Dairy Research Bulletin: Selected Articles from November 2024

Environmental Management and Sustainability

The 2024 report of the Lancet Countdown on health and climate change: facing record-breaking threats from delayed action. Lancet. 2024 Nov 9;404(10465):1847-1896.

Despite the initial hope inspired by the 2015 Paris Agreement, the world is now dangerously close to breaching its target of limiting global multiyear mean heating to 1·5°C. Annual mean surface temperature reached a record high of 1·45°C above the pre-industrial baseline in 2023, and new temperature highs were recorded throughout 2024. The resulting climatic extremes are increasingly claiming lives and livelihoods worldwide.
The 2024 report of the LancetCountdown, builds on the expertise of 122 leading researchers from UN agencies and academic institutions worldwide and reveals the most concerning findings yet in the collaboration’s 8 years of monitoring.
- The record-breaking human costs of climate change: Data in this year’s report show that people all around the world are facing record-breaking threats to their wellbeing, health, and survival from the rapidly changing climate. Of the 15 indicators monitoring climate change-related health hazards, exposures, and impacts, ten reached concerning new records in their most recent year of data.
- Fueling the fire: As well as exposing the inadequacy of adaptation efforts to date, this year’s report reveals a world veering away from the goal of limiting temperature rise to 1·5°C, with concerning new records broken across indicators monitoring greenhouse gas emissions and the conditions that enable them.
- Health-threatening financial flows: With the availability of financial resources a key barrier to tackling climate change, a rapid growth in predictable and equitable investment is urgently needed to avoid the most dangerous impacts of climate change. A growing body of literature shows that the economic benefits of a transition to net zero greenhouse gas emissions will far exceed the costs of inaction. Healthier, more resilient populations will further support more prosperous and sustainable economies.
- Defining the health profile of people worldwide:Following decades of delays in climate change action, avoiding the most severe health impacts of climate change now requires aligned, structural, and sustained changes across most human systems, including energy, transportation, agriculture, food, and health care. Importantly, a global transformation of financial systems is required, shifting resources away from the fossil fuel-based economy towards a zero emissions future. Putting people’s health at the center of climate change policy making is key to ensuring this transition protects wellbeing, reduces health inequities, and maximizes health gains. Some indicators reveal incipient progress and important opportunities for delivering this health-centered transformation.
- Hanging in the balance:With climate change breaking dangerous new records and emissions persistently rising, preventing the most catastrophic consequences on human development, health, and survival now requires the support and will of all actors in society. However, data suggest that engagement with health and climate change could be declining across key sectors: the number of governments mentioning health and climate change in their annual UN General Debate statements fell from 50% in 2022 to 35% in 2023, and only 47% of the 58 NDCs updated as of February, 2024, referred to health (indicator 5.4.1). Media engagement also dropped, with the proportion of newspaper climate change articles mentioning health falling 10% between 2022 and 2023.
As concerning records continue to be broken and people face unprecedented risks from climate change, the wellbeing, health, and survival of individuals in every country now hang in the balance.

The need for holistic, sector-tailored sustainability assessments for milk- and plant-based beverages. Maree E, Blignaut JN, Du Toit CJL, Meissner HH, Ederer P. Animal. 2024:101348.

Sustainable food systems encompass nutrition, the environment and socioeconomics, each aspect requiring unique assessment and consideration. This is especially important in the dairy industry, since livestock contributes 14.5% of global greenhouse emissions while also contributing 49% to global calcium supply and 12% to global protein supply. This necessitates strict measurement to ensure science-based decision-making while producing sustainably, ensuring adequate nutrient supply.
This review aimed to identify and evaluate existing measures of sustainability with the goal of generating recommendations for future sustainability measurements.
From a nutritional perspective, it identified existing measures such as nutritional life-cycle analysis, hybrid nutrient-rich food index, nutrient-rich food adjusted for adequate intake and nutrient deficiencies, as well as the priority micronutrient density score, as methods which consider broader nutrient profiles and utilize more recent research, and therefore serve as a basis for future models.
Major limitations exist in the incorporation of bioavailability or the food matrix effect in such measures, as well as food-group-specific indices. The Prospective Urban Rural Epidemiology healthy diet score also provides promise in serving as an updated version of current dietary guidelines.
Environmentally, the life cycle analysis approach forms a detailed basis for environmental footprint assessment, although the practical application thereof in modern agriculture may be cumbersome and may warrant the use of simpler metrics. However, the complexity of sustainability assessments due to differing production methods and system boundaries makes comparisons difficult, which justifies either standardized or contextualized indices.
Lastly, socioeconomics which are often measured only via retail price with a focus on economics also deserves consideration of affordability at consumer and producer level by evaluating the effect of the production system on the local and global economy, producer affordability and the potential to improve livelihoods.
In conclusion, a localized and holistic measure of sustainability is warranted which is both sector and context-specific and reported in sufficient detail to prevent the masking of poor results due to single metric expressions.

Biohydrogen production from co-substrates through dark fermentation by bacterial consortium. Mumtha C, Mahalingam PU. 3 Biotech. 2024 Nov;14(11):281.

