Check out the freshest Dairy Research from February! 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

Prediction of enteric methane production, yield and intensity in dairy cattle using an intercontinental database. Niu M, Kebreab E, Hristov AN, et al. Glob Chang Biol. 2018 Feb 16.

  • Enteric methane (CH4) production from cattle contributes to global greenhouse gas emissions. Measurement of enteric CH4 is complex, expensive and impractical at large scales; therefore, models are commonly used to predict CH4 production. However, building robust prediction models requires extensive data from animals under different management systems worldwide.
  • The objectives of this study were to (1) collate a global database of enteric CH4 production from individual lactating dairy cattle; (2) determine the availability of key variables for predicting enteric CH4 production (g/d per cow), yield (g/kg dry matter intake), and intensity (g/kg energy corrected milk) and their respective relationships; (3) develop intercontinental and regional models and cross-validate their performance; and (4) assess the trade-off between availability of on-farm inputs and CH4 prediction accuracy.
  • The intercontinental database covered Europe (EU), the US (US), Chile (CL), Australia (AU), and New Zealand (NZ). Enteric CH4 production, yield, and intensity prediction models developed on an intercontinental basis had similar performance across regions, however, intercepts and slopes were different with implications for prediction. Revised CH4 emission conversion factors for specific regions are required to improve CH4 production estimates in national inventories.
  • In conclusion, information on dry matter intake is required for good prediction, and other factors such as dietary neutral detergent fiber concentration, improve the prediction. For enteric CH4 yield and intensity prediction, information on milk yield and composition is required for better estimation. 

Integration of machine learning and meta-analysis identifies the transcriptomic bio-signature of mastitis disease in cattle. Sharifi S, Pakdel A, Ebrahimi M, Reecy JM, Fazeli Farsani S, Ebrahimie E. PLoS One. 2018 Feb 22;13(2):e0191227.

  • Gram-negative bacteria such as Escherichia coli (E. coli) are assumed to be among the main agents that cause severe mastitis disease with clinical signs in dairy cattle. Rapid detection of this disease is so important in order to prevent transmission to other cows and helps to reduce inappropriate use of antibiotics.
  • In the current meta-analysis research, 6 microarray-based studies that investigate the transcriptome profile of mammary gland tissue after induced mastitis by E. coli infection were used.
  • Twelve meta-genes were detected. The most informative genes included CXCL8 (IL8), NFKBIZ, HP, ZC3H12A, PDE4B, CASP4, CXCL2, CCL20, GRO1(CXCL1), CFB, S100A9, and S100A8. Interestingly, the results have been demonstrated that all of these genes are the key genes in the immune response, inflammation or mastitis.
  • The Decision tree models efficiently discovered the best combination of the meta-genes as bio-signature and confirmed that some of the top-ranked genes -ZC3H12A, CXCL2, GRO, CFB- as biomarkers for E. coli mastitis (with the accuracy 83% in average).
  • This research properly indicated that by combination of two novel data mining tools, meta-analysis and machine learning, increased power to detect most informative genes that can help to improve the diagnosis and treatment strategies for E. coli associated with mastitis in cattle.

Oleaginous Microalgae from Dairy Farm Wastewater for Biodiesel Production: Isolation, Characterization and Mass Cultivation. Sun Z, Fang XP, Li XY, Zhou ZG. Appl Biochem Biotechnol. 2018 Feb;184(2):524-537.

