Dairy Research Bulletin: Selected Articles from August 2024

Environmental Management and Sustainability

The DairyPrint Model: A Decision-Support Model to Help Dairy Farmers and Other Stakeholders Towards Improved Sustainability. da Silva TE, Cabrera VE. J Dairy Sci. 2024 Aug 2:S0022-0302(24)01049-X.

Dairy farmers face increasing pressure to reduce greenhouse gas (GHG) emissions [i.e., carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O)], but measuring on-farm GHG emissions directly is costly or impractical. Therefore, the dairy industry has relied upon mathematical models to estimate those emissions. However, current models tend to be not user-friendly, difficult to access or sometimes very research-focused, limiting their practical use.
To address this, researchers have introduced the DairyPrint model, a user-friendly tool designed to estimate GHG emissions from dairy farming. The model integrates herd dynamics, manure management, crop, and feed costs considerations, simplifying the estimation process while providing comprehensive insights.
The herd module simulates monthly herd dynamics based on inputs as total cows, calving interval, and culling rate, outputting average annual demographics and estimating various animal related variables (i.e., dry matter intake, milk yield, manure excretion, and enteric CH4 emissions).
These outputs feed into other modules, such as the manure module, which calculates emissions based on manure, weather data, and facility type. The manure module processes manure according to farm practices, and the crop module accounts for GHG emissions from manure, fertilizers, and limestone application, also estimating nutrient balances.
Researchers evaluated the model across 32 simulation scenarios by combining various factors and considering a standard free-stall system with 1000 dairy cows averaging 40 kg/day of milk production. These factors included 2 levels of NDF-ADF in the diet (28-22.8% and 24-19.5%), the presence or absence of 3-NOP dietary addition (yes or no) at an average dose of 70 mg/kg DM per cow daily, the type of bedding used (sawdust or sand), the frequency of manure pond emptying [once (only Fall) or twice a year (Fall and Spring)], and the utilization or non-utilization of a biodigester plus solid-liquid separator (Biod + SL).
For the results across the 32 scenarios simulated, the average GHG emission was 0.811 kgCO2eq/kg of milk corrected for fat and protein contents (4% and 3.3%, respectively), ranging from 0.644 to 1.082.
Notably, the scenario yielding the lowest GHG emission (i.e., 0.644 kgCO2eq/kg) involved a combination of factors, including a lower level of NDF-ADF in the diet in addition to incorporation of 3-NOP, utilization of sand as bedding, application of Biod + SL, and strategic manure pond emptying in both Fall and Spring. Conversely, the scenario that resulted in the highest GHG emission (i.e., 1.082 kgCO2eq/kg) involved a combination of higher level of NDF-ADF in the diet and excluded the incorporation of 3-NOP, utilization of sawdust as bedding, no application of Biod + SL, and manure pond emptying only in Fall.
All these scenarios can be easily simulated in the DairyPrint model and results obtained immediately for user evaluation. Therefore, the DairyPrint model can help farmers move toward improved sustainability, providing a user-friendly and intuitive graphical user interface allowing the user to ask what-if questions.

Comprehensive assessment of cow manure hydrothermal treatment products for land application and energy recovery. Ahmed M, Fonseca Acosta N, Garcia Hernandez H, Dupont C. J Environ Manage. 2024 Aug 22;368:122168.

Cow manure is an important source of nutrients evidenced by the common practice of applying manure directly to the land. However, this practice poses an environmental risk, as run-off and leaching of manure components such as nitrogen and phosphorus threaten water quality and lead to eutrophication of surrounding surface waters and contamination of groundwater, in addition to increased methane emissions and odor pollution.
These challenges necessitate environmentally sound alternatives for manure management that promote the principles of organic agriculture and circular bio-economy.
In this study, cow manure was hydrothermally treated in a 2-liter reactor for 1 hour at temperatures between 100 °C and 260 °C.
Both the raw manure and the solid and liquid products of the hydrothermal treatment were characterized to understand the fate of the inorganic elements and to assess the suitability of the products for land applications and energy recovery.
Satisfactory elemental balances were obtained for the organic and most inorganic elements and indicated that most inorganic elements were incorporated into the solids with lower solubility, with the exception of potassium and sodium, which were mostly solubilized in the process water; calcium and chlorine were also solubilized to a lesser extent in the process water.
Elemental composition and surface functional groups showed that hydrochar produced within the hydrothermal carbonization range (180-260 °C) seemed better suited for utilization as a soil amendment than raw cow manure.
The potential for energy recovery lies in the anaerobic digestion of the process water, from which higher methane yields can be obtained than from raw cow manure. Lower temperatures in hydrothermal carbonization are considered a compromise for the safe land applications of cow manure, energy recovery from the process water, and enhanced dewaterability.
These findings can help to eliminate bottlenecks in the upscaling of cow manure hydrothermal treatment and promote the circular bio-economy.

Comprehensive assessment of microalgal-based treatment processes for dairy wastewater. Singh P, Mohanty SS, Mohanty K. Front Bioeng Biotechnol. 2024 Aug 6;12:1425933.

