Control Milk Research Articles

The effect of milk types on enamel density in primary teeth: Research articl

Background: Early Childhood Caries (ECC) is a condition affecting primary teeth, caused by enamel demineralization due to bacterial acids from sugar metabolism. Remineralization, supported by calcium and phosphate, is crucial for repairing damage. Milk, rich in these minerals, may aid enamel remineralization and improve dental health. Purpose: To analyze the effects of various bovine milk types on the enamel density of primary teeth. Methods: Twelve extracted primary incisors were divided into four groups: distilled water (control), pure bovine milk, UHT bovine milk, and low-fat bovine milk. Teeth were immersed for 21 days, and enamel density was evaluated using a scanning electron microscope (SEM-EDX) and ImageJ software. The data were analyzed using One-Way ANOVA and Tukey HSD tests. Results: Significant differences were observed between treatment groups (p = 0.006). The highest enamel density was found in the low-fat bovine milk group (0.83±0.64 µm), followed by UHT milk (0.95±0.16 µm), and the lowest in pure bovine milk (2.09±0.19 µm). Tukey HSD results showed significant differences between the control and UHT milk groups (p = 0.11) and the control and low-fat milk groups (p = 0.09). Conclusion: Milk consumption positively affects enamel density in primary teeth, with low-fat and UHT bovine milk showing the most significant impact.

Влияние компонентов рациона на продуктивность и функциональное состояние коров холмогорской породы

Abstract. To realize the genetic potential of dairy cows with high productivity, the qualitative composition of the feed is of key importance. The purpose of this study is the effectiveness of publicly available feed additives – “Carbohydrate-protein mixture” (1st experiment) and “Protected fat” Energizer Gold (2nd experiment) on the productivity of Kholmogory cows, on the content of fat and protein in milk, on the functional state of animals, including taking into account the bloodline of the Holstein breed. Methods. Scientific and production experiments were carried out by the pair-analogue method on 40 lactating cows of the Kholmogory breed of Agrofirma Kholmogorskaya LLC, Arkhangelsk region. The scientific novelty consists in obtaining new knowledge about the effect of feed not only on productivity and fat and protein content in milk, but also on the functional state of Kholmogory cows, including those with different percentages of Holstein blood. Results. When assessing the average group results of daily milk yield, a positive effect was established from including it in the diet according to the feed recommendations. At the same time, the “Carbohydrate-protein mixture” increases the protein content in milk, no increase in the fat content of milk, stated in the recommendations for the use of “Protected fat”, was noted. A decrease in the fat to protein ratio in milk, reflecting the functional state of the cows, was noted, below the standard results in Experiment 1 already from the second, and in Experiment 2 from the fourth control milking, preserved until the end of the study. The best effect on the studied indicators for both feed additives was noted in the Kholmogory cow breed with less Holstein blood.

Comparison of the Effect of Maternal Breast Milk Odor, Facilitated Tucking, and Nonnutritive Sucking Applied to Preterm Neonates During Heel Stick on Pain and Physiological Parameters: A Randomized Controlled Trial.

