Survey on husbandry and cheese manufacturing practices in small ruminants' farmhouse dairies in Central Italy.

Farmhouse cheeses made from raw ovine or caprine milk are very popular among the consumers not only in Italy but also overseas because of their unique organoleptic properties. These cheeses are usually manufactured, according to traditional methods, in small rudimental facilities adjacent to the farm where the achievement of satisfactory hygienic standards can be challenging. However, the lack of systematic data about farm management and the cheese manufacturing processes hampers the conduction of specific risk assessment studies. In order to fill the knowledge gaps, we collected relevant data, through a questionnaire - based survey, from 125 small ruminants' farmhouse dairies spread in Lazio. Results showed that 1.1% of registered farms process their own milk for the production of raw milk cheeses. Hand milking is still applied in almost half of them and most products are subject to a short ­ to ­ medium ripening period which might not be sufficient to reduce eventual pathogen load. Products are mainly sold directly to consumers on the farm premises. Our results suggest the need to support these artisan cheese producers in order to improve the production standards without altering the traditional cheesemaking practices. The reported data are also useful for specific risk assessment studies.

Foodborne illness outbreaks linked to unpasteurised milk and relationship to changes in state laws - United States, 1998-2018.

Consumption of unpasteurised milk in the United States has presented a public health challenge for decades because of the increased risk of pathogen transmission causing illness outbreaks. We analysed Foodborne Disease Outbreak Surveillance System data to characterise unpasteurised milk outbreaks. Using Poisson and negative binomial regression, we compared the number of outbreaks and outbreak-associated illnesses between jurisdictions grouped by legal status of unpasteurised milk sale based on a May 2019 survey of state laws. During 2013-2018, 75 outbreaks with 675 illnesses occurred that were linked to unpasteurised milk; of these, 325 illnesses (48%) were among people aged 0-19 years. Of 74 single-state outbreaks, 58 (78%) occurred in states where the sale of unpasteurised milk was expressly allowed. Compared with jurisdictions where retail sales were prohibited (n = 24), those where sales were expressly allowed (n = 27) were estimated to have 3.2 (95% CI 1.4-7.6) times greater number of outbreaks; of these, jurisdictions where sale was allowed in retail stores (n = 14) had 3.6 (95% CI 1.3-9.6) times greater number of outbreaks compared with those where sale was allowed on-farm only (n = 13). This study supports findings of previously published reports indicating that state laws resulting in increased availability of unpasteurised milk are associated with more outbreak-associated illnesses and outbreaks.

Assessment of hygiene practices and microbial safety of milk supplied by smallholder farmers to processors in selected counties in Kenya.

Smallholder farmers dominate the Kenyan dairy sector producing 95% of the total milk. However, several concerns have been raised on the quality and safety of the milk they produce. This study assessed the hygienic practices and microbial safety of milk supplied by smallholder farmers to processors in Bomet, Nyeri, and Nakuru counties in Kenya. Interviews and direct observations were carried out to assess hygiene and handling practices by farmers and a total of 92 milk samples were collected along four collection channels: direct suppliers, traders, cooperatives with coolers, and cooperatives without coolers. Microbial analysis was done following standard procedures and data analysed using GenStat and SPSS. This study revealed that farmers did not employ good hygienic practices in their routine dairy management. They used plastic containers for milking and milk storage (34.2%); they did not clean sheds (47.9%) and did not set aside cows that suffered from mastitis factors (83.6%), resulting in poor microbial quality of raw milk along the collection channels. The highest mean total viable counts (8.72 log10 cfu/ml) were recorded in Nakuru while Nyeri had the highest mean E. coli counts (4.97 log10 cfu/ml) and Bomet recorded the highest mean counts of 5.13 and 5.78 log10 cfu/ml for Staphylococcus aureus and Listeria monocytogenes respectively. Based on all above-mentioned parameters, the microbial load in most samples from all three counties exceeded the set Kenyan standards. Farmer training, improving road infrastructure, use of instant coolers at cooperatives, and quality-based payment systems are recommended as measures to curb microbial growth.

