Here is some of the best Dairy Research from April! The 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


Selected Publications on Animal Health, Food Safety, and Sustainability

Invited review: Learning from the future – A vision for dairy farms and cows in 2067. Britt JH, Cushman RA, Dechow CD, Dobson H, Humblot P, Hutjens MF, Jones GA, Ruegg PS, Sheldon IM, Stevenson JS. J Dairy Sci. 2018 Feb 28. pii: S0022-0302(18)30181-4.

  • The worldwide population in 2067 will reach 10.4 billion with 81% residing in Africa or Asia. Arable land available for food production will decrease to 0.15 hectare per person. Temperature will increase in tropical and temperate zones, especially in the Northern Hemisphere, and this will push growing seasons and dairy farming away from arid areas and into more northern latitudes.
  • Dairy consumption will increase because it provides essential nutrients more efficiently than many other agricultural systems. Farm sizes will increase and there will be greater lateral integration of housing and management of dairy cattle of different ages and production stages. Dairy farming will become modernized in developing countries and milk production per cow will increase, doubling in countries with advanced dairying systems. Profitability of dairy farms will be the key to their sustainability.
  • Innovations in dairy facilities will improve the health of cows and permit expression of natural behaviors. Integrated sensors, robotics, and automation will replace much of the manual labor on farms. Managing the epigenome and microbiome will become part of routine herd management. Genetic improvements will include emphasis on the coding genome and associated noncoding epigenome of cattle, and on microbiomes of dairy cattle and farmsteads.
  • Herds will be viewed as superorganisms, and studies of herds as observational units will lead to improvements in productivity, health, and well-being of dairy cattle, and improve the agroecology and sustainability of dairy farms. Dairy farmers in 2067 will meet the world’s needs for essential nutrients by adopting technologies and practices that provide improved cow health and longevity, profitable dairy farms, and sustainable agriculture.

Climate Change and Implications for Prevention: California’s Efforts to Provide Leadership. Balmes JR. Ann Am Thorac Soc. 2018 Apr;15(Supplement_2):S114-S117.

  • The atmospheric concentration of carbon dioxide (CO2) and the temperature of the earth’s surface have been rising in parallel for decades, with the former recently reaching 400 parts per million, consistent with a 1.5°C increase in global warming.
  • Indicators of climate change are easily observable in many settings, including receding glaciers, rising sea levels, earlier spring vegetation blooms, tree lines shifting upward and pole-ward, and species moving into new, warmer habitats.
  • Climate change models predict that a “business as usual” approach, that is, no effort to control CO2 emissions from combustion of fossil fuels, will result in a more than 2°C increase in annual average surface temperature by approximately 2034. With atmospheric warming comes increased air pollution. Sources of greenhouse gases and climate-forcing aerosols (“black carbon”) are the same sources of air pollutants that harm health.
  • California has adopted robust climate change mitigation policies that are also designed to achieve public health co-benefits by improving air quality. These policies include advanced clean car standards, renewable energy, a sustainable communities strategy to limit suburban sprawl, a low carbon fuel standard, and energy efficiency.
  • A market-based mechanism to put a price on CO2 emissions is the cap-and-trade program that allows capped facilities to trade state-issued greenhouse gas emissions allowances. The “cap” limits total greenhouse gas emissions from all covered sources, and declines over time to progressively reduce emissions. An alternative approach is a carbon tax.
  • California’s leadership on air quality and climate change mitigation is increasingly important, given the efforts to slow or even reverse implementation of such policies at the U.S. national level.

Targeting Bacteria and Methanogens To Understand the Role of Residual Slurry as an Inoculant in Stored Liquid Dairy Manure. Habtewold J, Gordon R, Sokolov V, VanderZaag A, Wagner-Riddle C, Dunfield K. Appl Environ Microbiol. 2018 Mar 19;84(7). pii: e02830-17.

