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

Environmental Management and Sustainability

Methane emission, nutrient digestibility, and rumen microbiota in Holstein heifers fed 14 different grass or clover silages as the sole feed. Parnian-Khajehdizaj F, Noel SJ, Johansen M, Weisbjerg MR, Hellwing ALF, Højberg O, Hall MB, Lund P. J Dairy Sci. 2023 Apr 5:S0022-0302(23)00158-3.

Hydrogen and CO2 are produced in the rumen as a result of fermentation and are then used by methanogenic archaea to produce methane. Methane is therefore a natural by-product of anaerobic microbial fermentation of nutrients in the digestive tract of ruminants.
This experiment investigated the variation in enteric methane production and associated gas exchange parameters, nutrient digestibility, rumen fermentation, and rumen microbiome when a range of silages based on different forage types (grass or clover), and different species within the 2 types, were fed as the sole feed to heifers. Three grass species (perennial ryegrass, festulolium, and tall fescue) and 2 clover species (red clover and white clover) were included.
Sixteen Holstein heifers 16 to 21 months old and 2 to 5 months in pregnancy were fed the silages ad libitum as the sole feed in an incomplete crossover design. Each silage was fed to 4 heifers, except for the 2 perennial ryegrass silages, which were fed to 8 heifers; for a total of 64 observations. The CH₄production was measured for 3 day in respiration chambers.
Heifers fed clover silages had higher dry matter intake (DMI) compared with heifers fed grass silages, and heifers fed tall fescue silages had the numerically the lowest DMI. Compared with grass silages, feeding clover silages led to higher crude protein digestibility but lower neutral detergent fiber (NDF) digestibility.
Rumen pH was higher in heifers fed clover silages compared with those fed grass silages.
Based on composition analysis, the rumen microbiota of the heifers clustered clearly according to forage type and species. More specifically, 7 of the 34 dominating rumen bacterial genus-level groups showed higher relative abundances for the clover silages, whereas 7 genus-level groups showed higher abundances for the grass silages.
Methane yield was higher for heifers fed grass silages than for those fed clover silages when methane production was related to dry matter and digestible organic matter intake, whereas the opposite was seen when related to NDF digestion. The gross energy lost as methane (CH₄conversion factor, %) reduced from 7.5% to 6.7%, equivalent to an 11% reduction.
The present study gives the outlines for choosing the optimal forage type and forage species with respect to nutrient digestibility and enteric methane emission in ruminants.

Compaction effects on greenhouse gas and ammonia emissions from solid dairy manure. Chang F, Fabian-Wheeler E, Richard TL, Hile M. J Environ Manage. 2023 Apr 15;332:117399.

Nitrogen pollution and greenhouse gas emissions represent two of the most pressing global environmental challenges, with agricultural operations a major contributor to each. Livestock manure management can be a significant source of ammonia (NH3) and some greenhouse gases (GHG): carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O).
Waste management practices of solid dairy manures were evaluated under controlled conditions to study gas transport and emission inside manure piles.
Three applied stresses and three moisture contents were tested to represent manure conditions managed at various pile depths.
A Fourier-transform infrared spectroscopy monitor measured concentrations of greenhouses gases (CH4, CO2, N2O) and ammonia as part of gas flux rate calculations.
Results showed that carbon dioxide dominated the greenhouse gas emissions under all test conditions. Gas transfer, primarily diffusion, was facilitated by manure with high mechanical strength and high permeability.
Gas emission rates reduced dramatically when moisture content increased in manure with high water holding capacity, while compaction treatments did not as strongly affect the gas emission rates.
These results provide fundamental insights into management strategies for reducing gas emissions from solid dairy manure.

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;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.

Nitrogen transformation processes catalyzed by manure microbiomes in earthen pit and concrete storages on commercial dairy farms. Khairunisa BH, Loganathan U, Ogejo JA, Mukhopadhyay B. Environ Microbiome. 2023 Apr 11;18(1):32.