Qualidade do leite cru refrigerado avaliado por diferentes laboratórios credenciados pelo MAPA / Quality of refrigerated raw milk evaluated by different laboratories accredited by MAPA

O objetivo deste trabalho foi analisar e correlacionar os resultados de qualidade do leite cru refrigerado de dez propriedades rurais de Viçosa (MG) obtidos por métodos de referências do Ministério da Agricultura, Pecuária e Abastecimento e por espectrofotômetros de luz infravermelha em três laboratórios (A, B e C) credenciados pelo mesmo órgão de fiscalização. As amostras de leite foram analisadas quanto à contagem bacteriana, contagem de células somáticas (CCS) e teores de gordura, proteína e extrato seco desengordurado (ESD). Não houve discordância de amostras de leite quanto aos teores de proteína e gordura. Porcentagens diferentes de discordância foram observadas entre os resultados dos laboratórios e método de referência quanto à CCS, contagem bacteriana e teores de ESD. Os teores médios de proteína dos laboratórios A e B e os teores médios de ESD de todos laboratórios não foram estatisticamente iguais (p<0,05) aos teores obtidos pelo método de referência. Os teores de gordura obtidos no laboratório B não tiveram correlação estatística (p>0,05) com os teores obtidos pelo método de referência. Observou-se que as CCS e contagens bacterianas médias de todos os laboratórios foram estatisticamente iguais (p>0,05) e correlacionadas (p<0,05) às contagens médias obtidas pelos métodos de referência. Conclui-se que os teores de proteína em dois laboratórios e ESD em todos os laboratórios não são equivalentes com os métodos de referência do MAPA. É importante que os laboratórios revejam a calibração dos seus equipamentos quanto à quantificação dos teores de sólidos do leite.

The objective of this study was to analyze and to correlate the results of refrigerated raw milk quality in ten farms of Viçosa (MG). The milk was analyzed by the Ministério da Agricultura, Pecuária e Abastecimento standard methods and by infrared spectrophotometers in three laboratories (A, B and C) accredited by the same institution. The milk samples were analyzed for bacterial counts, somatic cell count (SCC) and fat, protein and solids not fat (SNF) tenors. There were no disagreement milk samples as the protein and fat tenors. Different percentages of disagreement were observed between the results of laboratory and standard method as the SCC, bacterial count and SNF tenor. The protein mean tenor of A and B laboratories and the SNF mean tenor of all laboratories were not statistically equal (p<0.05) the tenors obtained by standard method. The fat tenors obtained in B laboratory were not statistically correlated (p>0.05) with tenors obtained by the standard method. It was observed that the means of SCC and bacterial counts of all laboratories were statistically the same (p>0.05) and correlated (p<0.05) to the means counts obtained by standard methods. It is concluded that the protein tenors in two laboratories and SNF in all laboratories are not equivalent with the reference methods of MAPA. It is important that laboratories review the calibration of the equipment on the quantification of milk solids tenors.

The Impact of Toddler Milk Claims on Beliefs and Misperceptions: A Randomized Experiment with Parents of Young Children.

BACKGROUND: Toddler milk (ie, a nutrient-fortified milk-based drink marketed for children aged 12 to 36 months) has been marketed increasingly in the United States with structure/function claims on product packaging that are potentially misleading. OBJECTIVE: This study examined how structure/function claims impact parents' beliefs and perceptions about a toddler milk product. DESIGN: This was a 3-arm between-subjects randomized experiment. PARTICIPANTS: A diverse sample of 2,190 US parents of children aged 1 to 5 years were chosen to take an online survey. INTERVENTION: Participants were randomly assigned to view a toddler milk package with either an unrelated claim ("new and improved," ie, control condition), a "brain development" claim (ie, "brain" claim), or an "immunity-related" claim (ie, "immunity" claim). MAIN OUTCOME MEASURES: Outcomes included perceptions, intentions, and beliefs about the toddler milk product. STATISTICAL ANALYSES PERFORMED: Linear regression for continuous outcomes and logistic regression for dichotomous outcomes. RESULTS: Parents who were exposed to the "brain" claim or the "immunity" claim were more likely to incorrectly believe that the toddler milk was as healthy or healthier than cow's milk compared with those who saw the control claim (89% for brain claim, 87% for immunity claim, and 79% for control; P < .001 for both comparisons). Parents exposed to either the brain or immunity claim had higher intentions to give the toddler milk to their child, higher perceived product healthfulness, and stronger beliefs that pediatricians would recommend the product compared with parents exposed to the control (all, P < .001). CONCLUSIONS: These findings suggest that structure/function claims on toddler milk packaging may mislead parents and increase the appeal of toddler milk. Our findings support calls for public health policies to regulate marketing on toddler milk packaging.