  • Methane is the major greenhouse gas emitted from stored liquid dairy manure. Residual slurry left after removal of stored manure from tanks has been implicated in increasing methane emissions in new storages, and well-adapted microbial communities in it are the drivers of the increase. Linking methane flux to the abundance, diversity, and activity of microbial communities in stored slurries with different levels of residual slurry can help to improve the mitigation strategy.
  • In this study, six pilot-scale outdoor storage tanks with (10% and 20%) and without residual slurry were filled (gradually or in batch) with fresh dairy manure, and methane and methanogenic and bacterial communities were studied during 120 days of storage.
  • Regardless of filling type, increased residual slurry levels resulted in higher abundance of methanogens and bacteria after 65 days of storage. However, stronger correlation between methanogen abundance and methane flux was observed in gradually filled tanks.
  • During peak flux of methane, Methanosarcina was the major player in methane production. The results suggest that increased levels of residual slurry have little impact on the dominant methanogenic or bacterial phylotypes, but large population sizes of these organisms may result in increased methane flux during the initial phases of storage.

Bovine herpes virus type-4 infection among postpartum dairy cows in California: risk factors and phylogenetic analysis. Areda D, Chigerwe M, Crossley B. Epidemiol Infect. 2018 Apr 10:1-9.

  • Bovine herpes virus type-4 (BoHV-4) is associated with persistent infections and diseases including abortion, metritis, pneumonia, diarrhea, vaginitis and mammary skin infection.
  • The aims of this study were to determine the prevalence and associated risk factors of BoHV-4 infection and describe the genetic characteristics and predominant genotypes of the virus in Yolo and Tulare counties, California.
  • One hundred and forty-eight post-partum cows were enrolled from 11 dairy farms. The prevalence of BoHV-4 infection was 22.3%, while post-partum metritis was 33.8%. Cows with post-partum metritis were 4.51 times more likely to test positive for BoHV-4 infection compared with those without post-partum metritis.
  • This study demonstrated a strong association of BoHV-4 with post-partum metritis, multiparity, and early stage of lactation, signifying the need for implementing proper management (isolating infected animals, minimizing stress, early treatment of bacterial infections and proper dietary supplies) to minimize exposure to the virus from uninfected cows as well as from the environment following reactivation and shedding.


Selected Articles on Dairy Intake and Human Health

Review: Dairy foods, red meat and processed meat in the diet: implications for health at key life stages. Givens DI. Animal. 2018 Apr 2:1-13.

  • Social and health care provision have led to substantial increases in life expectancy. The different life stages give rise to important nutritional challenges and recent reductions in milk consumption have led to sub-optimal intakes of calcium by teenage females in particular when bone growth is at its maximum and of iodine during pregnancy needed to ensure that supply/production of thyroid hormones to the fetus is adequate.
  • This review aims to examine the role of dairy foods and red meat at key life stages in terms of their ability to reduce or increase chronic disease risk.
  • Recent meta-analyses show no evidence of increased risk of cardiovascular diseases from high consumption of milk and dairy foods but increasing evidence of a reduction in the risk of type 2 diabetes associated with fermented dairy foods, yogurt in particular.
  • The recently updated reports from the World Cancer Research Fund International/American Institute for Cancer Research on the associations between dairy foods, red meat and processed meat and various cancers provide further confidence that total dairy products and milk, are associated with a reduced risk of colorectal cancer and high intakes of milk/dairy are not associated with increased risk of breast cancer.
  • Earlier evidence of a significant increase in the risk of colorectal cancer from consumption of red and particularly processed meat has been reinforced by the inclusion of more recent studies. It is essential that nutrition and health-related functionality of foods are included in evaluations of sustainable food production.

Dairy intake and risk of type 2 diabetes. Talaei M, Pan A, Yuan JM, Koh WP. Clin Nutr. 2018 Apr;37(2):712-718.

