Greek yogurt is one of the fastest growing products in the dairy industry. It is also known as strained yogurt, which is obtained after draining the whey. As a result of the draining process, Greek yogurt has higher total solids and lower lactose than regular yogurt. Since it is a concentrated yogurt, its sensory characteristics are different from regular yogurt. However, there is little information about factors influencing the quality of Greek yogurt and sensory evaluation techniques applied to Greek yogurt. This review aims to describe the effects of ingredients, starter cultures, processing techniques and other parameters on quality characteristics and sensory properties of Greek yogurt. In addition, advantages and limitations of novel sensory evaluation techniques applied to Greek yogurt products are discussed. In particular, we take a look at advanced techniques such as the electronic nose and electronic tongue and the benefits of these techniques with regard to Greek yogurt. This review should help the Greek yogurt industry to improve its current products and develop innovative products based on appropriate food evaluation techniques.

Milk and dairy products have great importance in human nutrition related to the presence of different nutrients, including protein, fatty acid profile and bioactive compounds. Dietary supplementation with foods containing these types of compounds may influence the chemical composition of milk and dairy products and hence, potentially, the consumer. Our objective was to summarize the evidence of the effect of supplementation with antioxidants and phenolic compounds in the diets of dairy animals and their effects on milk and dairy products. We conducted a systematic search in the MEDLINE/PubMed database for studies published up until July 2022 that reported on supplementation with antioxidants and phenolic compounds in diets that included plants, herbs, seeds, grains and isolated bioactive compounds of dairy animals such as cows, sheep and goats and their effects on milk and dairy products. Of the 94 studies identified in the search, only 15 met the inclusion criteria and were analyzed. The review revealed that supplementation with false flax cake, sweet grass, Acacia farnesiana, mushroom myceliated grains and sweet grass promoted an effect on the milk lipid profile, whereas supplementation with dried grape pomace and tannin extract promoted an effect on the milk and cheese lipid profiles. In six studies, the addition of Acacia farnesiana, hesperidin or naringin, durum wheat bran, mushroom myceliated grains, dried grape pomace and olive leaves increased the antioxidant activity of milk. In conclusion, supplementation with bioactive compounds had a positive impact which ranged from an increase in antioxidant capacity to a decrease in oxidative biomarkers such as malondialdehyde.

Alpha-lactalbumin (α-LA) and β-lactoglobulin (β-LG) are contained in bovine milk whey. Chemical and physical treatments are known to alter the conformation of these proteins and we have previously reported that α-LA denatured with trifluoroethanol (TFE) and isolated from sterilized market milk inhibited the growth of rat crypt IEC-6 cells. In the present study, we aimed to evaluate the effects of TFE-treated α-LA and β-LG on cell growth using cultured intestinal cells and on their safety using a suckling mouse model. First, we investigated the effect of the TFE-treated whey proteins on human colonic Caco-2 cells at various differentiation stages. In the undifferentiated stage, we assessed cell growth by a water-soluble tetrazolium-1 method. The native whey proteins enhanced cell proliferation, whereas the TFE-treated whey proteins strongly inhibited cell growth. We investigated cell barrier function in the post-differentiated stage by measuring transepithelial electrical resistance (TER). Not only native but also the TFE-treated whey proteins increased TER. Next, we evaluated whether the TFE-treated α-LA and β-LG have adverse effects on healthy suckling mice. No mice given by the TFE-treated samples showed any adverse symptoms. We also performed a safety test using a human rotavirus infected gastrointestinal disease suckling mice model. Even the TFE-treated whey proteins appeared to prevent the development of diarrheal symptoms without any adverse effects. Although we cannot know the effect of long-term ingestion of denatured whey proteins, these results suggest that they have no adverse effects on differentiated intestinal cells and digestive tract, at least in short-term ingestion.

