Dairy Research Bulletin: Selected Articles from October 2023

Environmental Management and Sustainability

A Gridded Inventory of Annual 2012-2018 U.S. Anthropogenic Methane Emissions. Maasakkers JD, McDuffie EE, Sulprizio MP, Chen C, Schultz M, Brunelle L, Thrush R, Steller J, Sherry C, Jacob DJ, Jeong S, Irving B, Weitz M. Environ Sci Technol. 2023 Oct 19.

  • Nationally reported greenhouse gas inventories are a core component of the Paris Agreement’s transparency framework. Comparisons with emission estimates derived from atmospheric observations help identify improvements to reduce uncertainties and increase the confidence in reported values.
  • To facilitate comparisons over the contiguous United States, researchers present a 0.1° × 0.1° gridded inventory of annual 2012-2018 anthropogenic methane emissions, allocated to 26 individual source categories, with scale-dependent error estimates.
  • This inventory is consistent with the U.S. Environmental Protection Agency (EPA) Inventory of U.S. Greenhouse Gas Emissions and Sinks (GHGI), submitted to the United Nations in 2020. Total emissions and patterns (spatial/temporal) reflect the activity and emission factor data underlying the GHGI, including many updates relative to a previous gridded version of the GHGI that has been extensively compared with observations.
  • These underlying data are not generally available in global gridded inventories, and comparison to EDGAR version 6 shows large spatial differences, particularly for the oil and gas sectors. The researchers also found strong regional variability across all sources in annual 2012-2018 spatial trends, highlighting the importance of understanding regional- and facility-level activities.
  • This inventory represents the first time series of gridded GHGI methane emissions and enables robust comparisons of emissions and their trends with atmospheric observations.

Retrospective and projected warming-equivalent emissions from global livestock and cattle calculated with an alternative climate metric denoted GWP. Del Prado A, Lindsay B, Tricarico J. PLoS One. 2023 Oct 2;18(10):e0288341.

  • Limiting warming by the end of the century to 1.5°C compared to pre-Industrial times requires reaching and sustaining net zero global carbon dioxide (CO2) emissions and declining radiative forcing from non-CO2 greenhouse gas (GHG) sources such as methane (CH4). This implies eliminating CO2 emissions or balancing them with removals while mitigating CH4 emissions to reduce their radiative forcing over time.
  • The global cattle sector (including Buffalo) mainly emits CH4 and N2O and will benefit from understanding the extent and speed of CH4 reductions necessary to align its mitigation ambitions with global temperature goals.
  • This study explores the utility of an alternative usage of global warming potentials (GWP*) in combination with the Transient Climate Response to cumulative carbon Emissions (TCRE) to compare retrospective and projected climate impacts of global livestock emission pathways with other sectors (e.g. fossil fuel and land use change).
  • To illustrate this, researchers estimated the amount and fraction of total warming attributable to direct CH4 livestock emissions from 1750 to 2019 using existing emissions datasets and projected their contributions to future warming under three historical and three future emission scenarios.
  • These historical and projected estimates were transformed into cumulative CO2 equivalent (GWP100) and warming equivalent (GWP*) emissions that were multiplied by a TCRE coefficient to express induced warming as globally averaged surface temperature change.
  • In general, temperature change estimates from this study are comparable to those obtained from other climate models. Sustained annual reductions in CH4 emissions of 0.32% by the global cattle sector would stabilize their future effect on global temperature while greater reductions would reverse historical past contributions to global warming by the sector in a similar fashion to increasing C sinks.
  • The extent and speed with which CH4 mitigation interventions are introduced by the sector will determine the peak temperature achieved in the path to net-zero GHG.

Integrated production of hydrogen and methane in a dairy biorefinery using anaerobic digestion: Scale-up, economic and risk analyses. Almeida PS, de Menezes CA, Augusto IMG, Paulinetti AP, Lovato G, Rodrigues JAD, Silva EL. J Environ Manage. 2023 Oct 9;348:119215.

  • Anaerobic digestion has emerged as the most appealing waste management strategy in biorefineries. Particularly, recent studies have highlighted the energy advantages of waste co-digestion in industrial biorefineries and the use of two-stage systems. However, there are some concerns about moving the system from laboratory testing to industrial scale. One of them is the high level of investment that is required.
  • Therefore, this study carried out a techno-economic analysis (scale-up and energy production, economic and risk analysis, and factorial design) to assess the feasibility of single- and two-stage systems in the treatment of cheese whey and glycerin for the production of hydrogen and methane.
  • Scenarios (S1 to S9) considered thermophilic and mesophilic single and two-stage systems with different applied organic loading rates (OLRA).
  • The analyses of scale-up and energy production revealed that S3 (a thermophilic single-stage system operated at high OLRA3 kg-COD.m-3.d-1) and S9 (a thermophilic-mesophilic two-stage system operated at high OLRA134.8 kg-COD.m-3.d-1 and 20.5 kg-COD.m-3.d-1, respectively) were more compact and required lower initial investment compared to other scenarios.
  • The risk analysis performed by a Monte Carlo simulation showed low investment risks (10 and 11%) for S3 and S9, respectively, being the electricity sales price, the key determining factor to define whether the project in the baseline scenario will result in profit or loss. Lastly, the factorial design revealed that while the net present value (NPV) is positively impacted by rising inflation and electricity sales price, it is negatively impacted by rising capitalization rate.
  • Such assessments assist in making decisions regarding which system can be fully implemented, the best market circumstances for the investment, and how market changes may favorably or unfavorably affect the NPV and the internal rate of return (IRR).

