Dairy Research Bulletin: Selected Articles from July 2023 - California Dairy Research Foundation

Environmental Management and Sustainability

Policy Analysis of CO₂ Capture and Sequestration with Anaerobic Digestion for Transportation Fuel Production. Leonhardt BE, Tyson RJ, Taw E, Went MS, Sanchez DL. Environ Sci Technol. 2023 Jul 26.

Low carbon fuel and waste management policies at the federal and state levels have catalyzed the construction of California’s wet anaerobic digestion (AD) facilities.
Wet ADs can digest food waste and dairy manure to produce compressed natural gas (CNG) for natural gas vehicles or electricity for electric vehicles (EVs). Carbon capture and sequestration (CCS) of CO₂generated from AD reduces the fuel carbon intensity by carbon removal in addition to avoided methane emissions.
Using a combined lifecycle and techno-economic analysis, researchers aimed to determine the most cost-effective design under current and forthcoming federal and state low carbon fuel policies.
Under many scenarios, designs that convert biogas to electricity for EVs (Biogas to EV) are favored; however, CCS is only cost-effective in these systems with policy incentives that exceed $200/ton of CO₂ Adding CCS to CNG-producing systems (Biogas to CNG) only requires a single unit operation to prepare the CO₂for sequestration, with a sequestration cost of $34/ton.
When maximizing negative emissions is the goal, incentives are needed to either (1) fund CCS with Biogas to EV designs or (2) favor CNG over electricity production from wet AD facilities.

Scientific characterization methods for better utilization of cattle dung and urine: a concise review. Singh Y, Rani J, Kushwaha J, Priyadarsini M, Pandey KP, Sheth PN, Yadav SK, Mahesh MS, Dhoble AS. Trop Anim Health Prod. 2023 Jul 20;55(4):274.

Cattle are usually raised for food, manure, leather, therapeutic, and draught purposes. Biowastes from cattle, such as dung and urine, harbor a diverse group of crucial compounds, metabolites/chemicals, and microorganisms that may benefit humans for agriculture, nutrition, therapeutics, industrial, and other utility products.
Several bioactive compounds have been identified in cattle dung and urine, which possess unique properties and may vary based on agro-climatic zones and feeding practices. Therefore, cattle dung and urine have great significance, and a balanced nutritional diet may be a key to improved quality of these products/by-products.
This review primarily focuses on the scientific aspects of biochemical and microbial characterization of cattle biowastes. Various methods including genomics for analyzing cattle dung and gas chromatography-mass spectroscopy for cattle urine have been reviewed.
The presented information might open doors for the further characterization of cattle resources for heterogeneous applications in the production of utility items and addressing research gaps. Methods for cattle’s dung and urine characterization.

Effect of anaerobic digestion on odor and ammonia emission from land-applied cattle manure. Lemes YM, Nyord T, Feilberg A, Hafner SD, Pedersen J. J Environ Manage. 2023 Jul 15;338:117815.

High ammonia (NH₃) and odor emission can occur after land application of liquid animal manure.
This study was aimed at evaluating NH₃loss and odor nuisance after field application of cattle manure and how it is affected by two anaerobic digestion strategies: i) digestion of cattle manure alone and ii) digestion with catch crops and dilution by water.
A system of dynamic chambers with online measurements of NH₃and odorous compounds (summarized as odor activity value, OAV) was used. Two experiments were conducted under different temperature conditions.
The results demonstrated that anaerobic digestion did not affect NH₃loss but did decrease OAV. Addition of catch crops and water to the digestion process reduced both NH₃ loss and OAV.
Cool temperature in one of the experiments had a large effect on both NH₃and odor emissions, and at high temperature the differences between treatments increased.

Relating bacterial dynamics and functions to greenhouse gas and odor emissions during facultative heap composting of four kinds of livestock manure. Li L, Liu Y, Kong Y, Zhang J, Shen Y, Li G, Wang G, Yuan J. J Environ Manage. 2023 Jul 12;345:118589.

Although facultative heap composting is widely used in small and medium-sized livestock farms in China, there are few studies on greenhouse gas (GHG) and odor emissions from this composting system.
This study focused on GHG and odor emissions from facultative heap composting of four types of livestock manure and revealed the relationship between the gaseous emissions and microbial communities.
Results showed that pig, sheep, and cow manure reached high compost maturity (germination index (GI) > 70%), whereas chicken manure had higher phytotoxicity (GI = 0.02%) with higher electrical conductivity and a lower carbon/nitrogen ratio.
The four manure types significantly differed in the total GHG emission, with the following pattern: pig manure (308 g CO₂-eq·kg^-1) > cow manure (146 g CO₂-eq·kg^-1) > chicken manure (136 g CO₂-eq·kg^-1) > sheep manure (95 g CO₂-eq·kg^-1).
Bacterium with Fermentative, Methanotrophy and Nitrite respiratory functions (e.g. Pseudomonas and Lactobacillus) were enriched within the piles so that more than 90% of the GHGs were produced in the early (days 0-15) and late (days 36-49) composting periods.
CO₂contributed more than 90% in the first 35 days, N₂O contributed 40-75% in the late composting period, and CH₄ contributed less than 8.0%. NH₃ and H₂S emissions from chicken and pig manure were 4.8 times those from sheep and cow manure.
Overall, the gas emissions from facultative heap composting significantly differed among the four manure types due to the significant differences in their physicochemical properties and microbial communities.

Microbial composition, rumen fermentation parameters, enteric methane emissions, and lactational performance of phenotypically high and low methane-emitting dairy cows. Stepanchenko N, Stefenoni H, Hennessy M, Hristov AN, et al. J Dairy Sci. 2023 Jul 19:S0022-0302(23)00402-2.

