Dairy Research Bulletin: Selected Articles from November 2021

Dairy Research Bulletin
Selected Articles from November 2021

Environmental Management and Sustainability

Global Strategies to Minimize Environmental Impacts of Ruminant Production. Du Y, Ge Y, Chang J. Annu Rev Anim Biosci. 2021 Nov 15.

Demand for ruminant products (dairy products, beef, and sheep meat) is increasing rapidly with population and income growth and the acceleration of urbanization. However, ruminant animals exert the highest environmental impacts and consume the most resources in the livestock system.
Increasing studies have focused on various measures to reduce ammonia, greenhouse gas emissions, and resource depletion from ruminant production to consumption. This review offers supply- and demand-side management strategies to reduce the environmental impact of ruminant products and emphasizes the mitigation potential of coupling livestock production with cultivation and renewable energy.
On a global scale, more attention should be paid to the green-source trade and to strengthening global technology sharing. The success of these strategies depends on the cost effectiveness of technology, public policy, and financial support.
Future studies and practice should focus on global database development for sharing mitigation strategies, thus facilitating technology innovations and socioeconomic feasibility.

The role of seaweed as a potential dietary supplementation for enteric methane mitigation in ruminants: Challenges and opportunities. Min BR, Parker D, Augyte S, et al. Anim Nutr. 2021 Dec;7(4):1371-1387.

Seaweeds are macroalgae, which can be of many different morphologies, sizes, colors, and chemical profiles. They include brown, red, and green seaweeds. Brown seaweeds have been more investigated and exploited in comparison to other seaweed types for their use in animal feeding studies due to their large sizes and ease of harvesting.
Recent in vitro and in vivo studies suggest that plant secondary compound-containing seaweeds (e.g., halogenated compounds, phlorotannins, etc.) have the potential to mitigate enteric methane (CH₄) emissions from ruminants when added to the diets of beef and dairy cattle.
Red seaweeds including Asparagopsis are rich in crude protein and halogenated compounds compared to brown and green seaweeds. When halogenated-containing red seaweeds are used as the active ingredient in ruminant diets, bromoform concentration can be used as an indicator of anti-methanogenic properties. Phlorotannin-containing brown seaweed has also the potential to decrease CH₄production.
However, numerous studies examined the possible anti-methanogenic effects of marine seaweeds with inconsistent results. This work reviews existing data associated with seaweeds and in vitro and in vivo rumen fermentation, animal performance, and enteric CH₄emissions in ruminants.
Increased understanding of the seaweed supplementation related to rumen fermentation and its effect on animal performance and CH₄emissions in ruminants may lead to novel strategies aimed at reducing greenhouse gas emissions while improving animal productivity.

Atmospheric methane removal: a research agenda. Jackson RB, Abernethy S, Canadell JG, Zickfeld K, et al. Philos Trans A Math Phys Eng Sci. 2021 Nov 15;379(2210):20200454.

Atmospheric methane removal (e.g. in situmethane oxidation to carbon dioxide) may be needed to offset continued methane release and limit the global warming contribution of this potent greenhouse gas.
Because mitigating most anthropogenic emissions of methane is uncertain this century, and sudden methane releases from the Arctic or elsewhere cannot be excluded, technologies for methane removal or oxidation may be required.
Carbon dioxide removal has an increasingly well-established research agenda and technological foundation. No similar framework exists for methane removal and researchers believe that a research agenda for negative methane emissions-‘removal’ or atmospheric methane oxidation-is needed.
The researchers outline some considerations for such an agenda here, including a proposed Methane Removal Model Intercomparison Project (MR-MIP).

Regional trends and drivers of the global methane budget. Stavert AR, Saunois M, Zhuang Q, et al. Glob Chang Biol. 2021. Online ahead of print.