Hydrogen is a clean energy carrier that can be used as fuel for fuel cells. Dark fermentative biohydrogen production with other waste biomass needs to be explored as an alternative for sustainable biohydrogen production in future.
In this study, lab-scale bioreactor was carried out to produce biohydrogen from co-substrates using bacterial consortium at 37 ℃. For the experimental setup, a 1-L-working-volume reactor was used for biohydrogen production by bacterial monocultures and consortium on co-substrates.
A batch experiment was performed at 37 °C with an initial pH of 7.0 and a mixing ratio of 600:300 between dairy whey and sugarcane bagasse. Total solids (TS), volatile solids (VS), total chemical oxygen demand (TCOD), soluble chemical oxygen demand (SCOD), and hydrogen production rate (HPR) were determined from co-substrates during the dark fermentation process.
Morphologic changes of biohydrogen producing bacteria binds on co-substrates after the fermentation process were determined using SEM imaging. The bacteria can degrade the substrate when they attach to it causing hole formation and cracked the surface area.
The level of biohydrogen production by bacterial consortium was observed and the results revealed a hydrogen production rate of 35.9 mL H₂/L/h. In fermentative H₂production, it is quite similar to that of most H₂-producing bacteria previously studied, especially that of the bacterial consortium, and this indicates that the attempt to find an outstanding bacterial strain for fermentative H₂ production might be very difficult if not impossible.

Dairy sludge characteristics and its degradation during thermal treatment and thermal plasma treatment. Júnior PWPM, de Souza Miranda F, Petraconi Filho G, et al. Environ Technol. 2024 Nov 18:1-17.

Thermal plasma treatment technique is widely used in the treatment of domestic and industrial waste. The technique has the potential of converting organic portion of waste into synthetic gas that has energy value, while the inorganic portion is cemented into a vitreous slag which is stable to leaching of harmful heavy metals.
Thermal treatment and thermal plasma treatment processes of dairy sludge were conducted. The thermal treatment was undertaken at temperatures from 200 °C to 1000 °C to establish the chemical composition and thermal degradation of the sludge. These results served as a foundation for interpreting the properties of the vitreous slag obtained from the sludge treated in the DC-transferred arc plasma reactor.
The dairy sludge is characterized by a high volatile matter but also presents substantial ash content, with primary elements such as Al, P, Si, Ca, and Fe. The characterizations of the samples were made employing techniques like X-ray fluorescence, X-ray diffraction analysis (XRD), FT-IR spectrometry, Thermogravimetric analysis, and Differential Scanning Calorimetry.
The results highlight the degradation of primary milk components like lactose, casein protein, and milk fat, with distinct differential thermogravimetric peaks at 230, 316, and 479 °C. As the temperature of thermal treatments approached 1000°C, silicon dioxide, calcium silicon, dicalcium silicate, and hydroxyapatite were identified in XRD spectra.
Plasma-treated sludge features various oxide crystalline structures, including Al₂O₃, CaO(Al₂O₃)₆, CaO(Al₂O₃)₂, Ca₂Al(AlSi)O₇, KFeO₂, and ZrO₉₈. FTIR analysis of sludge identifies a complex organic composition presenting alkanes, amines, amides, hydroxyl groups, and metallic and semi-metallic oxide bond absorption.
The FTIR results suggest the degradation of organic compounds and retention of phosphorous and aluminum bonds, especially after 600 °C. The vitreous slag from plasma treatment exhibits distinct composition characteristics without organic compound, presenting a vitreous and metallic/ceramic matrix. This research underscores the potential of thermal plasma treatments to neutralize dairy sludge.

Revolutionizing dairy waste: emerging solutions in conjunction with microbial engineering. Bhatia R, Singh S, Kumar V, Taneja NK, Oberoi HS, Chauhan K. Biodegradation. 2024 Nov 15;36(1):6.

The dairy industry is grappling with significant challenges in managing effluent due to environmental concerns and stringent regulatory demands, necessitating innovative solutions.
The paper investigates how microbial engineering is transforming the treatment of dairy wastewater, offering advanced methods to minimize environmental impact and enhance sustainability. It delves into the current challenges faced by the dairy industry, such as regulatory compliance and the limitations of traditional treatment technologies, and introduces microbial engineering as a promising solution for effluent management.
Microbial engineering leverages genetic engineering techniques and microorganisms to enhance the efficiency of treatment processes like bioaugmentation and bioremediation. The environmental and economic benefits of microbial engineering, highlighting its potential to reduce pollution and lower operational costs for the dairy industry.
The specific figures can vary based on factors like farm size and location, studies suggest that microbial engineering can reduce wastewater pollution by up to 50% and nutrient runoff by 30%. It also identifies key challenges and there are still areas including strains for specific pollutants (drugs, hormones), enhance degradation pathways, and increase microbes’ stability (stress tolerance, long-term viability) that require further innovation to maximize its benefits.
Through case studies and success stories, the paper demonstrates practical applications of microbial engineering in managing dairy effluent, illustrating how it can revolutionize industrial practices for a more sustainable future.

Enhancing physico-chemical water quality in recycled dairy effluent through microbial consortium treatment. Velmurugan L, Pandian KD. Heliyon. 2024 Oct 20;10(21):e39501.