Methane (CH₄) is a potent greenhouse gas, representing approximately 10% of the total greenhouse gas emissions in the United States. In addition to the environmental burden created by enteric CH₄, it also represents a 4 to 12% gross feed energy loss in cattle and therefore reveals a theoretical potential to improve production performance.
This experiment was designed to investigate the relation of high and low methane-yield phenotypes with body weight (BW), dry matter intake (DMI), lactation performance, enteric CH₄emissions, and rumen fermentation parameters in lactating dairy cows.
A total of 130 multi- and primiparous Holstein cows were screened for enteric CH₄emissions using the GreenFeed system (C-Lock Inc.).
Out of these 130 cows, 5 were identified as phenotypically high (HM) and 5 as phenotypically low (LM) CH₄ Cows in the LM group had lower daily enteric CH₄emissions than cows in the HM group (on average 346 vs. 439 g/d, respectively), lower CH₄ yield (15.5 vs. 20.4 g of CH₄/kg of DMI), and CH₄ intensity (13.2 vs. 17.0 g of CH₄/ kg of energy-corrected milk yield).
Enteric emissions of CO₂and H₂ did not differ between HM and LM cows. These 10 cows were blocked by parity, days in milk, and milk production, and were used in a 5-week randomized complete block design experiment. Milk composition, production, and BW were also not different between LM and HM cows. The concentration of total volatile fatty acids in ruminal contents did not differ between CH₄ phenotypes, but LM cows had a lower molar proportion of acetate (57 vs. 62.1%), a higher proportion of propionate (27.5 vs. 21.6%, respectively), and therefore a lower acetate-to-propionate ratio than HM cows.
Consistently, the 16S cDNA analysis revealed the abundance of Succinivibrionaceae and unclassified Veillonellaceae to be higher in LM cows compared with HM cows, bacteria that were positively correlated with ruminal propionate concentration.
In this study, low and high CH₄-yield cows have similar production performance and milk composition, but total-tract apparent digestibility of organic matter and fiber fractions was lower in the former group of animals.

Enteric and manure emissions from Holstein-Friesian dairy cattle fed grass silage-based or corn silage-based diets. van Gastelen S, Jan van Dooren H, Bannink A. J Dairy Sci. 2023 Jul 19:S0022-0302(23)00390-9.

This study aimed to evaluate trade-offs between enteric and manure CH₄emissions, and the size of synergistic effects for CH₄ and nitrogenous emissions (NH₃ and N₂O).
Sixty-four Holstein-Friesian cows were blocked in groups of 4 based on parity, lactation stage, and milk yield. Cows within a block were randomly allocated to a dietary sequence in a crossover design with a grass silage-based diet and a corn silage-based diet.
The GS diet consisted of 50% grass silage and 50% concentrate, and CS consisted of 10% grass silage, 40% corn silage, and 50% concentrate (dry matter basis). The composition of the concentrate was identical for both diets.
Cows were housed in groups of 16 animals, in 4 mechanically ventilated barn units for independent emission measurement. Treatment periods were composed of a 2-week adaptation period followed by a 5-week measurement period, 1 week of which was without cows to allow separation of enteric and manure emissions. In each barn unit, ventilation rates and concentrations of CH₄, CO₂, NH₃, and N₂O in incoming and outgoing air were measured.
Cow excretion of organic matter was higher for corn silage compared with grass silage. Enteric CH₄and cow-associated NH₃ and N₂O emissions (i.e., manure emissions excluded) were lower for corn silage compared with grass silage (-11, -40, and -45%, respectively). The CH₄ and N₂O emissions from stored manure (i.e., in absence of cows) were not affected by diet, whereas that of NH₃ emission tended to be lower for corn compared with grass.
In conclusion, there was no trade-off between enteric and manure CH₄emissions, and there were synergistic effects for CH₄ and nitrogenous emissions when grass silage was exchanged for corn silage, without balancing the diets for crude protein content, in this short-term study.

Recoupling livestock and feed production in the Netherlands to reduce environmental impacts. van Selm B, Hijbeek R, van Ittersum MK, van Hal O, van Middelaar CE, de Boer IJM. Sci Total Environ. 2023 Jul 17:165540.

In many places on earth, livestock and feed production are decoupled, as feed is grown in one region and fed to livestock in another. This disrupts nutrient cycles by depleting resources in feed producing regions and accumulating resources in livestock areas, which leads to environmental degradation.
One solution is to recouple livestock and feed production at a more local level, which enhances nutrient circularity. Recoupling livestock and feed production creates a natural ceiling for livestock numbers based on the feed producing capacity of a region.
In this study we assess the consequences of recoupling livestock and feed production (i.e., by avoiding the import and export of animal feed) on ammonia and greenhouse gas (GHG) emissions, with and without feed-food competition.
To this end, the researchers in this study used FOODSOM, an agro-ecological food system optimisation model representing the Dutch food system.
The researchers found that recoupling decreased livestock numbers (beef cattle: -100 %; dairy cattle: -29 %; broiler chickens: -57 %; laying hens: -67 %; pigs: -62 %; sheep -100 %) and animal-sourced food exports (-59 %) in the Netherlands. Consequently, ammonia emissions and GHG emissions decreased, and the nitrogen use efficiency increased from 31 % to 38 % at the food systems level.
Recoupling alone was almost sufficient to meet national emission targets. Fully meeting these targets required further small changes in livestock numbers. Avoiding feed-food competition decreased livestock productivity and GHG emissions but did not improve nitrogen use efficiency.
Total meat production could not meet domestic consumption levels while avoiding feed-food competition, and resulted in additional beef cattle. Overall, the researchers were able to show that recoupling livestock and feed production is a promising next step to enhance circularity while decreasing agricultures environmental impact.