Background: Preterm infants in the neonatal intensive care unit (NICU) frequently undergo painful procedures, which can lead to both short-term and long-term complications, including potential mortality. Effective pain management is crucial in this context. Although numerous studies have explored non-pharmacological pain relief methods for preterm infants, no research has simultaneously compared the effects of maternal breast milk odor, facilitated tucking, and nonnutritive sucking. Aim: This study aims to comparatively investigate the efficacy of nonnutritive sucking, facilitated tucking, and maternal breast milk odor in reducing pain in preterm neonates during heel sticks. Methods: A randomized controlled trial was conducted in a tertiary-level NICU with 144 preterm neonates (gestational age 31-36 weeks) requiring heel sticks. The infants were randomly assigned to four groups: control, nonnutritive sucking, facilitated tucking, and maternal breast milk odor. Pain and physiological parameters were assessed through video recordings of the procedures and scored at 1-minute intervals using the Premature Infant Pain Profile and Data Evaluation Form. Data were collected at baseline and at 1, 2, and 3 minutes before, during, and after the heel stick. Results: The study found significant effects of the interventions on physiological parameters and pain (heart rate: F = 7.5, p < 0.001; oxygen saturation: F = 16.39, p < 0.001; respiratory rate: F = 6.56, p < 0.001; pain: F = 61.45, p < 0.001). Facilitated tucking resulted in significantly lower pain scores (6.61 ± 1.44) compared with the control group (14.22 ± 3.61), maternal breast milk odor (12.22 ± 3.08), and nonnutritive sucking (10.41 ± 1.71) (p < 0.001). Conclusions: All interventions demonstrated effectiveness in maintaining physiological stability and alleviating pain. Nevertheless, the intervention identified as most effective in reducing pain was facilitated tucking group.

Organoleptic and Physicochemical Profile Comparison of Cow Milk Yogurt and 'Eggurt' Made from Different Egg Whites

Yogurt is a widely consumed fermented dairy product known for its distinctive flavor, nutritional value, and health benefits. To expand its nutritional profile and enhance textural qualities, this study explores the use of egg whites as an alternative ingredient in yogurt production. The research compares the sensory and physicochemical properties of traditional milk yogurt with "eggurt" a yogurt variant made using different egg white sources: free-range chicken, caged chicken, and duck eggs. Four samples were prepared, including one control (milk yogurt) and three “eggurt” variants. Sensory quality was evaluated through organoleptic testing using a structured Likert scale to assess attributes such as color, surface gloss, aroma, mouthfeel, and flavor. Physicochemical analysis included moisture content, total dissolved solids, viscosity, ash content, and acidity measurements. Results showed that free-range “eggurt” was most like milk yogurt in terms of texture and flavor, displaying balanced viscosity and minimal surface liquid separation. In contrast, caged “eggurt” exhibited increased surface liquid, higher ash content, and stronger acidity, while duck eggurt was noted for its excessive thickness, very high viscosity, and pronounced acidity. These textural and compositional differences, despite the higher production costs, suggest that free-range “eggurt” is the most promising alternative, offering a comparable sensory experience to traditional yogurt while enhancing texture and overall quality.

Ethanol-activated microglial exosomes induce MCP1 signaling mediated death of stress-regulatory proopiomelanocortin neurons in the developing hypothalamus

BackgroundMicroglia, a type of resident immune cells within the central nervous system, have been implicated in ethanol-activated neuronal death of the stress regulatory proopiomelanocortin (POMC) neuron-producing β-endorphin peptides in the hypothalamus in a postnatal rat model of fetal alcohol spectrum disorders. We determined if microglial extracellular vesicles (exosomes) are involved in the ethanol-induced neuronal death of the β-endorphin neuron via secreting elevated levels of the chemokine monocyte chemoattractant protein 1 (MCP1), a key regulator of neuroinflammation.MethodsWe employed an in vitro model, consisting of primary culture of hypothalamic microglia prepared from postnatal day 2 (PND2) rat hypothalami and treated with or without 50 mM ethanol for 24 h, and an in vivo animal model in which microglia were obtained from hypothalami of PND6 rats fed daily with 2.5 mg/kg ethanol or control milk formula for five days prior to use. Exosomes were extracted and characterized with nanosight tracking analysis (NTA), transmission electron microscopy and western blot. Chemokine multiplex immunoassay and ELISA were used for quantitative estimation of MCP1 level. Neurotoxic ability of exosome was tested using primary cultures of β-endorphin neurons and employing nucleosome assay and immunocytochemistry. Elevated plus maze, open field and restraint tests were used to assess anxiety-related behaviors.ResultsEthanol elevated MCP1 levels in microglial exosomes both in vitro and in vivo models. Ethanol-activated microglial exosomes when introduced into primary cultures of β-endorphin neurons, increased cellular levels of MCP1 and the chemokine receptor CCR2 related signaling molecules including inflammatory cytokines and apoptotic genes as well as apoptotic death of β-endorphin neurons. These effects of microglial exosomes on β-endorphin neurons were suppressed by a CCR2 antagonist RS504393. Furthermore, RS504393 when injected in postnatal rats prior to feeding with ethanol it reduced alcohol-induced β-endorphin neuronal death in the hypothalamus. RS504393 also suppressed corticosterone response to stress and anxiety-like behaviors in postnatally alcohol-fed rats during adult period.ConclusionThese data suggest that alcohol exposures during the developmental period elevates MCP1 levels in microglial exosomes that promote MCP1/CCR2 signaling to increase the apoptosis of β-endorphin neurons and resulting in hormonal and behavioral stress responses.

