Nutritional Value Of Milk Research Articles

Knowledge about consumption of milk: Study involving consumers from two European Countries – France and Portugal

Abstract Milk assumes a pivotal role in human nutrition from early stages of life, although when going into adulthood the consumption habits can vary according to different perceptions from the consumer or even due to the presence of some intolerances. In this context, this research focuses on the consumption knowledge about the composition and nutritional value of milk and its effect on human health. The objective was to investigate how informed are the French and Portuguese participants and detect similarities or differences according to the country. For this purpose, a questionnaire survey was set up to recruit participants from two countries: France and Portugal. The total number of participants was 543, of which 333 were French and 210 were Portuguese. For treatment of data basic statistics and tests were used to compare the results between the two countries, using the software SPSS. The results showed significant differences between the two countries in what concerns the participant’s knowledge about milk composition and nutritive value and also the effects of milk on human health. From the 13 items used to assess knowledge about composition and nutritive value of milk, significant differences were found between countries for six of them. Regarding the ten items used to evaluate the effects of milk on human health, significant differences were found for seven of them. As so, the knowledge about the effects on human health are more differentiated between the participants from France and Portugal, than the knowledge about the milk composition. Factor analysis showed six groups of questions, with good internal reliability (values of alpha varying from 0.707 to 0.825). It is concluded that participants from different countries, exposed to different environments (societal, political, or educational) can have different perceptions about milk and its effects on health.

The Characteristics of Milk Fatty Acid Profile Predicted by Fourier-Transform Mid-Infrared Spectroscopy (FT-MIRS) in Chinese Holstein Cows.

Fatty acid is an important factor affecting the nutritional quality of milk. In this study, we collected and assessed 78,086 milk samples from 12,065 Chinese Holstein cows from 11 farms in Northern China from November 2019 to September 2022. The contents of eight fatty acid groups were predicted using FT-MIRS-based models. The contents of TFAs, SFAs, UFAs, MUFAs, PUFAs, and LCFAs in milk reached the highest at 96-125 DIM, and SCFA and MCFA contents reached the highest at 276-305 DIM. With the increase in somatic cell score, the contents of various fatty acid groups in milk gradually decreased, and the nutritional value of milk and flavor of dairy products gradually deteriorated. The contents of high-quality fatty acids in milk, particularly UFAs and MUFAs, were significantly higher in the non-pregnant state than in the pregnant state. However, SCFA and MCFA contents exhibited the opposite pattern. Our findings provided valuable information on the content and distribution range of fatty acid groups in milk from Chinese Holstein cows. Further analysis is warranted to explore the breeding of Chinese Holstein cows providing milk with abundant beneficial fatty acids.

Enhancing probiotic survival and quality of fermented goat milk beverages with bael (Aegle marmelos) fruit pulp

This study aimed to assess the impact of bael fruit pulp on the viability of probiotic Lacticaseibacillus rhamnosus GG (LGG) and some physicochemical properties of bael-goat milk-based beverages during 21 days of refrigerated storage. Bael fruit pulp (BFP) was incorporated into goat milk (GM) at different levels (0 %, 5 %, 10 %, and 20 %), and fermented with LGG combined with conventional yoghurt culture. Products were analyzed at weekly intervals. Fermented GM without bael served as control. Redness (a*), yellowness (b*), chroma, and LGG viability were all significantly increased while pH, lightness (L*), and whiteness were dramatically decreased by the addition of BFP. After 14 days of storage, all fermented milk containing bael exhibited considerably (p < 0.05) greater LGG counts than the control. The product containing 20 % bael had the greatest viability counts (7.01 log CFU/mL) at the end of storage. Throughout the storage period, all of the products—including the control—maintained viable probiotic counts of greater than 6 log CFU/mL. The pH of the products decreased over time but was stabilized by bael. In conclusion, the findings demonstrate that goat milk is a perfect vehicle for LGG, and adding bael may boost the fermented goat milk's probiotic viability, physicochemical qualities, and nutritional value, thus improving its overall quality.