Storing manure is an essential aspect of nutrient management on dairy farms. It presents the opportunity to use manure efficiently as a fertilizer in crop and pasture production. Typically, the manure storages are constructed as earthen, concrete, or steel-based structures. However, storing manure can potentially emit aerial pollutants to the atmosphere, including nitrogen and greenhouse gases, through microbial and physicochemical processes.
Therefore, researchers have characterized the composition of the microbiome in two manure storage structures, a clay-lined earthen pit and an aboveground concrete storage tank, on commercial dairy farms, to discern the nitrogen transformation processes, and thereby, inform the development of mitigation practices to preserve the value of manure.
First, the researchers analyzed the 16S rRNA-V4 amplicons generated from manure samples collected from several locations and depths (0.3, 1.2, and 2.1-2.75 m below the surface) of the storages, identifying a set of Amplicon Sequence Variant (ASVs) and quantifying their abundances. Then, the researchers inferred the respective metabolic capabilities.
These results showed that the manure microbiome composition was more complex and exhibited more location-to-location variation in the earthen pit than in the concrete tank. Further, the inlet and a location with hard surface crust in the earthen pit had unique consortia.
The microbiomes in both storages had the potential to generate ammonia but lacked the organisms for oxidizing it to gaseous compounds. However, the microbial conversion of nitrate to gaseous N₂, NO, and N₂O via denitrification and to stable ammonia via dissimilatory nitrite reduction seemed possible; minor quantities of nitrate was present in manure, potentially originating from oxidative processes occurring on the barn floor.
The nitrate-transformation linked ASVs were more prevalent at the near-surface locations and all depths of the inlet. Anammox bacteria and archaeal or bacterial autotrophic nitrifiers were not detected in either storage. Hydrogenotrophic Methanocorpusculum species were the primary methanogens or methane producers, exhibiting higher abundance in the earthen pit.
These findings suggested that microbial activities were not the main drivers for nitrogen loss from manure storage, and commonly reported losses are associated with the physicochemical processes. Finally, the microbiomes of stored manure had the potential to emit greenhouse gases such as NO, N₂O, and methane.

Climate change and socio-economic assessment of precision lifestock farming in dairy farms: Three case studies. Lovarelli D, Leso L, Bonfanti M, Porto S, Barbari M, Guarino M. Sci Total Environ. 2023 Apr 23:163639.

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

Calf management and welfare in the Canadian and US dairy industries: Where do we go from here? Roche S, Renaud DL, Bauman CA, Lombard J, Short D, Saraceni J, Kelton DF. J Dairy Sci. 2023 Apr 18:S0022-0302(23)00181-9.

Calf management and welfare represents an important area of focus for the dairy industry. Understanding how Canadian and US dairy producers are addressing these dairy management issues helps provide insight into the strengths, weaknesses, opportunities, and threats to the North American dairy industry.
The objective of this narrative review was to compare the results of the 2015 Canadian National Dairy Study and the 2014 US National Animal Health Monitoring System (NAHMS) Dairy Studies, with a specific focus on calf management and welfare, and to interpret these findings within more recent calf health research to describe where we need to go next in the North American dairy industry.
Situating results of periodic national studies within the context of past and recent research provides an opportunity to gauge adoption of recommendations and best practices and to help identify persistent and new challenges that the industry is wrestling with to help guide research needs.
Through this review of the 2 national studies, we identified several strengths of the Canadian and US dairy industries. In each area of calf health management, improvements relative to previous NAHMS studies and the published literature have been found in the level of mortality, amount of colostrum fed, housing, and the number of producers using pain control for disbudding and dehorning.
There were, however, some areas that present clear opportunities for improvement. Specifically, although mortality levels have improved, a large number of calves die at birth, within the first 48 hours of life, and during the preweaning period. To improve the health of calves in early life, producers could look at feeding high-quality colostrum at 10% of body weight in the first feeding, as well as feeding a larger amount of milk during the preweaning period.
The barriers to making these management changes and improving overall calf health need to be identified in future studies. The majority of preweaning calves in Canada and the United States are housed in individual housing. This represents a clear opportunity for improvement because recent research has identified the positive aspects of group housing.
Finally, with respect to pain control, improvements are needed (particularly in the United States) to ensure that pain management is provided when disbudding and dehorning calves. Although the science is clear on pain management, discussions with producers are needed to identify reasons for the lack of uptake.

Dairy calves are exposed to isoflavones during the developmentally most sensitive period of their life. Dewulf M, Van Eetvelde M, Wiczkowski W, Opsomer G. Theriogenology. 2023 Apr 15;201:53-58.