The dairy industry, notorious by generating wastewater rich in organic and nitrogenous content, necessitates sustainable recycling solutions. Biological treatment emerges as a cost-effective and chemical-free alternative.
This study delves into the potential of commercially available microbial consortium, Effective Microorganisms™ (EM) culture which contains beneficial microorganisms including lactic acid bacteria, photosynthetic bacteria, and yeast for recycling dairy effluent, aiming at water reclamation and environmental sustainability.
Effluent samples from Madurai’s Dairy Industry underwent microbial consortium treatment in a recycling prototype, with treatment efficacy assessed through physicochemical parameters and contaminant removal efficiency.
Guided by a biodegradability index of 4.51, the study showcased EM’s impact, revealing a notable decrease in pH levels, fostering an alkaline environment (2.35 ± 0.06 ppt). Dissolved oxygen increased significantly to 4.50 ppm, indicating improved aerobic conditions.
EM treatment led to substantial reductions in calcium (53 %), magnesium (95 %), nitrogen (22 %), sulfate (79 %), phosphate (86 %), BOD (78 %), and COD (82 %). In contrast, dairy effluent treated without microbial consortium during the sludge activation process exhibited negligible water quality improvement.
These findings underscore microbial consortium efficacy in advancing biological treatment of dairy effluent, demonstrating a significant reduction in contaminants and showcasing its potential for sustainable water reclamation. Improved alkalinity, dissolved oxygen, and nutrient content further signify positive impacts on ecosystem health.
Microbial consortium emerges as a promising avenue for recycling dairy effluent, offering an economically viable and environmentally friendly solution. The study emphasizes the crucial role of microbial treatments in achieving efficient water reclamation, contributing to a cleaner and sustainable environment.
Future research and broader implementation of microbial consortium in dairy industry wastewater management are recommended for enhanced environmental benefits.

The Path to Net-Zero in Dairy Production: Are Pronounced Decreases in Enteric Methane Achievable? Beauchemin KA, Kebreab E, Cain M, VandeHaar MJ. Annu Rev Anim Biosci. 2024 Nov 15.

Achieving net-zero greenhouse gas (GHG) emissions in dairy production will require >50% reduction in enteric methane (CH₄) emissions together with elimination of emissions from feed production, additional carbon sequestration, reduction in manure emissions, anaerobic digestion of manure, and decreased reliance on fossil fuel energy.
Over past decades, improved production efficiency has reduced GHG intensity of milk production (i.e., emissions per unit of milk) in the United States, but this trend will continue only if cows are bred for increased efficiency.
Genetic selection of low-CH₄-producing animals, diet reformulation, use of feed additives, and vaccination show tremendous potential for enteric CH₄mitigation; however, few mitigation strategies are currently available, and added cost without increased revenue is a major barrier to implementation.
Complete elimination of CH₄emissions from dairying is likely not possible without negatively affecting milk production; thus, offsets and removals of other GHGs will be needed to achieve net-zero milk production.

The One Health aspect of climate events with impact on foodborne pathogens transmission. Balta I, Lemon J, Corcionivoschi N, et al. One Health. 2024 Nov 3;19:100926.

The ongoing effects of climate change have exacerbated two significant challenges to global populations: the transmission of foodborne pathogens and antimicrobial resistance (AMR) through the food chain.
Using the latest available scientific information this review explores how climate-related factors such as rainfall, floods, storms, hurricanes, cyclones, dust, temperature and humidity impact the spread of the foodborne pathogens Salmonella, coli, Campylobacter, Vibrio, Listeria, and Staphylococcus aureus.
In this study, researchers explore the complex dynamics between environmental changes and the heightened risk of foodborne diseases, analyzing the contribution of wildlife, insects and contaminated environments in the proliferation of AMR and climate change.
This review paper combines a thorough analysis of current literature with a discussion on findings from a wide variety of studies to provide a comprehensive overview of how climatic factors contribute to the survival, persistence and transmission of bacterial pathogens in the food chain. In addition, the researchers discuss the necessity for effective mitigation strategies and policies.
By providing insights into the interrelationships between climate change and food safety, this review hopes to inform future research and policy development to promote safer and more sustainable food systems and further integration within the One Health approach.

Animal Health and Food Safety

North American perspectives for cattle production and reproduction for the next 20 years. Lucy MC, Pohler KG. Theriogenology. 2024 Nov 6;232:109-116.

Ruminant species are important to human society due to their ability to convert human-inedible sources of energy and protein to human-edible food. Greater efficiency of meat and milk production will require the management of the complex reproductive biology of many cattle with a limited capacity and limited budget within a smaller, hotter, and more climatically erratic land area.
The over-riding drivers of new reproductive technologies in North America will be smaller economic margins, larger herd size, fewer agricultural workers per farm, and a greater reliance on automation to offset the reduced agricultural labor force.
Climate change and the possibility that consumers may dictate the procedures used for animal reproductive management may present additional challenges. The successes of the past 20 years (timed AI, genomic selection for fertility in both bulls and cows, automated estrus detection, chemical and ultrasonographic pregnancy diagnosis, and gender selected semen) will be improved upon in the next 20 years as most of these technologies can be optimized further.
Improving embryo technologies and increasing our understanding of embryonic loss may provide the greatest challenges for the future. Researchers must attempt to devise practical methods to release more follicles from the primordial follicle pool so that a greater number of oocytes and embryos can be harvested from individual animals.
Embryonic loss continues to be an unsolved question that cuts the total number of potential offspring by nearly one-third. The identification of fertile embryos in vitro, better methods of cryopreservation, and the optimization of methods of transfer into recipient animals may improve the efficiency of advanced embryo technologies. The derivation of oocytes, sperm, and embryos from pluripotent stem cells may yield a vast supply of gametes and embryos from genetically superior animals and radically change the reproductive management in the future.

Avian influenza A (H5N1) virus in dairy cattle: origin, evolution, and cross-species transmission. Mostafa A, Naguib MM, Martinez-Sobrido L, et al. mBio. 2024 Nov 13:e0254224.

