Dairy Research Bulletin: Selected Articles from July 2022 - California Dairy Research Foundation

Environmental Management and Sustainability

Symposium review: Effective nutritional strategies to mitigate enteric methane in dairy cattle. Hristov AN, Melgar A, Wasson D, Arndt C. J Dairy Sci. 2022 Jul 18:S0022-0302(22)00392-7.

Intensive research in the past decade has resulted in a better understanding of factors driving enteric methane (CH4) emissions in ruminants. Methane inhibitors, alternative electron sinks, vegetable oils and oilseeds, and tanniferous forages are among the recommended strategies for mitigating CH4 emissions from dairy and beef cattle and small ruminants.
These strategies were also effective in decreasing CH4 emissions yield and intensity. However, a higher inclusion rate of oils may negatively affect feed intake, rumen function, and animal performance, specifically milk components in dairy cows. In the case of nitrates (electron sinks), concerns with animal health may be impeding their adoption in practice, and potential emission trade-offs have to be considered. Tannins and tanniferous forages may have a negative effect on nutrient digestibility, and more research is needed to confirm their effects on overall animal performance in long-term experiments with high-producing animals.
A meta-analysis of studies with dairy cows fed the CH4 inhibitor 3-nitrooxypropanol (3-NOP) at the Pennsylvania State University showed (1) a consistent 28 to 32% decrease in daily CH4 emissions or emissions yield and intensity; (2) no effect on dry matter intake, milk production, body weight, or body weight change, and a slight increase in milk fat concentration and yield; 3-NOP also appears to increase milk urea nitrogen concentration; (3) an exponential decrease in the mitigation effect of the inhibitor with increasing its dose; and (4) a potential decrease in the efficacy of 3-NOP over time, which needs to be further investigated in long-term, full-lactation or multiple-lactation studies.
The red macroalga Asparagopsis taxiformis has a strong CH4 mitigation effect, but studies are needed to determine its feasibility, long-term efficacy, and effects on animal production and health.
In conclusion, the widespread adoption of mitigation strategies with proven effectiveness by the livestock industries will depend on cost, government policies and incentives, and willingness of consumers to pay a higher price for animal products with decreased carbon footprint.

Dairy Manure Co-composting with Wood Biochar Plays a Critical Role in Meeting Global Methane Goals. Harrison BP, Gao S, Gonzales M, Thao T, Bischak E, Ghezzehei TA, Berhe AA, Diaz G, Ryals RA. Environ Sci Technol. 2022 Jul 14.

Livestock are the largest source of anthropogenic methane (CH4) emissions, and in intensive dairy systems, manure management can contribute half of livestock CH4. Recent policies such as California’s short-lived climate pollutant reduction law (SB 1383) and the Global Methane Pledge call for cuts to livestock CH4 by 2030. However, investments in CH4 reduction strategies are primarily aimed at liquid dairy manure, whereas stockpiled solids remain a large source of CH4.
Here, researchers measure the CH4 and net greenhouse gas reduction potential of dairy manure biochar-composting, a novel manure management strategy, through a composting experiment and life-cycle analysis.
The researchers found that biochar-composting reduces CH4 by 79%, compared to composting without biochar. In addition to reducing CH4 during composting, the added climate benefit from biochar production and application contributes to a substantially reduced life-cycle global warming potential for biochar-composting: -535 kg CO2e Mg1 manure compared to -194 kg CO2e Mg-1 for composting and 102 kg CO2e Mg-1 for stockpiling.
If biochar-composting replaces manure stockpiling and complements anaerobic digestion, California could meet SB 1383 with 132 less digesters. When scaled up globally, biochar-composting could mitigate 1.59 Tg CH4 yr-1 while doubling the climate change mitigation potential from dairy manure management.

Ammonia emissions and their key influencing factors from naturally ventilated dairy farms. Yang F, Han Y, Bi H, Wei X, Luo W, Li G. Chemosphere. 2022 Jul 18:135747.

Ammonia (NH3) contributes several adverse impacts to the environment, especially the crucial role of PM2.5 precursors. In China, approximately 13.5% of the total NH3 emissions from agricultural activities are related to dairy cows farming.
The goals of this study were to define NH3 emissions, localize emission factors, and clarify relationships between NH3 emissions and potential influencing factors from dairy farms.
The measurements were carried out in three typical naturally ventilated dairy farms with different scales, floor materials and manure managements over four seasons.
Results showed that NH3 emission rate from all areas changed in the range of 0.01-2.96 mg min-1 m-2 in the three farms. NH3 emission factors ranged from 5.21 to 38.10 kg a-1 cow-1 with the outdoor exercise area as the largest contributor. The variation of NH3 emissions in the three farms was consistent and positively related to ambient temperature (R2 >0.8, P < 0.01).
Strong relationships (p < 0.01) between NH3 emissions and relative humidity were found only in outdoor exercise and sedimentation tank of Farm A and manure storage of Farm B. The NH3 emission rates were dependent on floor material and the frequency of manure collection. However, the effect of manure collection methods on NH3 emissions was insignificant.
Results from this study provide accurate data to improve the atmospheric pollutant emission inventories, and clarify the impact of different influencing factors on NH3 emissions from livestock farms.

