Compiled and summarized by Kevin Comerford, Ph.D.

The Dairy Research Bulletin delivers a brief synopsis of the most current Human, Animal, and Environmental dairy research that is going on in the World, and also that which is of special interest to California dairy producers and consumers alike.

If you would like to peruse the most pertinent dairy research from months past, then visit the Dairy Research Bulletin Archive.


Environmental Management and Sustainability

Role of dairy and alternative plant products in a healthy and sustainable diet. Mena Sánchez G, Mogas B, Souza S. Nutr Hosp. 2021 Jul 29.

  • Dairy products and plant alternatives are two food groups that are part of popular diets. Both have a very different nutritional composition – unlike plant products, the high nutritional density of dairy products makes it easier to meet nutrient requirements at different stages of life.
  • Although the environmental impact of dairy production is greater than that of plant-based products, it falls below that of other food groups such as red meat, including pork and beef. Dairy and plant alternatives meet critical points of the sustainable diet definition, and several food guides from countries around the world are including them within healthy and sustainable eating patterns.
  • For this reason, it is necessary to clarify that both products can be part of a healthy and sustainable diet, although they belong to different food groups, which are not interchangeable and should not be used alternatively.

Carbon myopia: the urgent need for integrated social, economic and environmental action in the livestock sector. Harrison MT, Cullen BR, Mayberry DE, Cowie AL, Bilotto F, Brabazon Badgery W, Liu K, Davison T, Christie KM, Muleke A, Eckard RJ. Glob Chang Biol. 2021 Jul 27.

  • Livestock have long been integral to food production systems, often not by choice but by need. While our knowledge of livestock greenhouse gas emissions (GHG) mitigation has evolved, the prevailing focus has been – somewhat myopically – on technology applications associated with mitigation.
  • The objectives of this work are 3-fold:
    1. To examine the global distribution of livestock GHG emissions
    2. To explore social, economic, and environmental co-benefits and trade-offs associated with mitigation interventions
    3. To critique approaches for quantifying GHG emissions
  • This review uncovered many insights. First, while GHG emissions from ruminant livestock are greatest in low and middle-income countries (LMIC; globally, 66% of emissions are produced by Latin America and the Caribbean, East and southeast Asia, and south Asia), the majority of mitigation strategies are designed for developed countries. This serious concern is heightened by the fact that 80% of growth in global meat production over the next decade will occur in LMIC.
  • Second, few studies concurrently assess social, economic and environmental aspects of mitigation. Of the 54 interventions reviewed, only 16 had triple-bottom line benefit with medium-high mitigation potential.
  • Third, while efforts designed to stimulate adoption of strategies allowing both emissions reduction and carbon sequestration would achieve the greatest net emissions mitigation, carbon sequestration measures have greater potential mitigation and co-benefits.
  • The scientific community must shift attention away from the prevailing myopic lens on carbon, towards more holistic, systems-based, multi-metric approaches that carefully consider the raison d’être for livestock systems. Consequential life-cycle assessments and systems-aligned ‘socio-economic planetary boundaries’ offer useful starting points that may uncover leverage points and cross-scale emergent properties.
  • Derivation of harmonized, globally-reconciled sustainability metrics requires iterative dialogue between stakeholders at all levels. Greater emphasis on the simultaneous characterization of multiple sustainability dimensions would help avoid situations where progress made in one area causes maladaptive outcomes in other areas.

Review: Genetic selection of high-yielding dairy cattle toward sustainable farming systems in a rapidly changing world. Brito LF, Bedere N, Douhard F, Oliveira HR, Arnal M, Peñagaricano F, Schinckel AP, Baes CF, Miglior F. Animal. 2021 Jul 19:100292.

