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

Environmental Management and Sustainability

Enteric Methane Emissions and Animal Performance in Dairy and Beef Cattle Production: Strategies, Opportunities, and Impact of Reducing Emissions. Min BR, Lee S, Jung H, Miller DN, Chen R. Animals (Basel). 2022 Apr 7;12(8):948.

Enteric methane (CH₄) emissions produced by microbial fermentation in the rumen resulting in the emission of greenhouse gases (GHG) into the atmosphere. The GHG emissions reduction from the livestock industry can be attained by increasing production efficiency and improving feed efficiency, by lowering the emission intensity of production, or by combining the two.
The objectives of this review are to evaluate options that have been demonstrated to mitigate enteric CH4 emissions per unit of products (energy-corrected milk, milk yield, average daily gain, dry matter intake, and gross energy intake) from dairy and beef cattle on a quantitative basis and in a sustained manner, and to integrate approaches in feeding, rumen fermentation profiles, and rumen microbiota changes to emphasize the understanding of these relationships between enteric CH4 emissions and animal productivities.
In this work, information was compiled from peer-reviewed studies to analyze CH₄emissions calculated per unit of milk production, energy-corrected milk, average daily gain, dry matter intake (DMI), and gross energy intake, and related emissions to rumen fermentation profiles (volatile fatty acids [VFA], hydrogen [H₂]) and microflora activities in the rumen of beef and dairy cattle.
For dairy cattle, there was a positive correlation between CH4 emissions and DMI, milk production, energy-corrected milk, gross energy intake, and acetate/propionate (A/P) ratio. For beef cattle, CH4 emissions were positively correlated with dry matter intake and gross energy intake. Additionally, the average daily gain and A/P ratio were significantly associated with CH4 emission in beef steers.
This information may lead to cost-effective methods to reduce enteric CH4 production from cattle. The researchers conclude that enteric CH4 emissions per unit of energy-corrected milk, gross energy intake, and average daily gain, as well as rumen fermentation profiles, show great potential for estimating enteric CH4 emissions.

Livestock Use on Public Lands in the Western USA Exacerbates Climate Change: Implications for Climate Change Mitigation and Adaptation. Kauffman JB, Beschta RL, Lacy PM, Liverman M. Environ Manage. 2022 Apr 2.

Public lands of the USA can play an important role in addressing the climate crisis. About 85% of public lands in the western USA are grazed by domestic livestock, and they influence climate change in three profound ways:
1. they are significant sources of greenhouse gases through enteric fermentation and manure deposition;
2. they defoliate native plants, trample vegetation and soils, and accelerate the spread of exotic species resulting in a shift in landscape function from carbon sinks to sources of greenhouse gases;
3. they exacerbate the effects of climate change on ecosystems by creating warmer and drier conditions.
On public lands one cow-calf pair grazing for one month (an “animal unit month” or “AUM”) produces 875 kg CO₂e through enteric fermentation and manure deposition with a social carbon cost of nearly $36 per AUM. Over 14 million AUMs of cattle graze public lands of the western USA each year resulting in greenhouse gas emissions of 12.4 Tg CO₂e year^-1.
The social costs of carbon are > $500 million year^-1or approximately 26 times greater than annual grazing fees collected by managing federal agencies. These emissions and social costs do not include the likely greater ecosystems costs from grazing impacts and associated livestock management activities that reduce biodiversity, carbon stocks and rates of carbon sequestration.
Cessation of grazing would decrease greenhouse gas emissions, improve soil and water resources, and would enhance/sustain native species biodiversity thus representing an important and cost-effective adaptive approach to climate change.

Strategies to achieve a carbon neutral society: a review. Chen L, Msigwa G, Yang M, Osman AI, Fawzy S, Rooney DW, Yap PS. Environ Chem Lett. 2022 Apr 8:1-34.