The ongoing development of the Global Carbon Project (GCP) global methane (CH₄) budget shows a continuation of increasing CH₄ emissions and CH₄ accumulation in the atmosphere during 2000-2017.
Here, researchers decompose the global budget into 19 regions (18 land and 1 oceanic) and five key source sectors to spatially attribute the observed global trends. A comparison of top-down (TD) (atmospheric and transport model-based) and bottom-up (BU) (inventory- and process model-based) CH₄emission estimates demonstrates robust temporal trends with CH₄ emissions increasing in 16 of the 19 regions.
Five regions-China, Southeast Asia, USA, South Asia, and Brazil-account for >40% of the global total emissions (their anthropogenic and natural sources together totaling >270 Tg CH₄yr^-1 in 2008-2017). Two of these regions, China and South Asia, emit predominantly anthropogenic emissions (>75%) and together emit more than 25% of global anthropogenic emissions. China and the Middle East show the largest increases in total emission rates over the 2000 to 2017 period with regional emissions increasing by >20%.
In contrast, Europe and Korea and Japan show a steady decline in CH₄emission rates, with total emissions decreasing by ~10% between 2000 and 2017.
Coal mining, waste (predominantly solid waste disposal) and livestock (especially enteric fermentation) are dominant drivers of observed emissions increases while declines appear driven by a combination of waste and fossil emission reductions.
As such, together these sectors present the greatest risks of further increasing the atmospheric CH₄burden and the greatest opportunities for greenhouse gas abatement.

Greenhouse gas emissions of biosolid and cow manure during composting and vermicomposting and when applied to soil cultivated with wheat (Triticum sp. L.). Miranda-Carrazco A, Ramírez-Villanueva DA, Dendooven L. Environ Sci Pollut Res Int. 2021 Nov 27.

Biosolids are a by-product of wastewater treatment, and their nutritional composition makes them ideal for fertilizing crops. However, pre-treatments, such as conditioning and/or (vermi)composting, are often required to stabilize the product and remove pathogens.
In this study, biosolids from cow manure, and a 50-50% mixture were conditioned for 21 days, composted or vermicomposted with Eisenia fetida (Savigny 1826) for 28 days, and applied to soil cultivated with wheat (Triticum sp. L.).
Emissions of nitrous oxide (N₂O), methane (CH₄), and carbon dioxide (CO₂) were monitored.
Emissions of CH₄were large from the biosolid and N₂O from the cow manure during conditioning. Emissions of CH₄ remained high during (vermi)composting of the biosolids, while the emissions of N₂O from the cow manure dropped.
The addition of E. fetida did not affect the emissions of greenhouse gases during (vermi)composting. The emission of N₂O was higher when (vermi)composted biosolid was applied to soil cultivated with wheat than when (vermi)composted cow manure was applied.
The global warming potential (GWP) of the sum of the emitted greenhouse gases (GHG) during conditioning, (vermi)composting, and when the final product was applied to soil was 3 times larger from the cow manure than from the biosolid, but mixing biosolid with cow manure eliminated that difference.
It was concluded that mixing biosolid with cow manure might be a simple way to reduce the GWP of the emitted GHG during storage, (vermi)composting, and when applied to soil.

Livestock manure spiked with the antibiotic tylosin significantly altered soil protist functional groups. Nguyen BT, Chen QL, He JZ, Hu HW. J Hazard Mater. 2021 Nov 24:127867.

With the increasing global antibiotic uses in livestock husbandry, animal manures upon land application pose potential threats to the environments and soil microbiome. Nevertheless, effects of manures and antibiotic-administered manures on soil protists, an integral component of soil food web and primary regulators of bacteria, remain unknown.
Here, researchers assessed impacts of cattle and poultry manures with or without an antibiotic tylosin on soil protists and their functional groups in a 130-day microcosm incubation.
Protists were highly responsive to manure application, with a significant decline in their alpha diversity in all manure treatments. There were also significant temporal changes in the alpha diversity and composition of soil protists and their functional groups. Poultry manures had stronger negative influences on the community structure of protists compared to cattle manures, and more pronounced effects on protists were observed in tylosin-spiked manure treatments.
Furthermore, many consumer, phototrophic and parasitic taxa were highly susceptible to all manure treatments at Day 50 and 130. Altogether, our findings demonstrate negative effects of animal manures and tylosin on soil protists.
This study suggests that the applications of livestock manures and antibiotics may subsequently alter ecological functions of protists and their interactions with other soil microorganisms in agricultural systems.

Animal Health and Food Safety

Milk microbiome in dairy cattle and the challenges of low microbial biomass and exogenous contamination. Pollock J, Salter SJ, Nixon R, Hutchings MR. Anim Microbiome. 2021 Nov 18;3(1):80.