Combined Application of Manure and Chemical Fertilizers Alters Soil Environmental Variables and Improves Soil Fungal Community Composition and Rice Grain Yield. Iqbal A, Ali I, Yuan P, Khan R, Liang H, Wei S, Jiang L. Front Microbiol. 2022 Jul 14;13:856355.

Soil microorganisms play vital roles in energy flow and soil nutrient cycling and, thus, are important for crop production. A detailed understanding of the complex responses of microbial communities to diverse organic manure and chemical fertilizers (CFs) is crucial for agroecosystem sustainability. However, little is known about the response of soil fungal communities and soil nutrients to manure and CFs, especially under double-rice cropping systems.
In this study, we investigated the effects of the application of combined manure and CFs to various fertilization strategies on soil fungal communities’ structure and diversity, soil environmental variables, and rice yield.
- No N fertilizer (Neg-CF)
- 100% chemical fertilizer (Pos-CF)
- 60% cattle manure (CM) + 40% CF (high-CM)
- 30% CM + 70% CF (low-CM)
- 60% poultry manure (PM) + 40% CF (high-PM)
- 30% PM + 70% CF (low-PM)
Results showed that synthetic fertilizer plus manure addition significantly increased the soil fertility and rice grain yield compared to sole CFs’ application. Moreover, the addition of manure significantly changed the soil fungal community structure and increased the relative abundance of fungi such as phyla Ascomycota, Basidiomycota, Mortierellomycota, and Rozellomycota.
The relative abundances dramatically differed at each taxonomic level, especially between manured and non-manured regimes. Principal coordinates analysis (PCoA) exhibited greater impacts of the addition of manure amendments than CFs on fungal community distributions.
Redundancy analysis showed that the dominant fungal phyla were positively correlated with soil pH, soil organic C (SOC), total N, and microbial biomass C, and the fungal community structure was strongly affected by SOC. Network analysis explored positive relationships between microorganisms and could increase their adaptability in relevant environments. In addition, the structural equation model (SEM) shows the relationship between microbial biomass, soil nutrients, and rice grain yield.
The SEM showed that soil nutrient contents and their availability directly affect rice grain yield, while soil fungi indirectly affect grain yield through microbial biomass production and nutrient levels.
These results suggest that manure application combined with CFs altered soil biochemical traits and soil fungal community structure and counteracted some of the adverse effects of the synthetic fertilizer. Overall, the findings of this research suggest that the integrated application of CF and manure is a better approach for improving soil health and rice yield.

Nitrogen availability determines ecosystem productivity in response to climate warming. Liu Y, Men M, Peng Z, Houx JH 3rd, Peng Y.Ecology. 2022 Jul 20:e3823.

One of the major uncertainties for carbon-climate feedback predictions is an inadequate understanding of the mechanisms governing variations in ecosystem productivity response to warming.
Temperature and water availability are regarded as the primary controls over the direction and magnitude of warming effects, but some unexplained results signal that our understanding is incomplete.
Using two complementary meta-analyses, we present evidence that soil nitrogen (N) availability drives the warming effects on ecosystem productivity more strongly than thermal and hydrological factors over a broad geographical scale.
First, by synthesizing temperature manipulation experiments, meta-regression model analysis showed that the warming effect on productivity is mainly driven by its effect on soil N availability. Sites with higher warming-induced increase in N availability were characterized by stronger productivity enhancement and vice versa, suggesting that N is a limiting factor across sites.
Second, a synthesis of full-factorial warming×N addition experiments demonstrated that N addition significantly weakened the positive warming effect, because the additional N induced by warming may not further benefit plant growth when N limitation is relieved, providing experimental evidence that N regulates the warming effect.
Further, researchers demonstrated that warming effects on soil N availability were modulated by changes in dissolved organic N and soil microbes. Overall, these findings enrich a new mechanistic understanding of the varying magnitudes of observed productivity response to warming, and the N scaling of warming effects may help constrain climate projections.

Sustainable irrigation technologies: a water-energy-food (WEF) nexus perspective towards achieving more crop per drop per joule per hectare. Taguta C, Dirwai TL, Senzanje A, Sikka A, Mabhaudhi T. Environ Res Lett. 2022 Jul 1;17(7):073003.

Sustainable agricultural intensification requires irrigation methods and strategies to minimize yield penalties while optimizing water, land and energy use efficiencies.
Researchers assessed, from a silo-based and integrated water-energy-food (WEF) nexus perspective, the performance of irrigation technologies in different agro-climatic regions. Secondary to this, they assessed the impact of adopting systematic approaches such as the WEF nexus on improving efficiency in irrigated agriculture through irrigation modernization.
The best performance of irrigation technologies in dry regions in water, energy and food silos was achieved by sprinkler, drip and furrow irrigation systems, respectively. Thus, appraising irrigation technologies from a silos perspective promotes individual silos, which renders an unsustainable picture of the performance of irrigation systems. The integrative WEF nexus approach successfully highlighted the trade-offs and synergies in the nexus of water, energy and food in irrigated agriculture.
Drip irrigation led all irrigation technologies in WEF nexus performance in dry (21.44 unit2), tropical (23.98 unit2), and temperate regions (47.28 unit2).
Overall, the irrigation modernization pathway to drip technology from either furrow or sprinkler systems improves irrigated agriculture’s WEF nexus performance in all three regions for more crop per drop per joule per hectare under climate change. This can promote inclusive and sustainable irrigation development within the planetary boundaries.