The increasing global industrialization and over-exploitation of fossil fuels has induced the release of greenhouse gases, leading to an increase in global temperature and causing environmental issues. There is therefore an urgent necessity to reach net-zero carbon emissions.
Only 4.5% of countries have achieved carbon neutrality, and most countries are still planning to do so by 2050-2070. Moreover, synergies between different countries have hampered synergies between adaptation and mitigation policies, as well as their co-benefits.
In this paper, researchers present a strategy to reach a carbon neutral economy by examining the outcome goals of the 26th summit of the United Nations Climate Change Conference of the Parties (COP 26).
The researchers present decarbonization technologies and initiatives, and negative emissions technologies, and discuss carbon trading and carbon tax. The researchers propose plans for carbon neutrality such as shifting away from fossil fuels toward renewable energy, and the development of low-carbon technologies, low-carbon agriculture, changing dietary habits and increasing the value of food and agricultural waste.
Developing resilient buildings and cities, introducing decentralized energy systems, and the electrification of the transportation sector is also necessary. The paper also reviews the life cycle analysis of carbon neutral systems.

A review of the global climate change impacts, adaptation, and sustainable mitigation measures. Abbass K, Qasim MZ, Song H, Murshed M, Mahmood H, Younis I. Environ Sci Pollut Res Int. 2022 Apr 4:1-21.

Climate change is a long-lasting change in the weather arrays across tropics to polls. It is a global threat that has embarked on to put stress on various sectors.
This study is aimed to conceptually engineer how climate variability is deteriorating the sustainability of diverse sectors worldwide. Specifically, the agricultural sector’s vulnerability is a globally concerning scenario, as sufficient production and food supplies are threatened due to irreversible weather fluctuations. In turn, it is challenging the global feeding patterns, particularly in countries with agriculture as an integral part of their economy and total productivity.
Climate change has also put the integrity and survival of many species at stake due to shifts in optimum temperature ranges, thereby accelerating biodiversity loss by progressively changing the ecosystem structures. Climate variations increase the likelihood of particular food and waterborne and vector-borne diseases, and a recent example is a coronavirus pandemic. Climate change also accelerates the enigma of antimicrobial resistance, another threat to human health due to the increasing incidence of resistant pathogenic infections.
To better understand the problem, gathered the information in this report from various media outlets, research agencies, policy papers, newspapers, and other sources. This review is a sectorial assessment of climate change mitigation and adaptation approaches worldwide in the aforementioned sectors and the associated economic costs.
According to the findings, government involvement is necessary for the country’s long-term development through strict accountability of resources and regulations implemented in the past to generate cutting-edge climate policy. Therefore, mitigating the impacts of climate change must be of the utmost importance, and hence, this global threat requires global commitment to address its dreadful implications to ensure global sustenance.

Emissions of hydrogen sulfide from a western open-lot dairy. Grant RH, Boehm MT, Hagevoort GR. J Environ Qual. 2022 Apr 21.

Hydrogen sulfide emissions are considered hazardous to the environment. Animal agriculture operations must therefore report emissions exceeding a threshold to the National Response Center.
Estimating the emissions from operations is needed since monitoring at all operations is not possible. However, little is known about hydrogen sulfide (H₂S) emissions from open-lot dairy operations commonly found in dry regions.
Daily mean H₂S emissions from a Texas open-lot dairy were relatively uniform over the year. Emissions were greatest during the fall when air temperatures were relatively high and vapor pressure deficits were low.
Higher air temperatures and wind speeds and lower surface wetness corresponded with higher mean hourly emissions in winter, spring and summer. Hourly mean emissions in the fall differed substantially from those of the other seasons. These high fall emissions appear to have been associated with un-reported producer activity of hauling manure from the manure windrow storage onto the surrounding fields.
Mean annual live animal basis emissions were 3.6 g d^-1hd^-1 . Annual mean emissions for the entire 3400 head dairy were 12 kg d^-1 . The maximum measured daily emissions for this 3492-cow dairy were 33.1 kg d^-1 .