The blanket usage of antimicrobials at the end of lactation (or “drying off”) in dairy cattle is under increasing scrutiny due to concerns about antimicrobial resistance. To lower antimicrobial usage in dairy farming, farmers are now encouraged to use “selective dry cow therapy” whereby only cows viewed as at high risk of mastitis are administered antimicrobial agents.
It is important to gain a better understanding of how this practice affects the udder-associated microbiota and the potential knock-on effects on antimicrobial-resistant bacterial populations circulating on the farm. However, there are challenges associated with studying low biomass environments such as milk, due to known contamination effects on microbiome datasets.
In this study, researchers obtained milk samples from cattle at drying off and at calving to measure potential shifts in bacterial load and microbiota composition, with a critical assessment of contamination effects.
There was no significant difference in bacterial load between treatments (P > 0.05), but load was lower at calving than at drying off (P = 0.039). Escherichia coli counts by both sequence and culture data increased significantly in the presence of reduced bacterial load and a decreasing trend of microbiome richness and diversity.
The milk samples revealed diverse microbiomes not reflecting a typical infection profile and were largely comprised of gut- and skin-associated taxa, with the former decreasing somewhat after prolonged sealing of the teats.
In conclusion, the drying off period had a key influence on microbiota composition and bacterial load, which appeared to be independent of antimicrobial usage. The interactions between drying off treatment protocol and milk microbiome dynamics are clearly complex, and our evaluations of these interactions were restricted by low biomass samples and contamination effects.

Bedding system influences lying behavior in dairy cows. Leach KA, Charlton GL, Bradley AJ, et al. Vet Rec. 2021 Nov 21:e1066.

The nature and depth of bedding material have an important influence on cow lying behavior and comfort. Increasing use of recycled manure solids (RMS) as bedding led to an investigation of the influence of this material on cow lying behavior.
For this study, leg mounted accelerometers were used to estimate daily lying time and number and duration of lying bouts in four groups of 40 cows. Each group spent two 2-week periods on each of four bedding systems: deep sand, deep RMS, sawdust on mattresses and RMS on mattresses.
Total daily lying times were significantly shorter on both RMS treatments than on sawdust. Number of lying bouts per day was greater on sawdust than any other treatment, while lying bouts were 2.6 min longer on deep RMS and 9.3 min longer on sand, than on sawdust.
In conclusion,greater depth and apparent softness of bedding material does not necessarily result in longer total daily lying times. RMS may have some characteristics that reduce its attraction as a bedding material for cows. The influence of bedding system on number and duration of lying bouts and the resulting total lying time appear complex.

Assessing the microbiota of recycled bedding sand on a Wisconsin dairy farm. Pilch HE, Steinberger AJ, Czuprynski CJ, et al. J Anim Sci Biotechnol. 2021 Nov 11;12(1):114.

Sand is often considered the preferred bedding material for dairy cows as it is thought to have lower bacterial counts than organic bedding materials and cows bedded on sand experience fewer cases of lameness and disease. Sand can also be efficiently recycled and reused, making it cost-effective.
However, some studies have suggested that the residual organic material present in recycled sand can serve as a reservoir for commensal and pathogenic bacteria, although no studies have yet characterized the total bacterial community composition.
In this study, researchers sought to characterize the bacterial community composition of a Wisconsin dairy farm bedding sand recycling system and its dynamics across several stages of the recycling process during both summer and winter using 16S rRNA gene amplicon sequencing.
Bacterial community compositions of the sand recycling system differed by both seasons and stage. Summer samples had higher richness and distinct community compositions, relative to winter samples. In both summer and winter samples, the diversity of recycled sand decreased with time drying in the recycling room.
Compositionally, summer sand 14 d post-recycling was enriched in operational taxonomic units (OTUs) belonging to the genera Acinetobacter and Pseudomonas, relative to freshly washed sand and sand from cow pens. In contrast, no OTUs were found to be enriched in winter sand.
The sand recycling system contained an overall core microbiota of 141 OTUs representing 68.45% ± 10.33% SD of the total bacterial relative abundance at each sampled stage. The 4 most abundant genera in this core microbiota included Acinetobacter, Psychrobacter, Corynebacterium, and Pseudomonas.
Acinetobacter was present in greater abundance in summer samples, whereas Psychrobacter and Corynebacterium had higher relative abundances in winter samples. Pseudomonas had consistent relative abundances across both seasons.
These findings highlight the potential of recycled bedding sand as a bacterial reservoir that warrants further study.

Reducing milking frequency from twice to once daily as an adjunct treatment for ketosis in lactating dairy cows-A randomized controlled trial. Williamson M, Couto Serrenho R, Duffield TF, et al. J Dairy Sci. 2021 Nov 16:S0022-0302(21)01015-8.