Isoflavones represent a class of phytoestrogens present in plants. In dairy cows, dietary isoflavones have been shown to negatively affect reproductive performance. To the best of our knowledge, no studies have yet been conducted to determine if calves are pre- or neonatally confronted with isoflavones and their metabolites.
In the present study, researchers hypothesize that isoflavones are passed on from the dam to the offspring in utero.
Twenty-three pregnant Holstein Friesian dams and their calves, originating from three commercial dairy farms in Belgium, were included. Blood samples were collected during the first, second, and third trimester of gestation from all pregnant dams. Blood and hair samples were obtained from the offspring within 24 hours after parturition. Colostrum samples were collected from a subset of eight dams to determine the concentration of isoflavones and their metabolites.
During the first and second trimester of gestation, the dams were fed either a youngstock (nulliparous dams) or a lactation (multiparous dams) diet. During the third trimester, both groups received a similar dry cow diet.
Genistein and daidzein levels were unaffected by diet type, while their metabolite [equol, dihydrodaidzein (DHD), and o-desmethylangolensin (ODMA)] concentrations were significantly higher in the lactation group. Furthermore, metabolite concentrations decreased significantly during gestation. Isoflavones and their metabolites were detected in all colostrum samples. No correlation could be found between levels in colostrum and blood of pregnant dams or calves.
Peripheral levels of isoflavones and their metabolites were significantly lower in newborn calves in comparison to their dams. Genistein and daidzein concentrations were found to be significantly higher in the calves’ hair versus blood samples, suggesting prenatal exposure to isoflavones for an extended period of time. In contrast, no isoflavone metabolites were detected in the calves’ hair samples.
This is the first study to demonstrate that dairy calves are exposed to isoflavones during the developmentally most sensitive period of their lives. The results obtained from this work pave the way for more extensive research to examine which effects isoflavones might have on developing organ systems like the reproductive system.

Associations among Milk Microbiota, Milk Fatty Acids, Milk Glycans, and Inflammation from Lactating Holstein Cows. Coates LC, Durham SD, Storms DH, Magnuson AD, Van Hekken DL, Plumier BM, Finley JW, Fukagawa NK, Tomasula PM, Lemay DG, Picklo MJ, Barile D, Kalscheur KF, Kable ME. Microbiol Spectr. 2023 Apr 19:e0402022.

Milk oligosaccharides (MOs) can be prebiotic and antiadhesive, while fatty acids (MFAs) can be antimicrobial. Both have been associated with milk microbes or mammary gland inflammation in humans. Relationships between these milk components and milk microbes or inflammation have not been determined for cows and could help elucidate a novel approach for the dairy industry to promote desired milk microbial composition for improvement of milk quality and reduction of milk waste.
Therefore, researchers aimed to determine relationships among milk microbiota, MFAs, MOs, lactose, and somatic cell counts (SCC) from Holstein cows, using our previously published data.
Raw milk samples were collected at three time points, ranging from early to late lactation. Data were analyzed using linear mixed-effects modeling and repeated-measures correlation.
Unsaturated MFA and short-chain MFA had mostly negative relationships with potentially pathogenic genera, including Corynebacterium, Pseudomonas, and an unknown Enterobacteriaceae genus but numerous positive relationships with the symbionts Bifidobacterium and Bacteroides.
Conversely, many MOs were positively correlated with potentially pathogenic genera (e.g., Corynebacterium, Enterococcus, and Pseudomonas), and numerous MOs were negatively correlated with the symbiont Bifidobacterium. The neutral, nonfucosylated MO composed of eight hexoses had a positive relationship with SCC, while lactose had a negative relationship with SCC.
One interpretation of these trends might be that in milk, MFAs disrupt primarily pathogenic bacterial cells, causing a relative increase in abundance of beneficial microbial taxa, while MOs respond to and act on pathogenic taxa primarily through antiadhesive methods. Further research is needed to confirm the potential mechanisms driving these correlations.

Bovine paratuberculosis: results of a control plan in 64 dairy farms in a 4-year period. Scarpellini R, Giacometti F, Savini F, Arrigoni N, Garbarino CA, Carnevale G, Mondo E, Piva S. Prev Vet Med. 2023 Apr 22;215:105923.