Effect of dietary tannin supplementation on cow milk quality in two different grazing seasons.

Extensive farming systems are characterized by seasons with different diet quality along the year, as pasture availability is strictly depending on climatic conditions. A number of problems for cattle may occur in each season. Tannins are natural polyphenolic compounds that can be integrated in cows' diet to overcome these seasonal problems, but little is known about their effect on milk quality according to the season. This study was designed to assess the effects of 150 g/head × day of tannin extract supplementation on proximate composition, urea, colour, cheesemaking aptitude, antioxidant capacity, and fatty acid (FA) profile of cow milk, measured during the wet season (WS) and the dry season (DS) of Mediterranean climate. In WS, dietary tannins had marginal effect on milk quality. Conversely, in DS, the milk from cows eating tannins showed 10% lower urea and slight improvement in antioxidant capacity, measured with FRAP and TEAC assays. Also, tannin extract supplementation in DS reduced branched-chain FA concentration, C18:1 t10 to C18:1 t11 ratio and rumenic to linoleic acid ratio. Tannins effect on rumen metabolism was enhanced in the season in which green herbage was not available, probably because of the low protein content, and high acid detergent fibre and lignin contents in diet. Thus, the integration of tannin in the diet should be adapted to the season. This could have practical implications for a more conscious use of tannin-rich extracts, and other tannin sources such as agro-industrial by-products and forages.

Oxysterols in stored powders as potential health hazards.

Cholesterol oxidation products (COPs) have greater biological activity than cholesterol itself. Oxysterols reduce the nutritional value of foods and exhibit a wide range of biological activity, including pro-oxidant, carcinogenic, and cytotoxic properties. The most commonly detected oxysterols in foods are 7α-HC, 7ß-HC, a product of their dehydrogenation 7-KC and α-CE, ß-CE. The main dietary sources of oxysterols are eggs and egg-derived products, thermally processed milk and milk-based products, fried meat. This study aimed to measure the amount of cholesterol oxidation products in milk powder, egg powder and milk-egg powder during 24 months of storage. The changes in the selected oxysterols (determined by gas chromatography) were recorded. In milk powder, after the production process, the amount of cholesterol was 0.2 g 100 g-1 fat and in egg powder it was 3.4 g 100 g-1. After 6 months of storage, the dominant oxysterol in milk and egg powder was 7α-HC and in milk-egg powder it was 7-KC. After the storage period, oxysterols in powdered milk reached 1.81% of total cholesterol.  The most stable cholesterol was in the milk-egg mixture and its oxidation was the slowest. This study showed the presence of COPs in milk powder, egg powder and milk-egg powder and the effect of storage on cholesterol oxidation.

The effect of intense pulsed light on the sensory properties of nonfat dry milk.

Our objectives were to examine (1) how intense pulsed light (IPL) processing parameters (exposure time and initial temperature) affected aroma, flavor, and mouthfeel of nonfat dry milk, (2) which levels of each parameter produced aroma, flavor, and mouthfeel changes from an untreated control sample, and (3) whether minimal or intense processing conditions produced a noticeable appearance change from the control. Four exposure times (1, 2, 3, and 4 passes through the IPL chamber) and three initial temperatures (25, 30, and 35℃) were studied with untreated milk powder as the control. The samples were prepared as both milk powder and reconstituted milk for sensory evaluation. Using standard evaluating protocols, trained descriptive analysis panelists rated the aroma, flavor, and mouthfeel of these samples. Panelists compared the appearance of the IPL-treated samples that underwent a minimal or intense processing condition to the control by using a two-out-of-five difference test. Increasing the exposure time led to increased intensities of overall flavor, burnt flavor, and umami taste in both milk powder and reconstituted milk, while increasing temperature increased animal and sulfur aromas in reconstituted milk only. Compared to the control, all levels of exposure time at any initial temperature resulted in increased aroma and flavor including cardboard aroma, sulfur aroma, and brothy flavor in both milk powder and reconstituted milk. Only the 4-pass exposure at the initial temperature of 25℃ changed the appearance of milk powder. However, the appearance change was not noticeable in reconstituted milk. PRACTICAL APPLICATION: The standard evaluation protocols and lexicons provide useful tools for research on milk powder. Additionally, the understanding of critical factors impacting sensory properties will contribute to a better implementation of this decontamination technology.