The dairy industry is becoming one of the biggest sectors within the global food industry, and these industries use almost 34% of the water. The amount of water used is governed by the production process and the technologies employed in the plants. Consequently, the dairy industries generate almost 0.2-10 L of wastewater per liter of processed milk, which must be treated before being discharged into water bodies.
The cultivation of microalgae in a mixotrophic regime using dairy wastewater enhances biomass growth, productivity, and the accumulation of value-added product. The generated biomass can be converted into biofuels, thus limiting the dependence on petroleum-based crude oil.
To fulfill the algal biorefinery model, it is important to utilize every waste stream in a cascade loop. Additionally, the harvested water generated from algal biomass production can be recycled for further microalgal growth. Economic and sustainable wastewater management, along with proper reclamation of nutrients from dairy wastewater, is a promising approach to mitigate the problem of water scarcity.
A bibliometric study revealing limited work on dairy wastewater treatment using microalgae for biofuel production. Also, limited work is reported on the pretreatment of dairy wastewater via physicochemical methods before microalgal-based treatment.
Significant gaps remains in large-scale cultivation processes. It is also crucial to discover robust strains that are highly compatible with the specific concentration of contaminants, as this will lead to increased yields and productivity for the targeted bio-product.
Finally, research on reutilization of culture media in photobioreactor is necessary to augment the productivity of the entire process. Therefore, the incorporation of the microalgal biorefinery with the wastewater treatment concept has great potential for promoting ecological sustainability.

Vermifiltration as a green solution to promote digestate reuse in agriculture in small-scale farms. Cucina M, Castro L, Garfí M, et al. J Environ Manage. 2024 Aug 13;368:122164.

Digestates from low-tech digesters need to be post-treated to ensure their safe agricultural reuse.
This study evaluated, for the first time, vermifiltration as a post-treatment for the digestate from a low-tech digester implemented in a small-scale farm, treating cattle manure and cheese whey under psychrophilic conditions.
Vermifiltration performance was monitored in terms of solids, organic matter, nutrients, and pathogens removal efficiency. In addition, the growth of earthworms (Eisenia foetida) and their role in the process was evaluated. Finally, the vermicompost and the effluent of the vermifilter were characterized in order to assess their potential reuse in agriculture.
Vermifilters showed high removal efficiency of chemical oxygen demand (55-90%), total solids (60-80%), ammonium nitrogen (83-97%), and phosphate-P (28-49%). Earthworms effectively grew and reproduced on digestate (i.e. earthworms number increased by 183%), enhancing the vermifiltration performance, while reducing clogging and odor-related issues.
Both the vermicompost and effluent produced complied with legislation limits established for soil improvers and wastewater for fertigation, respectively. Indeed, there was an absence of pathogens and non-detectable heavy metals concentrations.
Vermifiltration may be thus considered a suitable post-treatment option for the digestate from low-tech digesters, allowing for its safe agricultural reuse and boosting the circular bioeconomy in small-scale farms.

Dynamics of antibiotic resistance genes during manure composting: Reduction in herbivores manure and accumulation in carnivores. Wang G, Gao X, Cai Y, Li G, Ma R, Yuan J. Environ Int. 2024 Aug;190:108900.

The elevated levels of antibiotic resistance genes (ARGs) in livestock manure represent a significant threat to both the environment and human health. Composting has been recognized as an effective strategy to mitigate the abundance of ARGs in manure. However, notable rebounds in ARGs abundance have been observed during this process.
This study explored the changes in ARGs abundance and the underlying influencing factors during the composting of carnivore (chicken and pig) and herbivore (sheep and cow) manures, along with mushroom residues.
The findings revealed that the total relative abundance of ARGs increased by 6.96 and 10.94 folds in chicken and pig manure composts, respectively, whereas it decreased by a remarkable 91.72% and 98.37% in sheep and cow manure composts.
Nitrogen content emerged as the primary physicochemical factors governing the abundance of ARGs in chicken and pig manure composts. Conversely, carbon content played a pivotal role in determining ARGs abundance in chicken and pig manure composts.
Furthermore, the presence of dominant hosts, such as Corynebacterium, Bacillus, and Clostridium, along with emerging bacteria like Thermobifida, Saccharomonospora, and Actinomadura, contributed significantly to the enrichment of total ARGs, including tetG, tetO, tetX, and sul2, in chicken and pig manure composts. The coexistence of these genes with mobile genetic elements and a plethora of host bacteria, coupled with their high abundance, renders them particularly high-risk ARGs.
On the other hand, the observed decrease in the abundance of total ARGs in sheep and cow manure composts can be attributed to the decline in the population of host bacteria, specifically Atopostipes, Psychrobacter, and Corynebacterium.
Collectively, these results provide crucial insights into the management of ARGs risks and offer essential theoretical support for enhancing the safe utilization of organic fertilizer in agriculture.

Animal Health and Food Safety

Unmasking seasonal cycles in a high-input dairy herd in a hot environment: How climate shapes dynamics of milk yield, reproduction, and productive status. Chavarría I, Alvarado AS, Mellado M, et al. J Therm Biol. 2024 Jul;123:103944.