  • The massive improvement in food production, as a result of effective genetic selection combined with advancements in farming practices, has been one of the greatest achievements of modern agriculture. For instance, the dairy cattle industry has more than doubled milk production over the past five decades, while the total number of cows has been reduced dramatically.
  • This was achieved mainly through the intensification of production systems, direct genetic selection for milk yield and a limited number of related traits, and the use of modern technologies (e.g., artificial insemination and genomic selection).
  • Despite the great betterment in production efficiency, strong drawbacks have occurred along the way. First, across-breed genetic diversity reduced dramatically, with the worldwide use of few common dairy breeds, as well as a substantial reduction in within-breed genetic diversity. Intensive selection for milk yield has also resulted in unfavorable genetic responses for traits related to fertility, health, longevity, and environmental sensitivity.
  • Moving forward, the dairy industry needs to continue refining the current selection indexes and breeding goals to put greater emphasis on traits related to animal welfare, health, longevity, environmental efficiency (e.g., methane emission and feed efficiency), and overall resilience.
  • The long-term sustainability of the dairy cattle industry will also require diversification of production systems, with greater investments in the development of genetic resources that are resilient to perturbations occurring in specific farming systems with lesser control over the environment (e.g., organic, agroecological, and pasture-based, mountain-grazing farming systems).
  • The conservation, genetic improvement, and use of local breeds should be integrated into the modern dairy cattle industry and greater care should be taken to avoid further genetic diversity losses in dairy cattle populations.

A meta-analysis of effects of dietary seaweed on beef and dairy cattle performance and methane yield. Lean IJ, Golder HM, Grant TMD, Moate PJ. PLoS One. 2021 Jul 12;16(7):e0249053.

  • There has been considerable interest in the use of red seaweed, and in particular Asparagopsis taxiformis, to increase production of cattle and to reduce greenhouse gas emissions.
  • Researchers hypothesized that feeding seaweed or seaweed derived products would increase beef or dairy cattle performance as indicated by average daily gain (ADG), feed efficiency measures, milk production, and milk constituents, and reduce methane emissions.
  • The researchers used meta-analytical methods to evaluate these hypotheses. A comprehensive search of Google Scholar, Pubmed and ISI Web of Science produced 14 experiments from which 23 comparisons of treatment effects could be evaluated.
  • Red seaweed (Asparagopsis taxiformis) and brown seaweed (Ascophyllum nodosum) were the dominant seaweeds used. There were no effects of treatment on ADG or dry matter intake (DMI). The type of seaweed used was not a significant covariable for ADG and DMI, but A. nodosum fed cattle had lesser feed to gains efficiency compared to those fed A. taxiformis.
  • Milk production was slightly increased with treatment. Extremely limited data suggest the possibility of increased percentages of milk fat and milk protein. The limited data available indicate dietary supplementation with seaweed produced a significant and substantial reduction in methane yield by 5.28 ± 3.5 g/kg DMI. In one comparison, methane yield was reduced by 97%.
  • The researchers conclude that while there was evidence of potential for benefit from seaweed use to improve production and reduce methane yield more in vivo experiments are required to strengthen the evidence of effect and identify sources of heterogeneity in methane response.


Animal Health and Food Safety

2018 Survey of factors associated with antimicrobial drug use and stewardship practices in adult cows on conventional California dairies: immediate post-Senate Bill 27 impact. Ekong PS, Abdelfattah EM, Okello E, Williams DR, Lehenbauer TW, Karle BM, Rowe JD, Aly SS. PeerJ. 2021 Jul 13;9:e11596.

