Please take a look at the November 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

An assessment of the economic costs to the U.S. dairy market of antimicrobial use restrictions. Lhermie G, Tauer LW, Gröhn YT. Prev Vet Med. 2018 Nov 15;160:63-67.

  • Antimicrobial resistance is a public threat for humans, generated by the use of antimicrobials in human medicine as well as animal agriculture. Consequently, governments set public policies aim at curbing antimicrobial use (AMU).
  • In dairy production, the occurrence of diseases triggers AMU to limit the costs associated with these afflictions. Therefore, any policies targeting AMU are likely to generate additional costs for farmer, and impact the dairy market.
  • The objective of our research was to assess at the market level the costs associated with potential regulations (a prohibition scenario and tax scenarios) surrounding antimicrobial use in the U.S. dairy sector, comparing to a business as usual scenario.
  • The researchers conducted a two-step analysis, first at the farm and then the market level, to estimate the costs to both farmers and consumers.
  • They found that potential policies restricting AMU would have a minor effect at the market level. In the case of prohibition of AMU, the average milk price would rise from $0.423 to $0.425 per liter. In the short run, the total annual losses would be $152 million.
  • Implementing taxes on AMU would also slightly increase milk price, up to $0.426 in the case of a tax multiplying by five the initial antimicrobial price. Under the prohibition scenario, the quantity of milk produced would decrease by 356 million kilograms, representing 0.4% of the average U.S. milk production over the period 2012-2016.
  • Implementing such policies would lead to a slight increase in costs of production, borne by both consumers and farmers through higher milk prices and lower milk production. As AMU in animal agriculture also fulfills animal welfare and public health objectives, the impacts of restricting AMU should be weighed with these other objectives in policy decisions.

A survey of dairy cow farmers in the United Kingdom: knowledge, attitudes and practices surrounding antimicrobial use and resistance. Higham LE, Deakin A, Tivey E, Porteus V, Ridgway S, Rayner AC. Vet Rec. 2018 Nov 9. pii: vetrec-2018-104986.

  • Antimicrobial resistance (AMR) is among the most pressing challenges facing humanity.
  • This survey of dairy cow farmers (n=372) was conducted to explore knowledge, attitudes and practices surrounding veterinary medicine use and to identify farmer-led solutions to reducing, replacing and refining antimicrobial use.
  • In this survey, antimicrobials were the most commonly reported veterinary medicines used.
  • Mastitis was rated as the most important health and welfare challenge and was the most common reason for medicine use.
  • Frequency of veterinary contact was associated with a decrease in the use of antibiotic footbaths, more ‘responsible’ treatment choices and increased knowledge of AMR. Purchasing medicine from a vet practice rather than elsewhere was associated with an increased likelihood of disposing of waste milk responsibly.
  • These findings highlight the important role of veterinarians in guiding responsible medicine use. 99% of participants stated that they were trying to reduce their antimicrobial use. Farmers suggested a wide array of alternative treatments and potential interventions for managing herd health.
  • Findings from this project could be used to target education and training surrounding best practice, supporting the important role that farmers play in protecting public health.

Microbial exposure to dairy farmers’ dwellings and COPD occurrence. Barrera C, Rocchi S, Degano B, Soumagne T, Laurent L, Bellanger AP, Laplante JJ, Millon L, Dalphin JC, Reboux G. Int J Environ Health Res. 2018 Nov 21:1-13.

  • Dairy farming is a risk factor for chronic obstructive pulmonary disease (COPD).
  • The aim of this study was to determine predictive markers either in blood samples or in dwelling dust samples by comparing COPD and healthy controls with or without farming activity.
  • The dwelling exposure of farmers was higher than in the non-farmers (Especially Eurotium amstelodami and Lichtheimia corymbifera). The IgG response against Wallemia sebi and Saccharopolyspora rectivirgula was more often higher in the farmers than the non-farmers.
  • However, exposure and sensitization to the microorganisms tested cannot explain the occurrence of COPD in the dairy farmers’ population. COPD development is probably caused by multiple factors associated with exposure over a period of several years.

Cow-to-mouse fecal transplantations suggest intestinal microbiome as one cause of mastitis. Ma C, Sun Z, Zeng B, Huang S, Zhao J, Zhang Y, Su X, Xu J, Wei H, Zhang H. Microbiome. 2018 Nov 8;6(1):200.

