Hello and welcome to the September 2018 Dairy Research Bulletin! 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

Multidrug residues and antimicrobial resistance patterns in waste milk from dairy farms in Central California. Tempini PN, Aly SS, Karle BM, Pereira RV. J Dairy Sci. 2018 Sep;101(9):8110-8122.

  • Waste milk is a common source of feed for preweaned calves in US dairy farms. However, limited information is available about characteristics of this product, including concentration of drug residues and potential hazards from antibiotic-resistant bacteria present in the milk.
  • The aims of this study were to:
    1. Identify and measure the concentration of antimicrobial residues in raw waste milk samples on dairy farms in the Central Valley of California
    2. Survey farm management practices for factors associated with the occurrence of specific antimicrobial residues in raw waste milk
    3. Characterize the antimicrobial resistance patterns of E. coli cultured from raw waste milk samples
    4. Evaluate the potential association between waste milk quality parameter and risk of identifying drug residues in milk
  • A single raw bulk tank waste milk sample was collected from 25 dairy farms located in California’s Central Valley. A questionnaire was used to collect information about farm management practices.
  • Of the 25 samples collected, 15 contained detectable concentrations of at least 1 antimicrobial. Of the drug residue-positive samples, 11 had detectable concentrations of β-lactams and 4 had detectable concentrations of tetracycline. The most prevalent drug residues were ceftiofur, oxytetracycline, and cephapirin.
  • Streptococcus spp. was the most common genus cultured from waste milk samples and was found in 21 samples, followed by Staphylococcus spp. (20 samples) and E.coli (10 samples).
  • No significant associations were identified between farm characteristics or management practices and presence of drug residues in waste milk. The presence of multidrug-resistant E. coli in waste milk urges the need for on-farm practices that reduce calf exposure to resistant bacteria, such as pasteurization.

Impacts of groundwater management on energy resources and greenhouse gas emissions in California. Hendrickson TP, Bruguera M. Water Res. 2018 Sep 15;141:196-207.

  • California faces significant energy and water infrastructure planning challenges in response to a changing climate. Immediately following the most severe recorded drought, the state experienced one of its wettest water years in recorded history. Despite the recent severe wet weather, much of the state’s critical groundwater systems have not recovered from the drought.
  • The recent Sustainable Groundwater Management Act (SGMA) aims to eliminate future depletion risks, but may force California basins to seek alternative water sources by limiting groundwater withdrawals during droughts. These alternative water resources, such as recycled water or desalination, can have significantly higher energy demands in treatment and supply than local groundwater or surface water resources.
  • This research developed potential scenarios of water supply sources for five overdrafted groundwater basins, and modeled the impacts of these scenarios on energy demands and greenhouse gas (GHG) emissions for water supply systems.
  • The results reveal that energy demands and GHG emissions in different water supply scenarios can vary substantially between basins, but could increase statewide energy consumption as much as 2% and GHG emissions by 0.5.
  • These results highlight the need to integrate energy and GHG impacts into water resource management. Better understanding these considerations enables water supply planners to avoid potential unintended consequences (i.e., increased energy demands and GHG emissions) of enhancing drought resilience.

Listeria monocytogenes colonization in a newly established dairy processing facility. Melero B, Stessl B, Manso B, Wagner M, Esteban-Carbonero ÓJ, Hernández M, Rovira J, Rodriguez-Lázaro D. Int J Food Microbiol. 2018 Sep 5;289:64-71.

  • Unlike many other bacterial foodborne pathogens, Listeria monocytogenes can grow in milk at refrigeration temperatures and reach potentially infectious levels in high-moisture and surface-ripened cheeses. The survival and growth of L. monocytogenes in dairy environments depends on the manufacturing, ripening and storage conditions.
  • The presence and colonization of L. monocytogenes were investigated in a newly established dairy processing plant during a one-year period. A total of 250 non-food contact surfaces, 163 food contact surfaces, 46 personnel and 77 food samples were analyzed in two different buildings according to the cheese production chain.
    • Building I (old facility) was used for initial steps, including salting
    • Building II (new facility) was used for the final steps, including ripening, cutting and packaging.
  • Overall, 218 samples were collected from building I and 318 from building II. L. monocytogenes isolates were subtyped by PFGE and MLST, and a questionnaire about quality measures was completed. The overall prevalence of L. monocytogenes was 8.40%, and while the presence of the pathogen was observed just during the first sampling in building I, L. monocytogenes was found in building II at the third sampling event.
  • The salting area in building I had the highest proportion of positive samples with the highest diversity of PFGE types. Moreover, L. monocytogenes PFGE type 3 (sequence type -ST- 204) was first detected in building II in the third visit, and spread through this building until the end of the study.
  • The answers to the questionnaire implied that lack of hygienic barriers in specific parts of the facilities and uncontrolled personnel flow were the critical factors for the spread of L. monocytogenes within and between buildings. Knowledge of the patterns of L. monocytogenes colonization can help a more rational design of new cheesemaking facilities, and improve the food safety within current facilities.