Mammary fat globules as a source of mRNA to model alterations in the expression of some milk component genes during lactation in bovines

BackgroundThe milk's nutritional value is determined by its constituents, including fat, protein, carbohydrates, and minerals. The mammary gland's ability to produce milk is controlled by a complex network of genes.Thereby, the fat, protein, and lactose synthesis must be boost in milk to increase milk production efficiency. This can be accomplished by fusing genetic advancements with proper management practices. Therefore, this study aimed to investigate the association between the Lipoprotein lipase (LPL), kappa casein CSN3, and Glucose transporter 1 (GLUT1) genes expression levels and such milk components as fat, protein, and lactose in different dairy breeds during different stages of lactation.MethodsTo achieve such a purpose, 94 milk samples were collected (72 samples from 36 multiparous black-white and red-white Holstein–Friesian (HF) cows and 22 milk samples from 11 Egyptian buffaloes) during the early and peak lactation stages. The milk samples were utilized for milk analysis and genes expressions analyses using non- invasive approach in obtaining milk fat globules (MFGs) as a source of Ribonucleic acid (RNA).ResultsLPL and CSN3 genes expressions levels were found to be significantly higher in Egyptian buffalo than Holstein–Friesian (HF) cows as well as fat and protein percentages. On the other hand, GLUT1 gene expression level was shown to be significantly higher during peak lactation than early lactation. Moreover, lactose % showed a significant difference in peak lactation phase compared to early lactation phase. Also, fat and protein percentages were significantly higher in early lactation period than peak lactation period but lactose% showed the opposite pattern of Egyptian buffalo.ConclusionTotal RNA can be successfully obtained from MFGs. The results suggest that these genes play a role in glucose absorption and lactose synthesis in bovine mammary epithelial cells during lactation. Also, these results provide light on the differential expression of these genes among distinct Holstein–Friesian cow breeds and Egyptian buffalo subspecies throughout various lactation phases.

ВЛИЯНИЕ МАКРОЭЛЕМЕНТОВ, СОДЕРЖАЩИХСЯ В РАСТЕНИЯХ ПАСТБИЩ ЗАО «ПЛЕМЗАВОД КРАСНОТУРАНСКИЙ» (КРАСНОТУРАНСКИЙ РАЙОН, КРАСНОЯРСКИЙ КРАЙ), НА КАЧЕСТВО МОЛОКА КОРОВ КРАСНО-ПЕСТРОЙ ПОРОДЫ

The purpose of the study is to identify macrochemical elements in plants that affect the quality of milk in cows of the red-motley breed of CJSC Plemzavod Krasnoturansky, Krasnoturansk District of the Kras-noyarsk Region. Objectives: study and identification of macrochemical elements in plants K+, Ca2+, PO34–, Mg2+; determination of the composition of phytogroups and testing of hay for macrochemical composition; study of the content of phosphoproteins and phospholipids in cow's milk. Based on the chemical composition, macrochemical elements were identified in plants. The most significant macrochemical elements Ca2+, PO34– for the quality of cow's milk have been identified. The highest Ca2+ content is 11.32 % in Bupleurum bicaule Helm., 11 % in Medicago sativa L.; PO34– – 2.7 % in Vicia sativa L. and 1.90 % in Bupleurum bicaule. The study used the methods of test sites used in geobotanical studies of ecological and biological factors affecting the quality of cows' milk using macrochemical analysis. The qualitative composition of chemical elements in the ash residue is determined. Fluctuations were noted in the content of macrochemical elements in the ash non-combustible residue during the seasons of the year. By autumn, the amount of Ca2+ and Mg2+ increases, and PO34– decreases. Studies were conducted on the in-fluence of Ca2+, PO34– on the formation of phosphoproteins and phospholipids in cow's milk. In summer (July) milk has a high fat content, in winter (February) – protein. Statistical processing of the data was carried out by calculating the percentage of organic matter using the ratio formula. The pastures of JSC Plemzavod Krasnoturansky belong to the zone-zonal groups: forest-steppe, forest-meadow, alpine, subalpine, located in the vicinity of the villages of Krasnoturansk and Lebyazhye, in the areas of the Unyuk and Turan mountain heights. The content of macroelements in the studied pastures of the farm was determined. Identification of macrochemical elements in plants provides an understanding of the influence of plants on the quality of cows' milk (nutritional value, value).