Rates and time trends in the consumption of breastmilk, formula, and animal milk by children younger than 2 years from 2000 to 2019: analysis of 113 countries.

BACKGROUND: Previous analyses of trends in feeding indicators of children younger than 2 years have been limited to low-income and middle-income countries. We aimed to assess time trends in the consumption of different types of milk (breastmilk, formula, and animal milk) by children younger than 2 years from 2000 to 2019 at a global level. METHODS: In this time-series analysis, we combined cross-sectional data from 487 nationally representative surveys from low-income and middle-income countries and information from high-income countries to estimate seven infant and young child feeding indicators in up to 113 countries. Multilevel linear models were used in pooled analyses to estimate annual changes in feeding practices from 2000 to 2019 for country income groups and world regions. FINDINGS: For the absolute average annual changes, we found significant gains in any breastfeeding at age 6 months in high-income countries (1·29 percentage points [PPs] per year [95% CI 1·12 to 1·45]; p<0·0001) and at age 1 year in high-income countries (1·14 PPs per year [0·99 to 1·28]; p<0·0001) and upper-middle-income countries (0·53 PPs per year [0·23 to 0·82]; p<0·0001). We also found a small reduction in low-income countries for any breastfeeding at age 6 months (-0·07 PPs per year [-0·11 to -0·03]; p<0·0001) and age 1 year (-0·13 PPs per year [-0·18 to -0·09]; p<0·0001). Data on exclusive breastfeeding and consumption of formula and animal milk were only available for low-income and middle-income countries, where exclusive breastfeeding in the first 6 months of life increased by 0·70 PPs per year (0·51-0·88; p<0·0001) to reach 48·6% (41·9-55·2) in 2019. Exclusive breastfeeding increased in all world regions except for the Middle East and north Africa. Formula consumption in the first 6 months of life increased in upper-middle-income countries and in east Asia and the Pacific, Latin America and the Caribbean, the Middle East and north Africa, and eastern Europe and central Asia, whereas the rates remained below 8% in sub-Saharan Africa and south Asia. Animal milk consumption by children younger than 6 months decreased significantly (-0·41 PPs per year [-0·51 to -0·31]; p<0·0001) in low-income and middle-income countries. INTERPRETATION: We found some increases in exclusive and any breastfeeding at age 6 months in various regions and income groups, while formula consumption increased in upper-middle-income countries. To achieve the global target of 70% exclusive breastfeeding by 2030, however, rates of improvement will need to be accelerated. FUNDING: Bill & Melinda Gates Foundation, through WHO.

Sequence-based genome-wide association study of individual milk mid-infrared wavenumbers in mixed-breed dairy cattle.

BACKGROUND: Fourier-transform mid-infrared (FT-MIR) spectroscopy provides a high-throughput and inexpensive method for predicting milk composition and other novel traits from milk samples. While there have been many genome-wide association studies (GWAS) conducted on FT-MIR predicted traits, there have been few GWAS for individual FT-MIR wavenumbers. Using imputed whole-genome sequence for 38,085 mixed-breed New Zealand dairy cattle, we conducted GWAS on 895 individual FT-MIR wavenumber phenotypes, and assessed the value of these direct phenotypes for identifying candidate causal genes and variants, and improving our understanding of the physico-chemical properties of milk. RESULTS: Separate GWAS conducted for each of 895 individual FT-MIR wavenumber phenotypes, identified 450 1-Mbp genomic regions with significant FT-MIR wavenumber QTL, compared to 246 1-Mbp genomic regions with QTL identified for FT-MIR predicted milk composition traits. Use of mammary RNA-seq data and gene annotation information identified 38 co-localized and co-segregating expression QTL (eQTL), and 31 protein-sequence mutations for FT-MIR wavenumber phenotypes, the latter including a null mutation in the ABO gene that has a potential role in changing milk oligosaccharide profiles. For the candidate causative genes implicated in these analyses, we examined the strength of association between relevant loci and each wavenumber across the mid-infrared spectrum. This revealed shared association patterns for groups of genomically-distant loci, highlighting clusters of loci linked through their biological roles in lactation and their presumed impacts on the chemical composition of milk. CONCLUSIONS: This study demonstrates the utility of FT-MIR wavenumber phenotypes for improving our understanding of milk composition, presenting a larger number of QTL and putative causative genes and variants than found from FT-MIR predicted composition traits. Examining patterns of significance across the mid-infrared spectrum for loci of interest further highlighted commonalities of association, which likely reflects the physico-chemical properties of milk constituents.