  • Antimicrobial drugs are critical for the treatment, control, and prevention of diseases in humans and food-animals. Good antimicrobial drug stewardship practices and judicious use of antimicrobial drugs are beneficial to the preservation of animal and human health from antimicrobial resistance threat.
  • This study reports on changes in antimicrobial drugs use and stewardship practices on California (CA) dairies, following the implementation of CA Senate Bill 27 (SB 27; codified as Food and Agricultural Code, FAC 14400-14408; here onward referred to as SB 27), by modeling the associations between management practices on CA conventional dairies and seven outcome variables relating to antimicrobial drug use and stewardship practices following SB 27.
  • A survey questionnaire was mailed to 1,282 grade A licensed dairies in CA in spring of 2018. Responses from 132 conventional dairies from 16 counties were included for analyses. The researchers employed machine learning classification models to determine which of the survey factors were the most important predictors of good-excellent antimicrobial drug stewardship practices of CA conventional dairy producers.
  • Having a valid veterinary-client-patient-relationship, involving a veterinarian in training employees on treatment protocols and decisions on antimicrobial drugs used to treat sick cows, tracking milk and/or meat withdrawal intervals for treated cows, and participating in dairy quality assurance programs were positively associated with producers’ familiarity with medically-important antimicrobial drugs.
  • Important variables associated with good-excellent antimicrobial drugs stewardship knowledge by CA conventional dairy producers included having written or computerized animal health protocols, keeping a drug inventory log, awareness that use of medically-important antimicrobial drugs required a prescription following implementation of SB 27, involving a veterinarian in antimicrobial drugs treatment duration determination, and using selective dry cow treatment.
  • This study identified management factors associated with reported antimicrobial drug use and antimicrobial stewardship practices on conventional dairies in CA within a year from implementation of SB 27. Producers will benefit from extension outreach efforts that incorporate the findings of this survey by further highlighting the significance of these management practices and encouraging those that are associated with judicious antimicrobial drug use and stewardship practices on CA conventional dairies.

Review: Livestock disease resilience: From individual to herd level. Doeschl-Wilson A, Knap PW, Opriessnig T, More SJ. Animal. 2021 Jul 23:100286.

  • Infectious diseases are a major threat to the sustainable production of high-producing animals. Control efforts, such as vaccination or breeding approaches often target improvements to individual resilience to infections, i.e., they strengthen an animal’s ability to cope with infection, rather than preventing infection per se.
  • There is increasing evidence for the contribution of non-clinical carriers (animals that become infected and are infectious but do not develop clinical signs) to the overall health and production of livestock populations for a wide range of infectious diseases.
  • Therefore, researchers strongly advocate a shift of focus from increasing the disease resilience of individual animals to herd disease resilience as the appropriate target for sustainable disease control in livestock. Herd disease resilience not only captures the direct effects of vaccination or host genetics on the health and production performance of individuals but also the indirect effects on the environmental pathogen load that herd members are exposed to.
  • For diseases primarily caused by infectious pathogens shed by herd members, these indirect effects on herd resilience are mediated both by individual susceptibility to infection and by characteristics (magnitude of infectiousness, duration of infectious period) that influence pathogen shedding from infected individuals.
  • This paper reviews what is currently known about how vaccination and selective breeding affect herd disease resilience and its underlying components, and outline the changes required for improvement. To this purpose, the authors also seek to clarify and harmonize the terminology used in the different animal science disciplines to facilitate future collaborative approaches to infectious disease control in livestock.

Review: Perspective on high-performing dairy cows and herds. Britt JH, Cushman RA, Dechow CD, Stevenson JS, et al. Animal. 2021 Jul 12:100298.

  • Milk and dairy products provide highly sustainable concentrations of essential amino acids and other required nutrients for humans; however, amount of milk currently produced per dairy cow globally is inadequate to meet future needs.
  • Higher performing dairy cows and herds produce more milk with less environmental impact per kg than lower performing cows and herds. In 2018, 15.4% of the world’s dairy cows produced 45.4% of the world’s dairy cow milk, reflecting the global contribution of high-performing cows and herds.
  • In high-performing herds, genomic evaluations are utilized for multiple trait selection, welfare is monitored by remote sensing, rations are formulated at micronutrient levels, health care is focused on prevention and reproduction is managed with precision. Higher performing herds require more inputs and generate more waste products per cow, thus innovations in environmental management on such farms are essential for lowering environmental impacts.
  • The focus of this review paper is to provide perspectives on technologies and practices that contribute most to sustainable production of milk from high-performing dairy cows and herds.

Both sampling seasonality and geographic origin contribute significantly to variations in raw milk microbiota, but sampling seasonality is the more determining factor.
 Guo X, Yu Z, Zhao F, Sun Z, Kwok LY, Li S. J Dairy Sci. 2021 Jul 9:S0022-0302(21)00731-1.