  • Mastitis, which affects nearly all lactating mammals including human, is generally thought to be caused by local infection of the mammary glands. For treatment, antibiotics are commonly prescribed, which however are of concern in both treatment efficacy and neonate safety.
  • Here, using bovine mastitis which is the most costly disease in the dairy industry as a model, the researchers showed that intestinal microbiota alone can lead to mastitis.
  • Fecal microbiota transplantation (FMT) from mastitis, but not healthy cows, to germ-free (GF) mice resulted in mastitis symptoms in mammary gland and inflammations in serum, spleen, and colon.
  • Probiotic intake in parallel with FMT from diseased cows led to relieved mastitis symptoms in mice, by shifting the murine intestinal microbiota to a state that is functionally distinct from either healthy or diseased microbiota yet structurally similar to the latter.
  • Despite conservation in mastitis symptoms, diseased cows and mice shared few mastitis-associated bacterial organismal or functional markers, suggesting striking divergence in mastitis-associated intestinal microbiota among lactating mammals.
  • Hence, dysbiosis of intestinal microbiota may be one cause of mastitis, and probiotics that restore intestinal microbiota function are an effective and safe strategy to treat mastitis.

Illumina sequencing analysis of the ruminal microbiota in high-yield and low-yield lactating dairy cows. Tong J, Zhang H, Yang D, Zhang Y, Xiong B, Jiang L. PLoS One. 2018 Nov 13;13(11):e0198225.

  • In this study, differences in the ruminal bacterial community between high-yield and low-yield lactating dairy cows under the same dietary conditions were investigated.
  • Sixteen lactating dairy cows with similar parity and days in milk were divided into high-yield (HY) and low-yield (LY) groups based on their milk yield. On day 21, rumen content samples were collected, and their microbiota compositions were determined.
  • The results showed that the milk of the LY group tended to have higher fat, protein and total solid contents than that of the HY group, while the HY group had higher ruminal propionate proportion and volatile fatty acid (VFA) concentrations.
  • Further analysis indicated significant differences in ruminal bacterial community compositions and structures between the HY group and LY group. The abundances of Ruminococcus 2, Lachnospiraceae and Eubacterium coprostanoligenes were significantly higher in the HY group than in the LY group.
  • In addition, Bacteroides, Ruminococcus 2 and Candidatus-Saccharimonas were positively correlated with ruminal propionate proportion.
  • These findings enhance the understanding of bacterial synthesis within the rumen and reveal an important mechanism underlying differences in milk production in dairy cows.

Drinking water intake of newborn dairy calves and its effects on feed intake, growth performance, health status, and nutrient digestibility. Wickramasinghe HKJP, Kramer AJ, Appuhamy JADRN. J Dairy Sci. 2018 Nov 8. pii: S0022-0302(18)31058-0.

  • Although it is recommended to offer free drinking water (called drinking water hereafter) immediately after birth, producers wait, on average, 17 d to first offer drinking water to newborn dairy calves.
  • The objective of this study was to examine water and feed intake, growth performance, health status, and nutrient digestibility of Holstein heifer calves offered drinking water from birth (W0) as compared with those offered it at 17 d of age (W17), when fed an ad libitum volume of milk.
  • 30 Holstein heifer calves were randomly assigned (n = 15) to W0 or W17. Calves had free access to drinking water and a starter ration, offered in 2 separate buckets, until they were 70 d of age. Calves were bottle-fed with pasteurized whole milk 3× per day. Calves were partially weaned at 42 d of age and completely weaned at 49 d of age.
  • When offered from birth, newborn calves consumed 0.75 ± 0.05 kg/d water aside from the water they received from ad libitum milk allowance during the first 16 d. Once offered, W17 calves drank more water (59%) than W0 calves during the preweaning period.
  • Starter intake of W0 and W17 calves was similar, but W0 calves consumed 0.285 kg/d more milk and tended to achieve greater body weight and heart girth compared with W17 calves during the preweaning period.
  • Offering water from birth versus offering it later did not affect the number of days with diarrhea, intensity of diarrhea, or blood hematocrit and haptoglobin concentrations of preweaned calves.
  • Despite a similar starter intake, W0 calves had greater hip height, body length, apparent total-tract digestibility of acid detergent fiber and neutral detergent fiber, and feed efficiency than W17 calves postweaning (50 to 70 d of age). When followed up to 5 mo of age, W0 calves had greater body weight than W17 calves.
  • In conclusion, the trovision of drinking water immediately after birth could improve growth and development of calves pre- and postweaning, potentially by stimulating rumen development, thus increasing nutrient availability.