Removal of aflatoxin B1 from contaminated milk and water by nitrogen/carbon-enriched cobalt ferrite -chitosan nanosphere: RSM optimization, kinetic, and thermodynamic perspectives

In view of the feed/foods inevitably contaminated by toxic and carcinogenic aflatoxin B1 (AFB1), efficient mesoporous metformin-chitosan/silica‑cobalt ferrite nanospheres (Mt-CS/CFS NSs) was prepared to remove AFB1 from aqueous/non-aqueous media. The morphological, functional, and structural characteristics and adsorption properties of C/N-enriched CS/CFS were investigated systematically. The interactive operating variables (temperature (5.0–35 °C); time (10–100 min); AFB1 dose (50–100 μg/mL); and Mt-CS/CFS dosage (0.5–3.5 mg) were optimized via the Box-Behnken design (BBD), which demonstrated good agreement between the experimental data and proposed model. The adsorption efficiency in artificially contaminated cow's milk as well as aqueous environment reached over 91.0 % in a wide pH range (3.0–9.0), without significant change in the nutritional value of milk. Freundlich isotherm and second-order adsorption kinetics were regarded as the most suitable models to fit the adsorption results, and the adsorption rate is dominated by the intra-particle diffusion and boundary layer diffusion. Thermodynamic analyses proved that the process was spontaneous and exothermic. The adsorption mechanism could be explained as physisorption via hydrogen bonding, n-π interaction, and hydrophobic/hydrophilic interactions. The porous Mt-CS/CFS NS derived from chitosan nanoparticles is therefore outstanding adsorbent, offering great adsorptive performance and recycabilities, which impedes economic losses in the food industry.

The use of ultrasonication in producing potato-based milk, and to determine its proximate composition

Plant-based food is gaining the limelight, as it is unique, with high nutritional content and zero cholesterol and calories. However, there are no known plant-based milk alternatives of vegetable origin. Hence, our research aims to develop milk from potatoes associated with ultrasonication. The obtained potato milk was assessed for its proximate composition, and it was determined to be 92.66 ± 0.032% moisture, 0.66 ± 0.044% ash, 7.34 ± 0.002% total solids, 7.1 ± 0.001 pH, 96 °C boiling point, 0% lactose, 0.09 ± 0.004% titratable acidity, 1.030 ± 0.098 specific gravity, and the color L* 92.33 ± 0.023, a* −2.33 ± 0.044, b* 10.12 ± 0.089. The total essential amino acid was 44.76 g/100 g, and the total non-essential amino acid was 53.48 g/100 g. The fatty acid profile of potato milk was palmitic acid (23.22 ± 0.12), stearic acid (5.33 ± 0.33), oleic acid (6.6 ± 0.10), linoleic acid (41.2 ± 0.05) and linolenic acid (19.4 ± 0.01). The potato milk's fat, protein, and carbohydrates were 0.3 ± 0.002%, 3.92 ± 0.341%, and 54.2 ± 0.046%, the dietary fiber was1.9 ± 0.234. The sugar content was 1 ± 0.087. The Vitamin-A and Vitamin-C content was 0.03 ± 0.001 and 28 ± 0.099, respectively. Hence, due to their similar proximate composition to bovine milk and good nutritional and fatty acid value, the produced potato milk can have functional properties and be a non-dairy alternative to bovine milk.

Non-thermal processing of milk: Principles, mechanisms and effect on milk components

The conventional thermal treatment causes chemical modifications to milk constituents such as protein denaturation, loss of vitamins and flavoring compounds, depression at freezing point, and nonenzymatic browning, which may result in adverse changes to the flavor, color, and nutritional value of milk. This review looks into the emerging non-thermal processing techniques such as high-pressure processing (HPP), pulsed electric field (PEF), ultrasonication and hydrodynamic, UV-irradiation and plasma technology, cavitation, and their effects on milk components and bioactive compounds. For consumer acceptability and safety, simultaneous and crucial needs exist: microbial safety, fresh like quality and preservation of bioactive compounds. Technologies like HPP and PEF have been capable of achieving microbial reduction with moderate thermal inputs. Ultrasonication and hydrodynamic cavitation have the dual functions of deactivating microorganisms and homogenizing, and plasma and UV-C radiation could ensure minimal loss of heat-sensitive components. These processing techniques could be an alternative to pasteurization and sterilization of milk with assured microbial inactivation and maximal retention of nutrients in dairy.