Cellulose-degrading bacteria improve conversion efficiency in the co-digestion of dairy and chicken manure by black soldier fly larvae. Zhang J, Luo Z, Li N, Yu Y, Cai M, Zheng L, Zhu F, Huang F, K Tomberlin J, Rehman KU, Yu Z, Zhang J.J Environ Manage. 2023 Oct 12;348:119156.

  • Black soldier fly larvae (BSFL) have potential utility in converting livestock manure into larval biomass as a protein source for livestock feed. However, BSFL have limited ability to convert dairy manure (DM) rich in lignocellulose.
  • Previous research has demonstrated that feeding BSFL with mixtures of 40% dairy manure and 60% chicken manure (DM40) provides a novel strategy for significantly improving their efficiency in converting DM. However, the mechanisms underlying the efficient conversion of DM40 by BSFL are unclear.
  • In this study, we conducted a holistic study on the taxonomic stucture and potential functions of microbiota in the larval gut and manure during the DM and DM40 conversion by BSFL, as well as the effects of BSFL on cellulosic biodegradation and biomass production.
  • Results showed that BSFL can consume cellulose and other nutrients more effectively and harvest more biomass in a shorter conversion cycle in the DM40 system. The larval gut in the DM40 system yielded a higher microbiota complexity. Bacillus and Amphibacillus in the BSFL gut were strongly correlated with the larval cellulose degradation capacity.
  • Furthermore, in vitro screening results for culturable cellulolytic microbes from the larval guts showed that the DM40 system isolated more cellulolytic microbes. A key bacterial strain (DM40L-LB110; Bacillus subtilis) with high cellulase activity from the larval gut of DM40 was validated for potential industrial applications.
  • Therefore, mixing an appropriate proportion of chicken manure into DM increased the abundance of intestinal bacteria (Bacillus and Amphibacillus) producing cellulase and improved the digestion ability (particularly cellulose degradation) of BSFL to cellulose-rich manure through changes in microbial communities composition in intestine.
  • This study reveals the microecological mechanisms underlying the high-efficiency conversion of cellulose-rich manure by BSFL and provide potential applications for the large-scale cellulose-rich wastes conversion by intestinal microbes combined with BSFL.

Climate Spaces and Cliffs: A Novel Bovine Thermodynamic and Mass Balances Model. Porter WP, Bertz AE, Mathewson PD, Solorzano LC, Dudley PN, Bonazza R, Gebremedhin KG. Animals (Basel). 2023;13(19):3043.

  • The effects of climate change on animals are typically viewed in terms of survivability and wellbeing. In this study, we broaden that purview to include climate impacts on reproductive capability.
  • There are not only climate spaces for daily function, but climate cliffs that represent reproductive failures in the face of climate warming. This alternative focus suggests that climate warming challenges may be more immediate and profound than initially imagined.
  • This research describes a state-of-the-art mechanistic model, Dairy Niche Mapper (DNM), and independent validation tests. Where test data are absent, the calculated results are consistent with expected responses.
  • Simulations of metabolic chamber conditions reveal the local steady-state impacts of climate and animal variables on milk production capacity, metabolic rate, food consumption and water needs. Simulations of a temperature humidity index (THI) show strengths and limitations of that approach. Broader time- and spatial-scale calculations applied in the western and eastern halves of the northern hemisphere identify current and future monthly latitudinal climate change impacts on milk production potential, feed and water needs in dairy cows of different sizes.
  • Dairy Niche Mapper (DNM) was developed from a broadly tested mechanistic microclimate-animal model, Niche Mapper (NM). DNM provides an improved quantitative understanding of the complex nonlinear interactions of climate variation and dairy bovine properties’ effects on current and future milk production, feed and water needs for grazing and confinement dairy operations.
  • DNM outputs include feasible activity times, milk production and water and feed needs of different-sized Holstein cows on high-grain (confinement feeding) versus high-forage (grazing feeding) diets at three arbitrary north latitudes, 12°, 30° and 60°, for North and Central America and for Asia. These three latitudes encompass current northern hemisphere bovine production environments and possible future production locations.
  • The greatest impacts of climate change will be in the low elevations in tropical and subtropical regions. Global regions above 30° and below 60° latitude with reliable rainfall will be least affected by current projected levels of climate change.
  • This work provides the basis for computational animal design for guiding agricultural development via breeding programs, genetic engineering, management options including siting or the manipulation of other relevant environmental and animal variables.


Animal Health and Food Safety

Effect of feeding dairy calves with milk fermented with selected probiotic strains on occurrence of diarrhea, carriage of pathogenic and zoonotic microorganisms and growth performance. Fresno AH, Alencar ALF, Liu G, Wridt MW, Andersen FB, Pedersen HS, Martin HL, Nielsen SS, Aabo S, Olsen JE, Jensen AN. Vet Microbiol. 2023 Oct 4;286:109885.