Decreasing farm number benefits the mitigation of agricultural non-point source pollution in China. Fan L, Yuan Y, Ying Z, Lam SK, Liu L, Zhang X, Liu H, Gu B. Environ Sci Pollut Res Int. 2018 Nov 7.

  • Agricultural non-point source pollution causes global warming and the deterioration of air and water quality.
  • It is difficult to identify and monitor the emission sources of agricultural pollution due to the large number of farms in China. Many studies focus on the technological aspect of achieving agricultural sustainability, but its socioeconomic aspect is poorly understood.
  • In this study the researchers report how group size (number of farms in a certain region) affects agricultural pollution governance through conducting a social science experiment.
  • They found that when communication was allowed among group members, a small group size facilitated cooperation.
  • These findings suggest that reducing number of farms and extending the length of farm property rights can benefit the mitigation of agricultural non-point pollution in China.

Using microalgae in the circular economy to valorize anaerobic digestate: challenges and opportunities. Stiles WAV, Styles D, Chapman SP, Esteves S, Bywater A, Melville L, Silkina A, Lupatsch I, Fuentes Grünewald C, Lovitt R, Chaloner T, Bull A, Morris C, Llewellyn CA. Bioresour Technol. 2018 Nov;267:732-742.

  • Managing organic waste streams is a major challenge for the agricultural industry.
  • Anaerobic digestion (AD) of organic wastes is a preferred option in the waste management hierarchy, as this process can generate renewable energy, reduce emissions from waste storage, and produce fertilizer material. However, Nitrate Vulnerable Zone legislation and seasonal restrictions can limit the use of digestate on agricultural land.
  • In this paper the researchers demonstrate the potential of cultivating microalgae on digestate as a feedstock, either directly after dilution, or indirectly from effluent remaining after biofertilizer extraction.
  • Resultant microalgal biomass can then be used to produce livestock feed, biofuel or for higher value bio-products.
  • The approach could mitigate for possible regional excesses and substitute conventional high-impact products with bio-resources, enhancing sustainability within a circular economy.

Metagenomics of pasteurized and unpasteurized gouda cheese using targeted 16S rDNA sequencing. Salazar JK, Carstens CK, Ramachandran P, Shazer AG, Narula SS, Reed E, Ottesen A, Schill KM. BMC Microbiol. 2018 Nov 19;18(1):189.

  • The microbiome of cheese is diverse, even within a variety.
  • The metagenomics of cheese is dependent on a vast array of biotic and abiotic factors. Biotic factors include the population of microbiota and their resulting cellular metabolism. Abiotic factors, including the pH, water activity, fat, salt, and moisture content of the cheese matrix, as well as environmental conditions (temperature, humidity, and location of aging), influence the biotic factors.
  • This study assessed the metagenomics of commercial Gouda cheese prepared using pasteurized or unpasteurized cow milk or pasteurized goat milk via 16S rDNA sequencing.
  • Results were analyzed and compared based on milk pasteurization and source, spatial variability (core, outer, and under the rind), and length of aging (2-4 up to 12-18 months).
  • The dominant organisms in the Gouda cheeses, based on percentage of sequence reads identified at the family or genus levels, were Bacillaceae, Lactococcus, Lactobacillus, Streptococcus, and Staphylococcus.
  • More genus- or family-level (e.g. Bacillaceae) identifications were observed in the Gouda cheeses prepared with unpasteurized cow milk (120) compared with those prepared with pasteurized cow milk (92).
  • When assessing influence of spatial variability on the metagenomics of the cheese, more pronounced differences in bacterial genera were observed in the samples taken under the rind; Brachybacterium, Pseudoalteromonas, Yersinia, Klebsiella, and Weissella were only detected in these samples.
  • Lastly, the aging length of the cheese greatly influenced the number of organisms observed. Twenty-seven additional genus-level identifications were observed in Gouda cheese aged for 12-18 months compared with cheese only aged 2-4 months.
  • Collectively, the results of this study are important in determining the typical microbiota associated with Gouda cheese and how the microbiome plays a role in safety and quality.