Animal Health and Food Safety

The Effect of Housing System on Disease Prevalence and Productive Lifespan of Dairy Herds-A Case Study. Witkowska D, Ponieważ A. Animals (Basel). 2022;12(13):1610.

Selected technological solutions can impact health status of animals.
The aim of this case study was to determine the effect of different housing systems on disease prevalence and the productive lifespan of dairy cows.
In total, 480 cows kept indoors on one farm in four buildings using four different housing systems (a free-stall barn with a slatted floor; a free-stall barn with a self-cleaning floor; an open-pack barn with deep litter; a tie-stall barn with shallow litter) were analyzed.
The study demonstrated that the average productive lifespan was longer, by up to more than 8 months, in the system with deep litter, which was also characterized by the lowest disease prevalence, especially foot and some reproductive disorders.
This trend was maintained in each year of the study period (2015-2020). In the tie-stall barn, the prevalence of mastitis was reduced, but the risk of lameness, retained placenta, parturient paresis and displaced abomasum was higher in this system.
Overall morbidity was highest in the free-stall barns. Lower morbidity was associated with an increase in productive herd life.

Effect of Flaxseed Supplementation on Milk and Plasma Fatty Acid Composition and Plasma Parameters of Holstein Dairy Cows. Huang G, Wang J, Wang J, et al. Animals (Basel). 2022 Jul 26;12(15):1898.

Oilseed supplementation is a strategy to improve milk production and milk composition in dairy cows; however, the response to this approach is inconsistent.
The objective of this study was to determine the effect of whole flaxseed and ground flaxseed supplementation on the composition of fatty acids in plasma and milk, particularly the content of omega-3 polyunsaturated fatty acids (n-3 PUFAs).
Thirty Holstein dairy cows were randomly assigned to three treatment groups. Cows were fed a total mixed ration without flaxseed (CK), 1500 g of whole flaxseed (WF), and 1500 g of ground flaxseed (GF) supplementation.
There were no differences observed in dry matter intake, milk yield, energy-corrected milk, and 4% fat-corrected milk. Compared with the CK group, the contents of α-linolenic acid (ALA), eicosatrienoic acid, and eicosapentaenoic acid increased in the plasma and milk WF and GF groups, and the content of docosahexaenoic acid and total n-3 PUFA was higher in GF than the other groups.
The ALA yield increased to 232% and 360% in WF and GF, respectively, compared to the CK group. Compared with the WF group, GF supplementation resulted in an increased milk ALA/ALA intake ratio. Flaxseed supplementation increased the activity of GSH-Px and decreased the concentration of MDA in milk. Plasma parameters did not differ among the treatments.
This result indicated that compared with the WF group, GF supplementation in the diet showed higher efficiency in increasing the total n-3 PUFA levels and the milk ALA/ALA intake ratio and decreased the ratio of n-6 PUFAs to n-3 PUFAs in milk.

UCD Vet Med Research – Effectiveness of Intramammary Antibiotics, Internal Teat Sealants, or Both at Dry-Off in Dairy Cows: Clinical Mastitis and Culling Outcomes. Aly SS, Okello E, ElAshmawy WR, Williams DR, Anderson RJ, Rossitto P, Tonooka K, Glenn K, Karle B, Lehenbauer TW. Antibiotics (Basel). 2022 Jul 15;11(7):954.

Intramammary antibiotic (AB) and internal teat sealants (TS) infusion at dry-off have been used to prevent intramammary infections (IMI) in dairy cows during the dry period and reduce the risk of mastitis during the dry period and subsequent lactation.
A randomized clinal trial was completed on eight California dairy herds to estimate the effects of different dry cow therapies (AB, TS, AB + TS or None) on clinical mastitis and culling.
A total of 1273 cows were randomized to one of the four treatment groups over summer and winter seasons. For each enrolled cow, microbiological testing was done on quarter milk samples collected from the first detection of clinical mastitis within the first 150 days in milk in the subsequent lactation.
There were no significant differences in the odds of clinical mastitis or culling between cows treated with AB, TS, or AB + TS compared to the controls.
Dry cow therapy with AB and/or TS had no statistically significant effect on clinical mastitis and cow culling during the first 150 days in milk.

UCD Vet Med Research – Potential impacts to antibiotics use around the dry period if selective dry cow therapy is adopted by dairy herds: An example of the western US. Ferreira FC, Martínez-López B, Okello E.Prev Vet Med. 2022 Jul 7;206:105709.