Ideally, regular all-year-round calvings are required to maximize profitability in intensive dairy farms. This strategy generates an even milk production pattern throughout the year, allowing dairy farmers to spread the workload and meet the demands of milk by the market. However, parturition patterns and milk yield are seasonal throughout the United States, regardless of the climatic conditions.
This study aimed to predict the annual herd milk yield, lactation, and reproductive cycle stages in a high-input dairy herd in a zone with prolonged thermal stress. Also, the impact of climatic conditions on milk yield and productive and reproductive status was assessed.
An autoregressive integrated moving average (ARIMA) model was used in data fitting to predict future monthly herd milk yield and reproductive status using data from 2014 to 2020.
Based on the annual total milk output, the highest predicted percentage of milk yield based on the yearly milk production was in February (9.1%) and the lowest in August (6.9%). The predicted highest percentage of pregnant cows for 2021 was in May (61.8%) and the lowest for November (33.2%).
The monthly percentage of dry cows in this study showed a steady trend across years; the predicted highest percentage was in September (20.1%;) and the lowest in March (7.5%). The predicted days in milk (DIM) were lower in September (158) and highest in May (220).
Percentage of calvings was seasonal, with the predicted maximum percentage of calvings occurring in September (10.3%) and the minimum in April (3.2%). The highest predicted culling rate for the year ensuing the present data occurred in November (4.3%) and the lowest in April (2.5%).
It was concluded that meteorological factors strongly influenced rhythms of monthly milk yield and reproductive status. Also, ARIMA models robustly estimated and forecasted productive and reproductive events in a dairy herd in a hot environment.

Dexamethasone administration restored growth in dairy calves exposed to heat stress. Yu Z, Cantet JM, Nair MRR, Ríus AG.J Dairy Sci. 2024 Aug 7:S0022-0302(24)01058-0.

Recent evidence indicates that the heat stress loss on the growth performance of calves is associated with the diversion of nutrients to control enteritis and systemic inflammation.
In this study, researchers investigated the impact of heat stress on markers of inflammation, feed use-efficiency, and growth of dairy calves.
The researchers hypothesized that dexamethasone, which is known for its immunosuppressive and anti-inflammatory properties, would reduce inflammation and restore the growth of calves exposed to heat stress.
Thirty-two Holstein bull calves (body weight (BW) 68.5 kg; age 3.5 week-old) were housed in individual pens in climate-controlled rooms at constant ambient temperature and allowed to adjust to facilities for 5 days before the start of treatments.
Calves were randomly assigned to one of 4 treatments (n = 8/treatment) in a 2 × 2 factorial arrangement of environment (ENV, thermoneutral or heat stress) and intervention (INT, saline or dexamethasone) imposed for 5 days as follow:
Thermoneutral (constant ambient temperature of 20°C 24 h/d) and administration of saline,
Thermoneutral (constant ambient temperature of 20°C 24 h/d) and administration of dexamethasone
Cyclic heat stress (40°C ambient temperature, from 0800 to 1900 h/d) and administration of saline
Cyclic heat stress (40°C ambient temperature, from 0800 to 1900 h/d) and administration of dexamethasone.
Dexamethasone (0.05 mg/kg BW), or saline (1.2 mL) was administered intramuscularly on day 1 and 3. Upon completion of treatments, calves were euthanized on day 5 to obtain jejunum mucosa samples. Commercial milk replacer, starter grain, and water were offered, and intake was monitored daily. Rectal temperature and respiratory rate were monitored 3 times daily. Blood samples were collected on d 1, 3, and 5 to determine serum pro-inflammatory cytokine concentrations. A section of the jejunum was collected and snap-frozen to determine the concentration of pro-inflammatory markers.
An ENV effect showed that heat stress increased rectal temperature (38.72 vs. 39.21°C), respiratory rate (36 vs. 108 breaths/min), and water intake (3.2 vs. 6.6 L/d). The treatments did not affect dry matter intake.
An ENV × INT interaction showed that heat stress with saline decreased average daily gain (ADG) by 35% and tended to decrease feed use-efficiency by 36%, but the use of dexamethasone to treat heat stress restored ADG and feed use-efficiency comparable to their basal levels. An ENV × INT interaction revealed that heat stress with saline increased jejunal interleukin (IL)-6 concentration 2-fold, but dexamethasone treatment of heat stress restored jejunal IL-6 concentration to basal levels.
The bioenergetic cost of the heat stress-immune pro-inflammatory response ranged between 1.18 and 1.50 Mcal of ME. Overall, the administration of dexamethasone reduced the jejunal concentration of a pro-inflammatory marker and restored the heat stress-associated reduction in growth and feed use-efficiency.
The immunomodulation and anti-inflammatory effects of dexamethasone could be part of a homeorhetic change that results in a shift from maintenance functions to support growth on calves exposed to heat stress.

Enhancing hoof health and locomotion in crossbred dairy cows: impact of recycled manure solids bedding on lameness incidence and gait kinematics. Praveen S, Kataktalware MA, Ramesha KP, et al. Trop Anim Health Prod. 2024 Aug 22;56(7):242.

Recycled manure solids have emerged as a promising alternative for animal bedding, owing to their economic feasibility, ready availability on farms, and soft, non-abrasive nature.
This research aimed to assess the impact of recycled manure solids (RMS) bedding, combined with a conditioner containing 7.5% lime and 6% sodium hydrosulphate, on dairy cow welfare and gait kinematics over three months.
Hock and knee injury scores, lameness incidence, and gait kinematic parameters were evaluated for animals housed on cement flooring (Control), RMS bedding (Treatment I), and conditioner-added RMS bedding (Treatment II) on days 0, 45, and 90 of the experiment with six crossbred cows in each group.
The results revealed a significant reduction in lameness scores (5-point scale) for animals in both the RMS and conditioner-added RMS groups, with scores of 1.09 and 1.04, respectively, compared to those on cement floors. Moreover, a noteworthy decrease in knee and hock injury scores (4-point scale) was observed in the RMS groups, indicating a potentially positive impact on joint health.
Gait kinematic analysis demonstrated that animals in the RMS (1.03 m/s) and conditioner-added RMS (1.02 m/s) groups exhibited higher walking speeds and increased step angles (158.59° and 149.58°) compared to their cement-floor counterparts. No significant changes were observed in stride length, step asymmetry, step length, and step width.
The study concluded that the conditioner incorporated recycled manure solids resulting in a substantial decrease in lameness incidence and a reduction in hock and knee injuries among dairy cows. Additionally, the improved gait kinematics observed in non-lame animals suggest that this bedding combination positively influences overall animal well-being. These findings underscore the potential of sustainable bedding practices to enhance both physical health and locomotor behavior in dairy cattle.