Food Byproducts as Sustainable Ingredients for Innovative and Healthy Dairy Foods. Iriondo-DeHond M, Miguel E, Del Castillo MD. Nutrients. 2018 Sep 22;10(10). pii: E1358.

  • Sustainability presents both an opportunity and a challenge to the dairy sector. It is an opportunity, because the possibility of using food-processing byproducts for bioactive compound and nutrient extraction has created enormous scope for waste reduction and indirect income generation. However, the challenge is to sustainably intensify the global food production system to enhance food security and nutrition without sacrificing the environment, and to render the concept of sustainable functional foods into a marketable product that is acceptable to consumers.
  • This narrative review provides an overview of the current trends in the use of food byproducts in the development of dairy foods.
  • The researchers revised the latest data on food loss generation, the group of byproducts most used as ingredients in dairy product development, and their function within the food matrix. They also address the challenges associated with the sensory properties of the new products including ingredients obtained from byproducts, and consumers’ attitudes towards these sustainable novel dairy foods.
  • Overall, 50 studies supported the tremendous potential of the application of food byproducts (mainly those from plant-origin) in dairy foods as ingredients. There are promising results for their utilization as food additives for technological purposes, and as sources of bioactive compounds to enhance the health-promoting properties of dairy products. However, food technologists, nutritionists and sensory scientists should work together to face the challenge of improving the palatability and consumer acceptance of these novel and sustainable dairy foods.

Review: Selecting for improved feed efficiency and reduced methane emissions in dairy cattle. Løvendahl P, Difford GF, Li B, Chagunda MGG, Huhtanen P, Lidauer MH, Lassen J, Lund P. Animal. 2018 Sep 26:1-14.

  • It may be possible for dairy farms to improve profitability and reduce environmental impacts by selecting for higher feed efficiency and lower methane (CH4) emission traits. It remains to be clarified how CH4 emission and feed efficiency traits are related to each other.
  • The rumen microbiome plays a dual role in digestion, facilitating nutrient extraction from fibre-rich feed while also generating CH4. There are clear indications of interactions between bovine hosts and their microbiomes, and both show genetic variation and covariation.
  • Nutrition studies indicate that selecting low emitting animals may result in reduced efficiency of cell wall digestion, that is neutral detergent fiber, a key ruminant characteristic in human food production. Moreover, many interacting biological factors that are not measured directly, including digestion rate, passage rate, the rumen microbiome and rumen fermentation, may influence feed efficiency and CH4 emission.
  • The strategy of preventing energy loss via eructed CH4 to make more energy available for lactation needs further study to clarify its feasibility and true potential, not least because the alternative is that energy can be lost as eructed hydrogen. The availability of low-cost, high-capacity recording methods can facilitate the development of genetic- and nutrition-based improvements in feed efficiency and reduction of emissions.

The extent that certain dairy farmer attitudes and behaviors are associated with farm business profitability. O’Leary NW, Bennett RM, Tranter RB, Jones PJ. J Dairy Sci. 2018 Sep 26. pii: S0022-0302(18)30877-4.

  • The way in which farm managers’ attitudes, personality, behavior, values, and sociodemographic characteristics influence farm business performance is, at best, only partially understood.
  • The study reported here expands on this understanding by analyzing the attitudes and personal attributes of 80 dairy farmers in Great Britain in relation to the profitability over 3 yr of their farm businesses.
  • Business goals, temperament, purchasing behavior, and having a growth mindset toward the business were found to be associated with profitability. Each of these variables were questions related to the participants’ personal attitudes or beliefs. Other assessed variables, such as specific husbandry behaviors or practices, or management practices and sociodemographic characteristics, did not warrant inclusion in the final model.
  • These results uniquely contribute to understanding how the attitudes, personality, behaviors, and attributes of dairy farmers are associated with, and thus likely to influence, the profitability of their farm businesses.


