Welcome to the October 2019 bulletin. 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


Selected Articles on Social Responsibility, Environmental Management, and Sustainability

The effects of improved performance in the U.S. dairy cattle industry on environmental impacts between 2007 and 2017. Capper JL, Cady RA. J Anim Sci. 2019 Oct 17. pii: skz291.

  • The U.S. dairy industry considerably reduced environmental impacts between 1944 and 2007, primarily through improved dairy cow productivity. Since 2007, milk yield per cow has increased in U.S., and therefore whole-system environmental impact analyses require new measurements.
  • The objective of this study was to compare the environmental impact of U.S. dairy cattle production in 2007-2017.
  • A deterministic model based on population demographics, metabolism, and nutrient requirements of dairy cattle was used to estimate resource inputs, nutrient excretion, and greenhouse gas (GHG) emissions per 1.0 × 106 t (one million metric t or MMT) of energy-corrected milk (ECM) produced in 2007 and 2017. System boundaries extended from the manufacture and transport of cropping inputs to milk at the farm gate. Milk transport, processing, and retail were not included.
  • The results showed that the resources required to produce 1.0 MMT ECM in 2017 were considerably reduced relative to those required in 2007, with 2017 production systems using 74.8% of the cattle, 82.7% of the feedstuffs, 79.2% of the land, and 69.5% of the water as compared to 2007.
  • Waste outputs were similarly reduced, with the 2017 U.S. dairy industry producing 79.4%, 82.5%, and 85.7% of the manure, N, and P excretion, respectively. Dairy production in 2017 emitted 80.9% of the CH4 and 81.5% of the N2O per 1.0 MMT ECM compared to 2007. Enteric and manure emissions contributed the major proportion (80%) of GHG emissions per unit of milk, with lesser contributions from cropping (7.6%) and fertilizer application (5.3%).
  • The GHG emissions per 1.0 MMT ECM produced in 2017 were 80.8% of equivalent milk production in 2007. Consequently, although total U.S. ECM production increased by 24.9% between 2007 and 2017, total GHG emissions from this milk production increased by only 1.0%.
  • In line with previous historical analyses, the U.S. dairy industry has made remarkable productivity gains and environmental progress over time. To maintain this culture of continuous improvement, the dairy industry must build on gains made to date and demonstrate its commitment to reducing environmental impacts while improving both economic viability and social acceptability.

Dairy farmers’ decision making to implement biosecurity measures: A study of psychosocial factors. Moya S, Tirado F, Espluga J, Ciaravino G, Armengol R, Diéguez J, Yus E, Benavides B, Casal J, Allepuz A. Transbound Emerg Dis. 2019 Oct 10.

  • Biosecurity measures are a set of management procedures that prevent the risk of introducing and spreading infectious diseases to a farm, although these measures are rarely implemented in dairy farms. There are some studies that have identified that the decision to implement biosecurity measures can be influenced by several psychosocial factors (attitudes and behaviors).
  • The objective of this study was to examine the psychosocial factors (and their interactions) influencing the implementation of biosecurity measures in dairy farms in Spain, through the views of dairy farmers and veterinarians from Catalonia (northeast Spain) and Galicia (northwest Spain).
  • Face to face in-depth interviews were performed with 16 dairy farmers (nine from Catalonia and seven from Galicia), and 16 veterinarians (eight from Catalonia and eight from Galicia).
  • The study identified the importance of veterinarians as a source of information, including their communication skills, the individual experiences of farmers, traditions of the farms and availability of time and space in the dairy farmer’s decisions making.
  • Further, it suggests the need to deepen the knowledge of the farm workers and the obligatory biosecurity measures. This research represents a starting point to develop future strategies to improve the implementation of biosecurity measures in dairy farms.