  • Calf-diarrhea is a major health problem in dairy calves and a primary reason for use of antimicrobials.
  • Therefore, researchers aimed to investigate the effect of feeding milk fermented with a combination of four probiotic bacterial strains to young-calves on; occurrence of diarrhea and associated-pathogens (bacteria, virus and parasites), shedding of Salmonella Dublin and Campylobacter, occurrence of virulence genes linked to Clostridium perfringens, Enterotoxigenic Escherichia coli and shiga-toxin producing coli (STEC), as well as growth performance.
  • For this, 143 new-born calves from three Danish dairy-farms were allocated into Treatment- (fed the fermented milk for the first 8-weeks-of-life) and Control-groups (fed regular farm-milk). Diarrhea was observed in 18.6 % (Farm 1), 22.4 % (Farm 2) and 15.7 % (Farm 3) of the total registrations mainly within the first 3-weeks-of-life.
  • perfringens was the most frequently detected pathogen. The treatment did not affect the occurrence of virulence genes linked to STEC and C. perfringens and, overall, their detection levels were very low/undetected.
  • The statistical model applied found no significant effect of the treatment on prevalence of early-diarrhea (≤ 3 weeks), late-diarrhea (>3 weeks), occurrence of perfringens and Cryptosporidium parvum or levels of Campylobacter spp. Limited detection of the other pathogens and associated virulence-genes under study, did not allow for assessment of the impact of the treatment on their occurrence.
  • Notably, the feeding-approach showed a significant detrimental effect on daily-weight-gain. The inefficacy of the treatment may be associated with the complexity of influencing factors under field conditions including management practices.

Quantitative Associations between Season, Month, and Temperature-Humidity Index with Milk Yield, Composition, Somatic Cell Counts, and Microbial Load: A Comprehensive Study across Ten Dairy Farms over an Annual Cycle. Bokharaeian M, Toghdory A, Ghoorchi T, Ghassemi Nejad J, Esfahani IJ. Animals (Basel). 2023 Oct 13;13(20):3205.

  • The dairy industry plays a pivotal role in global agriculture, serving as a primary source of essential nutrition and contributing significantly to economies worldwide. The efficiency and sustainability of dairy production are, however, challenged by a wide range of factors, including climatic changes, which have gained increasing attention due to their profound effects on livestock health and productivity.
  • Among these climatic factors, temperature and humidity levels are key determinants of environmental stressors faced by dairy cattle. As the world experiences shifts in climate patterns and more frequent extreme weather events, understanding the implications of these changes on dairy cattle is of paramount importance.
  • This current study addresses the knowledge gap regarding the influence of seasons, months, and THI on milk yield, composition, somatic cell counts (SCC), and total bacterial counts (TBC) of dairy farms in northeastern regions of Iran.
  • For this purpose, ten dairy herds were randomly chosen, and daily milk production records were obtained.
  • Milk samples were systematically collected from individual herds upon delivery to the dairy processing facility for subsequent analysis, including fat, protein, solids-not-fat (SNF), pH, SCC, and TBC. The effects of seasons, months, and THI on milk yield, composition, SCC, and TBC were assessed using an analysis of variance.
  • The investigation revealed noteworthy correlations between key milk parameters and seasonal, monthly, and THI variations. Winter showed the highest milk yield, fat, protein, SNF, and pH, whereas both SCC and TBC reached their lowest values in winter.
  • The highest values for milk yield, fat, and pH were recorded in January, while the highest protein and SNF levels were observed in March. December marked the lowest SCC and TBC values.
  • In conclusion, these findings underscore the significant impact of THI on milk production, composition, SCC, and TBC, offering valuable insights for dairy management strategies. In the face of persistent challenges posed by climate change, these results provide crucial guidance for enhancing production efficiency and upholding milk quality standards.

Milk as diagnostic fluid for udder health management. Rowe S, House JK, Zadoks RN. Aust Vet J. 2023 Oct 5

  • Mastitis is the major disease affecting milk production of dairy cattle, and milk is an obvious substrate for the detection of both the inflammation and its causative infectious agents at quarter, cow, or herd levels.
  • In this review, researchers examine the use of milk to detect inflammation based on somatic cell count (SCC) and other biomarkers, and for the detection of mastitis pathogens through culture-based and culture-free methods.
  • The use of SCC at a cow or bulk milk level to guide udder health management in lactation is well-established, and SCC is increasingly used to guide selective dry cow treatment. Other markers of inflammation include electrical conductivity, which is used commercially, and markers of disease severity such as acute phase proteins but are not pathogen-specific.
  • Some pathogen-specific markers based on humoral immune responses are available, but their value in udder health management is largely untested. Commercial pathogen detection is based on culture or polymerase chain reaction, with other tests, for example, loop-mediated isothermal amplification or 16S microbiome analysis still at the research or development stage.
  • Matrix-assisted laser desorption ionization time of flight (MALDI-ToF) is increasingly used for the identification of cultured organisms whilst application directly to milk needs further development.
  • Details of test sensitivity, specificity, and use of the various technologies may differ between quarter, cow, and bulk milk applications.
  • In conclusion, there is a growing array of diagnostic assays that can be used to detect markers of inflammation or infection in milk. The value of some of these methods in on-farm udder health improvement programs is yet to be demonstrated whilst methods with proven value may be underutilized.

Milk as an indicator of dietary imbalance. Lean IJ, Golder HM. Aust Vet J. 2023 Oct 2.