Climate change and socio-economic assessment of PLF in dairy farms: Three case studies. Lovarelli D, Leso L, Bonfanti M, Porto SMC, Barbari M, Guarino M. Sci Total Environ. 2023 Jul 15;882:163639.

Precision Livestock Farming (PLF) techniques include sensors and tools to install on livestock farms and/or animals to monitor them and support the decision-making process of farmers, finally early detecting alerting conditions and improving the livestock efficiency.
Direct consequences of this monitoring include enhanced animal welfare, health and productivity, improved farmer lifestyle, knowledge, and traceability of livestock products. The indirect consequences, instead, include improved Carbon Footprint and socio-economic indicators of livestock products.
In this context, the aim of this paper is to develop an indicator applicable to dairy cattle farming that takes into account concurrently these indirect consequences. The indicator was developed combining the three sustainability pillars (with specific criteria): environmental (carbon footprint), social (5 freedoms of animal welfare and antimicrobial use) and economic (cost of technology and manpower use).
The indicator was then tested on 3 dairy cattle farms located in Italy, where a baseline traditional scenario (BS) was compared with an alternative scenario (AS) where PLF techniques and improved management solutions were adopted.
The results highlighted that the carbon footprint reduced in all AS by 6-9 %, and the socio-economic indicators entailed improvements in animals and workers welfare with some differences based on the tested technique. Investing in PLF techniques determines positive effects on all/almost all the criteria adopted for the sustainability indicator, with case-specific aspects to consider.
Being a user-friendly tool that supports the testing of different scenarios, this indicator could be used by stakeholders (policy makers and farmers in particular) to identify the best direction towards investments and incentive policies.

Animal Health and Food Safety

Increased incidence of reproductive disorders associated with short gestation length in Holstein dairy cows. Pajohande K, Amirabadi Farahani T, Farsuni NE. Theriogenology. 2023 Jul 15;205:9-17.

Gestation length (GL) defines as the days from confirmed conception to calving. Determining the expected GL is crucial for management decisions such as drying off, movement between groups, and nutritional grouping.
The purpose of the current study was to investigate the effect of gestation length (GL) on productive performance, and the incidence of calving and reproductive diseases in Holstein dairy cows.
In total, 3780 Holstein singleton cows (2000 heifers and 1800 cows) from two commercial dairy farms were used. The average gestation length for cows in the study was 276 ± 5 days, which were classified as short (SGL; 258-270 d), average (AGL; 271-281 d), and long (LGL; range 282-294 d) gestation length.
In primiparous cows, the incidence of stillbirth, retained placenta, metritis, and clinical endometritis were higher in the SGL cows than in the AGL cows, but the incidence of dystocia was similar across groups.
In multiparous cows, the incidence of dystocia, retained placenta, and metritis were higher in the SGL cows than in the AGL cows, and the incidence of stillbirth was higher in the SGL and LGL cows than in the AGL cows.
In primiparous cows, milk yield was not different across groups. However, in multiparous cows, the SGL cows had lower milk yield than the AGL cows. In primiparous cows, the SGL cows had lower colostrum production than the AGL cows, but in multiparous cows, there was no difference in colostrum production across groups.
In general, cows with either short or long gestation length had impaired health and production, but this impact was more pronounced in cows with short gestation length.

Effects of the Breeding Strategy Beef-on-Dairy at Animal, Farm and Sector Levels. Ahmed RH, Schmidtmann C, Mugambe J, Thaller G. Animals (Basel). 2023 Jul 3;13(13):2182.

The decline in farm revenue due to volatile milk prices has led to an increase in the use of beef semen in dairy herds. While this strategy (“Beef-on-dairy” (BoD)) can have economic benefits, it can also lead to unintended consequences affecting animal welfare.
Semen sale trends from breeding organizations depict increasing sales of beef semen across the globe. Calves born from such breeding strategies can perform better when compared to purebred dairy calves, especially in terms of meat quality and growth traits.
The Beef-on-dairy strategy can lead to unintentional negative impacts including an increase in gestation length, and increased dystocia and stillbirth rates. Studies in this regard have found the highest gestation length for Limousin crossbred calves followed by calves from the Angus breed.
This increase in gestation length can lead to economic losses ranging from 3 to 5 US$ per animal for each additional day. In terms of the growth performance of crossbred animals, literature studies are inconclusive due to the vast differences in farming structure across the regions.
But almost all the studies agree regarding improvement in the meat quality in terms of color, fiber type, and intra-muscular fat content for crossbred animals. Utilization of genomic selection, and development of specialized Beef-on-dairy indexes for the sires, can be a viable strategy to make selection easier for the farmers.

CDRF-Funded Research Evaluation of Cow-Side Meters to Determine Somatic Cell Count in Individual Cow Quarter and Bulk-Tank Milk Samples. Jacobsen LA, Niesen AM, Lucey P, Rossow HA. Animals (Basel). 2023 Jul 1;13(13):2169.