In Vitro Lipid Digestion of Milk Formula with Different Lipid Droplets: A Study on the Gastric Digestion Emulsion Structure and Lipid Release Pattern.

In this study, the digestive properties of milk formulas (two concept milk formulas L1 and L2 with D4,3 ∼5 μm and a control milk formula S1 with D4,3 ∼0.5 μm) were evaluated using a dynamic digestion model simulating the infant gastrointestinal tract. The results showed that L1 and L2 had a lower lipolysis degree compared to S1 during gastric digestion and no significant difference at the end of the digestion process. Triacylglycerol lipolysis products were highly related to the lipid sources of milk formulas. At the end of digestion, glycerophospholipids in milk formulas were hydrolyzed to lysophospholipids (∼60-80%), while sphingomyelins were barely hydrolyzed. Concept milk formulas showed a complete spherical structure with a mean size of 3-5 μm during gastric digestion, while the control formula had large aggregates consisting of small lipid droplets. This study reveals that the structure of lipid droplets moderates the gastric digestion emulsion structure and further influences the digestive properties of milk formulas.

Electrochemical Sensors in the Food Sector: A Review.

In a world that is becoming increasingly concerned with health, safety, and the sustainability of food supply chains, the control and assurance of food quality have become of utmost importance. This review examines the application and potential of electrochemical sensors in the dynamic field of food science to meet these expanding demands. The article introduces electrochemical sensors and describes their operational mechanics and the components contributing to their function. A summary of the most prevalent electrochemical methods outlines the diverse food analysis techniques available. The review shifts to discussing the food science applications of these sensors, highlighting their crucial role in detecting compounds in food samples like meat, fish, juice, and milk for contemporary quality control. This paper showcases electrochemical sensors' utility in food analysis, underscoring their significance as powerful, efficient tools for maintaining food safety and how they could transform our approach to global food quality control and assurance.

Veterinary and sanitary assessment of milk quality in black-and-white cows fed with extruded compound feeds in North Kazakhstan

Background: Today, one of the most effective ways to increase the digestibility of nutrients is extrusion processing. Raw materials are exposed to high temperatures and pressure, which leads to qualitative and nutritional transformations. The study aims to identify the effect of extruded compound feeds on cow productivity and the qualitative composition of milk.Methods: Based on the chemical analysis of milk, the following indicators were studied: fat mass fraction, protein mass fraction, casein, lactose, dry matter, skimmed milk residue, urea, density, titrated acidity, active acidity, and somatic cells. An organoleptic evaluation of milk was carried out according to the following indicators: color, smell, taste, appearance, and consistency. Once a month, a control milking was carried out to account for productivity.Results: The EG's raw milk had higher casein and lactose content compared to the CG, with EG II showing the highest levels. Additionally, milk from the EG contained more solids, indicating better nutritional and technological properties, with solid content being 3.8-5.7% higher than in the CG.Conclusion: Based on the obtained results, it was found that milk productivity had increased by 10-20%, the fat mass fraction by 7-10%, the protein mass fraction by 5.1-6.5%, the amount of dry matter by 3.8-5.7%, and lactose by 1.1-4.3%.Keywords: Extruded Compound Feeds; Milk Productivity; Black-And-White Breed; Fat; Protein