  • Milk provides a readily available diagnostic fluid collected daily or more frequently on an individual animal or herd basis. Milk, as an aggregated sample in bulk tank milk (BTM) represents the status of a herd instead of a single animal.
  • In this review, we examine the potential for milk to predict risks to efficient production, reproductive success, and health on the individual cow and herd level.
  • For many conditions related to disorders of metabolism including hyperlipidemia and ketonemia, improved individual cow milk testing may allow a temporally useful detection of metabolic disorder that can target intervention. However, the extension of these tests to the BTM is made more difficult by the tight temporal clustering of disorder to early lactation and the consequent mixing of cows at even moderately different stages of lactation.
  • Integrating herd recording demographic information with Fourier-transformed mid-infrared spectra (FT-MIR) can provide tests that are useful to identify cows with metabolic disorders. The interpretation of BTM urea and protein content provides useful indications of herd nutrition. These may provide indicators that encourage further investigations of nutritional influences on herd fertility but are unlikely to provide strong diagnostic value.
  • The fat-to-protein ratio has a high specificity, but poor sensitivity for detection of fibre insufficiency and acidosis on an individual cow basis. Selenium, zinc, β-carotene, and vitamin E status of the herd can be determined using BTM.
  • In conclusion, there appears to be increasing potential for the use of milk as a diagnostic fluid as more in-parlor tests become available for individual cows. However, the BTM appears to have underutilized potential for herd monitoring.

Effect of Thermostable Enzymes Produced by Psychrotrophic Bacteria in Raw Milk on the Quality of Ultra-High Temperature Sterilized Milk. Qin X, Cheng J, Qi X, Guan N, Chen Q, Pei X, Jiang Y, Yang X, Man C. Foods. 2023 Oct 12;12(20):3752.

  • Ultra-high temperature sterilized milk (UHT) is a popular dairy product known for its long shelf life and convenience. However, protein gel aging and fat quality defects like creaming and flavor deterioration may arise during storage. These problems are primarily caused by thermostable enzymes produced by psychrotrophic bacteria.
  • In this study, four representative psychrotrophic bacteria strains which can produce thermostable enzymes were selected to contaminate UHT milk artificially.
  • After 11, 11, 13, and 17 weeks of storage, the milk samples, which were contaminated with Pseudomonas fluorescensChryseobacterium carnipullorumLactococcus raffinolactisand Acinetobacter guillouiae, respectively, demonstrated notable whey separation.
  • The investigation included analyzing the protein and fat content in the upper and bottom layers of the milk, as well as examining the particle size, Zeta potential, and pH in four sample groups, indicating that the stability of UHT milk decreases over time.
  • Moreover, the spoiled milk samples exhibited a bitter taste, with the dominant odor being attributed to ketones and acids. The metabolomics analysis revealed that three key metabolic pathways, namely ABC transporters, butanoate metabolism, and alanine, aspartate, and glutamate metabolism, were found to be involved in the production of thermostable enzymes by psychrotrophic bacteria.
  • These enzymes greatly impact the taste and nutrient content of UHT milk. This finding provides a theoretical basis for further investigation into the mechanism of spoilage.

UC Davis Research Antimicrobial resistance of Escherichia coli from dairy farms participating in an antimicrobial stewardship educational program for farm employees. Garzon A, Portillo R, Habing G, Silva-Del-Rio N, Karle BM, Pereira RV. J Dairy Sci. 2023 Oct 6:S0022-0302(23)00714-2.

  • Antimicrobial use in food-producing animals is under increasing scrutiny due to the potential impact on the selection of antimicrobial-resistant bacteria that may be transmitted to humans by direct contact, with the food chain, or the environment.
  • Novel data monitoring commensal coli from dairy farms is essential for understanding antimicrobial resistance (AMR) patterns and their association with herd health management practices.
  • The objectives of this study were to: 1) compare the prevalence of antimicrobial resistance in the coli isolates from the hospital, fresh, and mid-lactation pens from 18 conventional dairy farms participating in an educational training program in antimicrobial stewardship practices in California and Ohio, and 2) to characterize the prevalence of antimicrobial resistance of commensal E. coli isolated from pooled fecal pat samples before and 3 months after participating in the educational training program.
  • Pooled fecal pat samples were collected from the hospital pen, the fresh pen (1 to 5 DIM), and the mid-lactation pens (90 to 150 DIM) on conventional dairies in CA (n = 9) and OH (n = 9). Fecal samples were collected as part of a larger study using a quasi-experimental design that assigned farms to the training intervention group (TG; 9 per state) or the control group (CG; 3 per state). For the TG, farm worker(s) identified as having the task of diagnosis and treatment of adult cows on the farm participated in a training program on antimicrobial stewardship practices.
  • Pooled fecal samples (n = 7) were collected at enrollment and 3 months after completing the intervention on each of the participating farms (n = 18), followed by culture for coli isolation and antimicrobial sensitivity testing using the broth microdilution methodology.
  • No effect was observed in the prevalence of resistant isolates between the control and intervention farms after the training was delivered. Isolates from the hospital pens were 2.48 and 5.61 times, more likely to be resistant to streptomycin and chloramphenicol, respectively, than isolates from the mid-lactation pens.
  • These findings indicate there was a higher prevalence of AMR in coli associated with the hospital pen within the farm, while the training program for 3 months did not affect the prevalence of AMR in E. coli on the farms participating in the program. Further research efforts should be conducted to identify factors driving AMR at the pen level, as well as approaches that could be used to reduce the risk of disseminating AMR from sick pens to animals being housed and to other pens on the farm.

Is Personal Protective Equipment Worth the Hassle? Annual Risk of Cryptosporidiosis to Dairy Farmers and How Personal Protective Equipment and Handwashing Can Mitigate It.
Mraz AL, Mutyala N, Cleary S, Seals BF. Microorganisms. 2023 Sep 27;11(10):2413.