Animal Health and Food Safety

Effect of Type of Cow-Calf Contact on Health, Blood Parameters, and Performance of Dairy Cows and Calves. Wenker ML, Verwer CM, van Reenen CG, et al. Front Vet Sci. 2022 Apr 12;9:855086.

Prolonged cow-calf contact (CCC) could potentially improve dairy calf welfare. However, it is currently unknown how different types of CCC affect animals’ biological functions.
Therefore, researchers evaluated health and performance parameters of dairy calves and their dams, where calves:
1. had no contact with their dam (NC), in which the calf was removed from the dam directly after birth (n= 10);
2. were allowed to have partial contact (PC) with their dam, in which the calf was housed in a calf pen adjacent to the cow area allowing physical contact on the initiative of the dam but no suckling (n= 18);

were allowed to have full contact (FC) with their dam, including suckling, in which calves were housed together with their dams in a free-stall barn (n= 20).
Throughout the first 7 weeks postpartum, data were collected on the health status, fecal microbiota, hematological profile, immune and hormonal parameters, and growth rates of calves, and on the health status, metabolic responses, and performance of dams.
Overall, FC calves had more health issues and a tendency for higher antibiotic usage than NC calves. Additionally, FC calves showed elevated levels of erythrocytes, hematocrit, hemoglobin, and leukocytes on day 49 compared to NC calves.
Calf fecal microbiota changed over time, and showed preliminary evidence that fecal microbiota is affected by the type of CCC, as reflected by differences in relative abundances of taxa including Lactobacillusin FC calves compared to NC and PC calves except on days 7 and 66.
The FC calves had a greater average daily gain in body weight than NC and PC calves. Cow health was not affected by the type of CCC, although in the first 7 weeks of lactation FC cows had a lower machine-gained milk yield accompanied by a lower fat percentage than NC and PC cows.
These results indicate that full contact posed a challenge for calf health, presumably because the housing conditions of FC calves in this experimental context were suboptimal. Secondly, ad libitumsuckling leads to higher weight gains and negatively affected milk fat content besides machine-gained yields. More research into strategies to improve cow-calf housing and management in CCC systems is warranted.

Feeding and Manual Brushing Influence the Release of Oxytocin, ACTH and Cortisol Differently During Milking in Dairy Cows. Wredle E, Svennersten-Sjaunja K, Munksgaard L, Herskin MS, Bruckmaier RM, Uvnäs-Moberg K. Front Neurosci. 2022;16:671702.

Oxytocin released within the brain stimulates different types of social interactive behaviors and bonding, induces calmness, and induces anti-stress like effects such as a decrease of the activity of the sympathetic nervous system, which is reflected by, e.g., reduced plasma cortisol concentrations, blood pressure and heart rate.
This study aimed to examine the effects of feeding or abdominal brushing on the release of the hormones oxytocin, ACTH and cortisol during milking in dairy cows.
Twelve cows in early lactation were used, testing the effects of two types of sensory stimulation during milking over a 3 day period; feeding concentrate or manual abdominal brushing (1 stroke/s).
Milking was associated with an immediate and significant rise of oxytocin. When milking was combined with feeding, significantly higher levels of oxytocin were observed at 2 and 4 mins. No effect of brushing on oxytocin levels was observed.
Milking alone was associated with a significant rise of ACTH levels. Feeding in connection with milking reduced the immediate rise of ACTH levels, whereas no effects of brushing were found.
Milking caused a progressive rise of cortisol levels. Concomitant feeding did not influence cortisol levels, whereas brushing significantly decreased cortisol levels at 1, 5 and 14 mins after onset of milking.
Overall, feeding increases oxytocin release in response to milking and decreases ACTH levels. Abdominal brushing did not influence these variables, but decreased cortisol levels. These data demonstrate that activation of afferent vagal nerve fibers and of cutaneous sensory nerves originating from the abdominal skin in front of the udder influence milking related hormone release differently.