Information influenced consumers' attitudes toward A2 milk: An approach using text highlighting technique

AbstractDairy products are constantly launched, mainly focusing on healthiness, especially for the public, like people with food allergies. However, raising consumer awareness is a great challenge, especially about new products with health claims. This study used the text‐highlighting (TH) methodology associated with acceptance tests to assess Brazilian consumers' explicit attitudes toward A2 milk. In the task, consumers were asked to highlight in a text the terms they “liked” or “disliked” about the milk's nutritional importance, the difference between A1 and A2 milk, health benefits and harmful effects, and the necessity for more studies and awareness about the A2 milk. Sensory acceptance pre and post‐text were also measured. A high engagement of consumers with the TH could be observed, which suggests good intuitiveness of the technique. Including information about the nutritional value of milk and the difference between both kinds of milk may increase positive consumer perception, as it encourages consumers to express their value judgment in the form of “liked”. On the other hand, information simultaneously, the harms of the formation of BCM‐7 (in A1 milk) prompted consumers to express their value judgment in the “disliked” highlights. This underscores the importance of raising consumer awareness about the product and the need for more studies on the real effects of A2 milk on the body and the implementation of specific legislation. Moreover, it was observed that information should be in a simple and direct language, as technical terminology in the text did not have a positive effect, such as the information about the genetic mutation. TH produced valuable insights that can be used in communication strategies with A2 milk.Practical applicationThe findings of this study show practical utility for consumer‐based methodologies, focusing on the text‐highlighting method approach and its influence on consumer perceptions. Moreover, the results show practical utility to direct regulation, consumer awareness, and product commercialization of A2 milk.

Effects of ultra-high-temperature processes on metabolite changes in milk.

Processing can affect milk properties and alter the composition of milk metabolites, which has corresponding effects on milk flavor and quality. It is quite important to study the safe quality control of milk processing. Therefore, the purpose of this study was to identify metabolites at different steps of ultra-high-temperature-sterilized (UHT) milk processing using gas chromatography-mass spectrometry (GC-MS). These steps included raw milk, pasteurized milk (80°C for 15 s), semi-finished milk (after pasteurizing, it was homogenized at 75°C with pressure of 250 bar), UHT milk (at 140°C for 10 s), and finished milk (homogenized UHT milk). A total of 66 metabolites were identified across all samples, including 30 metabolites in the chloroform layers of the milk samples and 41 metabolites in the water layers; 5 metabolites were found in both layers. The metabolites were primarily fatty acids, amino acids, sugars, and organic acids. For example, pasteurized and ultra-high-temperature-sterilized kinds of milk had lactose contents similar to those of raw milk, with increases in saturated fatty acids such as hexadecanoic acid and octadecanoic acid. Additionally, these findings indicated that these methods of processing can affect the contents of some components of milk. Therefore, from the perspective of milk's nutritional value and consumer health, the excessive heating of dairy products should be avoided and the milk heat treatment process should be standardized from the source.

The Importance of Dietary Antioxidants on Oxidative Stress, Meat and Milk Production, and Their Preservative Aspects in Farm Animals: Antioxidant Action, Animal Health, and Product Quality-Invited Review.

The biological effects of oxidative stress and associated free radicals on farm animal performance, productivity, and product quality may be managed via dietary interventions-specifically, the provision of feeds, supplements, and forages rich in antioxidants. To optimize this approach, it is important first to understand the development of free radicals and their contributions to oxidative stress in tissue systems of farm animals or the human body. The interactions between prooxidants and antioxidants will impact redox homeostasis and, therefore, the well-being of farm animals. The impact of free radical formation on the oxidation of lipids, proteins, DNA, and biologically important macromolecules will likewise impact animal performance, meat and milk quality, nutritional value, and longevity. Dietary antioxidants, endogenous antioxidants, and metal-binding proteins contribute to the 'antioxidant defenses' that control free radical formation within the biological systems. Different bioactive compounds of varying antioxidant potential and bio-accessibility may be sourced from tailored feeding systems. Informed and successful provision of dietary antioxidants can help alleviate oxidative stress. However, knowledge pertaining to farm animals, their unique biological systems, and the applications of novel feeds, specialized forages, bioactive compounds, etc., must be established. This review summarized current research to direct future studies towards more effective controls for free radical formation/oxidative stress in farm animals so that productivity and quality of meat and milk can be optimized.