  • Cows are known carriers of Cryptosporidium parvum( parvum), a protozoa that can cause the gastrointestinal illness cryptosporidiosis in humans. Despite this potential exposure, dairy farmers tend to wear personal protective equipment (PPE) to protect the milk from contamination, rather than to protect themselves from zoonotic diseases, such as cryptosporidiosis.
  • In this study, cow feces were collected from individual cattle on dairy farms and analyzed for  parvumusing qPCR.
  • Quantitative microbial risk assessment (QMRA) was used to determine the risk of cryptosporidiosis to the dairy farmer with and without the use of handwashing and PPE (gloves and masks).
  • The annualized risk of cryptosporidiosis to dairy farmers was 29.08% but was reduced significantly in each of the three interventions. Among the individual interventions, glove use provided the greatest reduction in risk, bringing the annual risk of cryptosporidiosis to 4.82%. The implementation of regular handwashing, the use of gloves, and wearing a mask brought the annual risk of cryptosporidiosis to 1.29%.
  • This study provides evidence that handwashing and PPE use can significantly reduce the risk of cryptosporidiosis to farmers and is worth implementing despite potential barriers such as discomfort and cost.

Human Health and Nutrition

Dairy intake and risk of type 2 diabetes: results of a large prospective cohort. Zhang S, Meng G, Zhang Q, Liu L, Wu H, Gu Y, Wang X, Zhang J, Sun S, Wang X, Zhou M, Jia Q, Song K, Borné Y, Sonestedt E, Ma L, Qi L, Niu K. Food Funct. 2023 Oct 30;14(21):9695-9706.

  • Previous studies of primarily Western populations have consistently documented a lower risk of type 2 diabetes (T2D) among people with a higher yogurt intake, but an inconsistent association with milk intake. However, little is known about the association between dairy intake and risk of T2D among Chinese adults who consume considerably less dairy (mainly milk and yogurt) compared with Western populations.
  • The aim is to investigate the associations of dairy intake with the risk of incident T2D in the general adult population in China.
  • This cohort study consisted of 22,843 participants without prevalent cardiovascular disease, cancer, or diabetes at the baseline. Dietary data were collected using a validated food frequency questionnaire at the baseline (2013-2018); dairy intake was categorized into tertiles after zero consumers were taken as the reference.
  • In total, 735 incident T2D cases were recorded over a median follow-up of 4 years. Relative to zero consumers, the HRs (95% CIs) for incident T2D among participants in the highest tertiles were 0.70 for total dairy, 0.73 for milk, and 0.81 for yogurt. Such associations were slightly attenuated by additional adjustment for the body mass index.
  • In addition, such inverse associations were robust in sensitivity analyses and consistent in most of the subgroups defined by baseline characteristics. Overall, higher intakes of total dairy, milk, and yogurt were all associated with a lower risk of T2D among Chinese adults.

Dairy product consumption and lung cancer risk: A prospective analysis. Đoàn LN, Hu C, Zhang Z, Shannon J, Bobe G, Takata Y. Clin Nutr ESPEN. 2023 Oct;57:423-429.

  • Current evidence on prospective associations between dairy product, dairy fat and lactose intakes and lung cancer risk is limited and inconsistent.
  • Therefore, researchers conducted a prospective analysis of associations of lung cancer risk with dairy product intakes in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) cohort.
  • Pre-diagnostic dairy product intake was assessed through a validated Diet History Questionnaire. All incident lung cancer cases were pathologically verified. Multivariable Cox regression was used to calculate hazard ratios (HR) and 95% confidence intervals (CI) for associations of lung cancer risk with intakes of total, full-fat, low-fat dairy, fermented or non-fermented dairy products; milk fat content preference; and intakes of total and saturated fats and lactose from dairy products.
  • Among 101,709 adults (mean age of 65.5 years), a total of 1,583 lung cancer cases were identified during 1,167,239 person-years of follow up. Mean total dairy product intake was 156 g/1000 kilocalories (kcal), including 20 g/1000 kcal from fermented dairy products.
  • Total dairy intake was not associated with lung cancer risk comparing the highest quartile with the lowest. Fermented dairy intake was inversely associated with lung cancer risk (HR 0.85). In contrast, there were no statistically significant associations with low-fat, full-fat or non-fermented dairy product intakes.
  • The preference of whole milk when consuming milk as beverage was associated with a higher risk of lung cancer than the preference of <0.5% fat milk (HR 1.24). Total fat, saturated fat and lactose intakes from dairy products each were not associated with lung cancer risk.
  • These results suggest an inverse association of lung cancer risk with fermented dairy intake and a positive association with the whole milk preference in a US population. Future studies exploring underlying molecular mechanisms are warranted.

Unlocking the potential of milk whey protein components in colorectal cancer prevention and therapy. Xiao J, Ma J, Khan MZ, Alugongo GM, Chen T, Liu S, Li S, Cao Z. Crit Rev Food Sci Nutr. 2023 Oct 17:1-38.