Dissemination of Resistant Escherichia coli Among Wild Birds, Rodents, Flies, and Calves on Dairy Farms. Hickman RA, Agarwal V, Sjöström K, Emanuelson U, Fall N, Sternberg-Lewerin S, Järhult JD. Front Microbiol. 2022 Apr 1;13:838339.

Antimicrobial resistance (AMR) in bacteria in the livestock is a growing problem, partly due to inappropriate use of antimicrobial drugs. Antimicrobial use (AMU) occurs in Swedish dairy farming but is restricted to the treatment of sick animals based on prescription by a veterinary practitioner.
Despite these strict rules, calves shedding antimicrobial resistant Enterobacteriaceaehave been recorded both in dairy farms and in slaughterhouses. Yet, not much is known how these bacteria disseminate into the local environment around dairy farms.
In this study, researchers collected samples from four animal sources (fecal samples from calves, birds and rodents, and whole flies) and two environmental sources (cow manure drains and manure pits).
From the samples, Escherichia coliwas isolated and antimicrobial susceptibility testing performed. A subset of isolates was whole genome sequenced to evaluate relatedness between sources and genomic determinants such as antimicrobial resistance genes (ARGs) and the presence of plasmids were assessed.
The researchers detected both ARGs, mobile genetic elements and low rates of AMR. In particular, they observed four potential instances of bacterial clonal sharing in two different animal sources. This demonstrates resistant colidissemination potential within the dairy farm, between calves and scavenger animals (rodents and flies).
AMR dissemination and the zoonotic AMR risk is generally low in countries with low and restricted AMU. However, this study shows that interspecies dissemination does occur, and in countries that have little to no AMU restrictions this risk could be under-estimated.

Fate and seasonality of antimicrobial resistance genes during full-scale anaerobic digestion of cattle manure across seven livestock production facilities. Burch TR, Firnstahl AD, Spencer SK, Larson RA, Borchardt MA. J Environ Qual. 2022 Apr 6.

Anaerobic digestion has been suggested as an intervention to attenuate antibiotic resistance genes (ARGs) in livestock manure but supporting data have typically been collected at laboratory scale. Few studies have quantified ARG fate during full-scale digestion of livestock manure.
In this study, researchers sampled untreated manure and digestate from seven full-scale mesophilic dairy manure digesters to assess ARG fate through each system.
Samples were collected biweekly from December through August (i.e., winter, spring, and summer; n = 235 total) and analyzed by quantitative polymerase chain reaction for intI1, erm(B), sul1, tet(A), and tet(W).
Concentrations of intI1, sul1, and tet(A) decreased during anaerobic digestion, but their removal was less extensive than expected based on previous laboratory studies. Removal for intI1 during anaerobic digestion was equivalent to only 48% removal and notable given intI1’s role in horizontal gene transfer and multiple resistance.
Furthermore, tet(W) concentrations were unchanged during anaerobic digestion, and erm(B) concentrations increased 3.3-fold, which is important given erythromycin’s status as a critically important antibiotic for human medicine.
Seasonal log₁₀changes in intI1, sul1, and tet(A) concentrations were ≥50% of corresponding log₁₀ removals by anaerobic digestion, and variation in ARG and intI1 concentrations among digesters was quantitatively comparable to anaerobic digestion effects.
These results suggest that mesophilic anaerobic digestion may be limited as an intervention for ARGs in livestock manure and emphasize the need for multiple farm-level interventions to attenuate antibiotic resistance.

Human Nutrition and Health

The association between dairy products and the risk of COVID-19. Darand M, Hassanizadeh S, Marzban A, Mirzaei M, Hosseinzadeh M.Eur J Clin Nutr. 2022 Apr 29:1-7.