Effect of Total Mixed Ratio (TMR) Supplementation on Milk Nutritive Value and Mineral Status of Female Camels and Their Calves (Camelus dromedarius) Raised under Semi Intensive System during Winter

This study was conducted to investigate the nutritional values of female camels’ milk and the minerals status, for them and their calves, when fed a total mixed ration (TMR) beside alfalfa hay during winter. Thirty-seven lactating multiparous female camels and their calves were selected at mid-lactation in the Al-Kharj region. Group one was fed only alfalfa hay ad libitum (C) and group two was supplemented with a total mixed ratio (TMR; 4 kg/head/day), primarily containing a mix of barley grain, wheat feed, palm kernel cake, soya hulls, vitamins and minerals. Milk and blood samples were collected in the middle of the winter season and analyzed for minerals using ICP-OES. A significant (p &lt; 0.05) higher concentration was observed for protein and inorganic matter in milk from female camels supplemented with TMR in the T group. In addition, Mg, Co, Fe and Zn levels in milk significantly (p &lt; 0.05) increased compared with the control group (C). Blood serum concentrations of Ca, P, Mg, Cu, I, Se, Zn and Cd minerals in female camels were significantly (p &lt; 0.05) higher in the T group compared to the C group. Blood serum of the calves in the T group was significantly (p &lt; 0.05) at higher levels for all minerals than in the control group (C); except iodine. Furthermore, significant correlations were reported between Co and Mn elements with most other minerals under investigation. In conclusion, TMR supplementation in the T group of female camels during lactation in the winter season is highly recommended since it improves the milk composition and mineral profile.

MAIN DIRECTIONS FOR USAGE OF METABOLISM ENERGY OF CATTLE AND POULTRY

The 2021 World Climate Congress recognized the priority of natural methods of energy production and evaluation of the results of its use. For productive animal husbandry, the study of genetic and environmental factors in consumption of metabolic energy is the most important. The purpose of this work was a comparative study of the main processes of metabolic energy usage of mammals and birds, as well as their interaction and influence on productive qualities. The study was carried out on breeding farms and poultry farms on cows and chickens, similar in terms of rearing methods, age and housing technologies. The study adopted a single assessment of the studied phenomena, in MJ, characterizing the energy, released heat, and the work performed per day for the synthesis of products. Statistical analysis of energy inflow and outflow allowedto determine the direction of this relation and the level of their influence on animal productivity. As a result of the research, it was found that birds have 2.93 times higherintensity of basal metabolism compared to cattleor by 0.199 MJ/kg. It is required 23% more gross energy of plant feed for production of one MJ of milknutritional value than for an egg product. Highly productive animals havemore effective basic metabolism and high efficiency of interaction between the main processes of metabolic energy usage. The established difference between cattle and poultry in terms of main metabolism is biological basis for development of resource-saving technologies for production of food of animal origin.

ANTIOXIDANT ACTIVITY OF DAIRY PRODUCTS FOR BABY FOOD

Increasing the biological and nutritional value of breast milk substitutes by enriching different macro- and micronutrients is an important issue. To a certain extent, the nutritional value of milk is determined by its antioxidant activity.&#x0D; The research aims to compare the antioxidant activity of dairy products for baby food and breast milk.&#x0D; The current research studied cow pasteurized milk, drinking ultra-pasteurized “Tyoma,” sterilized milk for baby food “Agusha,” “NAN,” “Nutrilon,” and “Malyutka” milk mixtures, as well as breast milk of 17 women. The antioxidant activity was determined by the titrimetric permanganate method in aqueous and alcoholic milk extracts. The content of antioxidants in alcoholic extracts of milk and all dairy products significantly exceeds their levels in aqueous solutions. The content of water-soluble antioxidants in breast milk is significantly lower than in cow’s milk “Luzhaykino” and “Agusha,” but in infant formula, it corresponds to the indicators of breast milk. The level of alcohol-soluble antioxidants is lower in NAN and Nutrilon milk mixtures when compared with cow and breast milk. The milk mixture “Malyutka” does not differ from breast milk in terms of the antioxidant activity of alcohol- and water-soluble components.&#x0D; Discussion. The use of separate determination of hydrophilic and hydrophobic antioxidants revealed significant differences between breast and cow’s milk. The enrichment of milk with easily destructible, water-soluble ascorbic acid did not affect the antioxidant activity of dairy products for baby food (“Agusha” and “Tyoma”).&#x0D; The results obtained on the significant differences in the antioxidant properties of dairy products based on cow’s milk from breast milk indicate the need to optimize the composition of milk antioxidants for baby food and the creation of breast milk substitutes.

