Journal of Dairy Research最新文献

This study was undertaken to investigate the molecular detection of biofilm-producing Staphylococcus aureus (S. aureus) from goat mastitis. An overall 384 milk samples were initially screened for subclinical mastitis (SCM) followed by molecular characterization of S. aureus isolates. The biofilm formation was assessed using Congo Red agar (CRA), a microtiter plate and the presence of the icaA gene. The results revealed a molecular prevalence of 53.24% (115/216) for pathogenic S. aureus in milk samples of goats. The phenotypic prevalence of biofilm production by CRA and microtitre methods was recorded to be 38.26% (44/115) and 26.96% (31/115) respectively, while the molecularly confirmed biofilm-forming S. aureus through polymerase chain reaction targeting icaA gene was 58.26% (67/115). The phylogenetic analysis of icaA gene revealed high identity between sequences of study isolates and the isolates of other neighbouring countries. The antibiogram profiling of pathogenic S. aureus showed increased resistance to cefoxitin and oxytetracycline followed by gentamicin. Out of 115, 45.22% (52/115) were declared as multiple drug resistant with multiple antibiotic resistance index greater than 0.2. The study concluded that biofilm-producing S. aureus strains are considered to be a common cause of SCM in dairy goats of Pakistan and biofilm formation is associated with multidrug resistance of study isolates.

To achieve more targeted antibiotic use, this research paper addresses the investigation of a quarter-selective dry cow therapy (QSDCT) on 16 commercial dairy farms based solely on the pathogen species detected. Cytobacteriological analysis was performed on quarter milk samples collected 2 weeks prior to drying off and 3 to 5 days after calving. Treatment decisions were based on results before dry-off: Only quarters infected with major bacterial pathogens were treated with antibiotics. To prevent new intramammary infections (IMI), all quarters received an internal teat sealant. A total of 1,155 dry periods were evaluated. Only 8.1% of all quarters (range per farm 2.6% - 28.8%) were treated with antibiotics at dry-off and a high bacteriological cure risk of 97.1% was determined for IMI in these antibiotic-treated quarters. For IMI caused by minor pathogens a self-cure risk of 82.1% was observed. The risk of new IMI after calving was 14.6%. Results of binomial logistic regression models indicated that self-cure of IMI by minor pathogens was not related to the pathogen group, the level of quarter somatic cell count at dry-off, or the presence of at least one other quarter infected with minor pathogens in a cow. Furthermore, the risk for new IMI in uninfected quarters was not increased by the presence of at least one quarter infected with major pathogens within cow. However, 95.4% of all IMI by major pathogens after calving were due to new IMI. In conclusion, a pathogen-based QSDCT can be successfully applied on commercial dairy farms to reduce the antibiotic use, but more attention should be paid to prevent new IMI.

The present study aimed to conduct a meta-analysis using the random-effects model to merge published genetic parameter estimates for metabolic disorders [mastitis (MA), metritis (ME), ketosis (KE), milk fever (MF), retained placenta (RP), displaced abomasum (DA), and lameness (LA)] in dairy cows. A total of 239 heritability and 355 genetic correlation estimates were extracted from 61 peer-reviewed articles published between 1991 and 2024. Heritability estimates for metabolic disorders were generally low, ranging from 0.034 for ME to 0.067 for DA and MF. These estimates were associated with small standard errors and narrow 95% confidence intervals, with all estimates being statistically significant (P < 0.05). The estimates for genetic correlations between metabolic disorders were positive, ranging from 0.038 (MA-DA) to 0.522 (KE-DA). Furthermore, only the genetic correlations for DA-LA (0.147), RP-ME (0.472), MA-LA (0.239), MA-MF (0.365), KE-DA (0.522), KE-RP (0.124), and KE-ME (0.157) were significant (P < 0.05). Positive and low genetic correlations were observed between MA-milk yield (MY), MF-MY, and LA-MY (0.291, 0.135, and 0.263, respectively; P < 0.05). Similarly, positive correlations were found between DA-fat yield (FY), MA-FY, MA-protein yield (PY), LA-FY, and LA-PY (0.121, 0.170, 0.303, 0.176, and 0.236, respectively; P < 0.05). The genetic correlations between KE-fat to protein ratio (FPR) and DA-FPR were positive and ranged from low to moderate (0.520 and 0.196, respectively; P < 0.05). Significant genetic correlations were also noted between MA-days open (DO) (0.416), MA-days from calving to first service (DCFS) (0.207), and LA-calving interval (CI) (0.210; P < 0.05). This meta-analysis provides valuable insights into the genetic contribution to metabolic disorders in dairy cows and highlights the generally low heritability and the variable genetic correlations between these disorders and performance traits. These findings may contribute to more effective breeding strategies aimed at reducing the occurrence of metabolic disorders in dairy herds.