  • Accurately profiling and characterizing factors shaping raw milk microbiota would provide practical information for detecting microbial contamination and unusual changes in milk.
  • The current work was an observational study aiming to profile the microbiota of raw milk collected across wide geographic regions in China in different seasons and to investigate the contribution of geographical, seasonal, and environmental factors in shaping the raw milk microbiota.
  • A total of 355 raw cow milk samples from healthy Holsteins and 41 environmental samples (farm soil and surface of milking room floor) were collected from 5 dairy farms in 5 Chinese provinces in January, May, and September 2018.
  • The results showed that both seasonality and sampling region were significant factors influencing the milk microbiota; however, the raw milk microbiota was highly diverse according to seasonality, and sampling region was the less determining factor.
  • The wide variation in raw milk microbial communities between samples made it difficult to define a representative species-level core milk microbiota. Nevertheless, 3 most universal milk-associated species were identified: Lactococcus lactis, Enhydrobacter aerosaccus, and Acinetobacter lwoffii, which were consistently detected in 99%, 95%, and 94% of all analyzed milk samples, respectively (n = 355).
  • Unlike the milk microbiota, the environmental microbiota did not exhibit obvious pattern of seasonal or geographic variation. However, this study was limited by the relatively low number and types of environmental samples, making it statistically not meaningful to perform further correlation analysis between the milk and environmental microbiota. Nevertheless, this study generated novel information on raw milk microbiota across wide geographic regions of China and found that seasonality was more significant in shaping the raw milk microbiota compared with geographic origin.

Invited review: The welfare of dairy cattle housed in tiestalls compared to less-restrictive housing types: A systematic review.
 Beaver A, Weary DM, von Keyserlingk MAG. J Dairy Sci. 2021 Jul 9:S0022-0302(21)00717-7.

  • Many dairy cattle worldwide are housed in tiestalls, meaning that they are tethered by the neck to individual stalls. On some farms, tied cattle are permitted seasonal access to pasture, but otherwise their movements are restricted compared with cows housed in freestall barns or other loose housing systems.
  • The aim of this systematic review is to summarize the scientific literature pertaining the welfare of tied dairy cattle through comparison with less-restrictive housing systems. Articles identified by PubMed and Web of Science underwent a 5-phase screening process, resulting in the inclusion of 102 papers. These papers addressed measures of welfare related to affective state, natural behavior, and health (with the lattermost category subdivided into hoof and leg disorders, lameness, mastitis, transition disease, and other diseases or conditions).
  • Health was the most researched topic (discussed in 86% of articles); only 19% and 14% of studies addressed natural behavior and affective state, respectively. The review highlights different health benefits for tethered and loose cattle. For example, tied cattle experience reduced prevalence of white line disease and digital dermatitis, whereas loose cattle experience fewer leg lesions and injuries.
  • The prevalence of mastitis, transition diseases, and other conditions did not differ consistently across housing types. The researchers found that the expression of certain natural behaviors, particularly those associated with lying down (e.g., time spent kneeling, unfulfilled intentions to lie down), were impaired in tiestalls.

Evaluation of biomarkers of heat stress using automatic health monitoring system in dairy cows. Antanaitis R, Urbutis M, Juozaitienė V, Malašauskienė D, Televičius M. Pol J Vet Sci. 2021;24(2):253-260.

  • The aim of this study was to evaluate biomarkers of heat stress from an automatic milking system (AMS), the relationships between measurements of the temperature-humidity index, reticulorumen pH and temperature, and some automatic milking systems parameters in dairy cows (rumination time, milk traits, body weight and consumption of concentrate) during the summer period.
  • Lithuanian Black and White dairy cows (n=365) were selected. The cows were milked with Lely Astronaut® A3 milking robots with free traffic. Biomarkers were collected from the Lely T4C management program for analysis.
  • According to this study, during heat stress, the higher temperature-humidity index positively correlates with milk lactose, which increases the risk of mastitis and decreases consumption of concentrate, rumination time, body weight, and milk yield, reticulorumen pH, and milk fat:protein ratio.
  • Some biomarkers of heat stress can be milk yield, milk lactose, somatic cell count, concentrate intake, rumination time, body weight, reticulorumen pH, and milk fat:protein ratio. The researchers recommend monitoring these parameters in the herd management program to identify the possibility of heat stress.