Milk lipids characterization in relation to different heat treatments using lipidomics

Heat treatment is an important processing technique related to milk quality and nutritional value in the dairy industry. In this study, changes in milk lipids in response to different heat treatments were comprehensively characterized using a lipidomic approach. Ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) were used to identify and quantify 29 classes and 788 different lipids. In general, heat treatment promoted milk lipid hydrolysis and oxidation; in particular, ultra-high temperature (UHT) treatment resulted in more phospholipid hydrolysis than did pasteurization and extended shelf-life (ESL) treatment. Heat treatment resulted in further lipid oxidation reactions and a reduction in the amount of mild oxidation products. Moreover, the levels of lysophospholipids and free fatty acids (including oxidized free fatty acids) can be used to distinguish UHT-treated milk. In turn, oxidized phosphatidylcholine, oxidized phosphatidylethanolamine, ether-linked phosphatidylethanolamine, diacylglycerol, triacylglycerol, and oxidized triacylglycerol can be used to differentiate raw, pasteurized, and ESL milk. These biomarkers can potentially be used in the dairy industry to monitor the degree and method of heat treatment of milk.

48. The nutritional value of milk and meat, their association with human health/disease and how this is reflected in consumer information

48. The nutritional value of milk and meat, their association with human health/disease and how this is reflected in consumer information

Knockout of Stearoyl-CoA Desaturase 1 Decreased Milk Fat and Unsaturated Fatty Acid Contents of the Goat Model Generated by CRISPR/Cas9.

Goat milk contains a rich source of nutrients, especially unsaturated fatty acids. However, the regulatory mechanism of milk fat and fatty acid synthesis remains unclear. Stearoyl-CoA desaturase 1 (SCD1) is the key enzyme catalyzing monounsaturated fatty acid synthesis and is essential for milk lipid metabolism. To explore milk lipid synthesis mechanism in vivo, SCD1-knockout goats were generated through CRISPR/Cas9 technology for the first time. SCD1 deficiency did not influence goat growth or serum biochemistry. Plasma phosphatidylcholines increased by lipidomics after SCD1 knockout in goats. Whole-blood RNA-seq indicated alterations in biosynthesis of unsaturated fatty acid synthesis, cAMP, ATPase activity, and Wnt signaling pathways. In SCD1-knockout goats, milk fat percentage and unsaturated fatty acid levels were reduced but other milk components were unchanged. Milk lipidomics revealed decreased triacylglycerols and diacylglycerols levels, and the differential abundance of lipids were enriched in glycerolipid, glycerophospholipids, and thermogenesis metabolism pathways. In milk fat globules, the expression levels of genes related to fatty acid and TAG synthesis including SREBP1 were reduced. ATP content and AMPK activity were promoted, and p-p70S6K protein level was suppressed in SCD1-knockout goat mammary epithelial cells, suggesting that SCD1 affected milk lipid metabolism by influencing AMPK-mTORC1/p70S6K-SREBP1 pathway. The integrative analysis of gene expression levels and lipidomics of milk revealed a crucial role of SCD1 in glycerolipids and glycerophospholipids metabolism pathways. Our observations indicated that SCD1 regulated the synthesis of milk fat and unsaturated fatty acid in goat by affecting lipid metabolism gene expression and lipid metabolic pathways. These findings would be essential for improving goat milk nutritional value which is beneficial to human health.

Unraveling structural and conformational dynamics of DGAT1 missense nsSNPs in dairy cattle

Cattle are domestic animals that have been nourishing humans for thousands of years. Milk from cattle represents a key source of high-quality protein, fat, and other nutrients. The nutritional value of milk and dairy products is closely associated with the fat content, providing up to 30% of the total fat consumed in the human diet. The fat content in cattle milk represents a major concern for the scientific community due to its association with human health. The relationship between milk fat content and diacylglycerol o-acyltransferase 1 gene (DGAT1) is well described in literature. Several studies demonstrated the difference in fat contents and other milk production traits in a wide range of cattle breeds, to be associated with missense non-synonymous single nucleotide polymorphisms (nsSNPs) of the DGAT1 gene. As a result, an nsSNPs analysis is crucial for unraveling the DGAT1 structural and conformational dynamics linked to milk fat content. DGAT1-nsSNPs are yet to be studied in terms of their structural and functional impact. Therefore, state-of-the-art computational and structural genomic methods were used to analyze five selected variants (W128R, W214R, C215G, P245R, and W459G), along with the wild type DGAT1. Significant structural and conformational changes in the variants were observed. We illustrate how single amino acid substitutions affect DGAT1 function, how this contributes to our understanding of the molecular basis of variations in DGAT1, and ultimately its impact in improving fat quality in milk.