Intramammary infections, which cause mastitis, can increase treatment and labor costs, decrease milk production, and affect milk quality. Meters that measure quarter somatic cell count (SCC) could be used to make more informed dry cow therapy decisions. The objective of this study was to compare the RT-10 iPhone adapter (RT-10; Dairy Quality Inc., Newmarket, ON, Canada), DeLaval Cell Counter (DSCC; DeLaval, Gurnee, IL, USA), Porta Check Quick Test (PortaCheck, White City, OR, USA), California Mastitis Test (ImmuCell, Portland, ME USA), pH meter (Hanna Instruments, Smithfield, RI, USA), electrical conductivity meter (OHAUS, Parsippany, NJ, USA), and the dual laser infrared temperature thermometer (Klein Tools, Lincolnshire, IL, USA) for measuring SCC in individual Holstein mammary quarters in comparison to a reference standard, the Fourier Transform Spectrometer 600 Combi System (Combi; Bentley Instruments, Chaska, MN, USA). Meters were evaluated using 658 individual cow quarter samples and 100 bulk-tank samples to measure SCC. Individual quarter milk samples from 160 cows from four commercial dairy herds were collected just before dry off and tested within 4 h of collection. To test bulk-tank SCC, 100 bulk-tank milk samples (25 mL) were collected from UC Davis Veterinary Medicine Teaching and Research Milk Quality Lab. Meter SCC values were regressed on observed Combi SCC. Goodness of fit was then evaluated by partitioning the mean square predicted error (MSPE). For individual quarter SCC, RT-10 had the highest coefficient of determination (R²= 0.86), lowest MSPE, and highest proportion of MSPE due to random variation (96%). Both the RT-10 and DSCC had the highest sensitivity and specificity for identifying quarter SCC above and below 200,000 cells/mL. For bulk-tank SCC, DSCC had the highest coefficient of determination (R² = 0.45), lowest MSPE, and highest proportion of MSPE due to random variation (80%). The RT-10 and DSCC could be used to measure individual quarter SCC to determine which cows to treat at dry off potentially reducing antibiotic use.

Comprehensive review of resveratrol as a feed additive in dairy cows: exploring its potential diverse effects and implications. Rezaei Ahvanooei MR, Norouzian MA, Hedayati M, Ghaffari MH. Vet Res Commun. 2023 Jul 8.

Heat stress and growing demand for dairy products in tropical regions exert metabolic pressure on dairy cows, leading to metabolic diseases and economic losses. Resveratrol (RSV) is known for its numerous beneficial health effects and can be used as a barrier against metabolic abnormalities and prevent economic losses. Several studies have investigated the effects of RSV in humans and various animal species.
In this review, researchers attempted to investigate the effects of RSV from different aspects so that they could have a practical proposal for its utilization in dairy cows.
RSV was found to have potential antioxidant, anti-inflammatory, anti-obesity, and antimicrobial effects, leading to improved reproductive performance.
It is interesting that the effect of RSV on the microbial population leads to a significant decrease in methane emissions. However, high doses of RSV have been associated with possible adverse effects, underscoring the dose dependence of its efficacy.
In conclusion, RSV polyphenol at optimal doses is a promising agent for the prevention and treatment of metabolic abnormalities in dairy cows, based on our literature review and study results.

Evaluating the effects of direct-fed microbial supplementation on the performance, milk quality and fatty acid of mid-lactating dairy cows. Asil AK, Mohammadabadi T, Chaji M, Direkvandi E. Vet Med Sci. 2023 Jul 7.

The use of direct-fed microbial (DFM) may improve animal health and performance.
The objective of the experiment was to investigate the effect of a mixture of DFM on feed intake, nutrient digestibility, milk yield and composition, milk fatty acid and blood parameter in crossbred mid-lactating cows.
Twenty-four crossbred Holstein cows were used in a completely randomized design with three treatments:
1. CON = control without DFM
2. LS = inoculation with Lactobacillus fermentum (4.5 × 10⁸ CFU/day) plus Saccharomyces cerevisiae (1.4×10¹⁰ CFU/day)
3. LSM = inoculation with LS plus Megasphaera elsdenii (4.5 × 10⁸ CFU/day).
All animals received the same ration with 45.7% forage and 54.3% concentrate.
Results showed that the highest feed intake was observed in treatments LS and LSM. Compared with the CON, milk production, 4% fat-corrected milk, energy-corrected milk, fat (kg/day), protein (kg/day) and lactose (kg/day), FE and percent of fat were increased by LSM, but unaffected by LS.
Also, compared with the CON, both LS and LSM increased antioxidant activity. The concentration of C18:2c n-6 increased significantly in treatment LSM compared with the CON. The concentration of C20:0 increased significantly in treatment LS compared with the CON.
The highest concentrations of insulin, glucose, triglyceride and cholesterol were observed by LSM. Compared with the CON, both LS and LSM increased blood monocyte, neutrophil, eosinophil and basophil, and blood lymphocyte was increased only by LSM.
In conclusion, the results showed that the use of DFMs had no effect on the digestibility, microbial load and the major part of fatty acids in milk. However, it improved feed intake, milk yield and antioxidant activity of milk and increased the milk concentration of C18:2 n-6.

Effects of Wildfire Smoke PM2.5 on Indicators of Inflammation, Health, and Metabolism of Pre-Weaned Holstein Heifers. Pace A, Villamediana P, Rezamand P, Skibiel AL. J Anim Sci. 2023 Jul 19:skad246.