This review examines the role glycerophospholipids (PL) in dairy cow health, with specific focus on phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI) and phosphatidylserine (PS). Increasing parity of cows is associated with lower concentrations of plasma PL that contain very long-chain omega-3 fatty acids, including docosahexaenoic acid and eicosapentaenoic acid, which are precursors for prostaglandin synthesis, and have anti-inflammatory roles. Low concentrations of these PL could plausibly contribute to the increased risk of disease, reproductive failure and mortality in older cows. The bioavailability and metabolism of fatty acids may differ among supplements that are predominately neutral lipids, such as triacylglycerol-rich oils, and those bound to PL including pasture, whole or ground oilseeds and fish meal. Hepatic lipidosis can occur during the transition period if there is insufficient very-low density lipoproteins (VLDL) production in the liver to transport lipids into blood circulation. The PC are the primary PL of VLDL and are produced by two main pathways in the liver, the cytidine diphosphate-choline pathway that uses choline as a substrate, and the PE N-methyltransferase pathway that uses PE and methyl-donors as substrates. Co-supplementation strategies that target both pathways may increase PC production over a one-pathway supplementation strategy. The PIs are phosphoinositides precursors, which have broad physiological roles including regulating inflammatory processes and may offer targets for novel treatment and management of disease. Both the PI and PE are precursors to endocannabinoids, important regulators of energy metabolism, immune function and reproduction in mammals. Early findings on the endocannabinoid system in transition dairy cows yielded results that diverge from non-ruminant models. The PS expression on cytoplasmic membranes signals apoptosis, coagulation and contributes to sperm–oocyte recognition. As lipidomic diagnostics become increasingly available, understanding the metabolism of PL will continue to develop and promises to offer novel strategies for optimising cattle health and longevity.

This review describes the potentials of a new omics science in the dairy sector, particularly regarding the improvement of animal health and welfare. The three-dimensional network of water hydrogen bonds is a dynamic entity, subject to the influence of its components and properties of the environment. For this reason, it is sensitive to any chemical, physical or biological perturbation of the system. Therefore, the aqueous matrix acts as a sensitive sensor, reflecting the state, behaviour, and functionality of the system and providing similar information on its components. Aquaphotomics builds upon these underlying assumptions. It is a scientific discipline that combines spectroscopy with multivariate spectral analysis to extract the absorbance spectral pattern of water, which describes how water molecular structure changes in response to perturbations. Many studies assessed the applicability of this approach, including veterinary diagnostics. The water spectral pattern can be used as a multidimensional biomarker for rapid and non-invasive discrimination between healthy and diseased systems, even in the subclinical phase. Adopting such an approach, focused on precision farming, can foster subsequent optimisation of animal production performance and improve the overall profitability of farming operations.

This study explores Turkish yoghurt varieties, emphasizing their cultural significance, historical roots, and regional diversity. Traditionally made with animal- and plant-based coagulants, Turkish yoghurt has evolved from its origins in Central Asia and the Ottoman Empire into a dynamic industry. Variations are classified by texture, fat content, and flavour, shaped by Türkiye's geographical diversity. Unique regional types exhibit distinct sensory and nutritional traits. The study also highlights the integration of traditional methods into modern production, ensuring the preservation and innovation of Turkish yoghurt in today's markets. Turkish yoghurt varieties have rich diversity and cultural significance, offering valuable insights into the gastronomy field. The findings emphasize the unique sensory and nutritional characteristics of regional yoghurts, which can inspire innovative culinary applications. For instance, chefs and product developers can incorporate traditional yoghurts like Antakya Salted Yoghurt or Tavas Smoked Sheep Yoghurt into modern recipes, creating novel dishes that balance authenticity and creativity. The study also sheds light on the potential of yoghurt-based products such as ayran and keş to serve as sustainable and nutritious alternatives in contemporary gastronomy. Additionally, understanding traditional production methods opens avenues for preserving and reviving artisanal techniques, fostering a deeper appreciation for local food heritage. By bridging tradition and innovation, this research contributes to the development of gastronomy as both an art and a science, enhancing the global visibility of Turkish cuisine.

Staphylococci have been isolated from various sites of the body of healthy sheep, as well as from many infections of those animals, the main one being mastitis. The objective of this review is to appraise the importance and significance of staphylococci in causing mastitis in ewes. The review includes a brief classification and taxonomy of staphylococci and describes the procedures for their isolation and identification, as well as their virulence determinants and the mechanisms of resistance to antibacterial agents. Various staphylococcal species have been implicated in staphylococcal mastitis and the characteristics of isolates are discussed with regards to potential virulence factors. Staphylococcal mastitis is explicitly described, with reference to sources of infection, the course of the disease and the relevant control measures. Finally, the potential significance of staphylococci present in ewes’ milk for public health is discussed briefly.