Since the emergence of highly pathogenic avian influenza virus (HPAIV) H5N1 of clade 2.3.4.4b as a novel reassortant virus from subtype H5N8, the virus has led to a massive number of outbreaks worldwide in wild and domestic birds. Compared to the parental HPAIV H5N8 clade 2.3.4.4b, the novel reassortant HPAIV H5N1 displayed an increased ability to escape species barriers and infect multiple mammalian species, including humans.
The virus host range has been recently expanded to include ruminants, particularly dairy cattle in the United States, where cattle-to-cattle transmission was reported. As with the avian 2.3.4.4.b H5N1 viruses, the cattle-infecting virus was found to transmit from cattle to other contact animals including cats, raccoons, rodents, opossums, and poultry.
Although replication of the virus in cows appears to be mainly confined to the mammary tissue, with high levels of viral loads detected in milk, infected cats and poultry showed severe respiratory disease, neurologic signs, and eventually died. Furthermore, several human infections with HPAIV H5N1 have also been reported in dairy farm workers and were attributed to exposures to infected dairy cattle. This is believed to represent the first mammalian-to-human transmission report of the HPAIV H5N1.
Fortunately, infection in humans and cows, as opposed to other animals, appears to be mild in most cases. Nevertheless, the H5N1 bovine outbreak represents the largest outbreak of the H5N1 in a domestic mammal close to humans, increasing the risk that this already mammalian adapted H5N1 further adapts to human-to-human transmission and starts a pandemic.
Herein, researchers discuss the epidemiology, evolution, pathogenesis, and potential impact of the recently identified HPAIV H5N1 clade 2.3.4.4b in dairy cattle in the United States. Eventually, interdisciplinary cooperation under a One Health framework is required to be able to control this ongoing HPAIV H5N1 outbreak to stop it before further expansion of its host range and geographical distribution.

Bacterial Communities of House Flies from Beef and Dairy Cattle Operations are Diverse and Contain Pathogens of Medical and Veterinary Importance. Neupane S, Talley JL, Nayduch D, et al. Curr Microbiol. 2024 Oct 30;81(12):433.

Adult house flies (Musca domestica L.) are important reservoirs and mechanical vectors of bacteria in livestock operations. House fly bacterial communities are influenced by their local environment, yet a comprehensive understanding of bacterial diversity, pathogen prevalence, and bacterial source is not fully understood.
Researchers characterized bacterial communities from adult female house flies and associated manure samples from beef and dairy cattle farms in Kansas, Oklahoma, and Texas over four months (July-October).
Bacterial community composition in flies and manure reflected the local environment, and house flies shared the majority (≥ 99%) of bacterial taxa with manure. The variability of bacterial diversity was greater among individual fly (species richness range: 48-1747) samples than manure (species richness range: 345-1162). Temporal variability of fly bacterial diversity was observed within each farm type.
Bacterial taxa of veterinary and medical importance such as Corynebacterium, Turicibacter, Staphylococcus, Streptococcus, and Acinetobacter were highly prevalent in flies, constituting core bacterial communities.
The prevalence of bacterial taxa associated with bovine keratoconjunctivitis (IBK) and bovine respiratory disease (BRD) was higher in flies than in manure and prevalence varied monthly.
This study underscores the crucial role house flies play as carriers of cattle pathogens, contributing to their dissemination among animals and to off-site locations, where they pose a threat to surrounding communities and agricultural operations.

Host genetic regulation of specific functional groups in the rumen microbiome of dairy cows: Implications for lactation trait. Bai H, Lai Z, Mao S, et al. J Adv Res. 2024 Nov 12:S2090-1232(24)00531-9.

Ruminants play a pivotal role in our society by transforming non-consumable substances from industrial by-products and plant fibers into valuable resources such as meat and milk. This remarkable conversion ability is primarily attributed to the rumen microbiota, which is influenced by various factors, including diet, climate, and geographical location. In recent years, increasing research has shown that host factors (breed, genetic variation, etc.) also play vital roles in shaping rumen microbial composition and function in cattle.
This study aims to provide a theoretical basis and an opportunity for further investigating the regulation of lactation traits in dairy cows through host genetics and the interaction with the rumen microbiota.
The aim of this study wasto investigate the interactions between host genotype, rumen microbiota, and animal phenotype, researchers curated and analyzed the dairy herd improvement data, single nucleotide polymorphisms (SNPs) genotypes, and 16S rumen microbiota data from 1,169 Holstein dairy cows.
The researchers identified thirty-one heritable taxa, whose functions were predominantly enriched in carbohydrate metabolism and energy metabolism. The genome-wide association study revealed that nine heritable bacteria were significantly associated with forty-three SNPs. Functional genes located within or near these SNPs were primarily associated with rumen epithelial development.
Additionally, these nine heritable bacteria were primarily annotated as complex polysaccharide degraders and butyrate producers, which showed significant associations with milk yield and milk fat percentage. Compared to previous studies, we newly discovered the existence of a high heritability of Olsenella umbonate, Butyrivibrio hungatei, among others.
This study identified thirty-one heritable bacterial taxa in Holstein dairy cows’ rumen microbiota, with nine showing significant associations with forty-three SNPs related to rumen epithelial development. The discovery of novel heritable species and their correlations with lactation traits provides valuable insights for future breeding strategies aimed at improving dairy cattle productivity through the manipulation of host genetics and rumen microbiota.

Impact of training dairy farm personnel on milking routine compliance, udder health, and milk quality. Rodriguez Z, Lopez-Benavides M, Gentilini MB, Ruegg PL. J Dairy Sci. 2024 Nov 7:S0022-0302(24)01296-7.