Evaluation of milk quality from dairy cows fed maize (Zea mays) stover treated with chopped and mineralized groundnut (Arachis hypogea) and soybean (Glycine max) stover

This study evaluated the effect of upgrading the quality of maize stover (MS) on milk nutritive value. The study involved feeding MS improved using urea (U), chopped groundnut stover (cGS), chopped soybean stover (cSS), mineralized groundnut stover solution (mGS) and mineralized soybean stover solution (mSS) to lactating dairy cows. The feeding trial involved twelve (12) dairy cows in their second parity. Effect of supplementation with MS improved with U, cGS, cSS, mGS and mSS on milk quality was evaluated following on-station feeding trials. The study involved 22 factorial experiments within a Completely Randomised Design (CRD). Milk samples were analysed for protein, lactose, fat and solid not fat (SNF). Mean milk protein levels ranged from 3.52mg/ml to 3,73mg/ml (s.e=0.03) for milk from cows fed on MS improved using cGS and mGS respectively. Protein and Lactose were observed to be the least variable (3.64g/ml ±0.12, and 5.24g ±0.24 respectively). Average milk fat content was highest (4.78%, se=0.52) in milk from cows fed on UET treated MS and lowest (3.43%, se=0.52) in milk from cows fed on gGS protein based MS. Within legume type milk fat was higher(4.75%±1.99) in milk from cows fed on MS blended with mGS than that in milk from cows fed on MS improved with cGS (3.43%±1.99). Similar result was observed in milk fat from cows fed on MS improved with the use of soybean. Lactose in milk from cows fed on UET treated MS was highest (5.51g, se=0.061) and lowest (5.10g, se=0.061) in milk from cows fed on MS blended with cGS. Milk from cows fed on MS improved with mGS was higher (9.61p/cwt, se=0.14) in SNF and lowest (8.88p/cwt, se=0.14) in milk from cows fed on MS with cGS. The milk density values ranged from 32.65sg, se=0.53 for milk from cows fed on UET treated MS to 30.42sg, se=0.053 for milk from cows fed on MS blended with cGS. Milk components were higher when cows were fed on MS improved using mineralized legume stover solutions.

Environmental factors affecting milk composition in Holstein cattle breed

The incidence of mastitis in dairy herds is one of the main difficulties faced by dairy farmers, with a negative effect on the productivity of the herd and the welfare of the animals. Somatic cell count in milk is an indicator of udder health and frequency of clinical and subclinical mastitis incidence in dairy herds, and it is also often used to determine quality payments to dairy producers. Milk urea can be an indicator of the nutritional status of the dairy cows. The interpretation of these parameters assists in making important management decisions with regards to the health status and nutrition of dairy cattle. The objective of this study was to identify and evaluate environmental factors (farm, season, parity and stage of lactation) which affect the milk production and composition of Holstein breed, using field data. The presented research included 25,460 individual milk samples which were analysed as part of the Dairy Herd Improvement program, from 11 Holstein dairy farms in the region of Vojvodina, Northern Serbia. Analyses of raw milk samples were carried out on the FOSS instruments - CombiFossTMFT+, a combination instrument consisting of the MilcoScanTMFT+ and the FossomaticTMFC. Statistical data processing was carried out by applying General Linear Model procedure, Statistics 13. Farm, season of milk control, parity and stage of lactation were included in the models as fixed effects. Significant differences in milk urea concentrations and somatic cell count were observed between farms (P&lt;0.01), seasons (P&lt;0.01), parity (P&lt;0.01) and stage of lactation (P&lt;0.01). Results showed that there were a highly significant (P&lt;0.01) positive relationships between milk urea (MU) concentration and milk yield, MU and milk fat content, and between MU and solids non-fat (SNF), also between somatic cell count (SCC) and milk fat content, between SCC and protein content, as well as in between SCC and SNF. Highly significant negative relationships were found between milk urea and protein content and SCC, and between SCC and daily milk yield and lactose content. Proper analyses and interpretation of obtained results of milk samples obtained within the Dairy Herd Improvement program could contribute to better health management on the farms and it could have a positive impact on composition and nutritional value of milk, as well as on milk safety. It would be important to carry out further research in order to facilitate the detection of subclinical mastitis with MU as a potential indicator.