Wildfires are a growing concern as large, catastrophic fires are becoming more commonplace. Wildfire smoke consists of fine particulate matter (PM2.5), which can cause immune responses and disease in humans. However, the present knowledge of the effects of wildfire-PM2.5 on dairy cattle is sparse.
The present study aimed to elucidate the effects of wildfire-PM2.5 exposure on dairy calf health and performance.
Pre-weaned Holstein heifers (n = 15) were assessed from birth through weaning, coinciding with the 2021 wildfire season. Respiratory rate, heart rate, rectal temperatures, and health scores were recorded and blood samples were collected weekly or twice a week for analysis of hematology, blood metabolites, and acute phase proteins. Hourly PM2.5 concentrations and meteorological data were obtained, and temperature-humidity index (THI) was calculated. Contribution of wildfires to PM2.5 fluxes were determined utilizing AirNowTech Navigator and HYSPLIT modeling.
THI ranged from 48 to 73, while PM2.5 reached concentrations up to 118.8 µg/m³ during active wildfires. PM2.5 and THI positively interacted to elevate respiratory rate, heart rate, rectal temperature, and eosinophils on lag day 0 (day of exposure).
There was a negative interactive effect of PM2.5 and THI on lymphocytes after a 2-day lag, and total white blood cells, neutrophils, hemoglobin, and hematocrit after a 3-day lag, whereas there was a positive interactive effect on cough scores and eye scores on lag day 3. Glucose and NEFA were increased as a result of combined elevated PM2.5 and THI on lag day 1, whereas BHB was decreased.
Contrarily, on lag day 3 and 6, there was a negative interactive effect of PM2.5 and THI on glucose and NEFA, but a positive interactive effect on BHB. Serum amyloid A was decreased whereas haptoglobin was increased with elevated PM2.5 and THI together on lag day 0 to 4.
These findings indicate that exposure to wildfire-derived PM2.5, along with increased THI during the summer months, elicits negative effects on pre-weaned calf health and performance both during and following exposure.

Human Health and Nutrition

Harnessing the Magic of the Dairy Matrix for Next-Level Health Solutions: A Summary of a Symposium Presented at Nutrition 2022. Unger AL, Astrup A, Feeney EL, Holscher HD, Gerstein DE, Torres-Gonzalez M, Brown K. Curr Dev Nutr. 2023 Jun 1;7(7):100105.

An emerging body of scientific evidence demonstrates that the food matrix-the interaction among nutrients, bioactive components, and physical structure of a food-can affect health in significant, unexpected ways beyond its individual nutrients. In particular, research suggests that consumption of dairy foods such as milk, yogurt, and cheese may affect human health in a matrix-dependent fashion.
To disseminate and discuss the growing body of evidence surrounding the role of the dairy food matrix on cardiometabolic health, 3 expert researchers on the topic of the food matrix shared the latest science in a session entitled “Next-Level Health Solutions: The Magic of the Matrix” at the American Society for Nutrition’s 2022 LIVE ONLINE Conference.
This article is a summary of the literature presented and discussed during that session. A substantial body of literature demonstrates that full-fat dairy foods, particularly fermented dairy foods, may beneficially modulate cardiometabolic outcomes depending on an individual’s health status. These findings have important implications for current authoritative dietary guidance that recommends the consumption of low-fat or fat-free dairy foods.
Furthermore, this evidence may inform practical applications of harnessing dairy’s unique profile of bioactives for health promotion and disease prevention at the individual and community levels.

Diet, cardiovascular disease, and mortality in 80 countries. Mente A, Dehghan M, Rangarajan S, Yusuf S, et al. Eur Heart J. 2023 Jul 21;44(28):2560-2579.

Unhealthy diets have been ranked as a major factor for death and cardiovascular disease (CVD) globally. Previous diet pattern scores [Dietary Approaches to Stop Hypertension (DASH), Mediterranean, Healthy Eating Index (HEI), and, more recently, the EAT-Lancet Planetary diet] have been described and their relationship to CVD and mortality has been tested mainly in Western countries.
The aim of this study was to develop a healthy diet score that is associated with health outcomes and is globally applicable using data from the Prospective Urban Rural Epidemiology (PURE) study and replicate it in five independent studies on a total of 245,000 people from 80 countries.
A healthy diet score was developed in 147,642 people from the general population, from 21 countries in the PURE study, and the consistency of the associations of the score with events was examined in five large independent studies from 70 countries. The healthy diet score was developed based on six foods each of which has been associated with a significantly lower risk of mortality [i.e. fruit, vegetables, nuts, legumes, fish, and dairy (mainly whole-fat); range of scores, 0-6].
The main outcome measures were all-cause mortality and major cardiovascular events [cardiovascular disease (CVD)]. During a median follow-up of 9.3 years in PURE, compared with a diet score of ≤1 points, a diet score of ≥5 points was associated with a lower risk of mortality [hazard ratio (HR) 0.70;], CVD (HR 0.82), myocardial infarction (HR 0.86), and stroke (HR 0.81).
In three independent studies in vascular patients, similar results were found, with a higher diet score being associated with lower mortality (HR 0.73), CVD (HR 0.79), myocardial infarction (HR 0.85), and a non-statistically significant lower risk of stroke (HR 0.87).
Additionally, in two case-control studies, a higher diet score was associated with lower first myocardial infarction [odds ratio (OR) 0.72] and stroke (OR 0.57). A higher diet score was associated with a significantly lower risk of death or CVD in regions with lower than with higher gross national incomes (P <0.0001). The PURE score showed slightly stronger associations with death or CVD than several other common diet scores (P < 0.001 for each comparison).
In conclusion, a diet comprised of higher amounts of fruit, vegetables, nuts, legumes, fish, and whole-fat dairy is associated with lower CVD and mortality in all world regions, especially in countries with lower income where consumption of these foods is low.

Ultra-Processed Food Consumption and Risk of Type 2 Diabetes: Three Large Prospective U.S. Cohort Studies. Chen Z, Khandpur N, Desjardins C, Wang L, Monteiro CA, Rossato SL, Fung TT, Manson JE, Willett WC, Rimm EB, Hu FB, Sun Q, Drouin-Chartier JP. Diabetes Care. 2023 Jul 1;46(7):1335-1344.