The fast spread of the coronavirus disease 2019 (COVID-19) epidemic and its high mortality were quickly noticed by the health community. Dairy products have been recognized as part of a healthy diet that helps strengthen body immunity and prevent infections.
The present study can provide a comprehensive picture of the associations between dairy products consumption and COVID-19 incidence.
This study was undertaken on 8801 adults participants of Yazd Health Study (YaHS) and Taghzieh Mardom-e-Yazd (TAMIZ) study aged 20 to 70 years. Data on dietary intakes were obtained using a validated food frequency questionnaire (FFQ).
These findings indicated that moderate intake of total dairy (OR: 0.63) could reduce the odds of COVID-19 and higher intake of low-fat dairy products (OR: 0.51) and low-fat milk (OR: 0.47) had a protective effect on COVID-19 after adjusting for confounders.
However, higher intake of high-fat-dairy-product (OR: 1.40), high-fat milk (OR: 1.54), total yogurt (OR: 1.40), cheese (OR: 1.80), and butter (OR: 1.80) were related to increase the odds of COVID-19.
Moderate intake of total dairy could reduce odds of COVID-19 by 37% and, a higher intake of low-fat dairy products had a protective role on COVID-19. Although our study has promising results, stronger clinical studies are needed.

Health effects of yogurt consumption during pediatric age: a narrative review. Fiore G, Di Profio E, Sculati M, Verduci E, Zuccotti GV. Int J Food Sci Nutr. 2022 Apr 22:1-22.

Yogurt is a fermented milk product characterized by a peculiar nutritional composition with live and viable cultures of bacteria. Few studies have analyzed the benefits of yogurt consumption on health outcomes during pediatric age.
Recent epidemiological studies evaluating the nutritional impact of yogurt have demonstrated its significant contribution to nutrients intakes among children. Thus, consuming yogurt is a strategy to achieve recommended nutrient intake and healthier dietary choices, with potential impact on obesity and cardiometabolic outcome in children.
Yogurt’s effects on pediatric infectious diseases, gastrointestinal diseases and atopic-related disorders are ascribed to the specific probiotic strain administered. Interestingly, the benefits of yogurt consumption are most likely due to effects mediated through the gut microbiota and the enhancement of innate and adaptive immune responses.
Therefore, supplementing standard yogurt cultures with probiotic strains could be useful to promote health at different pediatric ages, although more evidence is needed regarding the strain-related effects and their interplay within the pediatric immune system.

Beneficial Effects of Bovine Milk Exosomes in Metabolic Interorgan Cross-Talk. García-Martínez J, Pérez-Castillo ÍM, Salto R, López-Pedrosa JM, Rueda R, Girón MD. Nutrients. 2022;14(7):1442.

Extracellular vesicles are membrane-enclosed secreted vesicles involved in cell-to-cell communication processes, identified in virtually all body fluids. Among extracellular vesicles, exosomes have gained increasing attention in recent years as they have unique biological origins and deliver different cargos, such as nucleic acids, proteins, and lipids, which might mediate various health processes.
In particular, milk-derived exosomes are proposed as bioactive compounds of breast milk, which have been reported to resist gastric digestion and reach systemic circulation, thus being bioavailable after oral intake.
In the present manuscript, researchers critically discuss the available evidence on the health benefits attributed to milk exosomes, and we provide an outlook for the potential future uses of these compounds.
The use of milk exosomes as bioactive ingredients represents a novel avenue to explore in the context of human nutrition, and they might exert important beneficial effects at multiple levels, including but not limited to intestinal health, bone and muscle metabolism, immunity, modulation of the microbiota, growth, and development.

Invited Review: Potential effects of short- and long-term intake of fermented dairy products on prevention and control of type 2 diabetes mellitus. Awwad SF, Abdalla A, Howarth FC, Stojanovska L, Kamal-Eldin A, Ayyash MM. J Dairy Sci. 2022 Apr 1:S0022-0302(22)00205-3.