Effective microorganism combinations improve the quality of compost-bedded pack products in heifer barns: exploring pack bacteria-fungi interaction mechanisms. Zhang Z, Gu Y, Wang M, et al. BMC Microbiol. 2024 Aug 13;24(1):302.

Compost-bedded pack barns (CBP) are getting huge attention as an alternative housing system for dairy cows due to their beneficial impact on animal welfare. Effective microorganisms (EM) inoculums are believed to enhance compost quality, improve soil structure and benefit the environment. However, little information is available on the impact of incubation with external EM combinations on the barn environment, compost quality and microbial diversity in CBP.
This experiment was carried out to investigate the effect of inoculating different combinations of EM [Lactobacillus plantarum (L), Compound Bacillus (B) and Saccharomyces cerevisiae (S)] on compost quality and microbial communities of CBP products, as well as the relationship with the heifers’ barn environment.
CBP barns were subjected to the following four treatments: CON with no EM inoculum, LB/LS/LBS were Incubated with weight ratios of 1:2 (L: B), 1:2 (L: S), 1:1:1 (L: B: S), respectively.
The results showed that the EM inoculation (LB, LS, LBS) reduced the concentration of respirable particulate matter (PM10 and PM2.5) in the CBP, and decreased the serum total protein and total cholesterol levels in heifers. Notably, LBS achieved the highest content of high-density lipoprotein compared to other treatments.
Microbiome results revealed that EM inoculation reduced the bacterial abundance (Chao1 index) and fungal diversity (Shannon & Simpson indexes), while increasing the relative abundance of various bacterial genera (Pseudomonas, Paracoccus, Aequorivita) and fungi (Pestalotiopsis), which are associated with cellulose decomposition that ultimately resulted in accelerating organic matter degradation and humification.
Furthermore, high nutrient elements (TK&TP) and low mycotoxin content were obtained with EM inoculation, with LBS showing a particularly pronounced effect. Meanwhile, LBS contributed to a decline in the proportion of fungal pathogen categories but also led to an increase in fungal saprotroph categories.
In general, EM inoculation positively impacted compost product quality as organic fertilizer and barn environment by modifying the abundance of cellulolytic bacteria and fungi, while inhibiting the reproduction of pathogenic microbes, especially co-supplementing with L, B and S achieved an amplifying effect.

Short communication: Bifidobacterium abundance in the faecal microbiota is strongly associated with milk traits in dairy cattle. Brulin L, Ducrocq S, Estellé J, et al. Animal. 2024 Aug;18(8):101243

The performance of dairy cows is influenced by the microbial communities hosted within their digestive tract. While the rumen microbiota has long been associated with host phenotypes, the impact of the fecal microbiota remains elusive.
In this study, we collected 697 fecal samples from commercial Holstein cows and analyzed them with 16S rRNA gene analyses. For each animal, routinely recorded data, i.e., milk yield, fat yield, protein yield, fat content, protein content, and an aggregate production trait (pINEL) based on the French economic dairy index, were available to assess the links between the faecal microbiota and host production.
These findings revealed a strong and significant association between the structure of the bacterial and prokaryote community (β-diversity) and dairy production. In addition, differential abundance analyses identified 48 genera whose abundances were significantly associated with pINEL, milk, fat and protein yield. Among these genera, the increased abundance of Bifidobacterium, and particularly an amplicon sequence variant with a 16S rRNA V3-V4 gene region identical to B. globosum and B. pseudolongum, was found to be the most important for high-yielding animals.
Bifidobacterium seemed to be a potential key member of the bovine fecal microbiota that should be further investigated. Conversely, the p-1088-a5 gut group genus was found more abundant in low-productive cows.
In conclusion, this study demonstrates significant associations between the fecal microbiota and the performance of dairy cows at the whole lactation scale. A better understanding of the physiology of the gut microbiota could help to improve dairy cow production.

Human Health and Nutrition

The Dairy Matrix: Its Importance, Definition, and Current Application in the Context of Nutrition and Health Mulet-Cabero AI, Torres-Gonzalez M, Rosales A, Peters S, et al. Nutrients. 2024 Aug 31.

Nutrition research has shifted from single nutrients to examining the association of foods and dietary patterns with health. This includes recognizing that food is more than the sum of the individual nutrients and relates to the concept of the food matrix. Like other foods, dairy foods are characterized by their unique matrices and associated health effects.
Although the concepts of the food matrix and/or dairy matrix are receiving increasing attention in the nutrition and health literature, there are different terms and definitions that refer to it.
This article aims to provide insights into the application of the concepts of the food matrix and dairy matrix and to provide a current overview of the definitions and terminology surrounding the food matrix and dairy matrix.
By analyzing these aspects, the researchers aim to illustrate the practical implications of the food matrix and dairy matrix on nutrition and health outcomes and evaluate their roles in shaping evidence-based policies for the benefit of public health.
There is a need for harmonized definitions within the literature. Therefore, the International Dairy Federation put forward harmonized terms to be internationally applicable: the “dairy matrix” describes the unique structure of a dairy food, its components (e.g., nutrients and non-nutrients), and how they interact; “dairy matrix health effects” refers to the impact of a dairy food on health that extend beyond its individual components.