PSVI-1 Supplemented milk replacer improves feed transition of dairy bull-calves

Abstract Neonatal calves are affected by pathogenic infections, compounded by stress, leading to enteric and respiratory disorders accounting for about 7.8% mortality rate and annual treatment costs exceeding $250 million. Federal restrictions on antibiotic use due antimicrobial resistance in humans has opened the door for viable alternatives like rumen enhancements which have been reported to aid the establishment of beneficial rumen flora leading to improved health and performance. It is hypothesized that nutritional formulation of milk replacers to help the calf prevent or cope with diarrhea can provide a leeway that will ensure better animal performance and transition to solid feed. The objective of study was to evaluate the performance of dairy bull-calves fed nutritionally supplemented milk replacers. Three milk replacers were tested with or without supplementation of metabolic enhancements (Control: no metabolic enhancer; Added: milk replacer with metabolic enhancer added at the time of mixing milk in shuttle; Composite: produced along with metabolic enhancer. Dairy bull-calves (n = 60; 2 to 5 d-old) were grouped into three treatments of milk replacers. The study lasted for 10 wk; 6 wk of milk-feeding and 4 wk of calf starter feeding. Body weights (BW) were taken on a weekly basis, while calf starter intake was measured daily and data were analyzed using one-way analysis of variance. Calves fed milk replacer with composite metabolic enhancer recorded the greatest intake and final BW over the 10-wk period. Calves fed milk replacer with added metabolic enhancer at the point of milk mixing recorded the poorest data in terms of BW gain and final BW. Calves fed metabolic enhancer, either added or composite recorded a better weaning and transition to solid feed from milk feeding. Calves fed control milk replacer experienced a poor transition from milk feeding to solid feed. It is concluded that composited rumen metabolite enhancers in milk replacer supported greater starter intake, average daily gain and better transition of calves to solid feed, and is recommended for the feeding of neonatal calves.

Detection of Antimicrobial Proteins/Peptides and Bacterial Proteins Involved in Antimicrobial Resistance in Raw Cow's Milk from Different Breeds.

Proteins involved in antibiotic resistance (resistome) and with antimicrobial activity are present in biological specimens. This study aims to explore the presence and abundance of antimicrobial peptides (AMPs) and resistome proteins in bovine milk from diverse breeds and from intensive (Pezzata rossa, Bruna alpina, and Frisona) and non-intensive farming (Podolica breeds). Liquid atmospheric pressure matrix-assisted laser desorption/ionization (LAP-MALDI) mass spectrometry (MS) profiling, bottom-up proteomics, and metaproteomics were used to comprehensively analyze milk samples from various bovine breeds in order to identify and characterize AMPs and to investigate resistome proteins. LAP-MALDI MS coupled with linear discriminant analysis (LDA) machine learning was employed as a rapid classification method for Podolica milk recognition against the milk of other bovine species. The results of the LAP-MALDI MS analysis of milk coupled with the linear discriminant analysis (LDA) demonstrate the potential of distinguishing between Podolica and control milk samples based on MS profiles. The classification accuracy achieved in the training set is 86% while it reaches 98.4% in the test set. Bottom-up proteomics revealed approximately 220 quantified bovine proteins (identified using the Bos taurus database), with cathelicidins and annexins exhibiting higher abundance levels in control cows (intensive farming breeds). On the other hand, the metaproteomics analysis highlighted the diversity within the milk's microbial ecosystem with interesting results that may reflect the diverse environmental variables. The bottom-up proteomics data analysis using the Comprehensive Antibiotic Resistance Database (CARD) revealed beta-lactamases and tetracycline resistance proteins in both control and Podolica milk samples, with no relevant breed-specific differences observed.