The consumption of fermented dairy products has been linked with lowering the risk of type 2 diabetes mellitus (T2DM), but studies have yet to demonstrate a definite association.
In this review paper, researchers evaluated evidence from a cross-sectional analysis of longitudinal studies and human and animal experimental trials to further understand the current knowledge linking short- and long-term consumption of fermented dairy products to T2DM.
Most cohort studies revealed a protective effect of fermented dairy products on T2DM development, with yogurt noted as the most consistent food item protecting against the disease. Human experimental trials and animal studies revealed improvements in biomarkers of glycemic control with short-term monitored intake of fermented dairy products from various sources.
Therefore, fermented dairy products may offer protection against the development and may have therapeutic benefits for individuals with T2DM. This could influence on dietary recommendations and the development of functional foods aiming to minimize the risk of T2DM.

Association of cow’s milk intake in early childhood with adiposity and cardiometabolic risk in early adolescence. McGovern C, Rifas-Shiman SL, Switkowski KM, Baidal JAW, Lightdale JR, Hivert MF, Oken E, Aris IM. Am J Clin Nutr. 2022 Apr 19:nqac103.

Prior studies have provided conflicting evidence regarding associations of pediatric milk consumption with subsequent adiposity.
Therefore, researchers aimed to estimate associations of the frequency and fat content of early childhood milk intake with early adolescent adiposity and cardiometabolic risk.
The researchers analyzed data collected prospectively from 796 children in Project Viva, a Boston-area pre-birth cohort. Parents reported the frequency (times/day) and fat content (higher-fat: whole (3.25%) or 2%; lower-fat: 1% or skim) of cow’s milk consumed in early childhood (mean 3.2 years) via food-frequency questionnaires. The researchers measured adiposity and cardiometabolic markers in early adolescence (mean 13.2 years).
The results showed that in early childhood, mean milk intake was 2.3 times/day, and 63% of children drank primarily higher-fat milk. Early childhood BMI z-score (BMIz) was inversely associated with the fat content of milk consumed in early childhood. After adjustment for baseline parent and child factors, early childhood intake of higher-fat compared with lower-fat milk was associated with lower adiposity.
Early childhood consumption of higher-fat milk (vs. lower-fat milk) was not associated with adverse cardiometabolic outcomes. The frequency of cow’s milk consumed in early childhood was not associated with adiposity or cardiometabolic risk in early adolescence.
In conclusion, consumption of higher-fat cow’s milk in early childhood was not associated with increased adiposity or adverse cardiometabolic health over a decade later. These findings do not support current recommendations to consume lower-fat milk to reduce the risk of later obesity and adverse cardiometabolic outcomes.

Innovation, Economics, and Dairy Alternatives

Artificial Intelligence Approach for Estimating Dairy Methane Emissions. Jeong S, Fischer ML, Breunig H, Marklein AR, Hopkins FM, Biraud SC. Environ Sci Technol. 2022 Apr 19;56(8):4849-4858.

California’s dairy sector accounts for ∼50% of anthropogenic CH₄emissions in the state’s greenhouse gas (GHG) emission inventory. Although California dairy facilities’ location and herd size vary over time, atmospheric inverse modeling studies rely on decade-old facility-scale geospatial information.
For the first time, researchers apply artificial intelligence (AI) to aerial imagery to estimate dairy CH₄emissions from California’s San Joaquin Valley (SJV), a region with ∼90% of the state’s dairy population.
Using an AI method, researchers process 316,882 images to estimate the facility-scale herd size across the SJV. The AI approach predicts herd size that strongly (>95%) correlates with that made by human visual inspection, providing a low-cost alternative to the labor-intensive inventory development process.
The researchers estimate SJV’s dairy enteric and manure CH₄emissions for 2018 to be 496-763 Gg/yr (mean = 624; 95% confidence) using the predicted herd size. They also apply their AI approach to estimate CH₄ emission reduction from anaerobic digester deployment. They identified 162 large (90th percentile) farms and estimate a CH₄ reduction potential of 83 Gg CH₄/yr for these large facilities from anaerobic digester adoption.
The results indicate that an AI approach can be applied to characterize the manure system (g., use of an anaerobic lagoon) and estimate GHG emissions for other sectors.