  • Producing biodiesel from microalgae grown in wastewater is environment-friendly and cost-effective. The ability of microalgae to grow in nutrient-rich environments and to accumulate nutrients from wastewaters makes them attractive for the sustainable and low-cost treatment of wastewater. The valuable biomass produced can be further used for the generation of bioenergy, animal feed, fertilizers, and biopolymers, among others.
  • The present study investigated the algae found in wastewater of a local dairy farm for their potential as biodiesel feedstocks. Thirteen native algal strains were isolated.
  • On the basis of morphology and 16S/18S rRNA gene sequences, one strain was identified to be a member of cyanobacteria, while other 12 strains belong to green algae. After screening, two Scenedesmus strains out of the 13 microalgae isolates demonstrated superiority in growth rate, lipid productivity, and sedimentation properties, and therefore were selected for further scale-up outdoor cultivation.
  • Both Scenedesmus strains quickly adapted to the outdoor conditions, exhibiting reasonably good growth and strong anti-contamination capabilities. In flat-plate photobioreactors (PBRs), algal cells accumulated predominantly neutral lipids that accounted for over 60% of total lipids with almost 70% being triacylglycerol. In addition, Scenedesmus obliquus had a high content of monounsaturated fatty acids, of which the amount of oleic acid (C18:1) was up to 27.11%.
  • Based on these findings, the dairy farm wastewater-isolated Scenedesmus strains represent promising sources of low-cost, high-quality oil for biofuel production.

Impact of subclinical mastitis on greenhouse gas emissions intensity and profitability of dairy cows in Norway. Özkan Gülzari Ş, Vosough Ahmadi B, Stott AW. Prev Vet Med. 2018 Feb 1;150:19-29.

  • Impaired animal health causes both productivity and profitability losses on dairy farms, resulting in inefficient use of inputs and increase in greenhouse gas (GHG) emissions produced per unit of product (i.e. emissions intensity).
  • In this study, the researchers used subclinical mastitis to benchmark alternative scenarios against an economic optimum and adjusted herd structure to estimate the GHG emissions intensity associated with varying levels of disease. Five levels of somatic cell count (SCC) classes were considered namely 50,000 (i.e. SCC50), 200,000, 400,000, 600,000 and 800,000cells/mL (milliliter) of milk.
  • The results show that there is a potential to reduce the farm GHG emissions intensity by 3.7% if the milk production was improved through reducing the level of SCC to 50,000cells/mL in relation to SCC level 800,000cells/mL.
  • In conclusion, preventing and/or controlling subclinical mastitis consequently reduces the GHG emissions per unit of product on farm that results in improved profits for the farmers through reductions in milk losses, optimum culling rate and reduced feed and other variable costs.


Selected Articles on Dairy Intake and Human Health

Genome-Wide Interactions with Dairy Intake for Body Mass Index in Adults of European Descent. Smith CE, Follis JL, Ordovás JM, et al.  Mol Nutr Food Res. 2018 Feb;62(3).

  • Body weight responds variably to the intake of dairy foods. Genetic variation may contribute to inter-individual variability in associations between body weight and dairy consumption.
  • Researchers conducted a genome-wide interaction study to discover genetic variants that account for variation in BMI in the context of low-fat, high-fat and total dairy intake in cross-sectional analysis was conducted. The researchers used data from nine studies involving 25,513 individuals of European descent.
  • In the cohorts, the genetic variant rs9635058 interacted with dairy (p-interaction = 7.36 × 10-8) such that each serving of low-fat dairy was associated with 0.225 kg m-2 lower BMI per each additional copy of the effect allele (A). A second genetic variant (ACTA2-rs1388) approached interaction replication significance for low-fat dairy exposure.
  • Body weight responses to dairy intake may be modified by genotype, in that greater dairy intake may protect a genetic subgroup from higher body weight.

Regular Yogurt Intake and Risk of Cardiovascular Disease Among Hypertensive Adults. Buendia JR, Li Y, Hu FB, Cabral HJ, Bradlee ML, Quatromoni PA, Singer MR, Curhan GC, Moore LL. Am J Hypertens. 2018 Feb 15.

  • High blood pressure (HBP) is a major cardiovascular disease (CVD) risk factor. Clinical trials have demonstrated beneficial effects of dairy consumption on risks of HBP and CVD. Yogurt, a fermented dairy product, may independently be related to CVD risk.
  • The objective of this study was to evaluate the association between yogurt consumption and CVD risk among hypertensive individuals in 2 large cohorts. Overall, 55,898 female Nurses’ Health Study and 18,232 male Health Professionals Follow-Up Study participants with prevalent HBP were included.
  • Yogurt intake was inversely associated with CVD risk (myocardial infarction and stroke) among hypertensive participants. Among participants consuming ≥2 servings/week of yogurt, women had a 17% lower risk while men experienced a 21% lower CVD risk compared to those who consumed <1 serving/month.