Microbial Safety of Dairy Manure Fertilizer Application in Raspberry Production. Sheng L, Shen X, Benedict C, Su Y, Tsai HC, Schacht E, Kruger CE, Drennan M, Zhu MJ. Front Microbiol. 2019 Oct 2;10:2276

  • Dairy manure, a by-product in the dairy industry, is also a potential source of nutrients for crops. However, improper application of biological soil amendments of animal origin can be a source of contamination with enteric foodborne pathogens.
  • A 2-year field study (2017-2018) was conducted to evaluate impacts of dairy manure fertilizer application on the microbial safety of red raspberry (Rubus idaeus L) production.
  • Fertilizers, including a standard synthetic fertilizer (CON), straight lagoon raw manure (SL), anaerobically digested liquid effluent (DLE), compost (COM) and dairy manure-derived refined fertilizers including ammonium sulfate (AS) and phosphorous solid (PS), were randomly applied in quadruplicate to raspberry plots.
  • Counts of total coliforms in soil were stable over the 2017 cropping season and were not impacted by fertilizer application. In 2018, total coliforms increased with season and soils treated with COM had a significantly higher coliform number than those treated with CON. Both total coliform and generic E. coli in raspberry fruit samples were below the detectable level (3 most probable number/g) regardless of fertilizer types.
  • In both years, no STEC or L. monocytogenes was detected from any of the collected samples regardless of fertilizer treatments. However, Salmonella were detected in some of the fertilizers, including PS (2017), DLE (2018), and SL (2018), which were transferred to soil samples taken directly after application of these fertilizers. Salmonella were not detected in soil samples 2 or 4 months post fertilizer application, foliar, or raspberry fruit samples regardless of fertilizer applications.
  • In summary, one-time application of raw dairy manure or dairy manure-derived fertilizers more than 4 months prior to harvest has no major impact on food safety of red raspberry (6 ft. tall) production in Lynden sandy loam under good agricultural practices.

Prospects for biogas production and H2S control from the anaerobic digestion of cattle manure: The influence of microscale waste iron powder and iron oxide nanoparticles. Farghali M, Andriamanohiarisoamanana FJ, Ahmed MM, Kotb S, Yamamoto Y, Iwasaki M, Yamashiro T, Umetsu K. Waste Manag. 2019 Oct 11;101:141-149.

  • Improving the quality and quantity of biogas usually requires pre-treatment to maximize methane yields and/or post-treatment to remove H2S, which involves considerable energy consumption and higher costs.
  • This study proposes a cost-effective method for the enhanced anaerobic digestion of dairy manure without pre/post-treatment by directly adding waste iron powder and iron oxide nanoparticles to batch digesters.
  • The results showed that the addition of iron in the form of microscale WIP (generated from the laser cutting of iron and steel) at concentrations of 100 mg/L, 500 mg/L, and 1000 mg/L improved methane yields by 36.99%, 39.36%, and 56.89%, respectively. In comparison, the equivalent dosages of oxide nanoparticles improved yields by 19.74%, 18.14%, and 21.11%, respectively.
  • Additionally, the highest waste iron powder dose (1000 mg/L) achieved the maximum improvement in the rate of hydrolysis, which was 1.25 times higher than in control reactions, and a maximum biomethane production rate.
  • The rate of H2S production was also significantly reduced (by 45.20%, 58.16%, and 77.24%) using the three waste iron powder concentrations in comparison with oxide nanoparticles (which achieved reductions of 33.59%, 46.30%, and 53.52%, respectively).
  • Therefore, the direct mixing of waste iron powder with cattle manure is proposed as a practical and economical means of addressing complex and high-cost pre- and post-treatments that are otherwise required in the digestion process.

Cross-sectional study of the relationships among bedding materials, bedding bacteria counts, and intramammary infection in late-lactation dairy cows. Rowe SM, Godden SM, Royster E, Timmerman J, Crooker BA, Boyle M. J Dairy Sci. 2019 Oct 9. pii: S0022-0302(19)30900-2.