Effect of Chinese Milk Vetch on Zinc Content and Zinc Absorption of Rice in Purple Tidal Mud Soil

Rice is a staple food crop that feeds billions globally. Addressing Zn deficiency in rice is crucial for improving nutrition and food security. Zn deficiency in rice is a widespread issue, especially in purple tidal mud substrates, which often exhibit low Zn availability. The objective of this two-year pot study was to explore the relationship between Zn content, yield components, and Zn absorption in rice grown in purple tidal mud substrate with varying amounts of Chinese milk vetch (Astragalus sinicus L.) incorporation. The experimental design consisted of seven treatments: an unfertilized control, a Chinese milk vetch control, a chemical fertilizer control, and four treatment variations incorporating Chinese milk vetch alongside chemical fertilizer applications. The results indicated that planting and applying Chinese milk vetch improved the grain yield of rice in purple tidal mud substrate, and the yield increased with higher levels of Chinese milk vetch applied. The increased grain yield resulted in higher Zn absorption in rice grains. The application of Chinese milk vetch, both solely and in combination with chemical fertilizers, had varying effects on zinc uptake and grain zinc formation efficiency in early and late rice, with the control and low-level Chinese milk vetch treatments generally exhibiting the highest performance across the two-year period. By introducing Chinese milkvetch following the use of chemical fertilizers, the Zn content in rice grains increased starting from the second year. The treatment with Chinese milkvetch applied at a rate of 2.25 t/hm2 showed the best results in increasing the Zn content in rice grains. The increase in Zn content and Zn uptake by the rice plants gave rise to a lowering of the DTPA-extractable Zn content in the purple tidal mud substrate. Sole Chinese milk vetch application and using Chinese milk vetch following chemical fertilizer application both increased Zn content extracted by DTPA in purple tidal mud substrate.

ANALYSIS OF THE DAIRY PRODUCTIVITY OF MARES NOVOOLEKSANDRIVSKA DRAFT BREED TAKING INTO ACCOUNT THE TYPE OF HIGHER NERVOUS ACTIVITY

The results of the analysis of the quantitative indices of milk yield of the mares of the Novo-Alexander weight-carrying breed and the determination of their type of higher nervous activity are given. The research was carried out using the motor-forage technique and monthly control milkings for two adjacent days. On the basis of the obtained data, the highest indicators of breeding in the herd were established in June. Record-breaking mares (Rizba, Fibr-ra) were identified according to the individual level of productivity, whose milk yield was more than 2000 liters per lactation, with an average value of1, 331 liters. Mares with a strong balanced mobile type of higher nervous activity prevailed in number and were characterized by significantly higher milk yield (p ˂ 0.05) compared to mares with a strong balanced inert and strong unbalanced type of higher nervous activity.

Influence of Heating Temperature and pH on Acid Gelation of Micellar Calcium Phosphate-Adjusted Skim Milk.

Micellar calcium phosphate (MCP) plays an important role in maintaining the structure and stability of the casein micelle and its properties during processing. The objective of this study was to investigate how heating (10 min at 80 or 90 °C) at different pH levels (6.3, 6.6, 6.9, or 7.2) impacted the acid-induced gelation of MCP-adjusted milk, containing 67 (MCP67), 100 (MCP100), or 113 (MCP113) % of the original MCP content. The unheated sample MCP100 at pH 6.6 was considered the control. pH acidification to pH 4.5 at 30 °C was achieved with glucono delta-lactone while monitoring viscoelastic behaviour by small-amplitude oscillatory rheology. The partitioning of calcium and proteins between colloidal and soluble phases was also examined. In MCP-depleted skim milk samples, the concentrations of non-sedimentable caseins and whey proteins were higher compared to the control and MCP-enriched skim milk samples. The influence of MCP adjustment on gelation was dependent on pH. Acid gels from sample MCP67 exhibited the highest storage modulus (G'). At other pH levels, MCP100 resulted in the greatest G'. The pH of MCP-adjusted skim milk also impacted the gel properties after heating. Overall, this study highlights the substantial impact of MCP content on the acid gelation of milk, with a pronounced dependency of the MCP adjustment effect on pH variations.