Among various farm procedures, an appropriate milking routine is crucial for reducing mastitis and enhancing milk safety and quality. However, inadequate compliance with milking routines remains a primary factor contributing to variability of milk quality among herds. Training farm workers is essential for ensuring compliance with milking routines, which directly impacts milk quality and udder health.
In this study, researchers aimed to assess the impact of a training session on dairy farm workers’ understanding of the milking routine, behavioral changes during milking, and subsequent effects on milk quality and udder health.
Farm workers (n = 112) from 16 commercial dairy farms in Michigan and Ohio participated in the project. The training session was delivered using an active learning approach prioritizing group discussions, and focused on the pathogenesis, identification, and risk factors for mastitis, and the rationale and importance of each step in the milking routine. Pre- and post-training evaluations were conducted to measure changes in knowledge, parlor evaluations were performed to determine behavioral change, and data from clinical mastitis cases and bulk tank somatic cell count were used to estimate udder health and milk quality.
Participants were mostly milking technicians (61.1%) with 70% of them having less than 1 year of experience and a median tenure in their jobs of 9 months. Knowledge of the milking routine increased from 49.3% to 67.6% of correct answers after training.
Based on parlor evaluations, the pre-milking disinfectant contact time increased by 9 seconds per cow. The percentage of milkings with inadequate preparation time decreased from 69% (before training) to 48% (after training). The proportion of insufficient teat coverage during post-milking disinfection decreased from 9.8% (77 out of 782) before training to 5.9% (34 out of 572) after training. There was a significant increase in clinical mastitis cases during the immediate week after the training. Additionally, the upward trend in bulk tank somatic cell count was halted.
These results suggest an improvement in overall mastitis identification and milk quality, underscoring the importance of targeted training programs for farm workers in improving milking routine compliance, enhancing milk quality, and promoting better udder health.

Larger Airway Functions in Poultry and Dairy Confinement Workers: A Cross-Sectional Study. Pavithran M, K P, P KP, Sivan G, Daniel R, Sadasivam K, K TS, A S. Cureus. 2024;16(10):e71045.

The peak expiratory flow (PEF) test is a crucial tool for assessing larger airway functions, particularly in individuals exposed to occupational hazards.
This study aims to compare PEF values between animal workers (poultry and dairy farm workers) who are regularly exposed to animal allergens and other respiratory irritants and normal workers who do not have such exposures.
A cohort of animal workers from poultry and dairy farms were evaluated alongside a control group of normal workers without known respiratory hazards. PEF measurements were taken using a computerized spirometer, and results were analyzed to determine differences in respiratory function between the two groups.
There was a significant difference in PEF values, with animal workers exhibiting lower PEF compared to their control group. Further, poultry farm workers had a significant decrease in PEF when compared to dairy farm workers.
This study represents a pioneering effort in the comparative analysis of respiratory health among workers in poultry and dairy farms. The findings indicate that occupational exposure to allergens and irritants associated with animal environments may have deleterious effects on respiratory health.
This study underscores the importance of regular respiratory health monitoring and implementation of protective measures for individuals in occupations with high exposure to respiratory irritants. Enhanced awareness and preventive strategies could mitigate the long-term health impacts on animal workers, ensuring safer working environments and improved overall health outcomes.

Nutrition and Health

Whole milk intake is associated with lower body weight and body mass index in American adults. Torres-Gonzalez M, Pikosky M.A., Ricklefs-Johnson K, Fulgoni K, Fulgoni V.L. III, Agarwal, S, Cifelli, C.J. Nutrition Research. 2024 Nov.

Traditionally, dietary recommendations to manage obesity have included fat-free or low-fat milk and other dairy products as part of healthy diets. These recommendations were based on the hypothesis that consuming lower fat and lower calorie dairy products would help reduce the risk of obesity and other adverse health effects.
However, emerging evidence suggests that it might not be as simple as that, and some scientific evidence also indicates that the association between dairy food consumption and body weight cannot be predicted based solely on calorie and fat content.
Additionally, some studies have shown that subjects reporting to consume more whole milk showed not gain of body weight or were in a lower risk of gaining weight over time. As such, more studies are needed not only to determine the association of whole milk with body weight and related parameters but also to provide further insights if consumer behaviors and history of whole milk intake are associated with body weight changes over time.
The objective was to determine if whole milk intake or total milk intake behaviors are associated with body weight (weight) and related parameters in adults.
The researchers hypothesize that whole milk intake would be inversely associated with body weight measures.
Whole milk (including flavored whole milk) intake was assessed using 24-hour dietary recall data of NHANES 2001-2018 for adults age 20+ years (N=43,038). Weight and related parameters were measured, and history of self-reported weights and total milk intake were obtained from questionnaire data.
The average BMI was about 29 kg/m2 and weight was 76 – 89 kg. About 66% of the population were overweight or obese. Average whole milk intake among consumers was 1.0-1.4 cups eq/day.
Whole milk intake was inversely associated (P<0.05) with weight, BMI, waist circumference and the prevalence of obesity. Whole milk intake was also positively associated (P<0.05) with desire to lose weight. In most cases, milk intake behavior at ages 5-12, 13-17, or 18-35 years was not associated with BMI.
The results indicate that whole milk intake was inversely associated with weight, BMI and prevalence of obesity, and these findings may provide additional evidence to support dietary recommendations for whole milk.

The prolonged impact of swapping non-fermented with fermented dairy products on cardiovascular disease: the ATTICA cohort study (2002-2022). Kouvari M, Tsiampalis T, Panagiotakos D, et al ; ATTICA study group. Eur J Clin Nutr. 2024 Nov 20.