Selected Articles on Dairy Intake and Human Health

Association of dairy intake with cardiovascular disease and mortality in 21 countries from five continents (PURE): a prospective cohort study. Dehghan M, Mente A, Rangarajan S, et al. The Lancet. September 11, 2018

  • Dietary guidelines recommend minimizing consumption of whole-fat dairy products, as they are a source of saturated fats and presumed to adversely affect blood lipids and increase cardiovascular disease and mortality. Evidence for this contention is sparse and few data for the effects of dairy consumption on health are available from low-income and middle-income countries.
  • The study objective was to assess the associations between total dairy and specific types of dairy products with mortality and major cardiovascular disease.
  • The Prospective Urban Rural Epidemiology (PURE) study is a large multinational cohort study of individuals aged 35–70 years enrolled from 21 countries in five continents. Dietary intakes of dairy products for 136,384 individuals were recorded using country-specific validated food frequency questionnaires. Dairy products comprised milk, yoghurt, and cheese; and were grouped into whole-fat and low-fat dairy.
  • Higher intake of total dairy (>2 servings per day compared with no intake) was associated with a lower risk of total mortality, non-cardiovascular mortality, cardiovascular mortality, major cardiovascular disease, and stroke. No significant association with myocardial infarction was observed.
  • Overall, this study showed that dairy consumption was associated with lower risk of mortality and major cardiovascular disease events in a diverse multinational cohort.

Cow’s Milk Consumption and Health: A Health Professional’s Guide. Marangoni F, Pellegrino L, Verduci E, et al. J Am Coll Nutr. 2018 Sep 24:1-12.

  • The most recent scientific evidence supports the consumption of cow’s milk and dairy products as part of a balanced diet. However, these days, the public and practicing physicans are exposed to a stream of inconsistent (and often misleading) information regarding the relationship between cow’s milk intake and health in the lay press and in the media.
  • The purpose of this article, in this context, is to facilitate doctor-patient communication on this topic, providing physicians with a series of structured answers to frequently asked patient questions. The answers range from milk and milk-derived products’ nutritional function across the life span, to their relationship with diseases such as osteoporosis and cancer, to lactose intolerance and milk allergy, and have been prepared by a panel of experts from the Italian medical and nutritional scientific community.
  • When consumed according to appropriate national guidelines, milk and its derivatives contribute essential micro- and macronutrients to the diet, especially in infancy and childhood where bone mass growth is in a critical phase. Furthermore, preliminary evidence suggests potentially protective effects of milk against overweight, obesity, diabetes, and cardiovascular disease, while no clear data suggest a significant association between milk intake and cancer.
  • Overall, current scientific literature suggests that an appropriate consumption of milk and its derivatives, according to available nutritional guidelines, may be beneficial across all age groups, with the exception of specific medical conditions such as lactose intolerance or milk protein allergy.

Consumption of dairy products in relation to the presence of clinical knee osteoarthritis: The Maastricht Study. Denissen KFM, Boonen A, Nielen JTH, Feitsma AL, van den Heuvel EGHM, Emans PJ, Stehouwer CDA, Sep SJS, van Dongen MCJM, Dagnelie PC, Eussen SJPM. Eur J Nutr. 2018 Sep 21.

  • Observational studies showed inverse associations between milk consumption and knee osteoarthritis. However, there is lack of information on the role of specific dairy product categories.
  • The purpose of this study was to explore the association between dairy product consumption and the presence of knee osteoarthritis.
  • The researchers studied 3010 individuals aged 40-75 years old. Data on dairy consumption were appraised by a 253-item FFQ covering 47 dairy products with categorization on fat content, fermentation or dairy type.
  • Significant inverse associations were observed between the presence of knee osteoarthritis and intake of full-fat dairy and semi-hard cheese. No significant associations were found for other dairy product categories.
  • In this population, higher intake of full-fat dairy and cheese, but not milk, was cross-sectionally associated with the lower presence of knee osteoarthritis.

Effect of Whey Protein Supplementation on Physical Performance and Body Composition in Army Initial Entry Training Soldiers. McAdam JS, McGinnis KD, Beck DT, Haun CT, Romero MA, Mumford PW, Roberson PA, Young KC, Lohse KR, Lockwood CM, Roberts MD, Sefton JM. Nutrients. 2018 Sep 6;10(9).