Mastitis is a prevalent and expensive disease in dairy herds worldwide. Blanket dry cow therapy (BDCT), in which all quarters of all cows are infused with antimicrobials at the dry-off, is a cornerstone for mastitis control in many countries. An alternative approach is the use of selective dry cow therapy (SDCT), in which only cows with high risk for intramammary infection (IMI) at dry-off receive antimicrobials.
The researchers’ objectives in this cross-sectional study were to estimate the potential reduction in the use of antimicrobials if SDCT was adopted in the US by using cow-level dairy herd data and to describe the factors associated with cows being classified as high-risk for an IMI at dry-off. Besides, we aimed to describe the seasonality in IMI at dry-off.
The researchers used cow-level somatic cell score (SCS) test-day data from herds in the western US (DHIA, Dairy Herd Improvement Association, AgriTech, Visalia, CA) to create five scenarios to classify cows as high risk for IMI at dry-off.
The point prevalence of IMI at the last test-day before dry-off varied between 15.0 % and 54 % for primiparous and 34.0 % and 85 % for multiparous cows, depending on the scenario. By extrapolating the results obtained from using data from dairies enrolled in the DHIA testing program for the western US, the researchers demonstrated that regardless of the criteria used to classify cows as high risk of IMI at dry-off (scenarios 1-5), if selective dry cow therapy is adopted in the US, the dairy industry could reduce the use of antimicrobials around the dry-off between 31 % and 66 %.
Multiparous cows had greater odds of being classified as high-risk than primiparous cows. Cows dried off in the spring, summer, and fall had lower odds of being classified as high-risk compared to cows dried off in the winter. Advanced days in milk at dry-off was associated with greater risk of IMI at dry-off. Greater milk yield and higher protein percentage at the last test-day before dry-off were associated with decreased odds of a cow being classified as high-risk at dry-off, cows in small herds had greater odds of being classified as high-risk at dry-off, and a variation among states was observed.

Shotgun metagenomic sequencing of bulk tank milk filters reveals the role of Moraxellaceae and Enterobacteriaceae as carriers of antimicrobial resistance genes. Rubiola S, Macori G, Chiesa F, Panebianco F, Moretti R, Fanning S, Civera T. Food Res Int. 2022;158:111579.

In the present context of growing antimicrobial resistance (AMR) concern, understanding the distribution of AMR determinants in food matrices such as milk is crucial to protect consumers and maintain high food safety standards.
Herein, the resistome of different dairy farms was investigated through a shotgun metagenomic sequencing approach, taking advantage of in-line milk filters as promising tools.
The application of both the reads-based and the assembly-based approaches has allowed the identification of numerous AMR determinants, enabling a comprehensive resolution of the resistome. Notably most of the species harboring AMR genes were predicted to be Gram-negative genera, namely Enterobacter, Acinetobacter, Escherichia, and Pseudomonas, pointing out the role of these bacteria as reservoirs of AMR determinants.
In this context, the use of de novo assembly has allowed a more holistic AMR detection strategy, while the reads-based approach has enabled the detection of AMR genes from low abundance bacteria, usually undetectable by assembly-based methods.
The application of both reads-based and assembly-based approaches, despite being computationally demanding, has facilitated the comprehensive characterization of a food chain resistome, while also allowing the construction of complete metagenome assembled genomes and the investigation of mobile genetic elements.
These findings suggest that milk filters can successfully be used to investigate the resistome of bulk tank milk through the application of the shotgun metagenomic sequencing. In accordance with these results, raw milk can be considered a source of AMR bacteria and genes; this points out the importance of properly informing food business operators about the risk associated with poor hygiene practices in the dairy production environment and consumers of the potential microbial food safety risks derived from raw milk products consumption.
Translating these findings as risk assessment outputs heralds the next generation of food safety controls.

Calves as Main Reservoir of Antibiotic Resistance Genes in Dairy Farms. Salerno B, Cornaggia M, Losasso C, et al. Front Public Health. 2022;10:918658.

A side effect of antibiotic usage is the emergence and dissemination of antibiotic resistance genes (ARGs) within microbial communities. The spread of ARGs among pathogens has emerged as a public health concern. While the distribution of ARGs is documented on a global level, their routes of transmission have not been clarified yet; for example, it is not clear whether and to what extent the emergence of ARGs originates in farms, following the selective pressure exerted by antibiotic usage in animal husbandry, and if they can spread into the environment.
In this paper, researchers address this cutting edge issue by combining data regarding antimicrobial usage and quantitative data from selected ARGs (bla TEM, bla CTXM , ermB, vanA, qnrS, tetA, sul2, and mcr-1) encoding for resistance to penicillins, macrolides-lincosamides-streptogramins, glycopeptides, quinolones, tetracyclines, sulfonamides, and colistin at the farm level.
Results suggest that dairy farms could be considered a hotspot of ARGs, comprising those classified as the highest risk for human health and that a correlation existed between the usage of penicillins and bla TEM abundances, meaning that, although the antibiotic administration is not exclusive, it remains a certain cause of the ARGs’ selection and spread in farms.
Furthermore, this study identified the role of calves as the main source of ARGs spread in dairy farms, claiming the need for targeted actions in this productive category to decrease the load of ARGs along the production chain.