Scientific evidence suggests that substituting non-fermented with fermented dairy products may confer cardiovascular health benefits.
The purpose of this study was to examine the role of fermented in relation to non-fermented dairy products on 20-year fatal/non-fatal cardiovascular disease (CVD) incidence.
In 2001-2002, n = 3042 free-of-CVD men and women from Attica, Greece, were recruited. Dietary assessment was based on a validated semi-quantitative food frequency questionnaire. CVD evaluation was performed in three follow-up time points at 5, 10 and 20 years, in n = 1988 participants (718 cases).
Participants reported >2 servings/day of fermented dairy products had 1.5 times lower risk to develop CVD compared with their lower level of consumption. Multi-adjusted analysis revealed similar cardioprotective properties per 1 serving increase in dairy consumption of fermented dairy products (Hazard Ratio (HR) = 0.82, as well as when the ratios of fermented:total dairy products (HR = 0.90) and fermented:non-fermented dairy products (HR = 0.74) were ≥0.76 and ≥2.5, respectively.
The associations were more evident in case of impaired inflammation status. Replacing 1 serving of non-fermented with 1 equivalent serving of fermented dairy products reduced CVD risk (0.74).
Substitution of low-fat with whole-fat yogurt increased CVD risk. Replacing cheese with low-fat yogurt reduced CVD risk while with whole-fat yogurt no significance was observed.
Shift of guidelines to a daily pattern of dairy intake yet with an inclination towards emphasizing the consumption of fermented products is recommended.

Dairy Intake in Relation to Prediabetes and Continuous Glycemic Outcomes: A Systematic Review and Dose-Response Meta-Analysis of Prospective Cohort Studies. Slurink IA, Vogtschmidt YD, Brummel B, Soedamah-Muthu SS, et al. Curr Dev Nutr. 2024 Sep 29;8(11):104470.

Modest inverse associations have been found between dairy intake, particularly yogurt, and type 2 diabetes risk. Investigating associations of dairy intake with early onset of type 2 diabetes offers opportunities for effective prevention of this condition.
This study aimed to investigate the relationships between the intake of different dairy types, prediabetes risk, and continuous glycemic outcomes.
Systematic literature searches across multiple databases were performed of studies published up to September 2023. Included were prospective cohort studies in healthy adults that examined the association between dairy intake and prediabetes risk according to diagnostic criteria, or continuous glycemic markers.
The meta-analyses encompassed 6,653 prediabetes cases among 95,844 individuals (age range 45-65 years) describing 9 cohorts. A quadratic inverse association was observed for total dairy intake and prediabetes risk, with the relative risk (RR) lowest risk at 3.4 servings/day (RR: 0.75).
Similarly, total, and high-fat cheese exhibited nonlinear inverse associations with prediabetes risk, showing the lowest risk at 2.1 servings/day (RR: 0.86), but a higher risk at intakes exceeding 4 servings/day.
Ice cream intake was linearly associated with prediabetes risk (RR = 0.85) at the highest median intake of 0.23 servings/day. Other dairy types showed no statistically significant associations.
Overall, the findings suggest an inverse association between moderate dairy and cheese intake in preventing prediabetes.

Associations between perinatal biomarkers of maternal dairy fat intake and child cognitive development: results from the EDEN mother-child cohort. Yuan WL, Armand M, Bernard JY, et al. Eur J Clin Nutr. 2024 Nov 20.

Offspring’s optimal neurodevelopment depends on maternal dietary lipids supply during the perinatal period. Dairy products are an important source of fat in Western diets.
Therefore, this study aimed at examining the associations between maternal dairy fat intake during pregnancy, evaluated through biomarkers in perinatal biofluids (C15:0 and C17:0) and child’s cognitive outcomes.
Participants (N up to 1200) were French mother-child pairs from the EDEN cohort study. Biomarkers were assessed in the following biofluids: maternal red blood cells (RBC) membrane at 24 weeks’ gestation, cord RBC membrane, and colostrum.
Cognitive outcomes were language abilities scores at ages 2 and 3 years and overall cognitive development scores at ages 3 and 5-6 years. Interaction of any breastfeeding duration on the associations with dairy fat biomarkers in colostrum was studied.
Positive associations were observed between levels of C17:0 in cord RBC and C15:0 in maternal RBC with language abilities. In children breastfed for at least 6 months, C15:0 level in colostrum was positively associated with language abilities at age 3 years and overall cognitive development at ages 3 and 5-6 years whereas C17:0 level was only associated with overall cognitive development at age 3 years.
These results suggest that maternal higher intake of dairy fat during perinatal period could be potentially associated with offspring’s better cognitive development. These pioneering results call for external validation to challenge their causality.

Dairy Intake and All-Cause, Cancer, and Cardiovascular Disease Mortality Risk in A Large Japanese Population: A 12-Year Follow-Up of the J-MICC Study. Miyagawa N, Takashima N, Matsuo K, et al ; J-MICC Study Group. J Atheroscler Thromb. 2024 Nov 13.

Researchers examined the association between dairy intake and all-cause, cancer, and cardiovascular disease mortality in a cohort of the general population followed up for 12 years across Japan.
They conducted a longitudinal cohort study of 79,715 participants from the Japan Multi-Institutional Collaborative Cohort study (57.2% women, mean age 54.7 years old). The amount of dairy (milk and yogurt) intake was determined using a validated short-food frequency questionnaire
During the follow-up period (932,738 person-years), 3,723 participants died, including 2,088 cancer and 530 cardiovascular disease deaths. The highest tertile of total dairy intake (versus the lowest tertile) was associated with a 19% lower all-cause mortality risk in women.
Similarly, the researchers observed inverse associations between milk intake and all-cause and cancer mortality risk in women, yogurt intake and cardiovascular disease risk in women, and yogurt intake and all-cause mortality risk in both sexes.
A higher total dairy and milk intakes in women and yogurt intake in both sexes were associated with a reduced risk of all-cause mortality in the general population across Japan during the 12-year follow-up period.

