Organic vs. Conventional Milk: Some Considerations on Fat-Soluble Vitamins and Iodine Content

Characterization and estimation of the bioaccessibility of essential elements in organic milk by INFOGEST protocol

The study estimated the bioaccessibility of calcium, phosphorus and magnesium in organic milk (ORG), compared to conventional (CNV) by the INFOGEST in vitro protocol. Total proteins, lipids and lactose were evaluated, the determination of essential minerals was performed by FAAS and phosphorus by colorimetric method. All ORG samples showed protein content equivalent to CNV and lower lactose and lipid content. Within different brands and batches, two batches of ORG presented higher levels of Na and lower levels of K and P, while all batches showed higher values for Ca and no differences for Mg. The bioaccessibility of magnesium was greater than 60%. ORG showed the highest values of bioaccessible calcium (12-65%) against CNV (11-27%). Phosphorus showed bioaccessibility higher than 74% in CNV. The variability of the results was related to different factors inherent to the matrices, such as casein and fatty-acids content and electrolytes standardized in the protocol.

Variation in macrominerals and trace elements in cows' retail milk and implications for consumers nutrition

Based on previous farm-level studies, this study hypothesised that production system (conventional, CON; organic, ORG; channel island, CHA) and season would cause variation in the concentrations of macrominerals and trace elements in retail milk. On average, milk retained its status as an excellent source of Ca, P, I, and Mo across different demographics, and a very good source of K, Mg, and Zn for children. Compared with CON and ORG, CHA milk contained higher concentrations of Ca, Mg, P, Cu, Mn, and Zn; and lower concentrations of K and I. Macrominerals did not show a clear seasonal pattern but trace elements were all at lower concentrations during the typical grazing season. Variation in mineral concentrations can have implications to Ca and P supply in children, and I and Zn supply across different consumer demographics; while the seasonal variation was more pronounced than that associated with production system.

Microbiota and Serum Metabolic Profile Changes in Korean Native Hanwoo Steer in Response to Diet Feeding Systems

The diversity of bacteria and their function in cattle gastrointestinal tracts can influence animal welfare. Next-generation sequencing (NGS) was used to investigate microbial diversity in the feces of Hanwoo steers reared under natural grazing (GS) and housing (HS) systems. Additionally, serum metabolic parameters, such as liver and kidney markers and mineral and lipid content changes, as well as their correlation with pyrotags, were studied. A total of 6468 ± 87.86 operational taxonomic units (OTUs) were identified in both steer groups, of which 3538 ± 38.17 OTUs were from grazing steer and 2930 ± 94.06 OTUs were from GS. Chao1 index analysis revealed a higher bacterial richness in GS. The dominant bacterial taxa were Bacteroidetes and Firmicutes. GS showed lower Bacteroidetes and higher Firmicutes abundance than HS. The serum of HS showed consistent increases in gamma-glutamyl transpeptidase (γGTP), glucose (GLU), total cholesterol (T-CHO), and triglyceride (TG) levels. The impact of GS on animal health and serum metabolic markers was strongly correlated with microbiota. As shown in this study, grazing has a significant impact on the fecal microbiota at the phylum and family levels, as well as the serum biochemical metabolites of Hanwoo steers.

Comparative Analysis of Fatty Acid Profile and Fat-Soluble Vitamin Content in Sheep and Goat Milk of Organic and Conventional Origin

Consumers tend to perceive organic foods as more nutritious and safer in comparison to conventional, due to the perception that organic food is eco- and animal-friendly. Since fatty acids and fat-soluble vitamins in dairy produce are important nutrients, this study aims to assess possible differences in the amount of these components included in organic and conventional ewes and goat raw milk in Greece, while identifying the potential determining factors. A total of 48 samples were collected from organic and conventional sheep and goat farms in Greece (Thessaly) during the lactation period. A standardized questionnaire, including information about the farming system, and a sampling protocol were completed. Samples were studied for the fat-soluble vitamins (all-trans-retinol and α-tocopherol) and the fatty acids profile, while the outcomes were statistically analyzed to explore any associations with the questionnaire data for potential factors affecting the results. According to the obtained results there are slight differences in milk fatty acid content, which indicates that organic and conventional sheep and goat milk in Greece do not have any substantial differences in terms of feeding strategies. Regarding the content of fat-soluble vitamins, the organic milk is generally found to contain a higher amount than the conventional one.

Organic versus Conventional Raw Cow Milk as Material for Processing

Milk, as one of the basic raw materials of animal origin, must be of adequate hygienic and physicochemical quality for processing. The aim of the article was to compare the quality of raw milk from three production systems, intensive, traditional (together referred to as conventional), and organic, as material for processing, as well as the quality of products made from it. Particular attention was focused on hygienic quality (somatic cell count and total bacterial count), physical characteristics (acidity), basic nutritional value (content of dry matter, total protein, casein, fat, and lactose), content of health-promoting substances (whey proteins, fatty acids, vitamins, and minerals), and technological parameters (rennet clotting time, heat stability, and protein-to-fat ratio). Research assessing the quality of organic milk and dairy products is significantly less extensive (if available at all) than for milk from conventional production (intensive and traditional). The available reports indicate that raw milk from organic farms is more valuable, especially in terms of the content of health-promoting compounds, including vitamins, fatty acids, whey proteins, and minerals. This applies to organic dairy products as well, mainly cheese and yoghurt. This is explained by the fact that organic farming requires that animals are kept in the pasture. However, the hygienic quality of the raw milk, and often the products as well, raises some concerns; for this reason, organic milk producers should be supported in this regard, e.g., through consultancy and training in Good Hygienic Practices. Importantly, milk production in the traditional and organic systems is in line with the concept of the European Green Deal.

Some challenges and opportunities for grazing dairy cows on temperate pastures

Grazing plays an important role in milk production in most regions of the world. In this review, some challenges to the grazing cow are discussed together with opportunities for future improvement. We focus on daily feed intake, efficiency of pasture utilization, output of milk per head, environmental impact of grazing and the nutritional quality to humans of milk produced from dairy cows in contrasting production systems. Challenges are discussed in the context of a trend towards increased size of individual herds and include limited and variable levels of daily herbage consumption, lower levels of milk output per cow, excessive excretion of nitrogenous compounds and requirements for minimal periods of grazing regardless of production system. A major challenge is to engage more farmers in making appropriate adjustments to their grazing management. In relation to product quality, the main challenge is to demonstrate enhanced nutritional/processing benefits of milk from grazed cows. Opportunities include more accurate diet formulations, supplementation of grazed pasture to match macro- and micronutrient supply with animal requirement and plant breeding. The application of robotics and artificial intelligence to pasture management will assist in matching daily supply to animal requirement. Wider consumer recognition of the perceived enhanced nutritional value of milk from grazed cows, together with greater appreciation of the animal health, welfare and behavioural benefits of grazing should contribute to the future sustainability of demand for milk from dairy cows on pasture.