Prevalence of bovine mastitis-related pathogens, identified in flies captured in the milking environment. Bertolini AB, Prado AM, Ribeiro MG, et al. Lett Appl Microbiol. 2022 Jul 24.

Diptera (Insecta) are able to transmit approximately 200 pathogenic microorganisms to humans and animals, causing more than 65 diseases, including bovine mastitis, which constitutes a major cause of economic losses in the dairy industry.
In this scenario, 217 adult specimens of Diptera were collected from nine farms and identified to the family and/or species-level. Of the 11 families recorded, Muscidae was the most prevalent (152 out of 217; 70%).
All Diptera specimens were subjected to microbiological culture using conventional and selective media, and isolates were then identified at the species-level by mass spectrometry. Two hundred seventy-five microorganisms were identified, with a predominance of pathogens related to environmental bovine mastitis (166/275=60.4%), i.e., Enterococcus species (70/275=25.4%) and Escherichia coli (49/275=17.8%). Nontraditional agents related to bovine mastitis (called miscellaneous) were detected in 28% (77/275), as well as microorganisms with well-known zoonotic behavior (e.g., Bacillus cereus).
This is study contributes with knowledge of diversity of microorganisms carried by Diptera in the dairy environment, including pathogens associated with environmental and contagious bovine mastitis, and agents with human relevance.

Understanding Antibiotic Resistance as a Perceived Threat towards Dairy Cattle through Beliefs and Practices: A Survey-Based Study of Dairy Farmers. Casseri E, Bulut E, Ivanek R, et al. Antibiotics (Basel). 2022 Jul 25;11(8):997.

Antibiotic use is an important component in dairy herd management both to treat bacterial diseases and to maximize animal welfare. However, there is concern among scientists that antibiotic misuse and/or overuse by farmers might promote the emergence of resistant pathogens.
Researchers conducted a cross-sectional web-based questionnaire study with dairy farmers/managers in New York, USA to evaluate their (i) level of concern about antibiotic resistance and (ii) interest in adopting new judicious antibiotic use practices regarding mastitis treatment.
A total of 118 responses were subjected to statistical analysis. The findings revealed that nearly half (45%) of study participants were undecided or disagreed that antibiotic resistance due to antibiotic use in dairy farming may negatively impact the health of dairy cattle.
In contrast, the majority (78%) of participants self-reported that they do not treat with antibiotics at the first sign of mastitis, and the majority (66%) have either fully or partially implemented culture-based mastitis treatment on their farm.
The self-reported adoption of culture-based mastitis treatment practices was statistically significantly associated with higher numbers of injectable and intramammary doses of antibiotics used on the participants’ farms. These findings will aid future research investigations on how to promote sustainable antibiotic use practices in dairy cattle.

Shelf-life studies of putative probiotic Lacticaseibacillus casei strains in milk and model yogurt. Aktas B, Budinich M, Hoza L, Rankin SA, Broadbent JR, Steele JL. Food Sci Technol Int. 2022 Jul 5:10820132221112260.

Lacticaseibacillus casei are commonly utilized as probiotic in a wide-range of fermented and unfermented dairy products. The stability of probiotics in fermented dairy products during shelf-life is of concern due to low pH and high level of organic acids.
The objective of this study is to evaluate L. casei for their ability to survive in a model yogurt and fluid milk; additionally, their impact on the pH, organic acids, and sensory attributes of these products was examined.
The strain-to-strain differences in cell densities in yogurt and milk inoculated at a therapeutic level at the end of shelf-life were 1.2 and 1.4 log CFU/ml, respectively. Five of the strains examined increased the pH of the yogurt, while two strains were observed to reduce the pH.
In milk, one strain raised the pH, while eleven strains reduced the pH. The levels of lactate, acetate, and formate in both the yogurt and milk were altered in a strain-specific manner.
The results suggested that the metabolism by these strains differed significantly during the shelf-life. Careful strain selection is required to identify probiotic L. casei strains that will survive through shelf-life in either yogurt or fluid milk and not impact product quality.

Human Nutrition and Health

Maternal Consumption of Milk or Dairy Products During Pregnancy and Birth Outcomes: A Systematic Review and Dose-Response Meta-Analysis. Huang D, Wu Q, Xu X, Ji C, Xia Y, Zhao Z, Dai H, Li H, Gao S, Chang Q, Zhao Y. Front Nutr. 2022;9:900529.