Paratuberculosis is considered one of the most economically devastating infectious diseases of domestic livestock, and the most effective control strategy is a combination of ‘test-and-cull’ and on-farm biosecurity measures.
In Italy, a Voluntary National Control Plan and guidelines have been introduced to reduce the impact of the disease, and farmers can voluntarily enroll in the control plan. The main aims of this study were:
the description of the trend over a 4-year period on total, within-herd and between herd apparent seroprevalences observed in 64 dairy herds members of a mutual company located in Italy after the introduction of a proposed “Customized Control Plan”;
the evaluation of its effectiveness in terms of percentage of participating farms that decided to join the Voluntary National Control Plan.
Analyses on serum samples were performed with Enzyme-Linked Immuno Sorbent Assay (ELISA) method and revealed a general decrease in both total, within-herd and between-herd apparent seroprevalence.
Total average apparent seroprevalence decreased from 2.39% in 2017 to 1% in 2020. Negative herds raised from 51.9% in 2017 to 71.1% in 2020, while farms with within-herd apparent seroprevalence > 5% decreased from 17.3% in 2017 to 4.4% in 2020. Between-herd apparent seroprevalence decreased from 51.2% in 2017 to 29.2% in 2020.
Among the 52 out of 64 herds that accepted to continue the proposed customized control plan after the first year, 41 (78.8%) joined in 2020 the Voluntary National Control Plan, that assessed the health ranking of the herds.
The results provide evidence that a control plan based on a farm-specific strategy and a subsidized testing process can effectively reduce the impact of paratuberculosis in dairy herds, especially in convincing farmers to continue in paratuberculosis control by joining the Voluntary National Control Plan, including them in a National context and increasing their awareness of the disease.

Changes in milk production and estimated income over feed cost of group-housed dairy cows when moved between pens. Bach A. J Dairy Sci. 2023 Apr 20:S0022-0302(23)00184-4.

Several studies have shown advantages of feeding cows in groups according to their nutrient requirements. However, there are concerns about losing milk when cows change from a high- to a low-nutrient diet.
Data from 1,960 cows from 3 herds were analyzed to assess the impact on milk yield and estimated income over feed cost (IOFC) when moving cows between pens and rations.
Pen feed intake and individual body weight and milk yield were recorded daily for 21 days before and 21 days after every pen movement. The data included 2,142 pen movements, and for each movement, milk production was recorded for 21 days before and 21 days after the change.
Within farm, group, and cow, milk yield during the 21 days preceding a pen movement was used to predict milk yield for the subsequent 21 days using linear regression.
In all 3 farms, every pen movement involved a change from a more expensive ration with more energy and protein than the one fed after the movement. On average, in all cases but one, observed milk yield was lower than the forecasted milk yield had cows not been moved.
However, IOFC, on average, was positive in all cases except for 2 pen movements on 2 farms.
Reasons for the improved IOFC with lower milk yield were due to a nutrient cost advantage, whereas, when IOFC decreased, differences in nutrient supply and dietary cost were not able to offset differences in milk yield.
Moving cows according to milk production level does not result in economic advantages when the unit cost of nutrients is greater in the original than in the receiving ration. However, when the cost and nutrient difference between the diets offset potential losses in milk, forming groups according to production is advantageous.

Human Health and Nutrition

Effects of Kefir Consumption on Cardiometabolic Risk Factors: A Systematic Review and Meta-analysis of Randomized Controlled Trials. Yahyapoor F, Haghighat N, Sahebkar A, et al. Curr Drug Targets. 2023 Apr 27.

Fermentation of lactose in milk by bacteria and yeasts naturally present in kefir grains produces a beverage that has been suggested to have cardiovascular benefits.
This systematic review and meta-analysis of randomized controlled trials (RCTs) aimed to evaluate the effects of this kefir beverage on cardiometabolic risk factors.
Cardiometabolic risk indices extracted included insulin and insulin resistance (HOMA_IR), total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), fasting blood sugar (FBS), hemoglobin A1c (HbA1c) and body weight.
In total, six RCTs (314 subjects) were selected for the meta-analysis. A random effects model was used to estimate the pooled WMD.
The results showed that kefir intake significantly reduced fasting insulin and HOMA-IR. No effect on TC, TG, HDL-C, LDL-C, FBS, HbA1c or body weight were found for kefir treatment.
In conclusion, kefir intake has a beneficial effect in decreasing insulin resistance; however, no effect was seen on body weight, FBS, HbA1C, and lipid profile.