Quantifying current and future raw milk losses due to bovine mastitis on European dairy farms under climate change scenarios. Guzmán-Luna P, Nag R, Martínez I, Mauricio-Iglesias M, Hospido A, Cummins E. Sci Total Environ. 2022 Apr 11;833:155149.

Bovine mastitis is an infectious disease that causes udder inflammation and is responsible for raw milk losses across European dairy farms. It is associated with reduced cow milk yield and contributes to elevated Somatic Cell Count (SCC) in raw milk.
Staphylococcus aureus is one of the most prevalent mastitis pathogens that cause subclinical and clinical mastitis and can be present as a coloniser bacterium in cows. Climate change and geographical variability may influence the prevalence of this pathogen.
Thus, this research aimed to predict the raw milk losses in three major dairy-producing regions across Europe (i.e. Mediterranean, Atlantic and Continental) under climate change scenarios.
An exposure assessment model and a stepwise probabilistic model were developed to predict potential cow milk yield reduction, S. aureus and SCC concentrations in the bulk tank milk at dairy farms. Baseline (i.e. present) and future climate change scenarios were defined, and the resultant concentrations of SCC and S. aureus were compared to the actual European regulatory limits.
Across the three regions, raw milk losses ranged from 1.06% to 2.15% in the baseline. However, they increased up to 3.21% in the climate change scenarios when no on-farm improvements were considered. Regarding geographical variation, the highest potential milk losses were reported for the Mediterranean and the lowest for the Continental region. Concerning the fulfilment of the regulatory limits, the mean of S. aureus and SCC levels in milk did not exceed them either in any region or scenario.
Nevertheless, when looking at percentiles, the 10th percentile remained above the limits of S. aureus in Atlantic and Mediterranean, but not in the Continental region.
The findings provide a snapshot of climate change impacts on raw milk losses due to mastitis. They will allow farmers to detect weaknesses and prepare them to develop adaptation plans to climate change.

Parents’ implicit perceptions of dairy milk and plant-based milk alternatives. Schiano AN, Nishku S, Racette CM, Drake MA. J Dairy Sci. 2022 Apr 1:S0022-0302(22)00208-9.

Dairy product consumption is motivated by both familiarity and habit. Milk consumption decreases with age, but milk consumption during childhood and adolescence increases the chances of lifetime milk consumption. Understanding how parents perceive dairy milk and other dairy foods further enables development of dairy-positive messaging that aligns with their perceptions.
The objective of this research was to understand parent belief systems around fluid dairy milk and plant-based alternatives.
This goal was accomplished by assessing parents’ implicit attitudes toward dairy milk and PBA with an implicit bias exercise (n = 331), followed by qualitative interviews to understand explicitly stated purchase motivations and guided recall of information heard about dairy milk and plant-based alternatives to better understand external influences on milk perception (n = 88).
The majority of parents (73.4%) implicitly associated dairy milk with positive attributes compared with those with a positive association with plant-based alternatives (13.8%) or with a neutral bias (12.7%). The stronger a parent’s implicit bias toward plant-based alternatives, the more likely they were to purchase these products either alongside or as a replacement for dairy milk.
Eighty-five percent of parents in this study could recall drinking milk at home as a child, and 58% remembered encouragement from their parents to drink milk. However, only 38% encouraged their own children to drink milk (the majority, 55%, were neutral toward their children’s milk consumption). Generally negative media messaging toward dairy milk and positive messaging toward plant-based alternatives may contribute to this trend, even if consumers are not explicitly aware of their perception changes.
Seventy-seven percent of parents felt generally confident in choosing dairy milk or plant-based alternatives for their children. However, only 26% of parents felt that nothing about dairy milk or plant-based alternatives information or messaging was confusing. Sources of uncertainty about dairy milk included hormones and antibiotics, animal welfare, ecological sustainability, potential contamination, and intolerances or allergies.
By addressing the most commonly encountered and recalled concerns about milk from parents, dairy producers may be able to increase trust and implicit bias toward dairy milk compared with plant-based alternatives.