As defined in the NOVA food classification system, ultra-processed foods (UPFs) are industrial formulations made mostly or entirely with substances extracted from foods, often chemically modified, with additives and with little, if any, whole foods added. UPFs and their components have been shown to negatively affect gut microbiota, systemic inflammation, insulin resistance, and body weight, raising concerns about their long-term effects on cardiometabolic health
The objective of this study was to examine the relationship between UPF intake and type 2 diabetes (T2D) risk among 3 large U.S. cohorts, conducted a meta-analysis of prospective cohort studies, and assessed meta-evidence quality.
The study included 71,871 women from the Nurses’ Health Study, 87,918 women from the Nurses’ Health Study II, and 38,847 men from the Health Professional Follow-Up Study. The researchers conducted a meta-analysis of prospective cohort studies on total UPF and T2D risk, and assessed meta-evidence quality using the NutriGrade scoring system.
Among the U.S. cohorts (5,187,678 person-years; n = 19,503 T2D cases), the hazard ratio for T2D comparing extreme quintiles of total UPF intake (percentage of grams per day) was 1.46. Among subgroups, refined breads; sauces, spreads, and condiments; artificially and sugar-sweetened beverages; animal-based products; and ready-to-eat mixed dishes were associated with higher T2D risk.
Cereals; dark and whole-grain breads; packaged sweet and savory snacks; fruit-based products; and yogurt and dairy-based desserts were associated with lower T2D risk.
In the meta-analysis (n = 415,554 participants; n = 21,932 T2D cases), each 10% increment in total UPF was associated with a 12% higher risk of T2D.
In conclusion, high-quality meta-evidence shows that total UPF consumption is associated with higher T2D risk. However, some UPF subgroups (e.g., yogurt and dairy-based desserts) were associated with lower risk in the U.S. cohorts.

Dairy product consumption and risk of non-alcoholic fatty liver disease: A systematic review and meta-analysis of observational studies. Yuzbashian E, Fernando DN, Pakseresht M, Eurich DT, Chan CB. Nutr Metab Cardiovasc Dis. 2023 Aug;33(8):1461-1471.

It is unclear whether regular consumption of dairy products is associated with the risk of developing non-alcoholic fatty liver disease (NAFLD).
Thus, researchers conducted a systematic review followed by a meta-analysis of studies reporting on the association of dairy consumption with NAFLD risk.
The researchers comprehensively searched PubMed, Web of Science, and Scopus for observational studies that evaluated the association between dairy intake and NAFLD likelihood that were published before September 1, 2022. The reported odds ratios (ORs) of fully adjusted models and their 95% confidence intervals (CIs) were pooled using a random-effects model for the meta-analysis.
Eleven observational studies, including 43,649 participants and 11,020 cases, were included in the study. Pooled OR indicated a significant association between dairy intake and NAFLD (OR = 0.90, n = 11). Pooled ORs revealed that milk (OR: 0.86; n = 6), yogurt (OR: 0.88; n = 4), and high-fat dairy (OR: 0.38; n = 5) consumption was inversely associated with NAFLD while cheese was not linked to NAFLD risk.
In conclusion, researchers observed that consumption of dairy products is linked to a reduced risk of developing NAFLD. Overall, the data in the source articles is of low to moderate quality; therefore, further observational studies are required to support the current findings.

Dairy products intake and the risk of postpartum depression among mothers: A pilot study. Almasaudi AS, Alashmali S, Baattaiah BA, Zedan HS, Alkhalaf M, Omran S, Alghamdi A, Khodary A. SAGE Open Med. 2023 Jul 20;11:20503121231187756.

Postpartum depression is a prevalent consequence of childbirth experienced by many women. There has been evidence linking dairy intake during pregnancy with a reduction in postpartum depression symptoms. However, there is still a lack of understanding regarding the effects of postpartum dairy consumption on postpartum depression.
The objective of this study was to examine whether dairy products intake and calcium in dairy is associated with postpartum depression.
A pilot study was conducted (n= 49 postpartum women). A food frequency questionnaire was used to evaluate the participants’ consumption of calcium and dairy products during pregnancy, and the Edinburgh Postnatal Depression Scale was used to screen for postpartum depression symptoms.
Of 49 participants, 26 (53%) were at risk for postpartum depression (Edinburgh Postnatal Depression Scale ⩾ 12). Consuming >1 serving of Laban (a type of fermented milk) per day is significantly associated with reduced risk of postpartum depression (odds ratio = 0.01).
Total dairy intake >1 serving per day is significantly associated with reduced risk of postpartum depression (odds ratio = 0.17). No significant association was found between the postpartum intake of milk, cheese, yogurt, or calcium and postpartum depression.
These findings indicate that higher total dairy intake was associated with a lower likelihood of postpartum depression. Further assessment with a larger sample size of participants could provide additional insight into the potential of dietary dairy to mitigate postpartum depression.

Sweet dreams are made of this: association between diet and sleep quality. Oliveira JL, Marques-Vidal P. J Clin Sleep Med. 2023 Jul 25.