Full-fat dairy products and cardiometabolic health outcomes: Does the dairy-fat matrix matter? Taormina VM, Unger AL, Kraft J. Front Nutr. 2024;11:1386257.

Reducing dairy fat intake is a common dietary guideline to limit energy and saturated fatty acid intake for the promotion of cardiometabolic health. However, research utilizing a holistic, food-based approach to assess the consumption of the fat found in dairy, a broad and diverse food group, may provide new insight into these guidelines.
Dairy fat is comprised of a diverse assembly of fatty acids, triacylglycerols, sterols, and phospholipids, all uniquely packaged in a milk fat globule. The physical structure of this milk fat globule and its membrane is modified through different processing methods, resulting in distinctive dairy-fat matrices across each dairy product.
The objectives of this narrative review were to first define and compare the dairy-fat matrix in terms of its unique composition, physical structure, and fat content across common dairy products (cow’s milk, yogurt, cheese, and butter).
With this information, researchers examined observational studies and randomized controlled trials published within the last 10 years (2013-2023) to assess the individual effects of the dairy-fat matrix in milk, yogurt, cheese, and butter on cardiometabolic health and evaluate the implications for nutrition guidance.
Searches conducted on Ovid MEDLINE and PubMed® utilizing search terms for cardiometabolic health, both broadly and regarding specific disease outcomes and risk factors, yielded 59 studies that were analyzed and included in this review. Importantly, this review stratifies by both dairy product and fat content.
Though the results were heterogeneous, most studies reported no association between intake of these individual regular-fat dairy products and cardiometabolic outcome measures, thus, the current body of evidence suggests that regular-fat dairy product consumption may be incorporated within overall healthy eating patterns.
Research suggests that there may be a beneficial effect of regular-fat milk and yogurt intake on outcome measures related to body weight and composition, and an effect of regular-fat cheese intake on outcome measures related to blood lipids, but more research is necessary to define the directionality of this relationship.

Association between yogurt and dietary supplements containing probiotic consumption with sleep disturbance in US adults: Results from NHANES, 2009-2018. Yang RZ, Lin SZ, Zeng K, et al. Heliyon. 2024 Aug 5;10(15):e35609.

Sleep disorders are common globally. Probiotics may improve human microbial diversity, offering potential benefits for sleep disturbances by enhancing sleep quality and reducing disorders.
Therefore, researchers aimed to use a population-based study to investigate the association between yogurt (a probiotic food) and probiotic consumption with sleep disturbances in US adults.
A total of 49,693 adults from the 2009-2018 National Health and Nutrition Examination Survey (NHANES) were included in the analyses. Sleep disorders and sleep duration were assessed according to the Sleep Disorders Questionnaire. The Dietary Questionnaire evaluated yogurt and dietary supplements containing probiotic consumption.
Of the study cohort, 3535 (14.24 %) participants consumed yogurt and/or dietary supplements containing probiotics. The prevalence of sleep disorders was 16.22 %. Only 53.51 % of the participants achieved the recommended amount of sleep (7-9 h), with 6.10 % and 33.48 % having excessive and insufficient sleep duration, respectively.
Weighted Logistic regression models indicated a significant association of probiotic intake with a decreased risk of sleep disturbances compared with those without yogurt or probiotic consumption after adjustments. (For sleep disorders: OR: 0.96, P < 0.001; for sleep duration: OR: 0.98, P = 0.081) Moreover, the effect size of the probiotic intake on sleep was especially significant in sex, race, and BMI subgroups.
The present study first indicated that yogurt and probiotic consumption were associated with a reduced risk of sleep disturbances in US adults, particularly among males, whites, and those with a normal BMI. Incorporating yogurt or probiotics into the diet could serve as a public health strategy for improving sleep disturbances, though further investigation into the underlying mechanisms is needed.

Effects of Milk and Dairy on the Risk and Course of Inflammatory Bowel Disease versus Patients’ Dietary Beliefs and Practices: A Systematic Review. Kempinski R, Arabasz D, Neubauer K. Nutrients. 2024 Aug 3;16(15):2555.

The role of the environment in the pathogenesis of inflammatory bowel disease (IBD) is undisputed, especially in light of numerous epidemiological data showing the increasing prevalence of IBD worldwide. Although no specific environmental factors have been identified, the diet has received the most attention as a potential modifier of the onset and course of IBD and as a therapeutic intervention.
The Westernization of the diet is repeatedly cited as a crucial aspect of the change in IBD prevalence, but data on the impact of diet on the course of IBD are still limited and the effectiveness of dietary interventions remains uncertain. Milk remains one of the most discussed dietary agents in IBD.
Therefore, researchers performed a systematic review of the literature published between January 2010 and March 2024 on three databases, Pubmed, Web of Knowledge, and Embase, to assess the impact of milk and dairy products on the risk and course of IBD, as well as patients’ dietary beliefs and practices.
The results included 37 original studies in our review.
The overall findings were that there is no clear evidence that milk and dairy products influence the incidence and course of IBD. The studies that assess this issue are characterized by great heterogeneity. Milk and dairy are among the most commonly excluded foods by patients with IBD, which may have clinical implications.