Selected Articles on Dairy Intake and Human Health

A critical review of the role of milk and other dairy products in the development of obesity in children and adolescents. Dougkas A, Barr S, Reddy S, Summerbell CD. Nutr Res Rev. 2018 Nov 27:1-22.

  • Existing reviews suggest that milk and other dairy products do not play a role in the development of obesity in childhood, but they do make an important contribution to children’s nutrient intake. It is thus curious that public health advice on the consumption of dairy products for children is often perceived as unclear.
  • The present review aimed to provide an overview of the totality of the evidence on the association between milk and other dairy products, and obesity and indicators of adiposity, in children
  • The researchers identified 43 cross-sectional studies, 31 longitudinal cohort studies and 20 randomised controlled trials.
  • They found that milk and other dairy products are consistently found to be not associated, or inversely associated, with obesity and indicators of adiposity in children. Adjustment for energy intake tended to change inverse associations to neutral.
  • Also, they found little evidence to suggest that the relationship varied by type of milk or dairy product, or age of the children, although there was a dearth of evidence for young children. Only 9 of the 94 studies found a positive association between milk and other dairy products and body fatness.
  • In conclusion, there is little evidence to support a concern to limit the consumption of milk and other dairy products for children on the grounds that they may promote obesity.

Different Growth Patterns Persist at 24 Months of Age in Formula-Fed Infants Randomized to Consume a Meat- or Dairy-Based Complementary Diet from 5 to 12 Months of Age. Tang M, Andersen V, Hendricks AE, Krebs NF. J Pediatr. 2018 Nov 6. pii: S0022-3476(18)31460-4.

  • The purpose of this study was to test the long-term effect on growth status at 24 months of age in formula-fed infants who were randomized to consume a meat-based (n = 27) or dairy-based (n=26) complementary diet from 5 to 12 months of age.
  • Observational assessments, including anthropometric, dietary, and blood biomarkers, were conducted at 24 months of age, 1 year after the intervention ended.
  • At 24 months of age, weight-for-age z score did not differ significantly between groups and was similar to that at 12 months. Length-for-age z score remained significantly higher in the meat group compared with the dairy group, and the average length was 1.9 cm greater in the meat group. Weight-for-length z score also did not differ significantly between groups.
  • Insulin-like growth factor 1 significantly increased from 12 to 24 months of age in both groups, but insulin-like growth factor-binding protein 3 and blood urea nitrogen did not change significantly from 12 to 24 months of age and were comparable between groups.
  • The protein source-induced distinctive growth patterns observed during infancy persisted at 24 months of age, suggesting a potential long-term impact of early protein quality on growth trajectories in formula-fed infants.

Association of calcium and dairy product consumption with childhood obesity and the presence of a Brain Derived Neurotropic Factor-Antisense (BDNF-AS) polymorphism. Marcos-Pasero H, Aguilar-Aguilar E, de la Iglesia R, Espinosa-Salinas I, Gómez-Patiño M, Colmenarejo G, de Molina AR, Reglero G, Loria-Kohen V. Clin Nutr. 2018 Nov 20. pii: S0261-5614(18)32536-6.

  • Calcium and dairy products have multiple health benefits.
  • The objective of this work was to evaluate the association between calcium/dairy intake, blood pressure, the BDNF-AS rs925946 polymorphism and nutritional status in a group of schoolchildren.
  • As part of the GENYAL study to childhood obesity prevention, 221 children belonging to different areas of the Community of Madrid were enrolled. Anthropometric and dietary data were collected, and children were genotyped according to the rs925946 polymorphism.
  • A significantly lower consumption of calcium in overweight versus normal weight children was observed. Moreover, an inverse association between blood pressures and calcium intake was detected. The number of dairy servings/day showed a protective effect against overweight.
  • Finally, common homozygous children (GG) showed an inverse association between the calcium intake and the BMI, which was not observed in children carrying the T allele.
  • Calcium and dairy were strongly associated with the nutritional status and blood pressure. The identification of differential effects of calcium/dairy consumption on the nutritional status according to genetics may contribute to the personalization of future nutritional advice.