Buttermilk and Whey as Functional Foods to Ameliorate Clindamycin-Induced Changes in Mouse Intestine: Modulation of Intestinal Motility and Toll-like Receptors Expression. Bellés A, Abad I, Buey B, Vergara C, Mesonero JE, Sánchez L, Grasa L. J Med Food. 2024 Nov 7.

Antibiotic treatment is one of the main causes of intestinal dysbiosis, leading, in turn, to other intestinal alterations given the multiple relationships of the microbiota with gut health.
Whey and buttermilk are two by-products from the dairy industry with numerous bioactive components.
This study aimed to assess the potential of two formulas, containing a mixture of lactoferrin, milk fat globule membrane (MFGM), and whey or buttermilk, to reverse the negative effects of clindamycin on gut motility, Toll-like receptors (TLRs) expression, and oxidative stress in the intestine.
For this purpose, a murine model of intestinal dysbiosis was established by clindamycin treatment. Male C57BL/6 mice were treated with saline (Control), clindamycin (Clin), a formula containing whey (F1), or buttermilk (F2) supplemented with lactoferrin and MFGM, Clin+F1, or Clin+F2.
Clin delayed the whole gut transit, reduced the response to acetylcholine, decreased TLR2expression, and increased TLR4 expression in the intestine. F1 and F2 formulas reversed the effects of Clin, restoring TLR2 receptor levels and normalizing intestinal dysmotility.
These results indicate that whey- and buttermilk-based formulas supplemented with lactoferrin and MFGM could be used as functional foods to prevent or treat motility disorders and restore some components of the immune system after antibiotic treatment.

Innovation, Economics, and Dairy Alternatives

High-throughput ecological interaction mapping of dairy microorganisms. Ndiaye A, Coulombe K, Fliss I, Filteau M. Int J Food Microbiol. 2024 Nov 6;427:110965.

To engineer efficient microbial management strategies in the food industry, a comprehensive understanding of microbial interactions is crucial. Microorganisms live in communities where they influence each other in several ways. Although much attention has been paid to the production of antagonistic metabolites in lactic acid bacteria (LAB), research that accounts for the complexity of their ecological interactions and their dynamics remains limited.
This study explores binary interactions within a mock community of 94 strains, including 23 LAB from culture collections and 71 isolated from dairy products.
Using a colony-picking robot and image analysis, bidirectional interactions were measured at high throughput on solid media, where one test strain was challenged against other mock community members as the target strains. Assays of 15 test strains (14 LAB and one yeast) yielded 1,142 bidirectionally mapped interactions, classified by ecological type over seven days.
The results showed variation in the strength, directionality, and type of interactions depending on the origin of the target strains. Cooperation rates increased for strains isolated from raw milk to pasteurized milk and cheese, while exploitation was more common in raw milk strains. Cooperating strains also exhibited more similar ecological behaviors than competing strains, suggesting the presence of microbial cliques.
Interestingly, Lactococcus cremoris ATCC 19257 developed pink-red pigmentation when co-cultured with Pseudomonas aeruginosa.
Overall, these findings present an unprecedented exploratory data set that significantly improves our understanding of microbial interactions at the system level, with potential applications in strain selection for food processes such as fermentation, bioprotection, and probiotics.

Dairy and nondairy proteins as nano-architecture structures for delivering phenolic compounds: Unraveling their molecular interactions to maximize health benefits. de Almeida CC, Baião DDS, Paschoalin VMF, et al. Compr Rev Food Sci Food Saf. 2024 Nov;23(6):e70053.

Phenolic compounds are recognized for their benefits against degenerative diseases. Clinical and nutritional applications are limited by their low solubility, stability, and bioavailability, compromising their efficacy. Natural macromolecules, such as lipids, polysaccharides, and proteins, employed as delivery systems can efficiently overcome these limitations.
In this sense, proteins are attractive due to their biocompatibility and dynamic structure properties, functional adaptability and self-assembly capabilities, offering stability, efficient encapsulation, and controlled release.
This review explores the potential use of dairy proteins, caseins, and whey proteins, and, alternatively, nondairy proteins, gelatin, human serum albumin, maize zein, and soybean proteins, in building wall materials for the delivery of phenolic compounds.
To optimize performance, aspects, such as protein-phenolic affinity and complex stability/activity, should be considered when designing particle nano-architecture. Molecular interactions between protein-phenolic compound complexes are, thus, further discussed, as well as the effects of temperature and pH and strategies to stabilize and preserve nano-architecture and retain phenolic compound activity.
All proteins harbor one or more putative binding sites, shared or not, depending on the phenolic compound. Preservation techniques are still a case-to-case study, as no behavior patterns among different complexes are noted.
This review broadens our understanding and opens new opportunities for the development of novel protein-based nanocarriers to obtain more effective and stable products, enhancing phenolic compound delivery and health benefits.

Collaborative Development of a Farm Systems Learning Platform “4D Virtual Farm”. Hallein E, Shallcross D, Barber S. J Vet Med Educ. 2024:e20230023.