  • Dairy products contain many components with potential anti-diabetes effects, including calcium, vitamin D, magnesium, and whey protein. Asian populations generally tend to have lower dairy intake compared to Western populations. The effect of total dairy products, milk, and calcium intake on risk of type 2 diabetes (T2D) require further study, particularly in Chinese populations.
  • The present study was based on a prospective cohort of 63,257 Chinese men and women aged 45-74 years residing in Singapore.
  • Intake of dairy food was significantly associated with reduced T2D risk; compared with the lowest quartile. Daily drinkers of milk had a significant 12% reduction in T2D risk compared with non-drinkers. While dairy calcium was associated with a decreased risk of T2D, no association was found for non-dairy calcium.
  • In this large cohort study of Chinese adults, dairy product intake and daily milk consumption was associated with a statistically significant, although modest, decrease in risk of developing T2D, which may be independent of its calcium content.

Dairy product consumption and risk of colorectal cancer in an older Mediterranean population at high cardiovascular risk. PREvención con DIeta MEDiterránea Study Investigators. Int J Cancer. 2018 Apr 16.

  • Prospective studies have reported an inverse association between the consumption of total dairy products and milk and the risk of colorectal cancer (CRC). Nonetheless, there is little and inconsistent evidence regarding subtypes of dairy product and CRC risk.
  • The researchers assessed the associations between the consumption of total dairy products, their different subtypes and CRC risk in older Mediterranean individuals at high cardiovascular risk.
  • A comparison of the highest vs lowest intake groups showed that higher daily amounts of total dairy product and low-fat milk consumption were both associated with significantly lower risk of CRC when compared to lower intake.
  • No significant associations with other dairy products (whole-fat and low-fat dairy products; total, low-fat and whole-fat yogurt; cheese; total, low-fat and whole-fat milk; concentrated full-fat dairy products, sugar-enriched dairy products and fermented dairy products) were found.

Association of dairy intake with weight change in adolescents undergoing obesity treatment. Wrotniak BH, Georger L, Hill DL, Zemel BS, Stettler N. J Public Health (Oxf). 2018 Apr 5.

  • The role of dairy products in obesity treatment for adolescents is unclear. The study purpose was to assess the association between dairy intake and changes in BMI during adolescent obesity treatment.
  • In total, 91 adolescents were studied. Each serving of total dairy, unflavored milk, reduced fat, and low fat/fat-free products was associated with a decrease in BMI over 12 months. These associations were no longer significant after adjustment for other dietary and physical activity factors.
  • Intakes of total dairy, unflavored milk, reduced fat dairy and low fat/fat-free dairy products are associated with improved obesity treatment outcomes among adolescents. This could be due to co-occurring healthy lifestyle behaviors or to replacement of other food and beverages associated with obesity, such as sugar-sweetened beverages, by dairy products.

Effects of Daily Intake of Calcium and Vitamin D-Enriched Milk in Healthy Postmenopausal Women: A Randomized, Controlled, Double-Blind Nutritional Study. Reyes-Garcia R, Mendoza N, Palacios S, Salas N, Quesada-Charneco M, Garcia-Martin A, Fonolla J, Lara-Villoslada F, Muñoz-Torres M. J Womens Health (Larchmt). 2018 Apr 20.

  • Postmenopausal women are at increased risk of bone loss and cardiovascular events. Clinical studies in elderly women have shown that combined calcium and vitamin D supplementation can reduce the risk of fracture.
  • Researchers conducted a two-year randomized controlled study, including 500 healthy postmenopausal women to determine the effect of the daily intake of calcium and vitamin D-enriched milk on vitamin D, bone metabolism, and cardiovascular risk factors. Participants were assigned to 500 mL/day of skimmed milk to one of three groups:
    • Control: (120 mg/100 mL calcium, vitamin D3 30 UI/100 mL)
    • Group A: calcium and vitamin D (180 mg/100 mL and 120 UI/100 mL)
    • Group B: calcium and vitamin D (180 mg/100 mL and 120 UI/100 mL) and FOS (5 g/L).
  • After 24 months, vitamin D concentrations did not change in the control group, but increased in group A and group B. The researchers observed an increase in femoral neck bone mineral density and an improvement in fasting plasma glucose, HbA1c, total cholesterol, low-density lipoprotein cholesterol, and apolipoprotein B 100.
  • Daily intake of milk enriched with calcium and vitamin D in postmenopausal healthy women induces a significant improvement in vitamin D status, a significant increase in bone mineral density at femoral neck, and also favorable effects on glucose and lipid profile.