Safety and quality aspects of whole and skimmed milk powders.

BACKGROUND: Nowadays, dried milk products are highly traded and consumed all over the world, so we aimed in this study to evaluate to what extent whole and skim milk powders are safe and comply with Egyptian standards. METHODS: Eighty samples of dried milk (50 whole milk powder and 30 skim milk powder) were gathered from several retailers and supermarkets for evaluation of their differing quality and safety parameters. RESULTS: The most frequent off-flavors recovered from whole milk powder samples were cooked ones and, in the case of skim milk powder samples, flat ones. Five samples of whole milk powder were of fair quality and three samples of poor quality, according to the sensory evaluation. The compositional parameters, moisture, %, fat, %, protein, %, and acidity, %, were measured as mean values of 3.90 ±0.15, 26.90 ±0.19, 25.53 ±0.27, and 0.99 ±0.03% in the examined whole milk powder samples and 3.77 ±0.08, 1.11 ±0.05, 34.62 ±0.29, and 1.22 ±0.03% in the examined skimmed milk powder samples, respectively. These results were within the range of component requirements set by the Egyptian Standard (2014; ES: 1780/2014) for dried milk products. Also, the microbiological safety of the milk powder samples was analyzed by assessment of the total viable count, total yeast and mold count, Coliforms count, Enterobacteriaceae, E. coli, C. sakazakii, Staphylococcus aureus, Salmonella, and Listeria monocytogenes. Staphylococcus aureus was the most prevalent isolate (36.00% and 6.67%) followed by Enterobacteriaceae (20.00% and 3.33%), of whole and skim milk powder, respectively. Enterobacteriaceae isolates included Enterobacter cloacae ssp. Cloacae, and Pantoea spp., which were specified by traditional biochemical tests and Vitek2 system. All Enterobacteriaceae isolated spp. were resistant to cephalothin, neomycin, tobramycin and colistin sulphate, and sensitive to chloramphenicol, gentamycin and nalidixic acid. E. coli, C. sakazakii, Salmonella, and Listeria monocytogenes couldn't be isolated from all the tested samples. By using Inductive Coupled Plasma - Mass Spectrometer (ICP-MS), we could measure lead and mercury as mean values of 0.243 ±0.069 and 0.261 ±0.052 mg/kg for whole milk powder samples at a percentage of 68.00 and 34.00%, while for the skim milk powder samples they were 0.150 ±0.037, and 0.347 ±0.110 mg/kg at a percentage of 66.67 and 40.00%, respectively. CONCLUSIONS: Finally, thirty-four whole milk powder and twelve skimmed milk powder samples didn't comply with Egyptian standards, so it is necessary for authorities to put more attention on this and regular monitor it.

Multiple authentications of high-value milk by centrifugal microfluidic chip-based real-time fluorescent LAMP.

Adulteration of food ingredients, particularly replacement of high-value milk with low-cost milk, affects food safety. For rapid and accurate identification of the possible adulterating milk species in an unknown sample, a centrifugal microfluidic chip-based real-time fluorescent multiplex loop-mediated isothermal amplification (LAMP) assay was developed to simultaneously detect milk from cow, camel, horse, goat, and yak. Using precoated primers in different reaction wells, the centrifugal microfluidic chip markedly simplified the detection process and reduced false-positive results. The entire amplification was completed within 90 min with a genomic detection limit of 0.05 ng/µL in cow, camel, horse, and goat milk and 0.005 ng/µL in yak milk. Using simulated adulterated samples for validation, the detection limit for adulterated milk samples was 2.5%, satisfying authentication requirements, as the proportion of adulterated milk higher than 10% affects economic interests. Therefore, this simple, centrifugal, microfluidic chip-based multiplex real-time fluorescent LAMP assay can simultaneously detect common milk species in commercial products to enable accurate labeling.

Simultaneous determination of cadmium, lead and copper in chocolate samples by square wave anodic stripping voltammetry.