In recent years, especially since the inception of the “developmental origins of health and disease” theory, the impact of maternal nutrition has been increasingly emphasized. Mounting evidence has indicated that maternal diet during pregnancy, a modifiable factor, is associated with birth outcomes. Among these nutritious foods during pregnancy, milk and its derivatives receives certain attention. There are increasing reports of maternal dairy intake contributing to birth outcomes; however, some associations remain inconclusive with the growing body of evidence.
This study aimed to systematically review current evidence and quantitatively evaluate the associations between milk or dairy consumption during pregnancy and birth outcomes.
In total, 42 studies were eligible for the present systematic review, and 18 of them were included in the outcome-specific meta-analyses. The dose-response meta-analysis from 9 studies predicted a maximum mean change in birthweight of 63.38 grams at 5 servings per day.
Intake of dairy products had the greatest protective effect (31% lower risk) on small for gestational age at a maximum of 7.2 servings per day. The risk of large for gestational age was predicted to be maximum at 7.2 servings per day of dairy consumption (30% higher risk). In addition, the relationship between dairy consumption and low birth weight (30% lower risk) and pre-mature birth (13% higher risk) was not significant, respectively.
Maternal consumption of dairy during pregnancy has a potential effect on fetal growth. Further well-designed studies are warranted to clarify the specific roles of individual dairy products.

Brain-immune-gut benefits with early life supplementation of milk fat globule membrane. Mohamed HJJ, Lee EKH, Woo KCK, Sarvananthan R, Lee YY, Mohd Hussin ZA. JGH Open. 2022 Jun 1;6(7):454-461.

The milk fat globule membrane (MFGM) has been recognized as a milk component for more than 60 years, but its exact benefits remain unknown. Research on human MFGM has revealed that the membrane holds a host of bioactive components with potential benefits for the brain-immune-gut (BiG) axis in early life.
Gangliosides and sphingomyelin, components within the MFGM, have been included in infant formulas for many years. Recent advancements in dairy milk processing have allowed the successful separation of MFGM from bovine milk, enabling it to be used for supplementing infant formulas.
Evidence indicates the potential benefits of MFGM in early life supplementation, including better cognitive development, reduction of infection risks, and modulation of the gut microbiome. However, larger and more robust randomized trials are needed, in addition to long-term outcome data beyond the infancy period.

Association Between Dairy Intake and Executive Function in Chinese Children Aged 6-12 Years. Zeng X, Cai L, Gui Z, Shen T, Yang W, Chen Q, Chen Y. Front Nutr. 2022 Jul 11;9:879363.

Association between dairy intake and executive function remains controversial, especially among children, a population with fast-developing executive functions.
This study aimed to explore this topic. Additionally, researchers further distinguished the role of dairy intake types (full- or low-fat milk or yogurt) in this relationship.
This survey included 5,138 children aged 6-12 years. Dairy intakes were assessed by validated questionnaires. Executive function was measured by the behavior rating inventory of executive function (BRIEF; Parent Version), and lower T-scores of BRIEF indices indicated superior executive function performance.
Results showed that children with higher dairy intake had statistically better performance in Shift, Initiate, and Working Memory.
After distinguishing dairy into milk and yogurt, the researchers observed that only milk intake, not yogurt, was significantly associated with better executive function performance in Shift and Initiate after adjusting for potential confounding factors.
This study shows that a higher intake of dairy, irrespective of fat content, is related to better executive function performance among children aged 6-12. In addition, a significantly positive relationship between dairy intake and executive function’s indices of Shift and Initiate only was observed in milk, not in yogurt.

The Role of Milk on Children’s Weight Status: An Epidemiological Study among Preadolescents in Greece. Kanellopoulou A, Kosti RI, , Panagiotakos DB, et al. Children (Basel). 2022 Jul 10;9(7):1025.

Milk consumption contributes greatly to children’s diet, playing a pivotal role in the development and structure of bones and the functioning of the musculoskeletal system and the heart.
This study investigated the association between the type of milk and childhood overweight/obesity. In the school period 2014-2016, 1728 students aged 10-12 years and their parents participated.
The measurement and classification of their weight status were performed through the criteria of the International Obesity Task Force. Among others, the type of milk consumption was recorded. Four categories of the type of milk children consumed were classified (white milk, chocolate milk, both types of milk, and no milk at all).
Children consuming only white milk were 33.1% less likely to be overweight/obese in comparison with children who were not consuming milk at all. The consumption of chocolate milk showed a protective role against childhood overweight/obesity although its association was not consistently significant.
This study highlights the significant contribution of milk (and particularly of white milk) consumption to weight management, and thus its promotion should be consistently encouraged. More studies are needed to shed light on the effects of different dairy foods on weight status in childhood.

Associations between food portion sizes, insulin resistance, VO2 max and metabolic syndrome in European adolescents: The HELENA study. Flieh SM, Miguel-Berges ML, González-Gil EM, et al; HELENA Study Group. Nutr Metab Cardiovasc Dis. 2022 May 31:S0939-4753(22)00227-7.