Calcium-fortified fresh milk ameliorates postmenopausal osteoporosis via regulation of bone metabolism and gut microbiota in ovariectomized rats

The aging of the global population has made postmenopausal osteoporosis prevention essential; however, pharmacological treatments are limited. Herein, we evaluate the effect of calcium-fortified fresh milk (FM) in ameliorating postmenopausal osteoporosis in a rat model established using bilateral ovariectomy. After 3 months of FM (containing vitamin D, and casein phosphopeptides, 1000 mg Ca/100 g) or control milk (110 mg Ca/100 g milk) supplementation, bone changes were assessed using dual-energy X-ray absorptiometry, microcomputed tomography, and bone biomechanical testing. The results revealed that FM can regulate bone metabolism and gut microbiota composition, which act on bone metabolism through pathways associated with steroid hormone biosynthesis, relaxin signaling, serotonergic synapse, and unsaturated fatty acid biosynthesis. Furthermore, FM administration significantly increased bone mineral content and density in the lumbar spine and femur, as well as femoral compressive strength, while improving femoral trabecular bone parameters and microarchitecture. Mechanistically, we found that the effects may be due to increased levels of estrogen, bone formation marker osteocalcin, and procollagen type I N-propeptide, and decreased expression of the bone resorption marker C-telopeptide and tartrate-resistant acid phosphatase 5b. Overall, the findings suggest that FM is a potential alternative therapeutic option for ameliorating postmenopausal osteoporosis.

Impact of cow, buffalo, goat or camel milk consumption on oxidative stress, inflammation and immune response post weaning time

Milk is a whitish liquid that is secreted from mammary glands; and considered as the primary source of nutrition for newborns since they are not able to digest solid food. However, it contains primary nutrients, as well as growth and immune factors. Early weaning is a critical issue that face women and their babies in developing countries. To avoid infant malnutrition, they tend to use other milk types instead of baby formula. Therefore, the present study aimed to evaluate the impact of cow, buffalo, goat or camel milk consumption on oxidative stress, inflammation and immune response in male and female Sprague Dawley rats post weaning time. The amino acids, fatty acids, minerals and vitamins in the tested milk types were evaluated. Animals were divided into 5 groups (control, cow, buffalo, goat and camel milk administrated groups) (10 rats/group); each animal was administrated by 3.4 ml/day. Rats were administered with milk for 6 weeks; at the end of the 5th week, five animals of each group were isolated and the remaining five animals were immunized with sheep red blood cells (SRBCs) and kept for another week to mount immune response. The effect of different milk types on rats’ immune response towards SRBCs was evaluated through pro-inflammatory cytokines, antioxidants, ESR and CRP measurement; together, with the histopathological examination of spleen samples and hemagglutination assay. Camel milk consumption reduced oxidative stress and inflammation in spleen that resulted from SRBCs immunization; in addition to, B cell stimulation that was apparent from the high level of anti-SRBCs antibodies. Camel milk is recommended for newborn consumption, due to its high-water content, unsaturated fatty acids, and vitamin C, as well as low lactose and fat content.