Animal welfare is a growing concern in dairy production, influencing consumer preferences and industry practices. While extensive research has been conducted in Europe and North America, limited data exist on consumers´ attitudes in Latin America, particularly Argentina. This study aimed to assess Argentine consumers' perceptions, knowledge, and preferences regarding dairy cow welfare in grazing and confined systems. An online survey was conducted among Argentine residents (n = 3,051), assessing sociodemographic characteristics, knowledge of animal welfare, perceptions of dairy production systems, and willingness to pay for animal welfare-certified products. Most respondents (99%) believed that cows feel pain, and 85% believed they have emotions. Most respondents (91%) agreed that pasture access improves animal welfare. A significant portion (70%) expressed willingness to pay a premium for animal welfare-certified dairy products, with women (p < 0.001) and younger consumers (p < 0.001) showing higher interest. Women and respondents connected to the agricultural sector considered animal welfare more frequently when buying animal-based products compared with men and those without an agricultural connection (p < 0.001). Consumers without a direct agricultural background were more likely to perceive confined systems negatively. Grazing systems were widely preferred, with respondents associating them with better welfare, healthier products, and environmental sustainability. Our findings indicate a consumer preference for pasture-based dairy systems in Argentina. These insights can help industry stakeholders refine their communication strategies and promote welfare-oriented production practices that better align with consumer expectations.

Synbiotic beverages have become a boon for health-conscious people as these beverages can offer a variety of health benefits. The present study aimed to produce a novel synbiotic beverage from browntop millet (Urochloa ramosa, previously Brachiaria ramosa). Lacticaseibacillus rhamnosus was used for the fermentation of the browntop millet. Multi-response methodology optimization was performed, and maximum ferric-reducing antioxidant power (FRAP) concentration, reducing sugar and protein concentration was observed at 757.42 µ mol Fe (II)/ml, 90.38 mg/ml, and 1.31 mg/ml, respectively. The study also observed an excellent cell hydrophobicity (85.7%) of the probiotic strain. Thus, the final product obtained had a DPPH value of 54.89 ± 2.2 %.

This research paper investigated the potential application of essential oils nano-emulsion after characterization as natural preservatives in the dairy sector, by measuring the minimum inhibitory concentration of ginger and clove oil nano-emulsion along with their impact on the sensory properties, starter culture activity and survivability of some foodborne pathogenic and spoilage microorganisms in fortified laboratory-manufactured labneh. The characterized EOs nano-emulsions exhibited significant antimicrobial effect against the tested microorganisms (Escherichia coli, Salmonella Typhimurium, Staphylococcus aureus, Pseudomonas aeruginosa, and Aspergillus flavus). S. aureus was completely inhibited in labneh fortified with 0.1 µg/mL clove and ginger nano-emulsion in the first and second weeks of the storage period, respectively. While A. flavus count was reduced by 100 and 35% in labneh fortified with 1 µg/mL clove and ginger nano-emulsion, respectively. Nonetheless, the overall acceptability and flavour of the fortified samples revealed scores that were not significantly different from the control samples (P > 0.05). These results were obtained without interfering with the starter culture activity during processing and storage period. In conclusion, the obtained results open a promising avenue for the EOs nano-emulsions application as safe and natural alternative in the dairy industry.