In this work, an effective and simple method is proposed for the simultaneous determination of cadmium, lead and copper in chocolate samples by Square Wave Anodic Stripping Voltammetry (SWASV). An ultrasonic bath was used for the extraction of cadmium, lead and copper from fourteen chocolate samples using HNO3 solution (7 mol L-1). The electrochemical system consisted of a cell with three electrodes and HCl solution (10 mmol L-1) as the supporting electrolyte. An efficient extraction of the metals (~100%) was attained after 1 h of ultrasonic pre-treatment. Quantitative analysis was carried out by the standard addition method. Good linearity, precision and accuracy were obtained in the range of concentrations examined. The accuracy was evaluated by means of a reference sample of spiked skim milk powder (BCR 151) to prove the reliability of the method. Detection limits (LOD) of 0.089, 0.059 and 0.018 µg g-1 were found for cadmium, copper and lead, respectively, in the chocolate samples. Concentrations in chocolate samples were 4.30-138 µg g-1 for Cu and 0.83-27.9 µg g-1 for Pb, with no significant Cd. The simultaneous determination brings advantages to other methods already reported for chocolate analysis and the samples preparation proposed avoids the traditional sample mineralization step. These characteristics show this new method is especially attractive for case studies and routine analysis.

Performance of Black Bengal goat: a 50-year review.

Black Bengal goat (BBG) is the most widely recognized legacy goat breed in Bangladesh. The breed is black in color yet likewise earthy, white, or dim colors additionally found. The breed has medium body size with grown-up weight 25-30 kg, little horns, short legs, and tight body structure. The BBG is one of the most compliant, all around adjusted, early maturing, prolific, productive, and tropical disease-resistant goat types of the world that produces incredible quality meat, milk, and skin. The breed is versatile in hot, moist, cruel, climatic conditions and flourishes well on a cacophonous dietary regimen from uncultivable decrepit grounds, residences, riversides, banks, sloping, and hilly territories where crop culture or dairy nourishing is inconceivable. In Bangladesh, the BBG is one of the main red meat-producing small ruminants which shares remarkable local interest during Eid-Ul-Adha, Eid-Ul-Fitr, wedding ceremony, birthday festival, circumcision, memorial programs, and other social celebrations with no social, cultural, and religious limitations. Being little in size, the BBG has been an amazing asset to advance supportable vocations for the negligible, little, and landless ranchers who rely upon free regular grazing lands for raising domesticated animals. Regardless of incredibly exceptional components and features, the production of BBG has not yet been popularized widely since meager consideration has been paid for improving their efficiency. Development of cutting edge hereditary, dietary, and health as well as disease control procedure and utilization of modern management frameworks may procure considerable changes in improving the overall performance of the BBG.

Effects of pressure, shear, temperature, and their interactions on selected milk quality attributes.

The effects of pressure, temperature, shear, and their interactions on selected quality attributes and stability of milk during ultra-shear technology (UST) were investigated. The UST experiments include pressure (400 MPa) treatment of the milk sample preconditioned at 2 different initial temperatures (25°C and 15°C) and subsequently depressurizing it via a shear valve at 2 flow rates (low: 0.15-0.36 g/s; high: 1.11-1.22 g/s). Raw milk, high-pressure processed (HPP; 400 MPa, ~40°C for 0 and 3 min) and thermal treated (72°C for 15 s) milk samples served as the controls. The effect of different process parameters on milk quality attributes were evaluated using particle size, zeta potential, viscosity, pH, creaming, lipase activity, and protein profile. The HPP treatment did not cause apparent particle size reduction but increased the sample viscosity up to 3.08 mPa·s compared with 2.68 mPa·s for raw milk. Moreover, it produced varied effects on creaming and lipase activity depending on hold time. Thermal treatment induced slight reduction in particle size and creaming as compared with raw milk. The UST treatment at 35°C reduced the effective diameter of sample particles from 3,511.76 nm (raw milk) to 291.45 nm. This treatment also showed minimum relative lipase activity (29.93%) and kept milk stable by preventing creaming. The differential effects of pressure, shear, temperature, and their interactions were evident, which would be useful information for equipment developers and food processors interested in developing improved food processes for dairy beverages.

Microbial quality and safety of milk and milk products in the 21st century.