Numerous studies have emphasized the significance of nutrition on the quality of sleep, but little have evaluated the effect of various coexisting dietary markers on middle-aged adults.
Therefore, researchers assessed the association between sleep quality and a large array of dietary markers among middle-aged, community-dwelling participants.
Data from the first, second and third follow-ups of a population-based study in Lausanne, Switzerland, was used. Sleep quality was assessed by the Pittsburgh Sleep Quality Index (PSQI). Dietary intake was assessed by a validated food frequency questionnaire.
Data from 3857 (53% women, 57.2±10.4 years), 2370 (52% women, 60.7±9.5 years) and 1617 (52% women, 63.5±9.0 years) participants from the first, second and third follow-ups was used.
Bivariate correlations showed fish, vegetables, fruit, and cheese intake to be associated with a better sleep quality (lower PSQI), while rusks, sugar, and meat intake were associated with a poorer sleep quality (higher PSQI).
No association was found between sleep quality and macro- or micronutrients in the three surveys.
Overall,no consistent associations were found between a large panel of nutritional markers and sleep quality. Components of the Mediterranean diet such as dairy, fruits and vegetables might favor good sleep quality, while increased consumption of sugary foods or meat might favor poor sleep quality.

Whey protein powder with milk fat globule membrane attenuates Alzheimer’s disease pathology in 3×Tg-AD mice by modulating neuroinflammation through the peroxisome proliferator-activated receptor γ signaling pathway. Li Y, Zhang ZH, Huang SL, Yue ZB, Yin XS, Feng ZQ, Zhang XG, Song GL. J Dairy Sci. 2023 Aug;106(8):5253-5265.

Whey protein powder, which is mainly derived from bovine milk, is rich in milk fat globule membrane (MFGM). The MGFM has been shown to play a role in promoting neuronal development and cognition in the infant brain. However, its role in Alzheimer’s disease (AD) has not been elucidated.
In this study, researchers showed that the cognitive ability of 3×Tg-AD mice (a triple-transgenic mouse model of AD) could be improved by feeding whey protein powder to mice for 3 months. In addition, whey protein powder ameliorated amyloid peptide deposition and tau hyperphosphorylation in the brains of AD mice. We found that whey protein powder could alleviate AD pathology by inhibiting neuroinflammation through the peroxisome proliferator-activated receptor γ (PPARγ)-nuclear factor-κB signaling pathway in the brains of AD mice.
This study revealed an unexpected role of whey protein powder in regulating the neuroinflammatory pathology of AD in a mouse model.

Innovation, Economics, and Dairy Alternatives

Towards sustainable Cleaning-in-Place (CIP) in dairy processing: Exploring enzyme-based approaches to cleaning in the Cheese industry. Pant KJ, Cotter PD, Wilkinson MG, Sheehan JJ. Compr Rev Food Sci Food Saf. 2023 Jul 17.

Cleaning-in-place (CIP) is the most commonly used cleaning and sanitation system for processing lines, equipment, and storage facilities such as milk silos in the global dairy processing industry.
CIP employs thermal treatments and nonbiodegradable chemicals (acids and alkalis), requiring appropriate neutralization before disposal, resulting in sustainability challenges. In addition, biofilms are a major source of contamination and spoilage in dairy industries, and it is believed that current chemical CIP protocols do not entirely destroy biofilms.
Use of enzymes as effective agents for CIP and as a more sustainable alternative to chemicals and thermal treatments is gaining interest. Enzymes offer several advantages when used for CIP, such as reduced water usage (less rinsing), lower operating temperatures resulting in energy savings, shorter cleaning times, and lower costs for wastewater treatment.
Additionally, they are typically derived from natural sources, are easy to neutralize, and do not produce hazardous waste products. However, even with such advantages, enzymes for CIP within the dairy processing industry remain focused mainly on membrane cleaning.
Greater adoption of enzyme-based CIP for cheese industries is projected pending a greater knowledge relating to cost, control of the process (inactivation kinetics), reusability of enzyme solutions, and the potential for residual activity, including possible effects on the subsequent product batches. Such studies are essential for the cheese industry to move toward more energy-efficient and sustainable cleaning solutions.

Exopolysaccharide-Producing Lacticaseibacillus rhamnosus Space Mutant Improves the Techno-Functional Characteristics of Fermented Cow and Goat Milks. Liu X, Liu W, Sun L, Li N, Kwok LY, Zhang H, Zhang W. J Agric Food Chem. 2023 Jul 19;71(28):10729-10741.

Lacticaseibacillus rhamnosusProbio-M9 (Probio-M9) is increasingly used as a co-fermentation culture in fermented milk production. Recently, a capsular polysaccharide (CPS)- and exopolysaccharide (EPS)-producing mutant of Probio-M9, HG-R7970-3, was generated by space mutagenesis.
This study compared the performance of cow and goat milk fermentation between the non-CPS/-EPS-producing parental strain (Probio-M9) and the CPS/EPS producer (HG-R7970-3), and the stability of products fermented by the two bacteria.
The results showed that using HG-R7970-3 as the fermentative culture could improve the probiotic viable counts, physico-chemical, texture, and rheological properties in both cow and goat milk fermentation.
Substantial differences were also observed in the metabolomics profiles between fermented cow and goat milks produced by the two bacteria. Comparing with Probio-M9-fermented cow and goat milks, those fermented by HG-R7970-3 were enriched in a number of flavor compounds and potential functional components, particularly acids, esters, peptides, and intermediate metabolites. Moreover, HG-R7970-3 could improve the post-fermentation flavor retention capacity.
These new and added features are of potential to improve the techno-functional qualities of conventional fermented milks produced by Probio-M9, and these differences are likely imparted by the acquired CPS-/EPS-producing ability of the mutant. It merits further investigation into the sensory quality and in vivo function of HG-R7970-3-fermented milks.

Consumer willingness to pay for shelf life of high temperature, short time pasteurized fluid milk: Implications for smart labeling and food waste reduction. Endara P, Wiedmann M, Adalja A. J Dairy Sci. 2023 Jul 18:S0022-0302(23)00379-X.