Randomized double-blind controlled clinical trial of the blood pressure-lowering effect of fermented milk with Lactococcus lactis: A pilot study. Beltrán-Barrientos LM, González-Córdova AF, Hernández-Mendoza A, Torres-Inguanzo EH, Astiazarán-García H, Esparza-Romero J, Vallejo-Cordoba B. J Dairy Sci. 2018 Apr;101(4):2819-2825.

  • Hypertension is a chronic degenerative disease that affects 1 billion people over the world and is a leading cause of death worldwide. In addition to pharmaceutical interventions, several foods have been identified that may help to reduce hypertension with milk and dairy products being some of the most widely studied.
  • In this study, the blood pressure-lowering effect of fermented milk with Lactococcus lactis NRRL B-50571 was evaluated in a double-blind randomized controlled clinical trial with prehypertensive subjects. Participants were randomized into 2 groups (n = 18 each group): one group treated with fermented milk with Lactococcus lactis NRRL B-50571 and a control group treated with artificially acidified milk.
  • Results revealed that after 5 weeks, systolic and diastolic blood pressure in the fermented milk group was lower than the control group. Additionally, triglyceride, total cholesterol, and low-density lipoprotein in blood serum were lower in the fermented milk group than in the control group.
  • Results demonstrated that daily consumption of fermented milk with Lactococcus lactis (NRRL B-50571) had a blood pressure-lowering effect on prehypertensive subjects. Regular consumption of this product may be used as a potential functional food.

Effect of whey protein supplementation on body composition changes in women: a systematic review and meta-analysis. Bergia RE 3rd, Hudson JL, Campbell WW. Nutr Rev. 2018 Apr 23.

  • A preponderance of evidence supports the beneficial effects of whey protein supplementation on body composition in men; however, there is currently insufficient evidence to make an equivalent claim in women.
  • This systematic review and meta-analysis assessed the effects of WP supplementation with or without energy restriction and resistance training on changes in body mass, lean mass, and fat mass in women.
  • Globally, whey protein supplementation increased lean mass while not influencing changes in fat mass relative to a non-whey protein control. The beneficial effect of whey protein on lean mass was lost when only studies with resistance training were included in the analysis.
  • The beneficial effect of whey protein on lean mass was more robust when only studies with an energy restriction component were included. There was no effect of whey protein on lean mass in studies without energy restriction.
  • Whey protein supplementation improves body composition by modestly increasing lean mass without influencing changes in fat mass. Body composition improvements from whey protein are more robust when combined with energy restriction.

Meat, eggs, full-fat dairy, and nutritional boogeymen: Does the way in which animals are raised affect health differently in humans? Haskins CP, Henderson G, Champ CE. Crit Rev Food Sci Nutr. 2018 Apr 19:1-23.

  • Food recommendations to improve cancer prevention are generally based on epidemiologic data and remain inconsistent. These epidemiologic studies, while controversial, have generally produced results that caution against the consumption of high-fat foods, including eggs, red meat, and full-fat dairy, such as butter and cheese. Yet, limited data exist assessing the quality of individual sources of these foods and the effect each has after its consumption.
  • This study set out to assess the impact sources of food within the same groups from animals raised differently on variables associated with health in human studies. Studies varied by animal, animal diet manipulation, food product, and overall design.
  • Significant differences were present between groups eating the same food (cheese, beef, eggs, and butter) from animals raised differently, including levels of: conjugated linoleic acid, omega-3 fatty acids (alpha linoleic acid, docosahexaenoic acid, and eicosapentaenoic acid), and inflammatory factors (triacylglycerol, interleukin-6, interleukin-8, tumor necrosis factor, and C-reactive protein).
  • This work highlights differences in human health markers after consumption of the same foods from animals raised differently. Overall, lipid levels remained relatively neutral, but significant changes in inflammatory and other serum markers and phospholipids were present. Future studies and dietary recommendations should consider how animals are raised, as this can produce different effects on health markers.