During the past decades, increasing prevalence of type 2 diabetes mellitus and prediabetic stages such as insulin resistance or impaired fasting glucose has been reported in children and adolescents. Dietary factors are environmental determinants of both adiposity, insulin resistance, and the components of metabolic syndrome.
This study aims to examine the associations of food portion size with markers of insulin resistance and clustered of metabolic risk score in European adolescents.
A total of 495 adolescents (53.5% females) from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study were included. The association between portion size from food groups and homeostasis model assessment of insulin resistance (HOMA-IR) index, VO2 max, and metabolic risk score was assessed.
Larger portion size from vegetables in both gender and milk, yogurt, and milk beverages in males were associated with higher VO2 max, while larger portion size from margarines and vegetable oils were associated with lower VO2 max. Males with lower HOMA-IR cutoff values consumed larger portion size from vegetables, milk, yogurt, and milk beverages. Females with lower HOMA-IR cutoff values consumed larger portion size from breakfast cereals, while those with higher HOMA-IR cutoff values consumed larger portion size from butter and animal fats.
The results show that larger portion size from dairy products, cereals, and high energy dense foods are a significant determinant of insulin resistance and VO2 max, and larger portion size from food with higher content of sugar were associated with higher metabolic risk score.

Health-Promoting and Therapeutic Attributes of Milk-Derived Bioactive Peptides. Samtiya M, Samtiya S, Badgujar PC, Puniya AK, Dhewa T, Aluko RE. Nutrients. 2022 Jul 22;14(15):3001.

Milk-derived bioactive peptides (BAPs) possess several potential attributes in terms of therapeutic capacity and their nutritional value. BAPs from milk proteins can be liberated by bacterial fermentation, in vitro enzymatic hydrolysis, food processing, and gastrointestinal digestion.
Previous evidence suggested that milk protein-derived BAPs have numerous health-beneficial characteristics, including anti-cancerous activity, anti-microbial activity, anti-oxidative, anti-hypertensive, lipid-lowering, anti-diabetic, and anti-osteogenic.
In this literature overview, researchers briefly discussed the production of milk protein-derived BAPs and their mechanisms of action. Milk protein-derived BAPs are gaining much interest worldwide due to their immense potential as health-promoting agents. These BAPs are now used to formulate products sold in the market, which reflects their safety as natural compounds.
However, enhanced commercialization of milk protein-derived BAPs depends on knowledge of their particular functions/attributes and safety confirmation using human intervention trials.

Non-Dairy Animal Protein Consumption Is Positively Associated with Overweight and Obesity in Israeli Adolescents. Dor C, Stark AH, Dichtiar R, Keinan-Boker L, Sinai T. Foods. 2022 Jul 12;11(14):2072.

Protein consumption apparently plays a role in weight control.
This cross-sectional study examined the association of protein consumption in Israeli adolescents with overweight/obesity.
7th-12th grade students participating in a national school-based survey (2015-2016) completed self-administered questionnaires, including a food frequency questionnaire, and height and weight measurements. WHO growth standards served to define weight status. Intakes of total protein and protein source were calculated.
Total protein intake on average was 62.5 grams/day, accounting for 12.0% of daily energy. Of participants, 31.4% were overweight/obese.
In multivariable models, overweight/obesity was positively associated (7%) with incremental increases of 10 grams/day in total protein intake, total animal protein intake (5%), and non-dairy animal protein intake (6%).
No associations were found with plant or dairy protein intake. These associations remained when protein intake was reported as a percentage of daily energy and when overweight and obesity were analyzed individually.
High daily protein intakes, principally from non-dairy animal sources, were positively associated with overweight/obesity in adolescents. Additional studies are needed to establish causality of these findings.

Innovation, Economics, and Dairy Alternatives

Improvement of the fuel properties of dairy manure by increasing the biomass-to-water ratio in hydrothermal carbonization. Aliyu M, Iwabuchi K, Itoh T. PLoS One. 2022 Jul 18;17(7):e0269935.

There are many advantages to liquid-based hydrothermal carbonization (L-HTC) but the need to immerse the biomass in water generates more post-process water, hindering the commercialisation of HTC.
To address this issue, this study investigated the feasibility of vapour-based HTC (V-HTC), which minimizes the water required.
Dairy manure was hydrothermally treated at temperatures of 200, 230, 255 and 270°C and biomass-to-water ratios (B/W) of 0.1, 0.18, 0.25, 0.43, 0.67 and 1.0 for 20 minutes, then the produced hydrochars were characterized by calorific, proximate, ultimate and thermogravimetric analyses.
The results showed that the mass yields of hydrochar decreased with increasing temperature but were essentially stable at high B/W ratios. Notably, the calorific values of the hydrochars increased with increasing temperature and B/W ratio, and the energy density increased by 46%.
Due to the higher mass yield and increased energy density, maximum energy yields at each temperature (86.0-97.4%) were observed at a B/W ratio of 1.0. The proximate and ultimate analyses revealed that the degree of coalification, such as the increase in carbon content and decrease in oxygen and volatile matter, progressed more under V-HTC than L-HTC conditions, likely because the lower liquid content in V-HTC facilitates the formation of secondary char and increases the reaction severity due to higher acidity.
This study showed a potential approach for upgrading a semi-solid-state biomass by V-HTC.