Low-fat yogurt consumption maintains biomarkers of immune function relative to nondairy control food in women with elevated BMI: A randomized controlled crossover trial. Hasegawa Y, Noll AL, Lang DJ, Akfaly EM, Liu Z, Bolling BW. Nutr Res. 2024 Jul 24;129:1-13.

Yogurt consumption may help reduce chronic inflammation associated with obesity. However, the underlying mechanism(s) by which yogurt consumption modulates the immune system have not been validated in human intervention studies.
Researchers hypothesized that 4-week yogurt consumption (12 oz/day) attenuates systemic inflammation by modulating the proportion of circulating T helper (Th) 17 and regulatory T (Treg) cells in adult women with elevated body mass index (BMI).
To test the hypothesis, researchers conducted a randomized crossover dietary intervention study consisted of a 4-week dietary intervention in which participants consumed 12 oz of either low-fat dairy yogurt or a soy pudding control snack per day, with a 4-week washout between treatments.
Thirty-nine healthy adult women with a BMI between 25 and 40 kg/m2 were enrolled and 20 completed the study. Changes in the biometrics, circulating T cells, and markers of systemic and colonic inflammation were assessed between the 2 treatment groups, as well as 24-hour diet recalls were conducted at baseline and following each treatment.
The primary study outcome, the change in the proportion of circulating Th17 cells, was unaffected by the treatments. Secondary outcome measures, circulating Treg, Th17, and markers of chronic inflammation, were maintained by yogurt treatment, whereas circulating Treg was increased and interleukin-10 was reduced by control snack treatment.
However, circulating Treg changes were not associated with changes to other biomarkers of inflammation, implying other immune cells and/or tissues may mediate circulating biomarkers of chronic inflammation.

Anticariogenic Effects of the Dairy Products on Human Saliva: An In Vivo Study. Gautam Y, Srivastava M, Verma P, Doley S. Int J Clin Pediatr Dent. 2024 Apr;17(4):456-460.

Dental caries is a multifactorial disease caused by four main factors—the host (primarily saliva and teeth), the microflora, the substrate (diet), and time. The role of diet deserves special consideration in the modern era, as soft and refined foods tend to adhere tenaciously to the tooth surface and are not removed due to a lack of roughness. In contrast, the diet of primitive man consisted of raw, unrefined foods with a great deal of roughage, which cleansed the teeth during normal chewing movements.
Milk and dairy products have been claimed to be cariostatic in nature. The ability of milk and its products to prevent tooth decay is attributed to the direct chemical effects of casein phosphopeptides, calcium, and phosphate. Based on available evidence, chewing hard cheeses, especially cheddar cheese, may help prevent enamel demineralization by stimulating salivary flow and promoting remineralization.
The aim of this study was to determine whether the intake of cheese, paneer, and yogurt may help in reversing the acidogenic challenge after the consumption of chocolate at different time intervals.
A total of 120 caries-free children between the ages of 4 and 13 years, with no decayed, missing, and filled teeth (DMFT), were randomly selected from the school. Baseline pH was obtained, and the subjects were asked to eat chocolate. pH was measured again after 10 minutes. Following chocolate exposure, the subjects were then randomly assigned to three groups-cheese, paneer, and yogurt. Salivary pH was measured at intervals of 15, 30, and 60 minutes using the same procedures for all subjects.
The highest pH value after 15 minutes was seen in cheese (6.43), followed by paneer (6.31) and yogurt (6.30). After 30 minutes, the maximum pH value was seen in the cheese group (6.63), followed by yogurt (6.46) and paneer (6.34). The mean pH value 60 minutes after the consumption of dairy products was highest in paneer (6.53), followed by cheese (6.43) and yogurt (6.37).
In conclusion, all the categories were observed in the zone of remineralization. It should be noted that the maximum pH value overall was seen in the cheese group. Therefore, dairy products help maintain salivary pH, which aids in improving enamel health. Hence, dietary dairy recommendations can be incorporated into patient education and caries prevention plans.

Innovation, Economics, and Dairy Alternatives

Qualitative social and human science research focusing on actors in and around dairy farming- An invited review. Vaarst M, Ritter C, Saraceni J, Roche S, Wynands E, Kelton D, Koralesky KE. J Dairy Sci. 2024 Aug 16:S0022-0302(24)01080-4.

Qualitative research related to humans, dairy cows, calves and farming has been published by scientists from a variety of disciplines in many journals targeting dairy science audiences.
Therefore, researchers aimed to investigate how scientific communities other than those working in dairy science describe, analyze and discuss dairy farming, because they found it important to bring this research to the attention of dairy scientists.
In total, 117 articles were identified as involving one or more qualitative research methods in relation to dairy cattle.
The review brought out a wealth of perspectives, new insights and discussions related to dairy cattle, farmers, farming and the sector, and in relation to societal issues and food and ecological landscapes. A broad range of qualitative research methods were used, and the literature targeted issues at the animal, farm, societal, food system and landscape level. Some raised critical questions about existing structures, highlighted unfairness in the industry, or pointed to new potential futures and contemporary agendas.
The researchers expect that it will be inspirational and stimulating for researchers to review new sources of literature and suggest a closer interdisciplinary collaboration among researchers from different disciplines for the future development of research involving dairy cattle.
Further, it could be relevant and even necessary to engage in such interaction to avoid increasing polarization around future development of the sector, for example related to climate change or how industrialization seems to push inequity or ignore the agency of animals themselves. Exploring perspectives of farming from different angles could enrich the outcomes of future dairy research.