This randomized controlled trial investigated the effects of temporarily reducing milking frequency on the resolution of ketosis and milk production in dairy cows in early lactation.
To detect ketosis [blood β-hydroxybutyrate (BHB) ≥1.2 mmol/L], Holstein cows were screened daily from 3 to 16 days in milk using a cow-side meter. Cows diagnosed with ketosis (n = 104) were randomly assigned to twice-daily milking or reduced to once-daily milking for 2 weeks, then returned to twice-daily milking.
Both treatment groups received a 5-day treatment of an oral propylene glycol drench (300 g) beginning on the afternoon of the diagnosis; cows received additional 5-day PG treatments if they had a ketotic test result (blood BHB ≥1.2 mmol/L) at least 4 d after finishing the first propylene glycol treatment.
Blood BHB tests were conducted for the first 3 days after ketosis diagnosis, and then once every 3 days for 21 days of trial. Milk and milk component data were collected weekly for 15 weeks following trial enrollment.
The ODM group showed rapidly and markedly decreased blood BHB concentrations. In addition, a logistic regression model indicated that once-daily milking cows were less likely to have blood BHB concentrations ≥1.2 mmol/L. The proportion of once-daily milking cows that required additional treatments of propylene glycol were substantially lower than the twice-daily milking group than the twice-daily milking cows during the initial 21-day period.
However, during the 2-week treatment period, cows in the once-daily milking group produced 26% less milk and 25% less energy-corrected milk than the twice-daily milking cows. During weeks 3 to 15, when all cows were milked twice daily, once-daily milking cows produced less milk (-14%) and energy-corrected milk (-12%) compared with the twice-daily milking group. Milk protein percentage was greater, and milk fat percentage and linear score tended to be greater in the once-daily milking group over 15 weeks.
In conclusion, a 2-week reduction of milking frequency in ketotic cows from twice to once daily with treatment with propylene glycol resolved ketosis and decreased blood BHB concentrations more effectively than treating twice-daily milking cows with propylene glycol alone. However, the 2-week milking frequency reduction had immediate and long-term (up to 13 weeks after cessation of milking frequency reduction) negative effects on milk production.

Reduction of the resistome risk from cow slurry and manure microbiomes to soil and vegetable microbiomes. Jauregi L, Epelde L, González A, Lavín JL, Garbisu C. Environ Microbiol. 2021 Nov 18.

In cow farms, the interaction between animal and environmental microbiomes creates hotspots for antibiotic resistance dissemination.
A shotgun metagenomic approach was used to survey the resistome risk in five dairy cow farms.
To this purpose, 10 environmental compartments were sampled: 3 of them linked to productive cows (fresh slurry, stored slurry, slurry-amended pasture soil); 6 of them to non-productive heifers and dry cows (feces, fresh manure, aged manure, aged manure-amended orchard soil, vegetables-lettuces and grazed soil); and, finally, unamended control soil.
The resistome risk was assessed using MetaCompare, a computational pipeline which scores the resistome risk according to possible links between antibiotic resistance genes (ARGs), mobile genetic elements (MGEs) and human pathogens.
The resistome risk decreased from slurry and manure microbiomes to soil and vegetable microbiomes. In total (sum of all the compartments), 18,157 ARGs were detected: 24% related to ansamycins, 21% to multidrugs, 14% to aminoglycosides, 12% to tetracyclines, 9% to β-lactams, and 9% to macrolide-lincosamide-streptogramin B.
All but two of the MGE-associated ARGs were only found in the animal dejections (not in soil or vegetable samples). Several ARGs with potential as resistome risk markers (based on their presence in hubs of co-occurrence networks and high dissemination potential) were identified.
As a precautionary principle, improved management of livestock dejections is necessary to minimize the risk of antibiotic resistance.

Human Nutrition and Health

Dairy Consumption and Total Cancer and Cancer-Specific Mortality: A Meta-Analysis of Prospective Cohort Studies. Jin S, Je Y. Adv Nutr. 2021 Nov 11:nmab135.