Stable fly activity is associated with dairy management practices and seasonal weather conditions. El Ashmawy WR, Abdelfattah EM, Williams DR, Gerry AC, Rossow HA, Lehenbauer TW, Aly SS. PLoS One. 2021 Jul 28;16(7):e0253946.

  • Stable flies (Stomoxys calcitrans) are blood-sucking insects commonly associated with cattle production systems worldwide and are known to cause severe irritation to cattle due to painful bites. Cattle react to biting stable flies with an aggregating behavior known as bunching. Bunching behavior reduces grazing or feed consumption and thus reduces cattle productivity and welfare. Cattle’s fly-repelling behaviors include foot stomping, head tossing, tail switching and skin twitching.
  • The study objectives were to estimate the association between environmental factors and dairy characteristics including facility design, feed and manure management, total mixed ration (TMR) components fed to cattle, and operational pest management procedures and the outcome stable fly activity on California dairies.
  • A longitudinal study was conducted in 2017 on 20 California dairies (average lactating herd size = 2,466) during the stable fly season from April to July. Stable fly activity was measured by counting stable flies on cow forelimbs (leg count) and on Alsynite traps (trap count) over the 13-week study period.
  • Leg counts were higher during the afternoon compared to morning. Ambient temperatures ≤30⁰C and relative humidity measurements <50% were associated with higher leg and trap counts. Traps located at the periphery of study dairies had higher stable fly counts compared to traps located in the interior of the dairy. Cow pens with trees on the periphery had higher leg counts in comparison to pens away from trees.
  • Specific TMR components were associated with both leg and trap counts. Dairies feeding by-products including almond hulls, wet distillers’ grain, fruits, and vegetables had higher trap counts compared to dairies that did not feed these ingredients.
  • At the pen level, pens with rations that contained straw had lower average leg counts compared to pens fed with rations that did not contain straw. Dairies that applied insecticides for fly control to their entire facility had lower trap counts compared to dairies that did not apply insecticides.
  • Stable fly activity measured on California dairies using leg and trap counts varied according to the month, environmental factors, pen surroundings, trap location, TMR components, and insecticide use.


Human Nutrition and Health

Theoretical substitutions between dairy products and all-cause and cause-specific mortality. Results from the Danish diet, cancer and health cohort. Laursen ASD, Thomsen AL, Beck A, Overvad K, Jakobsen MU. Br J Nutr. 2021 Jul 22:1-10.

  • A daily intake of dairy products is recommended in many countries in order to maintain optimal health throughout life. However, evidence regarding the association between intake of individual dairy products and mortality is limited.
  • Researchers therefore explored associations between intake of different dairy products and all-cause and cause-specific mortality using specified theoretical substitution analyses.
  • The researchers analyzed data from 55,775 Danish men and women aged 50-64 years between 1993 and 1997.
  • During a median follow-up of 19 years, 11.586 participants died. For all-cause mortality, the researchers observed that the intake of low-fat milk, whole-fat milk or low-fat yogurt products in place of cheese was associated with a higher rate of death (hazard ratios between 1·03 and 1·12 per serving/d substituted). The same pattern was present for CVD mortality.
  • For cancer mortality, whole-fat milk and low-fat yogurt products in place of cheese were also associated with a higher rate of death for men while for women, whole-fat milk in place of buttermilk was associated with a higher cancer mortality rate.
  • These results suggest that intake of low-fat milk, whole-fat milk or low-fat yogurt products in place of cheese is associated with a higher rate of all-cause and cause-specific mortality.