The Potentialities of Machine Learning for Cow-Specific Milking: Automatically Setting Variables in Milking Machines. Wang J, Lovarelli D, Rota N, Shen M, Lu M, Guarino M. Animals (Basel). 2022;12(13):

In dairy farming, milking-related operations are time-consuming and expensive, but are also directly linked to the farm’s economic profit. Therefore, reducing the duration of milking operations without harming the cows is paramount.
This study aimed to test the variation in different parameters of milking operations on non-automatic milking machines to evaluate their effect on a herd and finally reduce the milking time.
Two trials were set up on a dairy farm in Northern Italy to explore the influence of the pulsation ratio (60:40 vs. 65:35 pulsation ratio) and that of the detachment flow rate (600 g/min vs. 800 g/min) on milking performance, somatic cell counts, clinical mastitis, and teats score.
Moreover, the innovative aspect of this study relates to the development of an optimized least-squares support vector machine (LSSVM) classification model based on the sparrow search algorithm (SSA) to predict the proper pulsation ratio and detachment flow rate for individual cows within the first two minutes of milking.
The accuracy and precision of this model were 92% and 97% for shortening milking time at different pulsation ratios, and 78% and 79% for different detachment rates. The implementation of this algorithm in non-automatic milking machines could make milking operations cow-specific.

Pesticide residues in milk and dairy products: An overview of processing degradation and trends in mitigating approaches. Schopf MF, Pierezan MD, Rocha R, Pimentel TC, Esmerino EA, Marsico ET, De Dea Lindner J, Cruz AGD, Verruck S. Crit Rev Food Sci Nutr. 2022 Jul 23:1-15.

Milk and dairy products present considerable socioeconomic importance but are also a regular pesticide residue contamination source, which is considered a worldwide public health concern and a major international trade issue.
Thus, a literature review was conducted to assess pesticide residue levels in milk and dairy products, as well as the residue degradation capacity during its processing.
Organochlorine, organophosphate, synthetic pyrethroid and/or triazine were found in fluid milk, powder products, yogurts, cheese, butter, and sour cream.
Thermal processing reduced most residue levels, although some treatments increased total hexachlorocyclohexane and its isomers (α-, γ-, δ-, and β-). Emerging non-thermal treatments presented promising results, but some by-products had higher toxicity than their precursors.
Biodegradation by lactic acid bacteria were effective during yogurt and cheese fermentation. However, β-hexachlorocyclohexane level seems to increase in yogurts containing Lactobacillus acidophilus and Bifidobacterium animalis subsp. lactis, while increase or maintenance of pesticide residue concentration was observed during coagulation and cheese maturation.
Deep research is needed to understand the isomerization and degradation mechanisms after thermal, non-thermal, and fermentation processing. Emerging heat technology can be an excellent topic to be investigated for pesticide residues degradation in the future. These mitigation approaches can be a feasible future alternative to milk and dairy production.

Consumer perception and emotional responses to plant-based cheeses. Falkeisen A, Gorman M, Knowles S, Barker S, Moss R, McSweeney MB. Food Res Int. 2022 Aug;158:111513.

Consumer interest in plant-based cheeses (PBCs) has increased in the last few years due to consumer concern for animal welfare, environmental impact, and health.
In order to increase the acceptability of PBCs, sensory studies must be conducted. As such, the aim of this study was to evaluate the acceptability, sensory properties, and emotional responses to PBCs currently being sold in Canada.
There were two different sensory trials conducted. In the first trial (n = 100), raw PBCs were evaluated, and in the second trial (n = 93) melted PBCs were evaluated. In both trials, five different PBCs were evaluated using nine-point hedonic scales, a check-all-that-apply (CATA) question, and the CATA variant of the EsSense25 profile.
Participants were also asked to answer open-ended comment questions about PBCs. The results showed that participants thought PBCs are healthier than regular dairy cheese, but they did not like the flavor or textural properties of PBCs.
PBCs that are buttery, smooth, and have soft attributes were preferred by the participants. Participants mainly disliked PBCs that were mouthcoating, rubbery, and had off-flavors. The PBCs with higher overall liking scores were associated with positive emotions.

New Alternatives to Milk From Pulses: Chickpea and Lupin Beverages With Improved Digestibility and Potential Bioactivities for Human Health. Duarte CM, Mota J, Assunção R, Martins C, Ribeiro AC, Lima A, Raymundo A, Nunes MC, Ferreira RB, Sousa I. Front Nutr. 2022 Jul 14;9:852907.

There is a strong demand for plant-based milk substitutes, often low in protein content (<1.5% w/v). Protein-rich pulse seeds and the right processing technologies make it possible to make relevant choices.
The major objective of this study was to assess the impact of processing on the nutritional characteristics of beverages with a high impact on health, in particular on digestibility and specific bioactivities.
The results suggest that pulse beverages are as high in protein content (3.24% w/v for chickpea and 4.05% w/v for lupin) as cow’s milk. The anti-nutrient level characteristics of pulses have been considerably reduced by strategic processing. However, when present in small quantities, some of these anti-nutritional factors may have health benefits.
Controlling processing conditions play a crucial role in this fine balance as a tool to take advantage of their health benefits. There is evidence of protein hydrolysis by in vitro digestion and limited bioaccessibility of minerals.
In addition to being highly digestible, lupin and chickpea beverages have anti-inflammatory and anti-carcinogenic potential evaluated through the inhibition of metalloproteinase MMP-9.