MFGM-enriched whey displays antiviral activity against common pediatric viruses in vitro. Kramer E, Patil K, Triantis V, Bastiaans JAH, Mazzon M, Ramani S, Lambers TT. Front Nutr. 2024 Jul 31;11:1416352.

Among the most common mucosal viral infections in infants are rotavirus, one of the main causes of severe gastroenteritis in infants and children up to 5 years, and respiratory syncytial virus (RSV), one of the leading causes of lower respiratory tract infections.
Both human milk and bovine milk derived factors may provide protection against mucosal viral infections. More recently, a similar activity of milk derived proteins was suggested for SARS-CoV-2.
The goal of the current study was to test antiviral activity of the bovine milkfat globule membrane (MFGM) against rotavirus, RSV and SARS-CoV-2 and to further characterize MFGM-enriched whey to identify which components in MFGM-enriched whey may contribute to the inhibitory activity.
The effects of MFGM-enriched whey, its whey protein isolate counterpart (WPI, obtained from the same production process) and a conventional whey protein concentrate (WPC) on rotavirus (strains Wa and SA114F), RSV (strain RSV-A2) and SARS-CoV-2 (Alpha variant) infectivity were determined using MA104 cells, human alveolar basal epithelial (A549) cells and monkey kidney (Vero E6) cells, respectively.
Relative to its WPI counterpart, MFGM-enriched whey demonstrated a dose-dependent inhibition for both rotavirus and RSV whereas for SARS-CoV-2 inhibition was only observed at the highest concentration tested.
Label-free quantification (LFQ) and intensity based absolute quantification (iBAQ) of identified proteins revealed a clear difference between MFGM-enriched whey and its controls including enrichment of known MFGM proteins and non-MFGM proteins that are enriched simultaneously, some of which have previously been demonstrated to display anti-viral activity. Although not completely absent from other whey protein preparations, MFGM-enriched whey had the highest specific and total phospholipid levels.
MFGM-enriched whey displayed antiviral activity against multiple viruses of clinical importance. This study provides insights into the active components in MFGM-enriched whey and may contribute to previous clinical observations with MFGM-enriched formula demonstrating reduced respiratory and gastrointestinal infections in formula fed infants.

Trends in plant-based diets among U.S. adults, 1999-March 2020. Sullivan VK, Martínez-Steele E, Garcia-Larsen V, Rebholz CM.J Nutr. 2024 Aug 9:S0022-3166(24)00455-3.

Interest in plant-based eating has increased alongside increased variety and availability of highly processed plant-based meat and dairy alternatives. The impact of the shifting commercial landscape and public interest in plant-based eating on dietary intake is unknown.
The objective of this study was to examine trends in the consumption and composition of plant-based diets in U.S. adults.
Serial cross-sectional data from the National Health and Nutrition Examination Survey were used to assess trends in the proportion of U.S. adults aged ≥20 years consuming a plant-based diet (defined as ≥50% total protein from plants on a 24-hour dietary recall) from 1999-2000 to 2017-March 2020 (n=51,698). Trends in processing level (percentage energy intake from ultraprocessed foods) and diet quality (HEI-2020 scores) were assessed in the subset of adults consuming plant-based diets (n=8,327).
The results showed that the proportion of U.S. adults consuming plant-based diets increased from 14.4% to 17.2%. In all survey cycles, ultraprocessed foods accounted for the majority of energy intake and ultraprocessed food intake in plant-based diets did not significantly change over time (50.7% kcal in 1999-2000 vs. 52.7% kcal in 2017-March 2020. The quality of plant-based diets, measured by HEI-2020 scores, improved from 52.1 to 55.8.
Between 1999 and 2020, the proportion of U.S. adults consuming a plant-based diet increased. Among people consuming plant-based diets, ultraprocessed foods contributed most to energy intake and there was no sustained change in intake over time. Average diet quality was low but improved modestly.

Animal board invited review: Dietary transition from animal to plant-derived foods: Are there risks to health? Givens DI. Animal. 2024 Jul 20;18(9):101263.

Animal-derived foods (ADFs) are a very varied group of foods, but many are nutrient rich and contain higher quality protein than provided by plant-derived foods such that a simple replacement of ADF protein is likely to lead to a reduction in overall protein quality. In addition, many ADFs are richer in some nutrients than plant-based foods (e.g. Fe, Ca) and these often have a higher bioavailability.
ADFs also provide nutrients that plants cannot supply (e.g. vitamin B12) and some provide beneficial health functionality (e.g. hypotensive) which is not explained by traditional nutrition. However, there remains a good health reason to increase the proportion of plant-derived food in many diets to increase the intake of dietary fiber which is often consumed at very sub-optimal levels. It seems logical that the increased plant-derived foods should replace the ADFs that have the least benefit, the greatest risk to health and the highest environmental impact.
Processed meat fits these characteristics and should be an initial target for replacement with plant-based based protein-rich foods that additionally provide the necessary nutrients and have high-quality dietary fiber. Processed meat covers a wide range of products including several traditional foods (e.g. sausages) which will make decisions on food replacement challenging. There is therefore an urgent need for research to better define the relative health risks associated with the range of processed meat-based foods.
The aim of this review is to examine the evidence on the benefits and risks of this dietary transition including the absolute necessity to consider initial nutrient status before the replacement of ADFs is considered.