  • Extensive research from large prospective cohort studies and meta-analytical investigations over recent decades have consistently indicated that dairy foods have protective effects, reducing the risk of colorectal cancer.
  • Most of the literature has explored the potential role of milk minerals and vitamins in managing colorectal cancer. Yet, there is a paucity of a comprehensive summary of the anticancer attributes of milk protein components and their underlying mechanisms of action.
  • Recent advancements have spotlighted the potential of whey proteins, including β-lactoglobulin, α-lactalbumin, serum albumin, and lactoferrin, as promising candidates for both the prevention and treatment of colorectal cancer.
  • Notably, whey proteins have demonstrated a more pronounced capacity for suppressing carcinogen-induced tumors when compared to casein. Their strong binding affinity enables them to serve as effective carriers for small molecules or drugs targeting colon cancer therapy.
  • Furthermore, numerous studies have underscored the anti-inflammatory and antioxidant prowess of whey proteins in cancer prevention. Additionally, whey proteins have been shown to trigger apoptosis, hinder tumor cell proliferation, and impede metastasis.
  • This comprehensive review, therefore, not only substantiates the significance of incorporating whey protein components into a balanced daily diet but also underscores their potential in safeguarding against the onset and progression of colorectal cancer.

Isolate Whey Protein Promotes Fluid Balance and Endurance Capacity Better Than Isolate Casein and Carbohydrate-Electrolyte Solution in a Warm, Humid Environment. Gholizadeh M, Shakibaee A, Bagheri R, Camera DM, Shirvani H, Dutheil F. Nutrients. 2023 Oct 16;15(20):4374.

  • Protein ingestion is known to enhance post-exercise hydration. Whether the type of protein (i.e., whey, casein) can alter this response is unknown.
  • Accordingly, this study aimed to compare the effects of the addition of milk-derived whey isolate or casein protein to carbohydrate-electrolyte (CE) drinks on post-exercise rehydration and endurance capacity.
  • Thirty male soldiers (age: 24 ± 2.1 years; VO2max: 49.3 ± 4.7 mL/kg/min) were recruited. Upon losing ~2.2% of body mass by running in warm and humid conditions (32.3 °C, 76% relative humidity [RH]), participants ingested either a CE solution (66 g/L carbohydrate [CHO]), or CE plus isolate whey protein (CEW, 44 g/L CHO, 22 g/L isolate whey), or CE plus isolate casein protein (CEC, 44 g/L CHO, 22 g/L isolate casein) beverage in a volume equal to 150% of body mass loss.
  • At the end of the 3 hour rehydration period, a positive fluid balance was higher with CEW (0.22 L) compared to CEC (0.19 L) and CE (0.12 L). Overall mean fluid retention was higher in CEW (80.35%) compared with the CE (76.67%) and CEC trials (78.65%).
  • The time of the endurance capacity test [Cooper 2.4 km (1.5 miles) run test] was significantly higher in CEC (14.25 ± 1.58 min) and CE (12.90 ± 1.01 min) than in CEW (11.40 ± 1.41 min).
  • The findings of this study indicate that the inclusion of isolate whey protein in a CE solution yields superior outcomes in terms of rehydration and enhanced endurance capacity, as compared to consuming the CE solution alone or in conjunction with isolate casein protein.

Nutritional Value of Yogurt as a Protein Source: Digestibility/Absorbability and Effects on Skeletal Muscle. Sumi K, Tagawa R, Yamazaki K, Nakayama K, Ichimura T, Sanbongi C, Nakazato K. Nutrients. 2023 Oct 14;15(20):4366.

  • Yogurt is a traditional fermented food that is accepted worldwide for its high palatability and various health values. The milk protein contained in yogurt exhibits different physical and biological properties from those of non-fermented milk protein due to the fermentation and manufacturing processes.
  • These differences are suggested to affect the time it takes to digest and absorb milk protein, which in turn will influence the blood levels of amino acids and/or hormones, such as insulin, and thereby, the rate of skeletal muscle protein synthesis via the activation of intracellular signaling, such as the mTORC1 pathway.
  • In addition, based on the relationship between gut microbiota and skeletal muscle conditions, yogurt, including lactic acid bacteria and its metabolites, has been evaluated for its role as a protein source. However, the substantial value of yogurt as a protein source and the additional health benefits on skeletal muscle are not fully understood.
  • The purpose of this review is to summarize the research to date on the digestion and absorption characteristics of yogurt protein, its effect on skeletal muscle, and the contribution of lactic acid bacterial fermentation to these effects.

Bioaccessibility of docosahexaenoic acid in naturally and artificially enriched milk. Wang P, Chen P, Zhang X, Szeto IM, Li F, Tan S, Ba G, Zhang Y, Duan S, Yang Y. Food Chem. 2023 Oct 15;437(Pt 1):137772.

  • This study aimed to compare the bioaccessibility of docosahexaenoic acid (DHA) in naturally and artificially enriched milk and investigate the potential mechanisms involved.
  • The results indicated that the DHA in naturally enriched milk (NEM) had a higher bioaccessibility (76.9 %) and a lower digestive loss rate (18.1 %) compared to artificially enriched milk (ArEM).
  • Moreover, NEM contained a higher proportion of DHA-containing glycerophospholipids and sn-2 DHA, with fewer long-chain fatty acids and more saturated fatty acids adjacent to DHA in the same lipid molecule. During simulated intestinal digestion, NEM had a higher free fatty acid release and lipid digestion rate than ArEM.
  • These findings suggested that the bioaccessibility of endogenous DHA in milk was superior to that of externally added DHA due to its more easily digestible and absorbable chemical binding form and lower digestive loss rate. The easy digestibility of milk lipids in NEM also contributed to its high DHA bioaccessibility.