The association between dairy consumption and cancer mortality varies among studies and remains unclear. Thus, researchers conducted a comprehensive meta-analysis of prospective cohort studies to examine the association between dairy consumption and total cancer and cancer-specific mortality.
The researchers sought eligible studies in PubMed and Web of Science databases for all publications through March 2021, and pooled relative risks (RR) and 95% confidence intervals were calculated. They identified 34 prospective cohort studies including 3,171,186 participants and 88,545 deaths.
Compared with low milk consumption, high milk consumption was associated with higher cancer mortality in females (RR:1.10) and people consuming high/whole-fat milk (fat content ≥ 3.5%) (RR:1.17). Increased risks of cancer-specific mortality were detected for liver (RR:1.13), ovarian (RR:1.32), and prostate (RR:1.23) cancers.
Also, females with high consumption of fermented milk had a lower cancer mortality risk (RR:0.85). High cheese consumption was not associated with total cancer mortality, rather with higher colorectal cancer mortality (RR:1.22).
There was no association between butter (RR:1.06) or total dairy product consumption (RR:0.99) and cancer mortality.
These results imply that high milk consumption, especially high/whole-fat milk, was associated with higher cancer mortality, while fermented milk consumption was associated with lower cancer mortality, and this was particularly evident in females.

Association of dairy intake with all-cause, cancer, and cardiovascular disease mortality in Japanese adults: a 25-year population-based cohort. Lu Y, Sugawara Y, Matsuyama S, Fukao A, Tsuji I. Eur J Nutr. 2021 Nov 8.

The association between dairy intake and mortality remains uncertain, and evidence for the Japanese population is scarce.
Therefore, researchers aimed to investigate the association between dairy intake and all-cause, cancer, and cardiovascular disease (CVD) mortality in Japanese adults.
A total of 34,161 participants (16,565 men and 17,596 women) aged 40-64 years without a history of cancer, myocardial infarction, or stroke at baseline were included in the analysis, using data from the Miyagi Cohort Study initiated in 1990. The outcomes were all-cause, cancer, and CVD mortality.
During 750,016 person-years of follow-up, the total number of deaths was 6498, including 2552 deaths due to cancer and 1693 deaths due to CVD.
There was no association between total dairy intake and all-cause, cancer, and CVD mortality for both men and women.
The researchers also examined the associations between subgroup dairy products and mortality. For milk and yogurt intake, the results suggest null associations. However, cheese intake was modestly associated with lower all-cause mortality in women; compared with non-consumers.
In this study, dairy intake was not associated with mortality in Japanese adults, except for limited evidence showing a modest association between cheese intake and a lower all-cause mortality risk in women.

Animal protein intake is inversely associated with mortality in older adults: the InCHIANTI study. Meroño T, Zamora-Ros R, Andres-Lacueva C, et al. J Gerontol A Biol Sci Med Sci. 2021 Nov 27:glab334.

In general, plant protein intake has been shown to be inversely associated with mortality in studies in middle-aged adults.
The aim of this study was to evaluate the long-term associations of animal and plant protein intake with mortality in older adults.
A prospective cohort study including 1,139 community-dwelling older adults (mean age 75 years, 56% women) living in Tuscany, Italy, followed for 20 years (InCHIANTI study) was analyzed.
During the 20-years of follow up, 811 deaths occurred (292 of cardiovascular- and 151 of cancer-related causes). Animal protein intake was inversely associated with all-cause (HR per 1% of total energy from protein increase) and cardiovascular mortality (HR per 1% of total energy from protein increase).
Plant protein intake showed no association with any of the mortality outcomes, but an interaction with baseline hypertension was found for all-cause and cardiovascular mortality (p<0.05).
In conclusion,animal protein was inversely associated with all-cause and cardiovascular mortality in older adults. Further studies are needed to provide recommendations on dietary protein intake for older adults.

Higher yogurt intake is associated with lower blood pressure in hypertensive individuals: Cross-sectional findings from the Maine-Syracuse Longitudinal study. Wade AT, Guenther BA, Ahmed FS, Elias MF. Int Dairy J. 2021 Nov;122:105159.

Associations between fermented dairy products and blood pressure are unclear.
The current study therefore examined the association between yogurt and blood pressure in hypertensive and non-hypertensive individuals.
Cross-sectional analyses were undertaken on 915 community-dwelling adults from the Maine-Syracuse Longitudinal Study. Habitual yogurt consumption was measured using a food frequency questionnaire. The primary outcomes were systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and pulse pressure. Secondary outcomes included BMI (kg m^-2), total cholesterol (mg dL^-1), glucose (mg dL^-1), HDL (mg dL^-1), LDL (mg dL^-1), triglycerides (mg dL^-1), and plasma homocysteine (μmol L^-1).
The analyses revealed significant inverse associations between yogurt and both SBP (p< 0.05) and MAP (p < 0.05) in hypertensive (n = 564) but not non-hypertensive participants (n = 351). Future observational and intervention studies should continue to focus on at-risk individuals to examine the potential benefits of yogurt.