  • The objectives of this study were to (1) describe the intramammary infection (IMI) prevalence and pathogen profiles in quarters of cows approaching dry-off in US dairy herds, (2) compare IMI prevalence in quarters of cows exposed to different bedding material types, and (3) identify associations between bedding bacteria count and IMI in cows approaching dry-off.
  • Eighty herds using 1 of 4 common bedding materials (manure solids, organic non-manure, new sand, and recycled sand) were recruited in a multi-site cross-sectional study. Each herd was visited twice for sampling. At each visit, aseptic quarter-milk samples were collected from 20 cows approaching dry-off (>180 d pregnant).
  • Samples of unused and used bedding were also collected. Aerobic culture was used to determine the IMI status of 10,448 quarters and to enumerate counts (log10cfu/mL) of all bacteria, Staphylococcus spp., Streptococcus spp. and Streptococcus-like organisms (SSLO), coliforms, Klebsiella spp., noncoliform gram-negatives, Bacillus spp., and Prototheca spp. in unused (n = 148) and used (n = 150) bedding.
  • Quarter-level prevalence of IMI was 21.1%, which was primarily caused by non-aureus Staphylococcus spp. (11.4%) and SSLO (5.6%). Only modest differences in IMI prevalence were observed between the 4 common bedding material types.
  • The association between counts of all bacteria in used bedding and ALL-IMI varied by bedding type, with positive associations observed in quarters exposed to manure solids and organic non-manure and a negative association in quarters exposed to new sand.
  • Findings from this study suggest that quarter-level IMI prevalence in late-lactation cows is low in US dairy herds. Furthermore, bedding material type may not be an important risk factor for IMI in late lactation. Higher levels of bacteria in bedding may increase IMI prevalence at dry-off in general, but this relationship is likely to vary according to bedding material type.

Farmers’ Mental Health: Perceptions from a Farm Show. Rudolphi JM, Barnes KL. J Agromedicine. 2019 Oct 3:1-6.

  • Current economic and environmental conditions have increased awareness of farmers’ mental health. Agribusiness professionals may be important key informants to assist agricultural safety and health professionals in understanding the mental health experience of farmers and inform their potential role in mental health promotion.
  • The objectives of this study were to explore agribusiness personnel’s perceptions of their farmer clients’ mental health and their perceived role in mental health promotion.
  • Fifteen brief interviews of agribusiness personnel were conducted across 3 days in July 2018 at Farm Technology Days in Wood County, Wisconsin.
  • Many interviewees commented on the mental health status of farmers in Wisconsin, stating farmers are “stressed” and “depressed”. However, agribusiness personnel were hesitant about their organization’s role in mental health promotion. Several respondents cited lack of training and confidence as barriers to addressing mental health with their clients. Others were optimistic about their organization’s role in mental health promotion; however, participation would be mostly passive, stating mental health is a difficult topic to broach with some individuals.
  • To engage agribusiness in mental health promotion, efforts to reduce the stigma of mental health disorders and increase agribusiness representatives’ confidence and skills in talking about mental health will be necessary.


Selected Articles on Dairy Intake and Human Health

Elevating dairy research and extension through partnership: Outcomes from the United States Department of Agriculture and National Dairy Council collaborative meeting to develop a coordination roadmap. Tricarico JM, Slimko ML, Graves WB, Eve MD, Thurston JA. J Dairy Sci. 2019 Oct;102(10):9518-9524.

  • Dairy foods provide a significant portion of the recommended daily nutrition for much of the US population. Improving the availability of safe and nutritious dairy products and decreasing the environmental impact of the dairy community continue to be high priorities for both industry and the public sector.
  • In recognition of these shared priorities, scientists and other specialists from the USDA, National Dairy Council, industry, academia, and nongovernmental organizations participated in the “Elevating Dairy Research and Extension Through Partnership” meeting on June 19, 2018. The purpose of the meeting was to strengthen partnerships and identify dairy-related research and extension needs in human nutrition, environmental sustainability, food safety, and product innovation that would benefit from enhanced coordination and collaboration across the dairy community, academia, and government.
  • To catalyze further progress on these topics, the meeting organizers agreed to leverage the content and expertise that emerged from the meeting to develop a dairy research and extension coordination roadmap. The roadmap will establish and articulate a vision for coordinated collaboration between USDA researchers, the National Dairy Council, university researchers, extension specialists, and other dairy community stakeholders in the private and public sectors.

Multiple health and environmental impacts of foods. Clark MA, Springmann M, Hill J, Tilman D. Proceedings of the National Academy of Sciences, Oct 29, 2019; 201906908.