The reticulorumen, as the main fermentation site of ruminants, delivers energy in the form of short-chain fatty acids (SCFA) for both the animal as well as the ruminal wall. By absorbing these SCFA, the ruminal epithelium plays a major role in the maintenance of intraruminal and intraepithelial acid–base homoeostasis as well as the balance of osmolarity. It takes up SCFA via several pathways which additionally lead to either a reduction of protons in the ruminal lumen or the secretion of bicarbonate, ultimately buffering the ruminal content effectively. Nutrition of the epithelium itself is achieved by catabolism of the SCFA, especially butyrate. Catabolism of SCFA also helps to maintain a concentration gradient across the epithelium to ensure efficient SCFA uptake and stability of the epithelial osmolarity. Furthermore, the ruminal epithelium forms a tight barrier against pathogens, endotoxins or biogenic amines, which may emerge from ruminal microorganisms and feed. Under physiological conditions, it reduces toxin uptake to a minimum. Moreover, the epithelium seems to have the ability to degrade biogenic amines like histamine. Nonetheless, in high performance production animals like dairy cattle, the reticulorumen is confronted with large amounts of rapidly fermentable carbohydrates. This may push the epithelium to its limits, even though it possesses a great capacity to adapt to varying feeding conditions. If the epithelial limit is exceeded, increasing amounts of SCFA lead to an acidotic imbalance that provokes epithelial damage and thereby elevates the entrance of pathogens and other potentially harmful substances into the animal's body. Hence, the ruminal epithelium lays the foundation for the animal's health, and in order to ensure longevity and high performance of ruminant farm animals, it should never be overburdened.

Dairy products are major sources of high-quality protein and bioavailable nutrients and dairy production contributes to local, regional and national-level economies. Consumption of raw milk and raw milk products does, however, carry a zoonotic risk, as does direct contact with cattle by farm husbandry staff and other employees. This review will mainly focus on the latter, and deal with it from the standpoint of a well-developed dairy industry, using the example of the Netherlands. With regard to dairy cattle, the main bacterial pathogens are Salmonella spp., Listeria monocytogenes and Leptospira hardjo as well as Brucella abortus and Chlamydia abortus. The main viral pathogens associated with dairy are Rift Valley fever virus, rabies virus, cowpox virus and vaccinia virus. The main parasitological infections are Echinococcus granulosis, Cryptosporidium parvum and Giardia duodenalis, however, the last mentioned have mainly swimming pools as sources of human infection. Finally ectoparasites such as lice and mites and Trichophyton verrucosum may affect employees. Some pathogens may cause health problems due to contamination. Bacterial pathogens of importance that may contaminate milk are Campylolobacter jejuni, Escherichia coli, Mycobacterium avium subsp. paratuberculosis, Leptospira hardjo and Salmonella typhimurium. Excretion of zoonotic viruses in milk is negligible in the Netherlands, and the endoparasite, Toxocara vitulorum is mainly found in suckling and fattening calves, whilst the risk in dairy cattle is limited. Excretion of transmissible spongiform encephalopathies (TSEs) or mycoses in milk are not expected and are, therefore, not of importance here.

Being aware of the risks and working according to hygiene standards can substantially limit zoonotic risks for employees. Additionally, diseased employees are advised to limit their contact with cattle and to indicate that they work with cattle when consulting a physician. To prevent zoonotic risks through excretion of pathogens in milk, standard hygiene measures are necessary. Further, using only pasteurised milk for consumption and/or processing of milk can considerably limit the risks. If these measures are not possible, well-constructed monitoring can be followed. Monitoring programmes already exist for pathogens such as for Salmonella spp., Leptospira hardjo and Mycobacterium avium subsp. paratuberculosis. For others, like Campylobacter jejuni and E. coli, programmes are not available yet as far as we know.

Fungal feed additives offer a potential avenue to enhance dairy cattle health and productivity. This narrative review examines and consolidates literature investigating the effects of products containing, or derived from, anaerobic fungi (AF), obligately aerobic filamentous fungi and yeasts. There is a sparsity of research investigating supplemental AF in cattle, but existing literature demonstrates that AF can consistently increase the digestibility of feeds. Anaerobic fungal additives are limited by their oxygen vulnerability, although characterization of the resting stage of their lifecycle would aid in the development of products which could be used on farm. The majority of research investigating aerobic fungi in dairy cattle is based upon their fermentation products. These products often enhance digestibility variables in cattle, which sometimes benefits growth and production. Inconsistent responses, which are attributed to heterogenous product composition and rumen stability, hinder the industry utility of these additives, and further research is required to define the conditions required for efficacy. A large body of research exists examining the effects of active yeast and yeast derivatives in mature cattle and calves. In-depth examination of this research is beyond the scope of this review, but substantial evidence suggests that supplementing dairy cattle with yeast can be advantageous for gut health and development, production and stress tolerance. This review highlights the pathways through which exogenous fungi can enhance dairy production, and that further research is required to define the causes of inconsistent responses from treatments. This will increase the value of fungal additives to the dairy sector.