Food waste in the United States was valued at $285 billion in 2019, representing 70% of all food surplus; dairy and eggs alone represented 15.90% of food surplus. Milk is the fifth most consumed beverage in the United States, and therefore its contribution to food waste has significant economic and environmental ramifications.
Smart labels that provide precise spoilage information for fluid milk may help reduce food waste in fluid milk, but it is unclear if consumers will accept or pay for this novel technology. This paper examines consumer preferences for high temperature, short time pasteurized fluid milk shelf life and smart date labels and tests how information about the environmental impact of fluid milk food waste affects consumers’ acceptance and willingness to pay.
Researchers used a choice-based conjoint study administered in an online survey, along with a between-subject experiment to measure preferences under different information treatments about the environmental impact of food waste.
The results suggest that consumers’ valuations of extended shelf-life and an ecolabel is positive; however, using the smart label creates disutility for consumers, thereby hindering acceptance of new labeling technology that may facilitate food waste reduction in the milk industry.
These findings imply that retailers should find alternative means to enhance the communication of precise shelf-life information and its role in reducing food waste.

A time series analysis of milk productivity in US dairy states. Li M, Reed KF, Cabrera VE. J Dairy Sci. 2023 Jul 18:S0022-0302(23)00375-2.

As US dairy cow production evolves, it is important to characterize trends and seasonal patterns to project amounts and fluctuations in milk and milk components by states or regions. Hence, this study aimed to:

quantify historical trends and seasonal patterns of milk and milk components production associated with calving date by parities and states;
classify parities and states with similar trends and seasonal patterns into clusters; and
summarize the general pattern for each cluster for further application in simulation models.

The data set contained 9.18 million lactation records from 5.61 million Holstein cows distributed in 17 states during the period January 2006 to December 2016. Each record included a cow’s total milk, fat, and protein yield during a lactation.
The researchers used time series decomposition to obtain each state’s annual trend and seasonal pattern in milk productivity for each parity. Then, they classified states and parities with agglomerative hierarchical clustering into groups according to 2 methods: (1) dynamic time warping on the original time series and (2) Euclidean distance on extracted features of trend and seasonality from the decomposition.
Results showed distinguishable trends and seasonality for all states and lactation numbers for all response variables. The clusters and cluster centroid pattern showed a general upward trend for all yields [energy-corrected milk (ECM), milk, fat, and protein] and a steady trend for fat and protein percent for all states except Texas.
The researchers also found a larger seasonality amplitude for all yields (ECM, milk, fat, and protein) from higher lactation numbers and a similar amplitude for fat and protein percent across lactation numbers. The results could be used for advising management decisions according to farm productivity goals.
Furthermore, the trend and seasonality patterns could be used to adjust the production level in a specific state, year, and season for farm simulations to accurately project milk and milk components production.

Perceptions and knowledge of protein in dairy and plant-based alternatives among stakeholders in the US marketplace. Schlepphorst KI, Clark BE, Pope L, Donahue R, Belarmino EH. Nutr Bull. 2023 Jul 20.

This study explores beliefs about protein in dairy and plant-based alternatives among stakeholders in the US marketplace and whether beliefs are associated with product preferences.
Eight thousand and fifty-two unique comments submitted to the US Food and Drug Administration (FDA) in response to a request for public input on the labelling of PB dairy alternatives (FDA-2018-N-3522) were coded. Of these, 383 (4.8%) discussed protein and were analysed for protein-specific themes.
Themes were examined in relation to the submitter’s product preference. Most comments that discussed protein focused on protein content and/or health outcomes believed to be associated with intake.
Only one commenter who preferred dairy demonstrated an inaccurate understanding of protein content in dairy and plant-based alternatives, meanwhile, 14.2% who preferred plant-based alternatives demonstrated an inaccurate understanding regarding protein content in dairy and plant-based products.
The results suggest knowledge gaps exist regarding protein in plant-based dairy alternatives, especially among those who prefer non-dairy options.

Nutritional quality and price of plant-based dairy and meat analogs in the Canadian food supply system. Lee JJ, Srebot S, Ahmed M, Mulligan C, Hu G, L’Abbé MR. J Food Sci. 2023 Jul 17.

There has been an increased consumer interest and public health emphasis on plant-based protein foods, resulting in a rise in the availability of highly processed plant-based analogs.
The objectives of this study were to assess the nutritional quality and the price of plant-based dairy and meat analogs compared to their respective animal-derived products and to examine the association between processing levels and the nutritional quality among these products.
Using a branded food composition database, products in cheese, yogurt, milk, and meat categories were examined (n = 3231). Products were categorized as plant-based analogs versus animal-derived products using the ingredient list. Products were examined for their nutrient content, overall nutritional quality using the Food Standards Australia New Zealand nutrient profiling model, price, and processing levels using the NOVA classification.
All plant-based analogs had lower protein and higher total carbohydrate, sugar, and fiber content compared to their respective animal-derived products. Compared to their respective animal-derived products, plant-based milk and meat analogs had lower energy, total fat, and saturated fat content; plant-based yogurt and meat analogs had lower sodium content; and all plant-based dairy analogs had lower calcium content.
Plant-based cheese and yogurt analogs were more expensive than animal-based products; however, there was no significant difference among milk and meat products. There was no association between processing levels and overall nutritional quality among dairy and meat products.
Plant-based analogs may be part of a healthy and affordable diet to reduce the intakes of nutrients of concern; however, additional compositional guidelines and/or labeling may be needed to highlight the differences in the levels of nutrients to encourage.