Gut Microbiome Diversity and Composition Are Associated with Habitual Dairy Intakes: A Cross-Sectional Study in Men. Aslam H, Collier F, Loughman A, et al. J Nutr. 2021 Nov 2;151(11):3400-3412.

At a population level, the relation between dairy consumption and gut microbiome composition is poorly understood.
Therefore, researchers sought to study the cross-sectional associations between individual dairy foods (i.e., milk, yogurt, and cheese), as well as total dairy intake, and the gut microbiome composition in a large, representative sample of men living in south-eastern Australia.
Data on 474 men (mean ± SD: 64.5 ± 13.5 years old) from the Geelong Osteoporosis Study were used to assess the cross-sectional association between dairy consumption and gut microbiome. Men were categorized as consumers and nonconsumers of milk, yogurt, cheese, and high- and low-fat milk.
Milk, yogurt, and cheese intakes were summed to calculate the total dairy consumed per day and categorized into either low (<2.5 servings/d) or high (≥2.5 servings/d) total dairy groups. Fecal samples were analyzed using bacterial 16S ribosomal RNA (rRNA) gene sequencing. After assessment of α and β diversity, differential abundance analysis was performed to identify bacterial taxa associated with each of milk, yogurt, and cheese consumption compared with nonconsumption, low compared with high total dairy, and low- compared with high-fat milk consumption.
The results showed that α Diversity was not associated with consumption of any of the dairy groups. Differences in β diversity were observed between milk and yogurt consumption compared with nonconsumption. Taxa belonging to the genera Ruminococcaceae UCG-010 and Bifidobacterium showed negative and weak positive associations with milk consumption, respectively.
A taxon from the genus Streptococcus was positively associated with yogurt consumption, whereas a taxon from the genus Eisenbergiella was negatively associated with cheese consumption. No specific taxa were associated with low- compared with high-fat milk nor low compared with high total dairy consumption.
In men, community-level microbiome differences were observed between consumers and nonconsumers of milk and yogurt. Bacterial taxon-level associations were detected with milk, yogurt, and cheese consumption. Total dairy consumption was not associated with any microbiome measures, suggesting that individual dairy foods may have differential roles in shaping the gut microbiome in men.

Effects of Milkfat on the Gut Microbiome of Patients After Bariatric Surgery, a Pilot Study. O’Neill L, Pandya V, Phadtare S, et al. Obes Surg. 2021 Nov 19:1-9.

The efficacy of bariatric surgery may be in part attributed to altered metabolism via new gut microbiome. Milkfat may promote the growth of microbes that are beneficial in long-term weight loss. Understanding the specific gut microbiome changes after surgery and their relationship to milkfat consumption may yield important strategies for managing obesity after bariatric procedures.
In this pilot study, stool samples were collected from nine patients before and at the time of surgery, and at 1, 3, and 6 months post-surgery. At each time-point, dairy consumption was determined from dietary surveys. 16 s rRNA gene sequencing was performed followed by alpha diversity analysis. Comparisons of relative abundances of microbial taxa and analyses of fatty acids changes were performed.
Bariatric surgery led to enrichment of (i) Roseburia, associated with weight loss and (ii) Christensenellaceae, inversely related to body mass index. High milk-fat consumption correlated with enrichment of Blautia, inversely associated with visceral fat accumulation. Faecalibacterium, possibly associated with obesity, increased in patients with low milk-fat consumption.
Butter was associated with decreased alpha diversity in all subjects and the frequency of its use was associated with decreased alpha diversity in patients. Low-milk-fat consumers showed higher concentration of saturated fatty acids.
These results suggest that incorporating dairy products in post-bariatric-surgery dietary plans may help cultivate a gut microbiome that is effective in regulating fat storage as well as digesting beneficial metabolites. These observations will be helpful for the management of obesity in general population as well.

Innovation, Economics, and Dairy Alternatives

Consumer perception of ice cream and frozen desserts in the “better-for-you” category. Sipple LR, Racette CM, Schiano AN, Drake MA. J Dairy Sci. 2021 Nov 8:S0022-0302(21)01000-6.