Effect of probiotic yogurt on gestational diabetes mellitus: A systematic review and meta-analysis. Tabatabaeizadeh SA, Tafazoli N. Diabetes Metab Syndr. 2023 Apr 10;17(4):102758.

Gestational diabetes mellitus is one of the important complications of pregnancy and is related to many adverse events. There is evidence that probiotics can be considered a preventive and therapeutic option in gestational diabetes mellitus.
In this meta-analysis researchers focused on the effect of probiotic yogurt as a natural product on gestational diabetes mellitus. Four manuscripts with a total of 533 participants were included in this meta-analysis.
There was a statistically significant association between probiotic yogurt and reduced risk of gestational diabetes mellitus (Pooled OR 0.35). Furthermore, the mean reduction in the fasting plasma glucose was significantly higher in the probiotic yogurt groups (Hedges’ g = -0.37).
In conclusion, this meta-analysis suggests that probiotic yogurt lowers the risk of gestational diabetes mellitus. Also, it is related to a significant reduction in fasting plasma glucose. These findings promise that probiotic yogurt could be regarded as a safe and low-cost therapy and preventive option for gestational diabetes mellitus. However, more randomized controlled trials with different doses and more probiotic strains with varying systems of delivery are warranted.

The association between breast cancer and consumption of dairy products: a systematic review. Arafat HM, Omar J, Abusalah MAH, et al. Ann Med. 2023 Dec;55(1):2198256.

Around the world, the most frequently discovered and fatal cancer in women is breast cancer (BC). From the perspective of public health, estimating the BC risk linked to dairy intake may aid in comprehensive management.
Epidemiological research data on the association between eating dairy foods and the risk of BC are conflicting. Therefore, researchers sought to assess the link between dairy food consumption and the development of BC.
Researchers performed a systematic literature review. Of the 82 articles identified, only 18 met the inclusion criteria and were analyzed. Nine Prospective, seven Retrospective and two Cross-Sectional studies were finally identified.
Overall, dairy consumption was shown to be inversely associated with the risk of developing breast cancer. The effect of different types of dairy products, and possible dose-response relationships on BC risk remains unknown. Future studies will help elucidate the role of dairy products in human health, and their use within a balanced diet should be considered.

Dairy food consumption is beneficially linked with iodine status in US children and adults: NHANES 2001 – 2018. Qin Y, Cifelli CJ, Agarwal S, Fugoni VL. Public Health Nutr. 2023 Apr 24:1-29.

In many other countries, milk and milk products are the biggest dietary source of iodine by a considerable margin.
The objective of this study was to determine the association between the consumption of dairy foods with urinary iodine concentration (UIC) and iodine deficiency risk in a nationally representative sample of the US population.
24-hour dietary recall data and laboratory data for UIC (μg/L) from subjects 2+ years old US population participating in National Health and Nutrition Examination Surveys (NHANES) 2001-2018 were used (N = 26,838) for analyses after adjusting for demographic covariates.
The results showed that mean intakes of total dairy were 2.21, 2.17 and 1.70 cup equivalents (cup eq) among those 2-8, 9-18 and 19+ years respectively. Of the dairy components, intake of milk was highest followed cheese and yogurt for all age groups.
Total dairy intakes were positively associated with UIC among those 2-8 years and 9-18 years but not associated among those 19+ years. Total dairy intakes were associated with lowered risks (30%, 21% and 20% for among 2-8, 9-18 and 19+ years respectively) of being classified as iodine insufficient or lowered risk (47%, 30% and 26% among 2-8, 9-18 and 19+ years respectively) of being classified as iodine severely deficient (UIC<20 μg/L).
The results indicate that dairy foods are beneficially associated with UIC and lowered iodine deficiency risk.

Innovation, Economics, and Dairy Alternatives

Nondairy food applications of whey and milk permeates: Direct and indirect uses. O’Donoghue LT, Murphy EG. Compr Rev Food Sci Food Saf. 2023 Apr 17.