Impact of low-fat and full-fat dairy foods on fasting lipid profile and blood pressure: exploratory endpoints of a randomized controlled trial. Schmidt KA, Cromer G, Kratz M, et al. Am J Clin Nutr. 2021 Jul 13:nqab131

  • Dietary guidelines traditionally recommend low-fat dairy because dairy’s high saturated fat content is thought to promote cardiovascular disease (CVD). However, emerging evidence indicates that dairy fat may not negatively impact CVD risk factors when consumed in foods with a complex matrix.
  • The aim of this study was to compare the effects of diets limited in dairy or rich in either low-fat or full-fat dairy on CVD risk factors.
  • In this randomized controlled trial, 72 participants with metabolic syndrome completed a 4-week run-in period, limiting their dairy intake to ≤3 servings/week of nonfat milk. Participants were then randomly assigned to 1 of 3 diets, either continuing the limited-dairy diet or switching to a diet containing 3.3 servings/day of either low-fat or full-fat milk, yogurt, and cheese for 12 weeks.
  • In the per-protocol analysis (n = 66), there was no intervention effect on fasting serum total, LDL, and HDL cholesterol; triglycerides; free fatty acids; or cholesterol content in 38 isolated plasma lipoprotein fractions. There was also no intervention effect on diastolic blood pressure, but a significant intervention effect for systolic blood pressure, with a trend for a decrease in the low-fat dairy diet (-1.6 ± 8.6 mm Hg) compared with the limited-dairy diet (+2.5 ± 8.2 mm Hg).
  • In men and women with metabolic syndrome, a diet rich in full-fat dairy had no effects on fasting lipid profile or blood pressure compared with diets limited in dairy or rich in low-fat dairy. Therefore, dairy fat, when consumed as part of complex whole foods, does not adversely impact these classic CVD risk factors.

Dairy product consumption and incident prediabetes in Dutch middle-aged adults: the Hoorn Studies prospective cohort. Slurink IAL, den Braver NR, Soedamah-Muthu SS, et al. Eur J Nutr. 2021 Jul 10.

  • The aim of this study was to investigate prospective associations of consumption of total dairy and dairy types with incident prediabetes in a Dutch population-based study.
  • Two enrollment waves of the Hoorn Studies were harmonized, resulting in an analytic sample of 2262 participants without (pre-) diabetes at enrollment.
  • During 6.4 years of follow-up, 810 participants (35.9%) developed prediabetes. High fat fermented dairy, cheese and high fat cheese were associated with a 17%, 14% and 21% lower risk of incident prediabetes, respectively, in top compared to bottom quartiles.
  • High fat cheese consumption was continuously associated with lower prediabetes risk. Total dairy and other dairy types were not associated with prediabetes risk in adjusted models, irrespective of fat content. Replacing high fat cheese with alternative dairy types was not associated with prediabetes risk.
  • The highest intake of high fat fermented dairy, cheese and high fat cheese were associated with a lower risk of prediabetes, whereas other dairy types were not associated. Cheese seems to be inversely associated with type 2 diabetes risk, despite high levels of saturated fatty acids and sodium.

Association between milk and yogurt intake and mortality: a community-based cohort study (Yamagata study). Nakanishi A, Homma E, Osaki T, Sho R, Souri M, Sato H, Watanabe M, Ishizawa K, Ueno Y, Kayama T, Konta T. BMC Nutr. 2021 Jul 14;7(1):33.

  • Dairy products are known as health-promoting foods. This study prospectively examined the association between milk and yogurt intake and mortality in a community-based population.
  • The study population comprised of 14,264 subjects aged 40-74 years who participated in an annual health checkup. The frequency of yogurt and milk intake was categorized as none (< 1/month), low (< 1/week), moderate (1-6/week), and high (> 1/day) intake.
  • During the follow-up period, there were 265 total deaths, 40 cardiovascular deaths and 90 cancer-related deaths. The analysis showed that the total mortality in high/moderate/low yogurt intake and moderate/low milk intake groups was lower than that in ‘none’ group. The hazard ratio (HR) for total mortality significantly decreased in high/moderate yogurt intake group (38% lower for high intake, 30% lower for moderate intake) and moderate milk intake group (33% lower) compared with the ‘none yogurt and milk’ intake groups. A similar association was observed for cancer-related mortality, but not for cardiovascular mortality.
  • The study showed that yogurt and milk intake was independently associated with a decrease in total and cancer-related mortalities in the Japanese population.

[Importance of nutrition for immune defense. The role of milk and its natural components]. Bermejo López LM, Aparicio Vizuete A, Loria Kohen V, López Sobaler AM, Ortega RM. Nutr Hosp. 2021 Jul 28.