The consumption of ice cream and frozen desserts in the “better-for-you” (BFY) category has grown rapidly over the past few years, even as traditional ice cream sales remain stagnant.
To better understand consumer preferences within the BFY category, an online survey (n = 1,051) was conducted with ice cream and frozen dessert consumers, followed by consumer acceptance testing of commercial BFY frozen dairy desserts.
Consumers of BFY frozen desserts (n = 578) completed an adaptive choice-based conjoint survey and MaxDiff exercise to identify the attributes that drive purchase of BFY frozen desserts. MaxDiff exercises were also used to determine which attributes all frozen dessert consumers (n = 1,051) perceived to make a frozen dessert BFY and which stabilizers or emulsifiers were most attractive on an ice cream or frozen dessert label.
Subsequently, a consumer acceptance test (n = 186) was conducted using 4 commercial vanilla-flavored frozen dairy desserts made with different sweetening systems (sugar, sucralose + acesulfame K, monk fruit + allulose, and stevia + erythritol).
Half of consumers were primed or informed with the sweeteners and basic nutritional information for the frozen desserts before tasting, and the other half of consumers evaluated samples blinded, where they were only informed that they were tasting a vanilla-flavored frozen dessert.
Sweetener type and base (dairy vs. plant) were the most important attributes to BFY consumers when selecting a BFY frozen dessert (n = 578). For all ice cream and BFY dessert consumers (n = 1,051), sweetener-related claims (naturally sweetened, reduced sugar, no added sugar), along with “all natural” and a short ingredient list, were the top attributes that contributed to perception of a “healthier” frozen dessert.
When BFY frozen desserts were tasted by consumers, purchase intent decreased after tasting, suggesting that frozen desserts made with natural non-nutritive sweeteners did not meet consumer expectations.
Flavor of BFY frozen desserts remains more important than perceived healthiness. Consumers perceive frozen desserts, even those in the BFY category, as an indulgence. Frozen dessert manufacturers should focus on naturally sweetened, dairy-based desserts with minimal sweetener-related flavor defects when designing products for the BFY category.

Individual dairy cow identification based on lightweight convolutional neural network. Li S, Fu L, Gong H, et al. PLoS One. 2021 Nov 29;16(11):e0260510.

In actual farms, individual livestock identification technology relies on large models with slow recognition speeds, which seriously restricts its practical application.
In this study, researchers uses deep learning to recognize the features of individual cows. Alexnet is used as a skeleton network for a lightweight convolutional neural network that can recognize individual cows in images with complex backgrounds.
The model is improved for multiple multiscale convolutions of Alexnet using the short-circuit connected BasicBlock to fit the desired values and avoid gradient disappearance or explosion. An improved inception module and attention mechanism are added to extract features at multiple scales to enhance the detection of feature points.
In experiments, side-view images of 13 cows were collected. The proposed method achieved 97.95% accuracy in cow identification with a single training time of only 6 seconds, which is one-sixth that of the original Alexnet. To verify the validity of the model, the dataset and experimental parameters were kept constant and compared with the results of Vgg16, Resnet50, Mobilnet V2 and GoogLenet. The proposed model ensured high accuracy while having the smallest parameter size of 6.51 MB, which is 1.3 times less than that of the Mobilnet V2 network, which is famous for its light weight.
This method overcomes the defects of traditional methods, which require artificial extraction of features, are often not robust enough, have slow recognition speeds, and require large numbers of parameters in the recognition model. The proposed method works with images with complex backgrounds, making it suitable for actual farming environments. It also provides a reference for the identification of individual cows in images with complex backgrounds.

Proposed Nutrient Standards for Plant-Based Beverages Intended as Milk Alternatives. Drewnowski A, Henry CJ, Dwyer JT. Front Nutr. 2021 Oct 20;8:761442.