This study aimed to develop a predictive model to investigate the effect of temperature, pH, NaCl concentration, initial inoculum concentration and time on enterotoxin A (SEA) production by Staphylococcus aureus. Combinations of three levels of temperature (10, 15 and 25°C ), five levels of pH (5.3, 5.5, 6.0, 6.5 and 6.7), five levels of NaCl (0.8, 1.0, 1.5, 2.0 and 2.2%), three levels of inoculum concentration (0, 3 and 5 log CFU/mL) in brain heart infusion (BHI) broth were studied. Colonies were counted and SEA production was assessed at 24 h intervals for up to 240 h. A probabilistic logistic regression model was used to describe the production of SEA by Staphylococcus aureus. SEA production was influenced by all factors, except NaCl concentration. S. aureus produced SEA in all samples at 25°C, while the temperature of 10°C delayed the growth and SEA production of S. aureus at initial contamination levels of 3 log CFU/mL and 5 log CFU/mL and prevented it at 0 log CFU/mL. The model was statistically and experimentally validated, demonstrating a good fit, with a high percentage agreement, Nagelkerke's R² and the Hosmer and Lemeshow test for the SEA production model. The experimental validation confirmed the effectiveness of the models for predicting the probability of SEA production by S. aureus in Minas Frescal cheese.

Perfluorinated compounds (PFCs) are synthetic chemicals commonly used in various industries for their water-, grease-, and stain-repellent properties. These compounds are highly persistent in the environment and can be absorbed by farm animals, subsequently contaminating animal-derived products. This contamination poses a significant health risk to humans who consume these products. Previous studies have identified cow's milk as one of the primary animal products contaminated with PFCs. However, it remains unclear which specific PFCs increase in concentrations over time. In this study, we analysed data on the concentrations of 24 PFCs in cow's milk sourced from a milk processing plant in Taiyuan, Shanxi Province, China, over a three-year period, as provided by the National Agriculture Science Data Centre. Our analysis revealed that perfluoropentanoic acid (PFPeA) and perfluorobutanoic acid (PFBA) were the dominant PFCs that tended to accumulate in cow's milk over time. Consequently, consumers and milk producers should monitor the levels of PFPeA and PFBA in cow's milk to mitigate potential health risks associated with these pollutants.

Blockchain, an emerging technology exhibiting swift growth, significantly bolsters transparency within a given supply chain, enabling secure traceability, backtracking, and info tracing. Blockchain technology holds substantial promise for the dairy sector, offering enhancements unnecessary market intermediaries, thereby broadening access to credit and insurance for farmers, particularly in developing economies Such advancements could lead to more sustainable, efficient, and resilient livestock practices. However, the technology faces challenges, including the need for sophisticated infrastructure, cross-platform software, and skilled personnel with advanced expertise. Divergence in technological capabilities between developed and developing nations may hinder trade and exacerbate disparities. Regulatory barriers could also restrict blockchain's application. Thus, it is imperative to enhance blockchain knowledge among trade authorities and policymakers to facilitate its broader adoption. The objective of this review is to discuss principles of blockchain and proposed future work pathways for its use in the dairy industry.

The objective of this research paper was to assess consumer knowledge, attitudes, and perceptions towards dairy fat. Adult participants completed a web-based survey collected from November 2022 to February 2023, across Mexico, Chile, and Argentina. In total, 1,204 respondents completed the survey. Most respondents were between 18 and 39 years old, female, educated, and employed. For both women (χ² = 13.7, df = 4 p < 0.01) and men (χ² = 26.7, df = 4 p < 0.01), the percentage of people who consume dairy products at least once a day increases with age. However, neither gender nor age affected the consumption of milk, yogurt, butter, cheese, or cream. An effect of country (χ² = 330.2, df = 18 p < 0.01), age (χ² = 69.2, df = 36 p < 0.01), and gender (χ² = 69.2, df = 36 p < 0.01) was observed with respect to the type of milk consumed. In Mexico, whole milk consumption rates were highest, while semi-skimmed milk was favored in Chile, and skimmed milk in Argentina. Whole milk consumption was higher in men, however, skimmed and light milk were preferred by women. An effect of country (χ² = 30.4, df = 14 p < 0.01) and age (χ² = 70.1, df = 28 p < 0.01) was observed in relation to the type of fat that people consider most important. More respondents (48%) considered milk fat to be "healthy" or "very healthy" while no dependence was observed between countries and the relationship between the milk fat content and health. The best-known milk fat component in Argentina was omega-6 while Chilean consumers were less familiar with this component. Mexican consumers, gave greater importance to mono-unsaturated fats. Knowledge of other dairy fat groups and nutrients was similar across countries. This study benchmarks consumer knowledge and perceptions of dairy fat in Latin America, offering valuable insights for academia, industry, and consumers in the dairy sector.