Mechanistic insights into the changes of biological activity and physicochemical characteristics in Lacticaseibacillus paracasei fortified milk powder during storage

To clarify the change mechanism of biological activity and physicochemical characteristics in Lacticaseibacillus paracasei JY025 fortified milk powder (LFMP) during storage, morphological observation, JY025 survival, storage stability, and metabolomics of LFMP were determined during the storage period in this study. The results showed that the LFMP had a higher survival rate of JY025 compared with the bacterial powder of JY025 (LBP) during storage, which suggested that milk powder matrix could reduce strain JY025 mortality under prolonged storage in the LFMP samples. The fortification of strain JY025 also affected the stability of milk powder during the storage period. There was lower water activity and higher glass transition temperature in LFMP samples compared with blank control milk powder (BCMP) during storage. Moreover, the metabolomics results of LFMP indicated that vitamin degradation, Maillard reaction, lipid oxidation, tricarboxylic acid cycle, and lactobacilli metabolism are interrelated and influence each other to create complicated metabolism networks.

An innovative form of the essential trace element copper for fortification of dairy products

Microelementosis is a disease associated with a deficiency of certain vital microelements. Today, there are ways to combat the lack of essential micronutrients. In this article, the mechanochemical synthesis of a triple copper-containing complex with ascorbic acid and L-isoleucine, an essential amino acid, was carried out. Examination of the sample by X-ray diffractometry showed that the sample has a trigonal crystal structure with space group P31c. As a result of computer quantum chemical modeling, the values of the difference in total energy, chemical hardness, energy of the highest occupied molecular orbital and the lowest unoccupied molecular orbital were determined. We determined the optimal option for the interaction of copper with vitamin C and L-isoleucine, where the binding occurs through hydroxyl groups attached to the C2 and C3 atoms of ascorbic acid, and through the carboxyl group and α-amino group of isoleucine. The sample was examined by IR spectroscopy and confirmed by computer modeling data. The stability of the resulting complex was studied depending on the technological parameters — pH, temperature and exposure time. Using the Greco-Latin square method, a matrix for planning a multifactorial experiment was compiled. An analysis of the dependence of the change in optical density (∆ D) on pH, temperature and exposure time showed that the pH of the medium and the temperature of the solution have a significant effect on ∆ D: an increase in the pH of the medium and the temperature of the solution leads to an increase in ∆ D. Exposure time does not have a significant effect to change the optical density value (∆ D). The parameters at which sample stability is observed correspond to the lowest values of ∆ D: pH = 3–8, t = 25–70, τ = 5–15. The effect of the concentration of a copper-containing complex on the physicochemical parameters of milk was studied. It has been established that the optimal concentration of copper ascorbate isoleucinate for fortifying dairy products is 0.005 mol/l or less. Next, an organoleptic assessment of the indicators of milk enriched with copper ascorbate isoleucinate was carried out. The analysis of the results showed that the organoleptic parameters (smell and taste) of milk enriched with ascorbate-isoleucinate of copper are 0.1 points higher than those of milk enriched with the inorganic form of the essential trace element copper and 0.3 points lower than that of the control milk sample.

Study of the possibility of producing brine-ripened cheeses from frozen sheep’s milk

The article presents the results of a study of the quality indicators of brine-ripened cheeses produced from defrosted sheep’s milk. The objects of the study were natural and defrosted sheep’s milk, brine-ripened cheeses from this milk. The study of defrosted sheep’s milk (experiment) was carried out after 10 days of its storage at a temperature of –18 °C followed by defrostation at a temperature of 20 ± 2 °C. The composition of natural sheep’s milk (control) was examined after storage for 24 ± 12 hours at a temperature of 4 ± 2 °C. It has been found that the freezing of milk and its subsequent defrostation did not have a significant effect on the milk solids content, the mass fraction of protein and fat, titrated acidity; however, the mass fraction of calcium decreased, on average, by 20%. Freezing milk did not significantly affect the total number of micro- organisms, including spore aerobic microorganisms and molds. A decrease in the number of somatic cells (from 3.0 to 4.5 times) was found. There were no differences between the control and experimental milk samples in the renneting ability. The level of syneresis of clots in the control sample was 16 ± 1% higher compared to the experimental sample. The cheeses were produced according to the traditional technological scheme of brine-ripened cheese using a production mesophilic bacterial starter culture. The control and experimental cheeses did not differ significantly in physical and chemical parameters. According to the degree of proteolysis, there were no significant differences between the control and experimental variants. In the experimental sample, a decrease in the buffer capacity of the cheese mass was noted in comparison with the control cheeses. The freezing of milk did not have a significant effect on the taste characteristics of the cheeses: in both variants, the cheeses were characterized by a weakly expressed cheese, fermented milk taste with original taste of sheep’s milk. More noticeable differences were found in the consistency of the cheeses. In the control version, the consistency was characterized as tender, slightly brittle; in the experimental version, it was less tender, but brittle and slightly powdery. The greatest deterioration in consistency was observed in the samples of frozen cheese made from natural milk after defrosting; it was characterized as brittle, powdery, crumbly.