A Mediterranean diet supplemented with dairy foods improves mood and processing speed in an Australian sample: results from the MedDairy randomized controlled trial. Wade AT, Davis CR, Dyer KA, Hodgson JM, Woodman RJ, Keage HAD, Murphy KJ. Nutr Neurosci. 2018 Nov 8:1-13.

  • The Mediterranean diet has been linked to improved cognitive function and reduced risk of dementia. However, a traditional Mediterranean diet may not meet calcium requirements for older non-Mediterranean populations, which could limit long-term sustainability in Western countries.
  • The current study therefore aimed to determine the cognitive and psychological effects of a Mediterranean diet with adequate calcium for an ageing Australian population.
  • A randomized controlled cross-over design trial compared a Mediterranean diet with 3-4 daily serves of dairy food (MedDairy) with a low-fat (LF) control diet. Forty-one participants aged ≥45 years completed each dietary intervention for 8 weeks, with an 8-week washout period separating interventions.
  • Significant improvements were observed for processing speed, Total Mood Disturbance, Tension, Depression, Anger, and Confusion following the MedDairy intervention. No significant effects were found for attention, memory and planning, or measures of dementia risk.
  • Thisstudy provides evidence that a Mediterranean diet supplemented with dairy foods may benefit cognitive function and psychological well-being in an ageing population at risk of dementia.

Lactose Maldigestion, Malabsorption, and Intolerance: A Comprehensive Review with a Focus on Current Management and Future Perspectives. Fassio F, Facioni MS, Guagnini F. Nutrients. 2018 Nov 1;10(11). pii: E1599.

  • Milk is a fundamental component of the diet of every mammal; nevertheless, not every individual can tolerate this kind of food, especially in adulthood. However, lactose intolerance has only been recognized in the last 50 years, and currently, lactose intolerance is defined as a clinical syndrome characterized by pain, abdominal distention, flatulence, and diarrhoea that occur after lactose consumption.
  • The aim of this paper was to review the current knowledge about lactose intolerance and to discuss the potential for the use of specific probiotic strains such as dietary supplements in lactose-intolerant patients.
  • Lactose is currently a common disaccharide in human nutrition, both in breastfed infants and in adults, but its digestion requires a specialized enzyme called lactase. The genetically programmed reduction in lactase activity during adulthood affects most of the world’s adult population and can cause troublesome digestive symptoms, which may also vary depending on the amount of residual lactase activity; the small bowel transit time; and, especially, the amount of ingested lactose.
  • The treatment for lactose intolerance mainly consists of reducing or eliminating the dietetic amount of lactose until the symptoms disappear, but this is hard to achieve, as lactose is present in dairy products and is even commonly used as a food additive.
  • In addition to dietetic restriction of lactose-containing foods, lactase can be administered as an enzymatic food supplement, but its efficacy is still controversial. Recently, probiotics have been proposed for the management of lactose intolerance; certain probiotic strains have shown specific β-galactosidase activity, thus aiding in the digestion of lactose.

Milk intake and mammographic density in premenopausal women. Han Y, Zong X, Li Y, Colditz GA, Toriola AT. Breast Cancer Res Treat. 2018 Nov 20.

  • Mammographic density is a strong risk factor for breast cancer. Although diet is associated with breast cancer risk, there are limited studies linking adult diet, including milk intake, with mammographic density.
  • Here, the researchers investigated the association of milk intake with mammographic density in premenopausal women.
  • They analyzed data from 375 cancer-free premenopausal women who had routine screening mammography at Washington University School of Medicine, St. Louis, Missouri in 2016.
  • The results showed that volumetric percent density was 20% lower in the 1 dairy serving/week group, 14% lower in the 2-6 dairy servings/week group, and 12% lower in the ≥ 1 dairy servings/day group compared with women who consumed low/reduced-fat milk < 1 serving/week.
  • Attenuated and non-significant associations were observed for low/reduced-fat milk intake and dense volume. There were no associations of whole, skim, and soy milk intake with volumetric percent density and dense volume.
  • Studies on childhood and adolescent milk intake and adult mammographic density in premenopausal women are needed.