Vegetarian Diets During Pregnancy: with supplementation, ovo-vegetarian, lacto-vegetarian, vegan, and pescatarian adaptations of USDA Food Patterns can be nutritionally adequate. Hess JM, Comeau ME, Smith JL, Swanson K, Anderson CM. J Acad Nutr Diet. 2024 Aug 10:S2212-2672(24)00751-2.

The 2020-2025 Dietary Guidelines for Americans (DGA) includes a lacto-ovo vegetarian pattern (the Healthy Vegetarian Dietary Pattern; HVDP) as one recommended dietary patterns during pregnancy.
The objective of this study was to adapt the HVDP for vegan, ovo-vegetarian, lacto-vegetarian, and pescatarian diets during pregnancy.
Using food pattern modeling, four adaptations of the HVDP were developed at energy levels that may be appropriate during pregnancy (1800, 2000, 2200, 2400, and 2600 kcal/day). Models were run both with and without the addition of a composite prenatal supplement.
Main outcome measures were macro- and micronutrient adequacy without exceeding recommendations for saturated fat and added sugar. The 2020-2025 DGA Food Pattern Modeling Report was used to define food groups and nutrients in the HVDP. The HVDP was revised to remove dairy and/or eggs or to add seafood.
Across all examined energy levels (1800, 2000, 2200, 2400, and 2600 kcal per day), modeled dietary patterns provided sufficient macronutrients. Without prenatal supplements, each dietary pattern met most, but not all, micronutrient recommendations.
Micronutrients that were below recommendations in patterns without supplements included vitamin D, iron, vitamin E, sodium, and choline. With the addition of a “composite” prenatal supplement to these patterns, the nutrients below 100% of recommendations were vitamin D, choline, and sodium.
Overall, these results show that a HVDP and similar diets without meat, eggs, dairy, and/or seafood can provide most nutrients needed during pregnancy, albeit with some micronutrient challenges similar to those diets that include meat and other animal products.

A Comparison of the Effects of Dairy Products with their Plant-based Alternatives on Metabolic Responses in Healthy Young Canadian Adults: a randomized cross-over study. Da Silva N, Anderson GH, Amr AM, Vien S, Fabek H. Appl Physiol Nutr Metab. 2024 Aug 15.

Plant-based food demand is rapidly increasing. However, the metabolic responses of plant proteins within their commercially available form remains unclear.
Two randomized crossover experiments compared plant-based alternatives to dairy on postprandial glycemia, metabolic hormones, and appetite before and after a fixed size (12 kcal/kg body weight) pasta meal in sixteen healthy young adults (eight males and eight females). Blood glucose, insulin, and appetite were measured at baseline, post-treatment, and following a fixed-size pasta meal (post-meal) within 15-30 min.
In experiment one, participants (22.8±2.3y) consumed one-serving of Greek yogurt (175g), cheddar cheese (30g), plant-based cheese (30g), or plant-based yogurt (175g).
In experiment two, participants (22.3±2.4y) consumed one-serving (250 mL) of cow’s milk, vanilla soy beverage or vanilla almond beverage, and (30 g) of cheddar cheese or plant-based cheese.
In experiment two, C-peptide, GLP-1, and ghrelin were measured. Greek yogurt and cheddar cheese lowered post-meal blood glucose more than their plant-based alternatives (p <0.01) and post-treatment blood glucose was higher following almond beverage than cheddar cheese and plant-based cheese (p <0.01). In experiment 1, post-treatment insulin was higher after Greek yogurt than cheddar cheese and plant-based cheese and all treatments post-meal (p <0.02). Post-meal appetite was lower after plant-based yogurt than cheddar cheese and plant-based cheese (p <0.01).
In experiment 2, post-treatment insulin was higher after almond beverage compared to all treatments (p <0.01) and post-meal GLP-1 was higher after milk than almond beverage (p =0.03).
The researchers concluded that the physiological functionality of plant-based alternatives as measured by blood glucose, insulin, C-peptide, and GLP-1 did not replicate the metabolic functions of dairy products.

Bioactive (Poly)phenol Concentrations in Plant-Based Milk Alternatives in the US Market. Grainger EM, Jiang K, Clinton SK, et al. J Agric Food Chem. 2024 Aug 21;72(33):18638-18648.

Plant-based milk alternatives (PBMAs) are increasingly consumed as a dairy alternative. Plant foods are rich sources of (poly)phenols, but concentrations of these bioactive phytochemicals in processed PBMAs are not well documented.
Researchers procured twenty-seven PBMA products of 6 types (almond, coconut, oat, pea, rice, and soy) for (poly)phenol analysis.
Samples were analyzed via ultra high-performance liquid chromatography-diode array with mass spectrometry.
The (poly)phenol content of PBMAs varies and is dependent on plant source, brand, and added flavorings. Soy milk had the highest concentration (91.9 ± 2.7 mean mg ± SD/cup serving) and rice milk had the lowest (0.9 ± 0.2 mean mg ± SD/cup serving). Almond milk, the most widely consumed PBMA, averaged 12.1 ± 8.2 mg/cup serving, but the majority of (poly)phenols are derived from added flavorings.
PBMAs contain a wide range of potentially bioactive (poly)phenols and may contribute significantly to overall dietary (poly)phenol intake with the potential to impact health outcomes.