Over the past 20 years, a lower percentage of veterinary and animal science students entering Australian and New Zealand schools have a background or ongoing contact with livestock production systems. The increasing use of digital technologies over the same time provides a practical option to introduce students to the seasonal operations on livestock farms.
This article describes the development of the 4D Virtual Farm, established to showcase 11 representative livestock farms across Australasia allowing students to virtually travel through seasons and place over each farming enterprise.
Students can virtually visit different beef cattle, prime lamb, wool-sheep and dairy cattle farms, and a piggery. Any electronic device connected to the web including mobile phones, tablets, computers, and virtual reality headsets can be used to view the enterprises.
For educators, the virtual farm can be used for a range of teaching and learning scenarios, such as demonstration of a particular production system via weblink for lectures or embedding within learning management systems.
It also allows students to start at a particular point in time and space and guide themselves to other areas for self-learning or for a range of assessment tasks. This site provides an example that could be used in other teaching areas including abattoirs, exotic diseases, surgery, communication, and many other veterinary examples.

Consumer Acceptance of Protein Beverage Ingredients: Less is More. Rovai D, Watson ME, Barbano DM, Drake MA. J Dairy Sci. 2024 Nov 7:S0022-0302(24)01300-6.

An array of ingredients are added to protein beverage formulations. These ingredients may not be desirable to consumers.
The objective of this study was to determine consumer perception of ingredients in protein beverages.
An online survey was conducted with protein beverage consumers (n = 405). Maximum difference scaling and projective mapping were applied to determine the relative acceptance of ingredients based on their functional role (protein source, sweetener, stabilizer, thickener).
Subsequently, 4 120-min focus groups were conducted (n = 25 consumers). Consumer sentiment from focus groups was compiled and grouped based on themes that emerged across multiple focus groups.
Consumers placed the highest importance on the amount of protein followed by protein type in protein beverages. Plant protein, whey protein, and milk protein were most appealing, while soy protein, collagen, and casein/caseinates were less appealing.
Natural sweeteners (agave, monk fruit, cane sugar) were the most appealing sweeteners. Fibers and starches were more appealing than gums (carrageenan, gellan gum). Stabilizers were the least desirable class of beverage ingredients, with sodium and potassium phosphates the least desirable.
In regard to the packaging of a protein beverage, consumers placed the greatest importance on recognizable ingredients and plain language. Consistent with survey results, consumers in focus groups expressed skepticism and feeling overwhelmed by all of the ingredients on the label of protein beverages.
Protein was their primary desire and the presence of sweeteners was acceptable, but they did not desire additional ingredients. There is an opportunity to increase the acceptance and competitiveness of dairy protein beverages by reformulating beverages to include fewer and more familiar ingredients. Functional proteins, such as those derived from dairy, may have opportunities to exclude undesirable ingredients (stabilizers, thickeners) from the label.

Probiotic Milk and Oat Beverages with Increased Protein Content: Survival of Probiotic Bacteria Under Simulated In Vitro Digestion Conditions. Pawlos M, Szajnar K, Znamirowska-Piotrowska A. Nutrients. 2024;16(21):3673.

The increasing prevalence of plant-based dietary preferences, driven by lactose intolerance, allergies, and adherence to vegan diets, has necessitated the exploration of alternative food matrices for probiotic delivery.
This study aimed to evaluate the effects of whey protein isolate, pea protein isolate, and soy protein isolate on the viability of caseiand L. johnsonii during simulated in vitro gastrointestinal digestion. Furthermore, the study investigated the impact of two distinct matrices-cow’s milk and an oat-based beverage-on the survival of these probiotic strains.
Fermented products were prepared using cow’s milk and an oat-based beverage as matrices, with simulated digestion performed following a seven-day storage period at 5 °C. The in vitro digestion model encompassed oral, gastric, and small intestinal phases, with probiotic viability assessed using the plate-deep method at each stage.
Before digestion, caseiexhibited higher populations than L. johnsonii in both matrices. Including 3% soy and pea protein, isolates promoted the growth of L. casei in both fermented milk and oat beverages. However, a marked reduction in probiotic viability was observed during the gastric phase, with L. casei counts decreasing by 6.4-7.8 log cfu g^-1 in fermented milk and 3.1-4 log cfu g^-1 in oat beverages, while L. johnsonii demonstrated similar reductions.
These findings underscore the protective role of dairy components on probiotic viability, while the oat-based matrix exhibited a reduced capacity for sustaining probiotic populations throughout digestion.

Dairy milk: There are alternatives but no equivalents. Beckett EL, Cassettari T, Starck C, Fayet-Moore F. Food Sci Nutr. 2024;12(10):8470-8482.

Dairy milk is a core food in many food-based guides to healthy eating. However, plant-based milk alternatives are becoming increasingly available as substitutes. While these products serve a subset of the population unable or unwilling to consume milk, plant-based milk alternatives can be perceived by consumers as direct equivalents, or even more healthful alternatives to dairy milk.
This commentary addresses the significant differences in nutrient content that may have implications for the intake of key nutrients in the case of direct substitutions. Furthermore, while there is a significant body of knowledge demonstrating the significant health benefits associated with dairy milk consumption and a small number of potentially negative associations, there is a paucity of data on the health benefits of plant-based milk alternatives directly.
A “health halo” may exist based on matching individual nutrients through fortification, lower energy levels, and the health properties of the unprocessed raw characterizing ingredients of plant-based milk alternatives. This may mislead consumers regarding healthfulness. Similarly, environmental attributes based on volumes of production, without considering contribution to nutrients, may also skew consumer perception.
Positioning of plant-based milk alternatives in food-based dietary guidelines, marketing, and personal recommendations should acknowledge the differences in nutritional, bioactive, and health properties between plant-based milk alternatives and dairy milk to ensure appropriate adaptations are made to account for shortfalls in nutrients.