, P, and Se) in the yogurt.
Control yogurt was made from whole milk powder and calcium caseinate, while hybrid yogurt was composed of 50 % dairy protein substitution by almond protein. The study followed the INFOGEST 2.0 in vitro digestion protocol and applied flame atomic absorption spectrometry, ultraviolet-visible spectrophotometry, and hydride generation atomic absorption spectrometry for mineral quantification.
Although hybrid yogurt exhibited higher total Mg, P, and Se levels, its bioaccessibility was significantly lower. The control yogurt had the highest amounts of bioaccessible Ca (92 %), Mg (81 %), P (58 %), and Se (29 %), compared to the hybrid yogurt, which showed bioaccessible levels of all minerals below 50%.
Among the primary factors influencing mineral bioaccessibility in the hybrid matrix is the presence of antinutritional compounds, including polyphenols and protease-inhibiting peptides inherent to the plant-based component.
The findings suggest that compounds from the plant protein source may have disrupted the gastrointestinal digestion process by impairing enzymatic activity, thereby reducing the release of minerals at the final stage of intestinal digestion.