  • An increasing percentage of soldiers report to Army Initial Entry Training (IET) with low levels of physical fitness, which is a primary contributor to the high rates of musculoskeletal injuries found in the military population. To help combat this problem the Army has implemented strategies such as the Army Performance Triad which focuses on improving sleep, exercise, and nutrition. Protein supplementation may be a strategy to help combat nutritional deficits during military training.
  • The researchers investigated the effects of whey protein supplementation on body composition and physical performance in soldiers participating in IET,
  • Sixty-nine, male United States Army soldiers volunteered for supplementation with either twice daily whey protein (77 g/day protein, ~580 kcal/day) or energy-matched carbohydrate drinks (127 g/day carbohydrate, ~580 kcal/day) for eight weeks during IET.
  • Physical performance was evaluated using the Army Physical Fitness Test during weeks two and eight. Body composition was assessed using 7-site skinfold assessment during weeks one and nine.
  • Post-testing push-up performance averaged 7 repetitions higher in the whey protein group compared to the carbohydrate group when controlling for baseline. Whey protein had a large effect on fat mass loss, while carbohydrate had a medium effect. In conclusion, twice daily supplementation with whey protein improved push-up performance and potentiated reductions in fat mass during IET training in comparison to carbohydrate supplementation.

Effect of whey protein supplementation after resistance exercise on the muscle mass and physical function of healthy older women: A randomized controlled trial. Mori H, Tokuda Y. Geriatr Gerontol Int. 2018 Sep;18(9):1398-1404.

  • Sarcopenia is defined as an age‐related decrease in skeletal muscle mass and physical function. There is current evidence of a positive effect of a supplementation of approximately 20–25 g of whey protein or daily total protein intake of at least of 1.2 g/kg bodyweight/day during resistance exercise training in older individuals.
  • To objective of the study was to evaluate the effectiveness of a 24-week program of whey protein supplementation, ingested after resistance exercise, in increasing muscle mass and physical function among community-dwelling healthy older Japanese women.
  • The researchers carried out a randomized controlled trial, with 81 healthy women, aged 65-80 years, allocated to three groups of 27 participants each:
    1. Exercise and protein supplementation group
    2. Exercise only group
    3. Protein supplementation only group
  • A 24-week program of resistance exercise, carried out twice per week, was combined with whey protein supplementation, containing 22.3 g of protein.
  • The pre- to post-intervention increase in the skeletal muscle mass index was significantly higher for the exercise and protein supplementation group than for either the exercise only or protein supplementation only groups. Similarly, the increase in grip strength and gait speed was significantly greater for the exercise and protein supplementation group than for the protein supplementation only group.
  • In conclusion, whey protein supplementation, ingested after resistance exercise, could be effective for the prevention of sarcopenia among healthy older women.

Conference Proceedings: Dairy Nutrition, An Engine for Economic Growth. Whitsett-Morrow D. Food Nutr Bull. 2018 Sep;39(2_suppl):S27-S29.

  • At the inaugural conference of the U.S. Dairy Export Council’s Dairy for Global Nutrition Initiative titled, “Dairy Nutrition: An Engine for Economic Growth,” the science supporting dairy products’ role in battling malnutrition, stimulating local economies, and improving long-term health globally was explored and discussed. Selected summaries of the speaker presentations are presented below.
  • Stobaugh’s research showed that whey-based supplementary food is more effective at treating moderate-acute malnutrition in children than soy-based supplementary food. Of note is that whereas whey-based supplementary food is more expensive to produce than soy-based supplementary food, cost-effectiveness per child is recovered when the cost of administration and success rate are considered, thereby nullifying the extra cost of whey.
  • Schlossman described her research which indicates that whey supplementation could beneficially affect infant and child growth in Guinea-Bissau. Importantly, dairy protein has been demonstrated to prevent moderate-acute malnutrition in children under 2 years of age in Guinea-Bissau, independent of their family dynamic.
  • Clark explored the association between maternal diet and low birth weight and stunting. His findings indicate an association between moderate dairy protein consumption and reduced risk of low birth weight babies. Of interest is the association between protein-to-carbohydrate ratios and gestational weight gain and fetal programming.
  • Moses explained the role of the International Finance Corporation (IFC) in helping companies expand to emerging markets. The dairy product sector has unique challenges and opportunities that the IFC, as part of the World Bank Group, could help capitalize on.
  • The final speaker, Dr. DiRienzo, outlined a call to action to put research findings into practice. He reminded the audience of the importance of the first 1000 days as a critical window in preventing stunting and malnutrition. He stressed the importance of protein quality in supplemental nutrition and questioned whether higher-cost dairy product ingredients were truly costlier in the long term, because of their high-quality protein content and effectiveness at helping to prevent malnutrition and decrease the risk of chronic disease.