Preservation of colostrum for neonatal dairy calves has seldom been seldom in recent years, much of the peer reviewed literature having been published in the 1970s and 1980s. First milking colostrum is high in bioactive immune enhancers such as immunoglobulins, lactoferrins, lysozymes and cytokines and is vital to confer passive immunity to newborn dairy calves to promote their health, welfare and future productivity. Bovine colostrum is advisedly restricted from the bulk milk supply for the first 8 milkings post calving due to high somatic cell counts and the risk of antimicrobial residues. As such, many producers refer to ‘colostrum’ as not only the first milking post calving, but also the aformentioned ‘transition’ milk. Colostrum is preserved in order to protect supply for feeding when production may be poor or where there is a glut of colostrum such as in seasonal calving systems. There are multiple reasons for newborn calves not to have access to their dam's colostrum, including multiple births, acute mastitis or maladapted maternal behaviour, especially in first lactation heifers. Shortages in colostrum may also be precipitated by purposeful discarding of colostrum from cows infected with Mycobacterium avium subsp paratuberculosis and Mycoplasma bovis. Broadly, colostrum may be preserved using low temperature (refrigeration or freezing) or chemical preservatives. The aim of this scoping review article was to identify options for preservation and gaps in research and to propose best practice for colostrum preservation.

Bovine glycomacropeptide (GMP), present in cheese whey, is a glycan–phosphopeptide complex released from κ-casein by the action of chymosin during cheese making. Because GMP lacks phenylalanine and tyrosine, it is considered a potential dietary source of amino acids for patients with phenylketonuria or tyrosinaemia type I – genetic disorders affecting phenylalanine and tyrosine metabolism, respectively. The development of methods to obtain high-purity GMP remains a long-standing challenge in the dairy industry. This review discusses isolation and purification techniques suitable for producing GMP for dietary management of these disorders. Ultrafiltration (or dialysis) and deproteinization are widely used to remove non-GMP components from whey prior to chromatographic separation. Among chromatographic methods, anion exchange chromatography is regarded as the most versatile for selectively adsorbing GMP. Laboratory-scale purification yielding GMP with undetectable levels of contaminating amino acids can be achieved by a combined method with dialysis, deproteinization and anion exchange techniques. In our laboratory, bovine whey protein concentrate prepared by dialysis and commercial whey protein isolate were used as starting materials. Each sample was deproteinized by heat and acid treatments to obtain the soluble whey fraction, which was subsequently fractionated by anion exchange chromatography (or its batch method) to recover GMP free of detectable phenylalanine and tyrosine – making it applicable to the dietary treatment of the above-mentioned disorders. Future research should investigate GMP in ‘second cheese whey’, an industrial by-product from the manufacture of whey cheeses (e.g., Ricotta). Another challenge is developing large-scale GMP production methods using inexpensive, food-grade anion exchangers (e.g., chitin).

The aim of this review was to present various topics related to lactose intolerance with special attention given to the role of fermented foods and probiotics in alleviating gastrointestinal symptoms. Lactose intolerance is a common digestive problem in which the human body is unable to digest lactose, known as milk sugar. Lactose intolerance can either be hereditary or a consequence of intestinal diseases. Recent work has demonstrated that fermented dairy products and probiotics can modify the metabolic activities of colonic microbiota and may alleviate the symptoms of lactose intolerance. We suggest that, lactose free dairy products could be recommended as alternatives for the alleviation of lactose intolerance and for the promotion of human health and wellness.

This Review describes the objectives and methodology of the DairyWater project as it aims to aid the Irish dairy processing industry in achieving sustainability as it expands. With the abolition of European milk quotas in March 2015, the Republic of Ireland saw a surge in milk production. The DairyWater project was established in anticipation of this expansion of the Irish dairy sector in order to develop innovative solutions for the efficient management of water consumption, wastewater treatment and the resulting energy use within the country's dairy processing industry. Therefore, the project can be divided into three main thematic areas: dairy wastewater treatment technologies and microbial analysis, water re-use and rainwater harvesting and environmental assessment. In order to ensure the project remains as relevant as possible to the industry, a project advisory board containing key industry stakeholders has been established. To date, a number of large scale studies, using data obtained directly from the Irish dairy industry, have been performed. Additionally, pilot-scale wastewater treatment (intermittently aerated sequencing batch reactor) and tertiary treatment (flow-through pulsed ultraviolet system) technologies have been demonstrated within the project. Further details on selected aspects of the project are discussed in greater detail in the subsequent cluster of research communications.