Applications of Plant Protein in the Dairy Industry. Hu GG, Liu J, Wang YH, Yang ZN, Shao HB. Foods. 2022 Apr 7;11(8):1067.

In recent years, a variety of double protein dairy products have appeared on the market. It is a dairy product made by replacing parts of animal protein with plant protein and then using certain production methods.
For some countries with limited milk resources, insufficient protein intake and low income, double protein dairy products have a bright future. More and more studies have found that double protein dairy products have combined effects which can alleviate the relatively poor functional properties of plant protein, including solubility, foaming, emulsifying and gelling. In addition, the taste of plant protein has been improved.
This review focuses on the current state of research on double protein dairy products. It covers some salient features in the science and technology of plant proteins and suggests strategies for improving their use in various food applications.
At the same time, it is expected that the fermentation methods used for those traditional dairy products as well as other processing technologies could be applied to produce novelty foods based on plant proteins.

Mixed dairy and plant-based yogurt alternatives: Improving their physical and sensorial properties through formulation and lactic acid bacteria cocultures. Canon F, Maillard MB, Famelart MH, Thierry A, Gagnaire V. Curr Res Food Sci. 2022 Apr 4;5:665-676.

Food transition requires incorporating more plant-based ingredients in our diet, thus leading to the development of new plant-based products, such as yogurt alternatives.
This study aimed at evaluating the impact of lactic acid bacteria (LAB) cocultures and formulation on the physico-chemical and sensory properties of yogurt alternatives.
Yogurt alternatives were made by emulsifying anhydrous milk fat (AMF) or coconut oil in milk and lupin protein suspensions. The starters used, in mono- and cocultures, were the strains Lactococcus lactisNCDO2125, Enteroccocus faecalis CIRM-BIA2412 and Lactiplantibacillus plantarum CIRM-BIA1524.
Some cocultures led to higher firmness, viscosity, and water holding capacity of yogurt alternatives, compared to monocultures. AMF and a milk:lupin protein ratio of 67:33 gave firmer and more viscous yogurt alternatives. Yogurt alternatives were sensorially discriminated on the basis of protein ratio and fat type, but not of starters.
The cocultures exhibited more diverse functional outputs, such as texturing, production of flavor compounds, proteolysis, when the strains associated in coculture had distinct capacities. Appropriate associations of LAB and formulation offer interesting solutions to improve the perception of yogurt alternatives, and ultimately, encourage their consumption.

Black soldier fly larvae for organic manure recycling and its potential for a circular bioeconomy: A review. Liu T, Klammsteiner T, Dregulo AM, Kumar V, Zhou Y, Zhang Z, Awasthi MK. Sci Total Environ. 2022 Apr 9;833:155122.

Livestock farming and its products provide a diverse range of benefits for our day-to-day life. However, the ever-increasing demand for farmed animals has raised concerns about waste management and its impact on the environment.
Worldwide, cattle produce enormous amounts of manure, which is detrimental to soil properties if poorly managed. Waste management with insect larvae is considered one of the most efficient techniques for resource recovery from manure. In recent years, the use of black soldier fly larvae (BSFL) for resource recovery has emerged as an effective method.
Using BSFL has several advantages over traditional methods, as the larvae produce a safe compost and extract trace elements like Cu and Zn.
This paper is a comprehensive review of the potential of BSFL for recycling organic wastes from livestock farming, manure bioconversion, parameters affecting the BSFL application on organic farming, and process performance of biomolecule degradation. The last part discusses the economic feasibility, lifecycle assessment, and circular bioeconomy of the BSFL in manure recycling. Moreover, it discusses the future perspectives associated with the application of BSFL.
Specifically, this review discusses BSFL cultivation and its impact on the larvae’s physiology, gut biochemical physiology, gut microbes and metabolic pathways, nutrient conservation and global warming potential, microbial decomposition of organic nutrients, total and pathogenic microbial dynamics, and recycling of rearing residues as fertilizer.