Milk-derived small extracellular vesicles: a new perspective on dairy nutrition. Zhang Y, Lin Y, He J, Song S, Luo Y, Lu Y, Chen S, Wang Q, Li Y, Ren F, Guo H. Crit Rev Food Sci Nutr. 2023 Oct 11:1-22.

  • Milk contains bioactive compounds that have multiple essential benefits. Milk-derived small extracellular vesicles (M-sEVs) have emerged as novel bioactive milk components with various beneficial biological functions and broad applications.
  • The M-sEVs from different mammalian sources have similar composition and bioactive functions. The digestive stability and biocompatibility of the M-sEVs provide a good foundation for their physiological functions.
  • Evidence suggests that M-sEVs promote intestinal, immune, bone, neural, liver, and heart health and show therapeutic effects against cancer, indicating their potential for use in functional foods. In addition, M-sEVs can be developed as natural delivery carriers owing to their superior structural characteristics.
  • Further studies are needed to elucidate the relationship between the specific components and functions of M-sEVs, standardize their extraction processes, and refine relevant clinical trials to advance the future applications of M-sEVs.
  • This review summarizes the structure and composition of M-sEVs isolated from different milk sources and discusses several common extraction methods. Since the introduction of M-sEVs for digestion and absorption, studies have been conducted on their biological functions. Furthermore, the researchers outline the theoretical industrial production route, potential application scenarios of M-sEVs, and the future perspectives of M-sEV research.

Innovation, Economics, and Dairy Alternatives

Incorporation of Yogurt Acid Whey in Low-Lactose Yogurt Ice Cream. Sakkas L, Karela M, Zoidou E, Moatsou G, Moschopoulou E. Foods. 2023 Oct 21;12(20):3860.

  • Yogurt acid whey (YAW), a by-product of strained yogurt production, is a strong environmental pollutant because of its high organic load. Hence, efforts are made for its utilization to minimize its disposal in the environment.
  • This study deals with the incorporation of YAW in yogurt ice cream (YIC) by partial replacement of yogurt with simultaneous lactose hydrolysis (LH) of the formulated YIC mix.
  • Six YIC mix formulations were made, two without YAW (non-LH- and LH-control samples, A and AH), two with 12.5% YAW (samples B and BH), and two with 18.75% YAW (samples C and CH).
  • The results showed that the partial replacement of yogurt with YAW decreased significantly the total solids of B, BH, C, and CH products (31.72, 31.92, 30.94, and 31.27, respectively) compared to the total solids of control products A and AH (33.30 and 33.74, respectively).
  • In contrast, the overruns increased (51.50, 58.26, 56.86, and 65.52 for the B, BH, C, and CH products, respectively) compared to control samples (42.02 and 49.53 for A and AH, respectively).
  • LH significantly decreased the freezing point and the viscosity of the YIC mixes but increased the overruns of the products as shown previously. YAW significantly decreased the hardness of the B and C products (56.30 N and 43.43 N, respectively) compared to control A (81.14 N), and LH decreased it even more, leading to a rather soft scoop YIC. AH, BH, and CH YICs exhibited better melting properties despite the lack of fat destabilization in all samples.
  • After 60 days of storage, counts of yogurt starter microorganisms were still >107cfu/g and DPPH radical scavenging activity had increased in all products. In the sensory evaluation test, lactose-hydrolyzed samples AH, BH, and CH had less intense sandiness and, as expected, more intense sweetness.
  • In conclusion, in the framework of the circular economy, it is possible for the YAW to be used as a resource material at a ratio of 12.5% to produce a YIC product without leaving behind any new waste.

Endothelialization of Whey Protein Isolate-Based Scaffolds for Tissue Regeneration. Genç H, Friedrich B, Alexiou C, Pietryga K, Cicha I, Douglas TEL. Molecules. 2023 Oct 12;28(20):7052.

  • Whey protein isolate (WPI) is a by-product from the dairy industry, whose main component is β-lactoglobulin. Upon heating, WPI forms a hydrogel which can both support controlled drug delivery and enhance the proliferation and osteogenic differentiation of bone-forming cells.
  • This study makes a novel contribution by evaluating the ability of WPI hydrogels to support the growth of endothelial cells, which are essential for vascularization, which in turn is a pre-requisite for bone regeneration.
  • In this study, the proliferation and antioxidant levels in human umbilical vascular endothelial cells (HUVECs) cultured with WPI supplementation were evaluated using real-time cell analysis and flow cytometry. Further, the attachment and growth of HUVECs seeded on WPI-based hydrogels with different concentrations of WPI (15%, 20%, 30%, 40%) were investigated.
  • Supplementation with WPI did not affect the viability or proliferation of HUVECs monitored with real-time cell analysis. At the highest used concentration of WPI (500 µg/mL), a slight induction of ROS production in HUVECs was detected as compared with control samples, but it was not accompanied by alterations in cellular thiol levels.
  • Regarding WPI-based hydrogels, HUVEC adhered and spread on all samples, showing good metabolic activity. Notably, cell number was highest on samples containing 20% and 30% WPI.
  • In conclusion,the demonstration of the good compatibility of WPI hydrogels with endothelial cells in these experiments is an important step towards promoting the vascularization of hydrogels upon implantation in vivo, which is expected to improve implant outcomes in the future.

Do you see the pattern? Make the most of sensor data in dairy cows. Kok A, Ternman E, Thorup VM.J Dairy Res. 2023;90(3):252-256.