  • The immune system is a complex and integrated system whose main function is to protect the body from external aggression by microorganisms, allergens, or toxic agents. Different studies show that maintaining optimal amounts of different nutrients in the body is essential to ensure the synthesis of different factors related to the immune system.
  • Most interesting nutrients and bioactive compounds include: vitamins A, B6, B12, C, D, E, folic acid (B9) and biotin (B7); minerals such as zinc, iron, selenium, magnesium and copper; proteins (lactoferrin) and bioactive peptides; omega-3 fatty acids; and other nutrients and bioactive compounds such as fiber, polyphenols, carotenoids, probiotics, etc.
  • Following a varied and balanced diet, including the servings recommended by food guides for each food group, is essential to achieve nutrient requirements.
  • Food groups to which special attention should be paid are: fruits and vegetables (because of their high content in micronutrients and antioxidant compounds), fatty fish (because it contains omega-3 fatty acids), and dairy products (because this group contains a large amount of nutrients).
  • In particular, milk-especially enriched milk-contains many of the nutrients mentioned above. And their daily consumption, within a balanced diet, can help significantly cover their nutrient reference values.
  • Finally, it is important to consider enriched milks as a good dietary alternative to increase the intake of some important nutrients for the proper functioning of the immune system, most especially some of them such as vitamin D, since a large percentage of the population have nutritional deficiencies.

A systematic review and meta-analysis of observational studies on the association between animal protein sources and risk of rheumatoid arthritis. Asoudeh F, Jayedi A, Kavian Z, Ebrahimi-Mousavi S, Nielsen SM, Mohammadi H. Clin Nutr. 2021;5;40(7):4644-4652.

  • Rheumatoid arthritis (RA) is characterized by inflammation of the synovial tissues in the joints. The association between animal protein consumption and RA is unclear.
  • The aim of this study was to investigate the linear and nonlinear dose-response associations of animal-based dietary protein intake and risk of developing RA.
  • A systematic search of MEDLINE, Scopus and Embase was conducted up to October 2020. Observational studies that report risk estimates of RA for animal-based protein consumption were included.
  • Seven cohort studies (n = 457,554) with 3,545 incident cases and six case-control studies with 3,994 cases and 5,252 controls were identified. Highest compared with the lowest category of fish consumption was associated with an 11% lower risk of RA. Also, a 100 g/day increment in fish intake was associated with a 15% decreased risk of RA. Dose-response analysis showed a modest U-shaped association between fish consumption and incidence of RA, with the lowest risk at a fish intake of 20-30 g/day (Pnon-linearity= 0.04). We found no significant association between consumption of red meat, poultry or dairy and the risk of RA.
  • The present study revealed a significant reverse association between fish consumption and risk of RA. While it observed no association between red meat, dairy or poultry consumption and risk of RA.

The association between drought conditions and increased occupational psychosocial stress among U.S. farmers: An occupational cohort study. Berman JD, Ramirez MR, Bell JE, Bilotta R, Gerr F, Fethke NB. Sci Total Environ. 2021 Jul 24;798:149245.

  • Drought represents a globally relevant natural disaster linked to adverse health. Evidence has shown agricultural communities to be particularly susceptible to drought, but there is a limited understanding of how drought may impact occupational stress in farmers.
  • The researchers used repeated measures data collected in the Musculoskeletal Symptoms among Agricultural Workers Cohort study, including 498 Midwestern U.S. farmers surveyed with a Job Content Questionnaire (JCQ) at six-month intervals in 312 counties from 2012 through 2015.
  • The researchers evaluated associations between drought and psychological job demand and job decision latitude, the job strain components, and applied a stratified analysis to evaluate differences by participant sex, age, and geography.
  • During the growing season, the job strain ratio increased by 0.031 during drought conditions, an amount equivalent to a one-half standard deviation change compared to non-drought conditions. The association between drought and the job strain ratio was driven mostly by increases in the psychological job demand. No risk differences were observed by sex, age group, or geographic region.
  • These results suggest a previously unidentified association between drought and increased occupational psychosocial stress among farmers. With North American climate anticipated to become hotter and drier, these findings could provide important health effects data for federal drought early warning systems and mitigation plans.