Normal/high-fat milk consumption is associated with higher lean body and muscle mass in Japanese women aged between 40 and 60 years: a cross-sectional study. Sukenobe Y, Terauchi M, Hirose A, Hirano M, Akiyoshi M, Kato K, Miyasaka N. BMC Womens Health. 2018 Feb 2;18(1):32.

  • Milk is known to contain various nutrients that may have health benefits for postmenopausal women who are at an increased risk of cardiovascular and musculoskeletal diseases.
  • The researchers investigated the association between whole- and low-fat milk consumption and body composition in 85 Japanese women aged 40 to 60 years.
  • Compared with non-consumers and exclusive low-fat milk consumers, exclusive high-fat milk consumers had significantly higher lean body mass and muscle mass. Both lean body and muscle masses were significantly correlated with vitamin D intake from milk.

The role of whey protein in postprandial glycaemic control. Stevenson EJ, Allerton DM. Proc Nutr Soc. 2018 Feb;77(1):42-51.

  • Epidemiological studies demonstrate that poor glycemic control is an independent risk factor for cardiovascular disease. There is a need for more refined strategies to tightly control postprandial glycemia, particularly in those with type 2 diabetes, and nutritional strategies around meal consumption may be effective in enhancing subsequent glycemic control.
  • Whey protein administration around meal times has been demonstrated to reduce postprandial glycemia, mediated through various mechanisms including an enhancement of insulin secretion. Whey protein ingestion has also been shown to elicit an incretin effect, enhancing the secretion of glucose-dependent insulinotropic peptide and glucagon-like peptide-1, which may also influence appetite regulation.
  • Acute intervention studies have shown some promising results however many have used large dosages (50-55 g) of whey protein alongside high-glycemic index test meals, such as instant powdered potato mixed with glucose, which does not reflect realistic dietary strategies. Long-term intervention studies using realistic strategies around timing, format and amount of whey protein in relevant population groups are required.

Higher dairy food intake is associated with higher spine Quantitative Computed Tomography (QCT) bone measures in the Framingham Study for men but not women. van Dongen LH, Kiel DP, Soedamah-Muthu SS, Bouxsein ML, Hannan MT, Sahni S. J Bone Miner Res. 2018 Feb 26.

  • Previous studies found that dairy foods were associated with higher areal bone mineral density (BMD). However, data on bone geometry or compartment specific bone density is lacking.
  • In this cross-sectional study, the association of milk, yogurt, cheese, cream, milk + yogurt and milk + yogurt + cheese intakes were examined on bone parameters. Participants were 1,522 men and 1,104 women from the Framingham Heart Study.
  • In men, higher intake of milk, milk + yogurt and milk + yogurt + cheese was associated with higher integral and trabecular volumetric BMD and vertebral compressive strength. Further, a higher cheese intake was related with higher cross-sectional area. The associations appeared to be stronger in older men.
  • In women, no significant results were observed for the dairy foods, except for a positive association of cream intake with cross-sectional area.

Milk and other dairy foods and risk of hip fracture in men and women. Feskanich D, Meyer HE, Fung TT, Bischoff-Ferrari HA, Willett WC. Osteoporos Int. 2018 Feb;29(2):385-396.

  • The purpose of this study was to examine whether higher milk and dairy food consumption are associated with risk of hip fracture in older adults following a report of an increased risk for milk in Swedish women.
  • In two US cohorts, 80,600 postmenopausal women and 43,306 men over 50 years of age were followed for up to 32 years.
  • Each serving of milk per day was associated with a significant 8% lower risk of hip fracture in men and women combined. A suggestive inverse association was found for cheese in women only. Total dairy food intake, of which milk contributed about half, was associated with a significant 6% lower risk of hip fracture per daily serving in men and women.
  • In conclusion, in this group of older US adults, higher milk consumption was associated with a lower risk of hip fracture, with a glass of milk per day associated with an 8% lower risk of hip fracture.