  • Dietary choices are a leading global cause of mortality and environmental degradation and threaten the attainability of the UN’s Sustainable Development Goals and the Paris Climate Agreement.
  • To inform decision making and to better identify the multifaceted health and environmental impacts of dietary choices, the researchers describe how consuming 15 different food groups is associated with 5 health outcomes and 5 aspects of environmental degradation. The researchers also consider how consuming an additional serving per day of each of the 15 foods is associated with health and environmental impacts.
  • The results showed that many foods associated with improved adult health also often have low environmental impacts, indicating that the same dietary transitions that would lower incidences of noncommunicable diseases would also help meet environmental sustainability targets.
  • Of the foods associated with improved health (whole grain cereals, fruits, vegetables, legumes, nuts, olive oil, and fish), all except fish have among the lowest environmental impacts, and fish has markedly lower impacts than red meats and processed meats.
  • Foods with intermediate environmental impacts or that are not significantly associated with health outcomes, such as refined grain cereals, dairy, eggs, and chicken, could also contribute to meeting international health-focused or environmental-focused sustainability targets if they are used to replace foods that are less healthy or have higher environmental impacts such as unprocessed red meat and processed red meat.
  • Foods associated with the largest negative environmental impacts—unprocessed and processed red meat—are consistently associated with the largest increases in disease risk.

Associations of types of dairy consumption with adiposity: cross-sectional findings from over 12,000 adults in the Fenland Study, UK. Trichia E, Imamura F, Brage S, De Lucia Rolfe E, Griffin SJ, Wareham NJ, Forouhi NG. Br J Nutr. 2019 Oct 28;122(8):928-935.

  • Evidence from randomized controlled trials supports beneficial effects of total dairy products on body weight, fat and lean mass, but evidence on associations of dairy types with distributions of body fat and lean mass is limited.
  • The researchers aimed to investigate associations of total and different types of dairy products with markers of adiposity, and body fat and lean mass distribution.
  • The researchers evaluated cross-sectional data from 12,065 adults aged 30-65 years recruited to the Fenland Study between 2005 and 2015 in Cambridgeshire, UK.
  • The medians of milk, yogurt and cheese consumption were 293, 35.3 and 14.6 grams/day, respectively. Low-fat dairy consumption was inversely associated with visceral:subcutaneous fat ratio per serving/day. Habitual consumption per serving/day (200 g) of milk was associated with 0.33 kg higher lean mass.
  • These findings suggest that the influence of milk consumption on lean mass and of low-fat dairy consumption on fat mass distribution may be potential pathways for the link between dairy consumption and metabolic risk.

Circulating Very-Long-Chain SFA Concentrations Are Inversely Associated with Incident Type 2 Diabetes in US Men and Women. Ardisson Korat AV, Malik VS, Furtado JD, Sacks F, Rosner B, Rexrode KM, Willett WC, Mozaffarian D, Hu FB, Sun Q. J Nutr. 2019 Oct 16. pii: nxz240.

  • Very-long-chain SFAs (VLCSFAs), such as arachidic acid (20:0), behenic acid (22:0), and lignoceric acid (24:0), have demonstrated inverse associations with cardiometabolic conditions, although more evidence is needed to characterize their relation with risk of type 2 diabetes. In addition, little is known regarding their potential dietary and lifestyle predictors.
  • This study aimed to examine the association of plasma and erythrocyte concentrations of VLCSFAs with incident type 2 diabetes risk.
  • The researchers used existing measurements of fatty acid concentrations in plasma and erythrocytes among 2,854 and 2,831 participants in the Nurses’ Health Study (NHS) and Health Professionals Follow-Up Study, respectively. During 39,941 person-years of follow-up, the researchers documented 243 cases of type 2 diabetes.
  • Intakes of peanuts, peanut butter, vegetable fat, dairy fat, and palmitic/stearic (16:0-18:0) fatty acids were significantly, albeit weakly, correlated with plasma and erythrocyte VLCSFA concentrations .
  • The findings suggest that, in US men and women, higher plasma concentrations of VLCSFAs are associated with lower risk of type 2 diabetes. More research is needed to understand the mechanistic pathways underlying these associations.