Innovation, Economics, and Dairy Alternatives

Application of E-nose technology combined with artificial neural network to predict total bacterial count in milk. Yang Y, Wei L. J Dairy Sci. 2021 Jul 22:S0022-0302(21)00752-9.

  • Total bacterial count (TBC) is a widely accepted index for assessing microbial quality of milk, and cultivation-based methods are commonly used as standard methods for its measurement. However, these methods are laborious and time-consuming.
  • This study proposes a method combining E-nose technology and artificial neural network for rapid prediction of TBC in milk. The qualitative model generated an accuracy rate of 100% when identifying milk samples with high, medium, or low levels of TBC, on both the testing and validating subsets.
  • Predicted TBC values generated by the quantitative model demonstrated strong correlation with reference values. Mean relative difference between predicted and reference values of TBC were 1.1% and 0.4% on the testing and validating subsets involving 24 and 28 tested samples, respectively.
  • As low as ∼1 log cfu/mL of TBC present in tested samples were precisely predicted. Results of this study indicated that combination of E-nose technology and artificial neural network generated reliable predictions of TBC in milk.
  • The method proposed in this study was reliable, rapid, and cost efficient for assessing microbial quality milk, and thus would potentially have realistic application in dairy section.

Perspective: Identifying Ultra-Processed Plant-Based Milk Alternatives in the USDA Branded Food Products Database. Drewnowski A. Adv Nutr. 2021 Jul 21:nmab089.

  • This study explored the characteristics of plant-based beverages (PBBs) that are marketed as “milks” in the United States.
  • First, machine searches of product names and ingredients in the USDA Branded Food Products Database (BFPDB) yielded 641 nondairy PBBs that included almond, soy, coconut, cashew, other tree nut, flax/hemp, pea, and quinoa and rice “milks.”
  • The products varied in energy density and the majority of PBBs contained added salt (69%) and added sugar (53%). Scores on nutrient density metrics [Nutri-Score, Choices, and the Nutrient Rich Food index 7.3 (NRF7.3)] were higher for almond and pea products and lower for coconut PBBs, which contained saturated fat.
  • Ingredient lists were searched further for added flavors, stabilizers, or preservatives said to be characteristic of the NOVA food classification system’s ultra-processed group. Most PBBs (90.1%) and 95% of almond milks met the NOVA criteria for ultra-processed foods, because they were created from food components and contained multiple substances not used in normal cooking.
  • Replacing milk and dairy products with plant-based alternatives will necessarily involve the use of ultra-processed foods.

Life cycle assessment of animal-based foods and plant-based protein-rich alternatives: an environmental perspective. Detzel A, Krüger M, Busch M, Blanco-Gutiérrez I, Varela C, Manners R, Bez J, Zannini E. J Sci Food Agric. 2021 Jul 7.

  • In the European Union proteins for food are largely animal based, consisting of meat and dairy products. Almost all soy but also a larger part of pulses and cereals consumed in the European Union are used for animal nutrition.
  • While livestock is an important source of proteins, it also creates substantial environmental impacts. The food and feed system is closely linked to the planetary and health boundaries and a transformation to healthy diets will require substantial dietary shifts towards healthy foods, such as nuts, fruits, vegetables and legumes.
  • Extrudated vegetable meat alternatives consisting of protein combined with amaranth or buckwheat flour and a vegetable milk alternative made from lentil proteins were shown to have the potential to generate significantly less environmental impact than their animal-based counterparts in most of the environmental indicators examined, taking into account both functional units (mass and protein content).
  • The underlying field-to-fork life cycle assessment models include several variants for both plant and animal foods. The optimized plant-based foods show a clear potential for improvement in the environmental footprints.
  • Development of higher processed and therefore higher performing products is crucial for appealing to potential user groups beyond dedicated vegetarians and vegans and ultimately achieving market expansion.
  • The Protein2Food project showed that prototypes made from European-grown legumes and pseudocereals are a valuable source for high-quality protein foods, and despite being substantially processed they could help reduce the environmental impact of food consumption.