  • Sensors are increasingly being used to monitor animal behavior. Data handling methods have, however, lagged behind the continuous data stream to some extent, often being limited to summarizing data into daily averages at group level.
  • This research reflection presents our opinion of the neglected application of 24-hour pattern analysis. Recent studies of dairy cow behavior have demonstrated that additional ways of analyzing data improve our understanding of animal behavior and add value to data that were already retrieved.
  • The terminology for the described 24-hour patterns differs between these studies, making them difficult to compare. Thus, diurnal, circadian, daily, periodicity and 24-hour pattern are all terms used to describe dairy cow activities over a 24-hour period.
  • Several studies have shown that the 24-hour behavioral pattern at herd level is relatively consistent over time, and that with well-established management routines, a specific herd signature will be evident. However, within a herd, individual cows may have individual 24-hour patterns with more or less variability.
  • Recent studies suggest that deviations from herd and/or individual 24-hour patterns can be used to describe cow robustness, as well as to predict disease. Therefore, the researchers strongly believe that individual and herd 24-hour patterns provide a great deal of information about behavior and that these patterns offer opportunity for more precise and timely health management and welfare monitoring.

Health Status Classification for Cows Using Machine Learning and Data Management on AWS Cloud. Dineva K, Atanasova T. Animals (Basel). 2023 Oct 18;13(20):3254.

  • The health and welfare of livestock are significant for ensuring the sustainability and profitability of the agricultural industry. Addressing efficient ways to monitor and report the health status of individual cows is critical to prevent outbreaks and maintain herd productivity.
  • The purpose of the study is to develop a machine learning (ML) model to classify the health status of milk cows into three categories.
  • In this research, data are collected from existing non-invasive IoT devices and tools in a dairy farm, monitoring the micro- and macroenvironment of the cow in combination with particular information on age, days in milk, lactation, and more.
  • A workflow of various data-processing methods is systematized and presented to create a complete, efficient, and reusable roadmap for data processing, modeling, and real-world integration. Following the proposed workflow, the data were treated, and five different ML algorithms were trained and tested to select the most descriptive one to monitor the health status of individual cows.
  • The highest result for health status assessment is obtained by random forest classifier (RFC) with an accuracy of 0.959, recall of 0.954, and precision of 0.97. To increase the security, speed, and reliability of the work process, a cloud architecture of services is presented to integrate the trained model as an additional functionality in the Amazon Web Services (AWS) environment. The classification results of the ML model are visualized in a newly created interface in the client application.

CowMesh: a data-mesh architecture to unify dairy industry data for prediction and monitoring. Pakrashi A, Wallace D, Mac Namee B, Greene D, Guéret C. Front Artif Intell. 2023 Oct 4;6:1209507.

  • Dairy is an economically significant industry that caters to the huge demand for food products in people’s lives. To remain profitable, farmers need to manage their farms and the health of the dairy cows in their herds.
  • There are, however, many risks to cow health that can lead to significant challenges to dairy farm management and have the potential to lead to significant losses. Such risks include cow udder infections (i.e., mastitis) and cow lameness.
  • As automation and data recording become more common in the agricultural sector, dairy farms are generating increasing amounts of data. Recently, these data are being used to generate insights into farm and cow health, where the objective is to help farmers manage the health and welfare of dairy cows and reduce losses from cow health issues.
  • Despite the level of data generation on dairy farms, this information is often difficult to access due to a lack of a single, central organization to collect data from individual farms. The prospect of such an organization, however, raises questions about data ownership, with some farmers reluctant to share their farm data for privacy reasons.
  • In this study, we describe a new data mesharchitecture designed for the dairy industry that focuses on facilitating access to data from farms in a decentralized fashion. This has the benefit of keeping the ownership of data with dairy farmers while bringing data together by providing a common and uniform set of protocols. Furthermore, this architecture will allow secure access to the data by research groups and product development groups, who can plug in new projects and applications built across the data.
  • No similar framework currently exists in the dairy industry, and such a data mesh can help industry stakeholders by bringing the dairy farms of a country together in a decentralized fashion. This not only helps farmers, dairy researchers, and product builders but also facilitates an overview of all dairy farms which can help governments to decide on regulations to improve the dairy industry at a national level.

Insights and Perspectives on Plant-Based Beverages. Popova A, Mihaylova D, Lante A. Plants (Basel). 2023;12(19):3345.

  • The emerging demand for everyday food substitutes is increasing on a daily basis. More and more individuals struggle with allergies and intolerances, which makes it mandatory to provide alternatives for simple products like dairy milk.
  • Plant-based beverages (PBBs) are currently trending due to the multiple diets that promote their consumption with or without a justification. PBBs can derive from various types of plants, not exclusively nuts. Some of the most well-known sources are almonds, soy, rice, and hazelnuts, among others.
  • In view of the need for sustainable approaches to resource utilization and food production, novel sources for PBBs are being sought, and those include fruit kernels. The plant kingdom offers a palette of resources with proven bioactivity, i.e., containing flavonoids, phenolic acids, vitamins, carotenoids, and phenolics, among others. Many of these beneficial substances are water soluble, which means they could be transferred to the plant beverage compositions.
  • The current review aims at comparing the vast number of potential formulations based on their specific nutritional profiles and potential deficiencies, as well as their expected health-promoting properties, based on the raw material(s) used for production. Special attention will be given to the anti-nutrients, usually abundant in plant-based sources.