Milk and milk products have been utilized by humans for many thousands of years. With the advent of metagenomic studies, our knowledge on the microbiota of milk and milk products, especially as affected by the environment, production, and storage parameters, has increased. Milk quality depends on chemical parameters (fat and protein content and absence of inhibitory substances), as well as microbial and somatic cells counts, and affects the price of milk. The effects of hygiene and effective cooling on the spoilage microbiota have shown that proteolytic and lipolytic bacteria such as Pseudomonas or Acinetobacter spp. predominate the spoilage bacterial populations. These bacteria can produce heat-stable proteases and lipases, which remain active after pasteurization and thus can spoil the milk during prolonged storage. Additionally, milk can become contaminated after pasteurization and therefore there is still a high demand on developing better cleaning and sanitation regimes and equipment, as well as test systems to (quantitatively) detect relevant pathogenic or spoilage microorganisms. Raw milk and raw milk cheese consumption is also increasing worldwide with the growing demand of minimally processed, sustainable, healthy, and local foods. In this context, emerging and re-emerging pathogens once again represent a major food safety challenge. As a result of global warming, it is conceivable that not only microbiological risks but also chemical risks relating to presence of mycotoxins or plant toxins in milk will increase. Herein, we provide an overview of the major microbial hazards occurring in the 21st century.

Milk quality, production process and physicochemical characteristics of Porungo, an artisanal cheese from the state of Sao Paulo, Brazil.

Porungo is a traditional pasta filata cheese produced using raw milk throughout the southwest region of the state of São Paulo, Brazil. The objectives of this Research Communication were to evaluate the quality of raw milk used to make Porungo cheese, to characterize its production process, and to determine its chemical composition. The results showed that the raw milk met both Brazilian and international quality requirements. Chemically, Porungo can be classified as a medium to full fat semi-hard fresh cheese. Our study has allowed the first standards and regulations for Porungo to be established in Brazil. By virtue of this, the local producers are able to formalize their activity while consumers can have access to a safe and certified product.

A mycotoxin-deactivating feed additive counteracts the adverse effects of regular levels of Fusarium mycotoxins in dairy cows.

Little is known about the effects of commonly found levels of Fusarium mycotoxins on the performance, metabolism, and immunity of dairy cattle. We investigated the effects of regular contamination levels, meaning contamination levels that can be commonly detected in dairy feeds, of deoxynivalenol (DON) and fumonisins (FB) in total mixed ration (TMR) on the performance, diet digestibility, milk quality, and plasma liver enzymes in dairy cows. This trial examined 12 lactating Holstein dairy cows using a 3-period × 3-treatment Latin square design. The experimental period was 21 d of mycotoxin exposure followed by 14 d of washout. During treatment periods, cows received one of 3 diets: (1) CTR (control) diet of TMR contaminated with 340.5 µg of DON/kg of dry matter (DM) and 127.9 µg FB/kg of DM; (2) MTX diet of TMR contaminated with Fusarium mycotoxins at levels higher than CTR but below US and European Union guidelines (i.e., 733.0 µg of DON/kg of DM and 994.4 µg of FB/kg of DM); or (3) MDP diet, which was MTX diet supplemented with a mycotoxin deactivator product (i.e., 897.3 µg of DON/kg of DM and 1,247.1 µg of FB/kg of DM; Mycofix, 35 g/animal per day). During washout, all animals were fed the same CTR diet. Body weight, body condition score, DM intake, dietary nutrient digestibility, milk production, milk composition and rennet coagulation properties, somatic cell count, blood serum chemistry, hematology, serum immunoglobulin concentrations, and expression of multiple genes in circulating leucocytes were measured. Milk production was significantly greater in the CTR group (37.73 kg/d) than in the MTX (36.39 kg/d) and the MDP (36.55 kg/d) groups. Curd firmness and curd firming time were negatively affected by the MTX diet compared with the other 2 diets. Furthermore, DM and neutral detergent fiber digestibility were lower after the MTX diet than after the CTR diet (67.3 vs. 71.0% and 42.8 vs. 52.3%). The MDP diet had the highest digestibility coefficients for DM (72.4%) and neutral detergent fiber (53.6%) compared with the other 2 diets. The activities of plasma liver transaminases were higher after the MTX diet than after the CTR and MDP diets. Compared with the CTR diet, the MTX diet led to slightly lower expression of genes related to immune and inflammatory functions, indicating that Fusarium mycotoxins had an immunosuppressive effect. Our results indicated that feed contaminated with regular levels of Fusarium mycotoxins adversely affected the performance, milk quality, diet digestibility, metabolic variables, and immunity of dairy cows, and that supplementation with mycotoxin deactivator product counteracted most of these negative effects.

Inbreeding depression across the genome of Dutch Holstein Friesian dairy cattle.