Permeates are generated in the dairy industry as byproducts from the production of high-protein products (e.g., whey or milk protein isolates and concentrates). Traditionally, permeate was disposed of as waste or used in animal feed, but with the recent move toward a “zero waste” economy, these streams are being recognized for their potential use as ingredients, or as raw materials for the production of value-added products.
Permeates can be added directly into foods such as baked goods, meats, and soups, for use as sucrose or sodium replacers, or can be used in the production of prebiotic drinks or sports beverages. In-direct applications generally utilize the lactose present in permeate for the production of higher value lactose derivatives, such as lactic acid, or prebiotic carbohydrates such as lactulose.
However, the impurities present, short shelf life, and difficulty handling these streams can present challenges for manufacturers and hinder the efficiency of downstream processes, especially compared to pure lactose solutions. In addition, the majority of these applications are still in the research stage and the economic feasibility of each application still needs to be investigated.
This review will discuss the wide variety of nondairy, food-based applications of milk and whey permeates, with particular focus on the advantages and disadvantages associated with each application and the suitability of different permeate types (i.e., milk, acid, or sweet whey).

Whey permeate as a phosphorus source for algal cultivation. Nham Q, Mattsson L, Legrand C, Lindehoff E. Water Environ Res. 2023 Apr;95(4):e10865.

Microalgal cultivation for biodiesel and feed requires recycled nutrient resources for a sustainable long-term operation. Whey permeate from dairy processing contains high organic load (lactose, oils, and proteins) and nitrogen (resources tested for microalgal cultivation) and organic phosphorus that has not yet been tested as a phosphorus source for microalgal cultivation.
Therefore, researchers explored the potential of green algae strains (brackish) and polyculture (freshwater) in exploiting phosphorus from whey permeate added to a medium based on either seawater or landfill leachate.
Both strains showed a capacity of using organic phosphorus in whey permeate with equal growth compared with chemical phosphate treatments. The polyculture had comparable growth rate and biomass yield and similar or higher nutrient removal rate in the leachate-whey permeate medium compared with the leachate-chemical phosphate medium.
This study showed that Whey permeate is a comparable phosphorus source to standard fertilizers used in algal cultivation. Green algae removed phosphorus effectively from whey permeate. Microalgal cultivation is a good approach for treatment of whey permeate in combination with a nitrogen-rich wastewater.

Use of whey protein as a natural polymer for the encapsulation of plant biocontrol bacteria: A review. Saberi Riseh R, Gholizadeh Vazvani M, Hassanisaadi M, Thakur VK, Kennedy JF. Int J Biol Macromol. 2023 Apr 15;234:123708.

Climate changes, drought, the salinity of water and soil, the emergence of new breeds of pests and pathogens, the industrialization of countries, and environmental contamination are among the factors limiting the production of agricultural products.
The use of chemicals (in the form of fertilizers, pesticides and fungicides) to enhance products against biotic and abiotic stresses has limitations. To eliminate the effects of agricultural chemicals, synthetic agrochemicals should be replaced with natural substances and useful microorganisms.
To be more effective and efficient, plant biocontrol bacteria need a coating layer around themselves to protect them from adverse conditions. Whey protein, a valuable by-product of the cheese industry, is one of the important natural polymers.
Due to its high protein content, safety, and biodegradability, whey can have many applications in agriculture and encapsulation of bacteria to resist pests and plant diseases. This compound is a rich source of amino acids that can activate plant defense systems and defense enzymes.
Considering the amazing potentialities of formulation whey protein, this review attends to the efficiency of whey protein as coating layers on fruit and vegetables and in the packaging system to increase the shelf life of agricultural products against phytopathogens.

Physico-chemical, microbiological, and sensory characteristics of yogurt as affected by ingredients that help treat leaky gut. Aleman RS, Cedillos R, Page R, Olson D, Aryana K. J Dairy Sci. 2023 Apr 18:S0022-0302(23)00175-3.