Fermented Milk Products and Bone Health in Postmenopausal Women: A Systematic Review of Randomized Controlled Trials, Prospective Cohorts, and Case-Control Studies. Ong AM, Kang K, Weiler HA, Morin SN. Adv Nutr. 2019 Oct 11. pii: nmz108.

  • Milk and milk product consumption is positively associated with bone mineral density (BMD). Emerging evidence suggests that fermented milk products may have specific beneficial effects on skeletal health.
  • The researchers conducted a systematic review and meta-analysis to assess the effect of fermented milk products on bone health indicators in postmenopausal women given their increased risk for osteoporosis and fragility fractures.
  • Electronic databases were searched for randomized controlled trials (RCTs) and prospective cohort and case-control studies that examined the relation between fermented milk products and bone health outcomes (fracture incidence, BMD, BMD T-score, and percentage change in bone turnover markers) in postmenopausal women.
  • Results of the meta-analysis of 3 cohort studies (n = 102,819) suggest that higher yogurt consumption was associated with reduced hip fracture risk, but no difference in hip fracture risk was found between higher and lower cheese consumption.
  • Case-control studies revealed that cheese intake had either a null or a protective effect against osteoporosis. Daily yogurt or cheese intervention (<2 mo) decreased bone resorption marker concentrations, but had no effect on bone formation markers.
  • In postmenopausal women, of the fermented milk products studied, only greater yogurt consumption was associated with a reduced risk of hip fracture compared with low or no intake.

Total Fermented Dairy Food Intake Is Inversely Associated with Cardiovascular Disease Risk in Women. Buziau AM, Soedamah-Muthu SS, Geleijnse JM, Mishra GD. J Nutr. 2019 Oct 1;149(10):1797-1804.

  • The relation between fermented dairy consumption and type 2 diabetes and cardiovascular disease in an Australian population remains to be established.
  • The aim of this study was to investigate the association between fermented dairy consumption and type 2 diabetes and cardiovascular disease risk.
  • The Australian Longitudinal Study on Women’s Health included Australian women (aged 45-50 y) at baseline in 2001, who were followed up through 5 surveys until 2016.
  • Of 7,633 women free of diabetes at baseline, 701 (9.2%) developed type 2 diabetes during a maximum 15-y follow-up period. Women in the highest tertile of yogurt intake had lower adjusted odds of type 2 diabetes than those in the lowest tertile. This relation became nonsignificant after adjustment for dietary variables and total energy intake.
  • Of 7,679 women free of cardiovascular disease at baseline, 835 (10.9%) cases of cardiovascular disease were reported during follow-up. High intake of yogurt and total fermented dairy was associated with lower cardiovascular disease risk than observed in the lowest tertile of dairy product intake. Additional adjustment attenuated the relation.
  • No associations were found with other dairy groups. The findings from this population-based study of Australian women suggest an inverse association between total fermented dairy intake and cardiovascular disease risk, which may partly be accounted for by other dietary components.

Infant dietary intake of yogurt and cheese and gastroenteritis at 1 year of age: The Japan Environment and Children’s Study. Nakamura M, Hamazaki K, Matsumura K, Kasamatsu H, Tsuchida A, Inadera H; Japan Environment and Children’s Study Group. PLoS One. 2019 Oct 7;14(10):e0223495.

  • The important role played by intestinal bacterial flora in human health has recently attracted public attention worldwide. Although yogurt is thought to help in preventing the onset of gastroenteritis, this property has rarely been examined in epidemiological studies.
  • This study analyzed data obtained by the Japan Environment and Children’s Study. From a dataset of 103,062 pregnancies, 82,485 were selected for this analysis.
  • Dietary intake of fermented foods (yogurt and cheese) in 1-year-old infants was assessed with a food frequency questionnaire. Parent-reported physician-diagnosed gastroenteritis in early childhood was determined from a questionnaire conducted when the child was 1 year old.
  • The incidence of gastroenteritis was significantly lower in infants who consumed yogurt ≥ 7 and 3-6 times/week than in infants who consumed yogurt < 1 time/week. Frequency of weekly cheese consumption was not associated with the incidence of gastroenteritis.
  • In conclusion, the results showed that consumption of yogurt, but not cheese, at 1 year of age was associated with a reduced risk of gastroenteritis.