Improvement of Raw and Pasteurized Milk Quality through the Use of Lactoperoxidase Systems (LPSs) along the Dairy Value Chain, under Real Conditions in Ethiopia.

Lactoperoxidase systems (LPSs) can enhance the microbiological quality of raw milk when there is lack of cooling facilities. In this study, a total of 250 milk samples were collected from farmers, collectors, and factories. Experimental samples were both LPS-activated morning and overnight milk. The samples were tested with several chemical and microbiological tests, such as total bacterial count (TBC), total coliform count (TCC), and Escherichia coli count (EC). Results indicated that all LPS-activated milk samples had a higher quality than all the control samples. For instance, both the morning and overnight farm milk samples had mean TBCs of 5.79 log and 6.55 log cfu/mL, which is significantly (p < 0.05) lower than the control samples' mean TBC of 6.73 log and 7.31 log cfu/mL, respectively. When this was compared with the Ethiopian Standard, 51.4% of morning and 39.5% of overnight farm milk with LPS activation met the acceptable quality, while only 28% of morning and 15.7% of overnight control milk met the standard. Moreover, LPS activation has also significantly improved the shelf life of collectors' raw milk and pasteurized milk at the factories. Therefore, a better hygienic practice with LPS application can be practiced in conditions that lack cooling infrastructure and electricity.

The conjugation of productive features of dairy cattle of the Holstein breed

Relevance. Currently, in the Sverdlovsk region, more than 75% of the total number of cattle belongs to the Holstein breed, created by absorbing domestic black-and-white cattle into Holsteins. The study of the variability of the productive qualities of cows during lactation is important for identifying the possibility of increasing productive longevity and the efficiency of breeding and using Holstein cattle of the Ural selection in the conditions of the Middle Urals.Methods. The study was conducted in one of the typical livestock complexes of the Holstein black-and white cattle breed in the Sverdlovsk region. All cows that completed four lactation periods were included in the assessment. Milk productivity was assessed by control milks, milk quality indicators: MJ and MDB in milk in an average milk sample from each cow, once a month correlation coefficients between productive characteristics were calculated in the Uralplemcenter dairy laboratory. The automated program “SELEX. Dairy cattle.”Results. As a result of the conducted studies, it was found that significantly more milk was produced from age-and-sex cows during the third lactation than during the first and second, as well as the fourth lactation (p ≤ 0.01 — for the first, p ≤ 0.05 — for the second and fourth). The live weight significantly increased with age in the second lactation at p ≤ 0.01 relative to the first, and from the third onwards — at p ≤ 0.001 relative to the first lactation. There is a tendency to decrease the mass fraction of fat (MJ) in milk and a simultaneous increase in MDB with age from the first to the fourth lactation. When carrying out breeding work, it is possible to take into account the positive correlation coefficients for predicting the further milk productivity of cows according to the milk yield of the first heifers, the invariance of milk quality indicators with changes in milk yield and the positive effect of live weight of cows on their productivity. The research is exploratory and was carried out within the framework of scientific research of the Ural State Agrarian University (state registration No. AAAA19-1191014000069).