BACKGROUND: Inbreeding depression refers to the decrease in mean performance due to inbreeding. Inbreeding depression is caused by an increase in homozygosity and reduced expression of (on average) favourable dominance effects. Dominance effects and allele frequencies differ across loci, and consequently inbreeding depression is expected to differ along the genome. In this study, we investigated differences in inbreeding depression across the genome of Dutch Holstein Friesian cattle, by estimating dominance effects and effects of regions of homozygosity (ROH). METHODS: Genotype (75 k) and phenotype data of 38,792 cows were used. For nine yield, fertility and udder health traits, GREML models were run to estimate genome-wide inbreeding depression and estimate additive, dominance and ROH variance components. For this purpose, we introduced a ROH-based relationship matrix. Additive, dominance and ROH effects per SNP were obtained through back-solving. In addition, a single SNP GWAS was performed to identify significant additive, dominance or ROH associations. RESULTS: Genome-wide inbreeding depression was observed for all yield, fertility and udder health traits. For example, a 1% increase in genome-wide homozygosity was associated with a decrease in 305-d milk yield of approximately 99 kg. For yield traits only, including dominance and ROH effects in the GREML model resulted in a better fit (P < 0.05) than a model with only additive effects. After correcting for the effect of genome-wide homozygosity, dominance and ROH variance explained less than 1% of the phenotypic variance for all traits. Furthermore, dominance and ROH effects were distributed evenly along the genome. The most notable region with a favourable dominance effect for yield traits was on chromosome 5, but overall few regions with large favourable dominance effects and significant dominance associations were detected. No significant ROH-associations were found. CONCLUSIONS: Inbreeding depression was distributed quite equally along the genome and was well captured by genome-wide homozygosity. These findings suggest that, based on 75 k SNP data, there is little benefit of accounting for region-specific inbreeding depression in selection schemes.

The influence of automatic associations on preference for milk type.

In recent decades, organic milk has been an exception to the trend of decreased fluid milk consumption in the United States. However, the reasons behind consumer preference for organic milk over conventional and other milk types are ill-defined. The objective of this study was to use an implicit association test (IAT) and primed and unprimed preference testing to determine if fluid milk consumer preferences for milk types are influenced by implicit biases and, if so, to define these biases within the context of the consumer sensory experience. Self-reported fluid milk consumers (n = 473) participated in online IAT exercises where pairwise comparisons of milk types (conventional, organic, local, pasture-raised) were measured on both positive and negative dimensions related to cow-welfare, sustainability, health, trust, safety, and quality. Latency times from IAT responses were subsequently transformed into standardized D-scores to categorize bias effect sizes. Additionally, fluid milk consumers (n = 174) participated in preference tests that compared commercial milks representing different milk types through presentations where milk type was shown (primed) or hidden (unprimed). Following preference tests, consumers were asked to explain their preferred sample using check-all-that-apply tasks. Analysis of IAT results showed that conventional milk was more associated with negative dimension descriptors compared with organic, local, and pasture-raised milks. Additionally, a positive bias in favor of organic milk was expressed when compared with pasture-raised milk offerings; however, no differences were found in pairwise comparisons of other nonconventional milk type pairings, suggesting that consumers may conflate these designations. Blinded preference testing showed that milk preferences were largely dictated by flavor, with consumers differentiating milk types based upon flavors related to packaging, pasteurization method, and feeding systems. In primed evaluations, consumers generally expressed preferences that aligned with their explicit beliefs, and flavor considerations appeared to be a secondary differentiator of preference. Based on these results, conventional milk is associated with negative implicit beliefs related to production and product quality more often than other milk types, which was reflected in IAT evaluations and primed preference tests. However, the blinded tastings suggested that conventional milk was preferred, or competitive with, other milk types based on flavor alone. Findings from this study suggest consumer differentiation and preference of milks is significantly affected by perceptions and beliefs related to milk type. In particular, conventional milk was associated with relatively few unique belief descriptions, indicating strict utilitarian consumer categorization. Organic and local milks were comparatively associated with greater care for nutrition, sustainability, animal welfare, and local farm support. These results demonstrate a need for greater education related to conventional milk offerings to dispel factors influencing negative implicit bias. Furthermore, improving product narrative via label information and alignment with locality and regionality were identified as possible opportunities for improving consumer sentiments related to conventional milk. A more thorough understanding of these attributes may reinforce stated beliefs more effectively and stave off consumer losses to plant-based alternatives that fulfill similar beliefs.