The milk fat globule membrane (MFGM) is formed by complex cell biological processes in the lactating mammary epithelial cell which result in the release of the milk fat globule (MFG) into the secretory alveolus. The MFG is bounded by a continuous unit membrane (UM), separated from the MFG lipid by a thin layer of cytoplasm. This unique apocrine secretion process has been shown in all of the mammary species so far investigated. Once the MFG is released into the alveolus there is a considerable transformation of the UM with its attached cytoplasm. This is the MFGM. The transformation is stable and expressed milk shows the same transformed MFGM structure. Again, this transformation of structure is common to all mammalian species so far investigated. However, the explanation of the transformation very much depends on the method of investigation. Transmission electron microscope (TEM) studies suggest a literal breakdown to a discontinuous UM plus cytoplasm in patches and strands, whereas more recent confocal laser scanning light microscopy (CLSM) studies indicate a separation, in a continuous UM, of two phases, one liquid ordered and the other liquid disordered. This review is designed to show that the TEM and CLSM results show different views of the same structures once certain deficiencies in techniques are factored in.

Increased animal productivity has reduced animal fitness, resulting in increased susceptibility to infectious and metabolic diseases, locomotion problems and subfertility. Future animal breeding strategies should focus on balancing high production levels with health status monitoring and improved welfare. Additionally, understanding how animals interact with their internal and external environment is essential for improving health, fitness, and welfare. In this context, the continuous validation of existing biomarkers and the discovery and field implementation of new biomarkers will enable us to understand the specific physiological process and regulatory mechanisms used by the organism to adapt to different environmental conditions. Thus, biomarkers may be used to monitor welfare and improve management and breeding strategies. In this article, we describe major achievements in the establishment of biomarkers in dairy cows and small ruminants. This review mainly focuses on the physiological biomarkers used to monitor animal responses to, and recovery from, environmental perturbations. We highlight future avenues for research in this field and present a timely positioning document to the scientific community.

The aim of this review is to quantify the strength of evidence for the efficacy of exogenous enzymes (EE) in dairy calf rearing, by systematically identifying, consolidating and discussing existing research on the subject. This review identified 17 articles that measured the effect of EE alone or in combination with another treatment on indicator variables for calf performance, behaviour, health or environmental output; 15 studies realised a positive effect of enzyme supplementation on at least one variable, and one study realised a negative effect of treatment on body parameters. Inconsistent results were noted for effects of EE on growth and feed efficiency. Studies that combined EE with another treatment, did not tend to find performance improvements compared to stand-alone treatments. However, several studies were underpowered which could have limited their ability to detect effects on primary response variables. All papers that measured digestibility found an increase in fibre digestibility from enzyme treatment; however, this did not always result in improved feed efficiency or growth. Reductions in non-nutritive oral behaviour, increased resting time and rumination, were observed in studies measuring calf behaviour, as were enhanced rumen development and reduced cost of calf rearing; suggesting that EE could enhance calf health and welfare, whilst having additional advantages for rearing economics. Future research into the efficacy of EE in dairy calves is worth pursuing. However, a targeted and evidence-based approach to experimental design is required, with due consideration given to enzyme actions and interactions, as well as robust power analysis for sample size.

Scientific studies demonstrate the importance of intestinal microbiota to human health and how probiotic microorganisms can positively affect health when administered regularly and in adequate amounts. Probiotic bacteria can be part of fermented products and their functional importance is associated mainly with their metabolism. They are thought to benefit individuals to maintain their health and also to strengthen resistance against various types of diseases. The acceptance of probiotic cultures and products by consumers increased when these bacteria were marketed as natural cultures that help in digestion and health. Considering this, the food industry has an increasing demand for new candidates as probiotic cultures, and the dairy industry has a particular interest for fermented milks and other dairy products, since these are the most common food vehicles for probiotic cultures. Therefore, the dairy industries are increasingly seeking to improve their products with these beneficial bacteria. However, the legal peculiarities and excess of control agencies in Brazil makes the registration of these products and the collection of data very complex. Prospective analysis suggests that probiotic foods have the potential to effect a considerable expansion of the dairy industry, allowing the dairy sector to grow and for these products to be increasingly sought by consumers globally. For this, not only actions on research and innovation are necessary, but also official clarifications on the claims for considerations of microbiological security and functionality of these products. This review aims to elucidate important probiotic research regarding the isolation and characterization of beneficial cultures in Brazil, and to demonstrate the relevance of the dairy chain as a potential source of novel cultures for the development of new probiotic products to expand the Brazilian dairy industry.