Plant-based beverages (PBB) that are marketed as alternatives to cow milk are gaining in popularity worldwide. Nutrient quality of PBB can be highly variable.
The study’s objective was to develop a set of voluntary or mandatory nutrient standards for the PBB product category in order to assist innovation and guide product development and reformulation.
The present goal was to develop standards for PBB energy content, minimum protein content and quality, maximum content for added fat, sugar, and salt, and to suggest fortification levels for selected vitamins and minerals. The standards were based on dietary recommendations and guidelines and current practices of federal agencies in the US.
The proposed energy and nutrient content for PBB milk alternatives are maximum 85-100 kcal energy per 100 g; a minimum for 2.2/100 g of high-quality protein, low content of saturated fat (<0.75/100 g) and added sugar (5.3-6.25/100 g) and consistent fortification with calcium, vitamins A, D, B-2, and B-12 at levels comparable to those found in cow milk (1%). Ideally, the protein content ought to be increased (2.8/100 g) and added sugar content reduced even further (2.7-3.1/100 g) for “best of class” products.
These proposed standards were applied to the 641 existing PBB products listed in the 2018 version of the USDA Branded Food Products Database (BFPDB). The standards were met by <5% of the PBB on the US market.
In conclusion, although often viewed as equivalent to milk in nutritional value, many PBB are often low in protein and are fortified with varying amounts of calcium, and vitamins A and D. Nutrient standards for this category should be adopted by the food industry, by public health regulatory authorities, and by standardization bodies such as the Codex Alimentarius.

Nutritional Content and Health Profile of Non-Dairy Plant-Based Yogurt Alternatives. Craig WJ, Brothers CJ. Nutrients. 2021 Nov 14;13(11):4069.

Yogurt is considered a healthy, nutritious food in many cultures. With a significant number of people experiencing dairy intolerance, and support for a more sustainable diet, consumer demand for dairy alternatives has surged.
The aim of this study was to conduct a cross-sectional survey of plant-based yogurt alternatives to assess their nutritional content and health profile.
A total of 249 non-dairy yogurt alternatives were analyzed from the nutrition label listed on the commercial package. The various yogurt alternatives contained extracts of coconut (n= 79), almonds (n = 62), other nuts or seeds (n = 20), oats (n = 20), legumes (n = 16), and mixed blends (n = 52).
At least one-third of the yogurt alternatives had 5 g or more of protein/serving. Only 45% of the yogurt alternatives had calcium levels fortified to at least 10% of daily value (DV), while only about one in five had adequate vitamin D and B12 fortification at the 10% DV level.
One-half of the yogurt alternatives had high sugar levels, while 93% were low in sodium. Except for the coconut-based products, the yogurts were not high in fat or saturated fat. The yogurt alternatives were not fortified as frequently or to the same levels as the corresponding non-dairy, plant-based beverages.

Vegan Alternatives to Processed Cheese and Yogurt Launched in the European Market during 2020: A Nutritional Challenge? Boukid F, Lamri M, Castellari M, et al. Foods. 2021 Nov 12;10(11):2782.

Vegan alternatives to cheese (VAC) and yogurt (VAY) are fast-growing markets in Europe due to the increasing interest in plant-based alternatives to dairy products.
This study aimed to take a closer look at the year 2020 and accordingly retrieved the nutritional information of dairy cheese and yogurt and their vegan counterparts for comparison.
It was found that VAY (n= 182) provide more energy, total fats, and carbohydrates than dairy yogurt (n = 86), while saturated fatty acids (SFAs), sugars, and salt were not different between the two categories.
Compared to dairy products (25.6%), 72.9% of the alternative products were declared low/no/reduced allergen, hence providing a larger spectrum of products to respond to consumers’ requirements.
VAC (n= 114) showed high versatility of form compared to dairy (n = 115). Nutritionally, VAC have higher total fats, SFAs, and carbohydrates, but lower protein, salt, and sugar than dairy cheese.
Food developers will continue to look for clean label solutions to improve the nutritional values of vegan products through the incorporation of natural ingredients, besides enhancing their taste and texture to appeal to flexitarians.

Recent patent applications in beverages enriched with plant proteins. Arbach CT, Alves IA, de Carvalho da Costa J, et al. NPJ Sci Food. 2021 Nov 1;5(1):28.

Recently, many consumers have been adding plant-based beverages to their diets, due to different reasons. The addition of plant proteins to enrich these products in order to make them more nutritionally balanced has become a trend, mainly because of their lower prices and reduced environmental damage.
Thus, the aims of the present patent review are to discuss the potential of, and challenges posed by, plant proteins to the beverage industry, as well as to check market trends, focused on raw materials and beverage types.
Based on the results, pea, rapeseed, bean, peanut, chickpea, lentil, hempseed, sunflower seed, and cottonseed were among the most often addressed raw materials. Furthermore, this enrichment process is not limited to create products that mimic dairy, therefore expansion in plant proteins used to enrich carbonated beverages, sports drinks, or even juices is expected to happen.
Thus, plant-derived proteins have been promising to high-quality beverage production, as well as to ensure food security, animal welfare, and low environmental impacts.