L-Glutamine, quercetin, slippery elm bark, marshmallow root, N-acetyl-d-glucosamine, licorice root, maitake mushrooms, and zinc orotate have been reported to help treat leaky gut.
The purpose of this research was to explore the impact of these functional ingredients on the physico-chemical, microbiological, and sensory properties of yogurt.
The milk from same source was equally divided into 9 pails and the 8 ingredients were randomly assigned to the 8 pails. The control had no ingredient. Milk was fermented to yogurt.
The pH, titratable acidity, syneresis, viscosity, color (L*, a*, b*, C*, and h*), Streptococcus thermophilus counts, and Lactobacillus delbrueckii spp. bulgaricus counts of yogurts were determined on d 1, 7, 14, 21, 28, 35, and 42, whereas coliform counts, yeast and mold counts, and rheological characteristics were determined on d 1 and 42.
The sensory study was performed on day 3 and particle size of the functional ingredients (powder form) was also determined.
When compared with control, the incorporation of slippery elm bark into yogurts led to less syneresis. L-Glutamine increased pH and n’ values (relaxation exponent derived from G’) and lowered titratable acidity values. N-Acetyl-d-glucosamine incorporation resulted in higher n’ and lower titratable acidity values, whereas maitake mushroom led to lower n’ values. Incorporating quercetin increased the growth of L. bulgaricus.
Adding maitake mushrooms increased the growth of S. thermophilus but lowered apparent viscosity values, whereas quercetin decreased its S. thermophilus counts. Thixotropic behavior increased with the addition of licorice root and quercetin. Adding slippery elm bark, N-acetyl-d-glucosamine, licorice root, maitake mushrooms, and zinc orotate into yogurt did not affect the sensory properties, whereas yogurts with quercetin had the lowest sensory scores.
Overall, most of these ingredients did not cause major changes to yogurt properties.

Pro-pre and Postbiotic Fermentation of the Dietetic Dairy Matrix with Prebiotic Sugar Replacers. Eroglu E, Ozcan T. Probiotics Antimicrob Proteins. 2023 Apr 24.

In this study, bacterial growth, postbiotic short-chain fatty acids (SCFAs) formation, and gelation properties of sugar-free probiotic milk gels produced with stevia and inulin as a sugar replacer and synbiotic interactions were investigated with regard to prebiotic/bio-therapeutic potential and consumer preference.
Lactobacillus acidophilus and Bifidobacterium animalis subsp. lactis cultures were used in the manufacture of dietetic milk gels. The addition of stevia and inulin promoted the viability of bacteria and enhanced milk gel firmness throughout its shelf life.
The activity of the probiotic bacteria was identified to be within the potential prebiotic effects (> 8.30 log₁₀ cfu mL^-1) in a food matrix. However, it was determined that especially stevia and stevia + inulin addition increased the survival rate of probiotic bacteria and in vitro total SCFA production with higher scores for consumers’ preferences rather than with the addition of stevia alone.
Yogurts containing B. animalis subsp. lactis have improved the instrumental textural properties, whereas yogurts containing L. acidophilus had higher scores for sensorial attributes.

Farm biogas project considering carbon trading indicates promising economic results-a case study. Zhang C, Wu L. Environ Sci Pollut Res Int. 2023 Apr 24.

The application of the farm biogas project is a perfect measure to deal with the increasingly nervous global climate problem and energy crisis and can support the accomplishment of urgently needed carbon peaking and carbon neutrality effectively. But the poor economic benefits hinder its better development.
Thus, this paper aims to enhance the economics of farm biogas projects and explore a win-win model for economic and environmental benefits by studying the economic impact of participation in carbon trading on three types of farm biogas projects.
First, economic analysis of farm biogas projects based on life cycle cost is carried out using case analysis. Second, the greenhouse gas emission reductions are calculated and benefits from carbon trading are considered. Then, the economic robustness was tested.
Specifically, the economics of all three types of farm biogas projects is improved after carbon trading. The ecological farm biogas project has the best economic performance, with a net present value of $551,689.11, internal rate of return of 49%, and payback period of 2.39 years. In addition, the emission reductions of 5045.79 t CO₂e, 7420.28 t CO₂e, and 148.41 t CO₂e are very significant.
Based on these, suggestions for developing farm biogas projects and introducing biogas projects to carbon trading are put forward for the reference of governments and investors when making investments and reforms.
According to the result, participation of farm biogas projects in carbon trading can effectively enhance economic benefits and accelerate the achievement of the greenhouse gas emission reduction target which is of great significance to the urgent goal of global green and low-carbon transformation.