Journal of Dairy Research最新文献

Currently, alternative sources of protein are being sought to replace not only meat but also dairy products in the diet. From this perspective, it is worth examining how consumers perceive these products, what motivates them to choose them and what barriers they encounter, especially with regard to attitudes towards dairy products. The present study aimed to compare attitudes towards plant-based dairy alternatives (PBDAs) in three European countries - Poland, Germany and the UK. Furthermore, the study aims to examine the extent to which two main arguments appearing in the media, intended to persuade consumers to replace dairy products with PBDA - referring to ethical concerns (animal welfare) or emphasising ecological considerations (environmental impact) - are actually convincing to them. An online survey was conducted in each of the three countries on a representative sample of dairy consumers (2,157 respondents in total). Curiosity proved to be the primary motivation for trying PBDA in all countries. In contrast, the arguments commonly used in PBDA communication (referring to environmental protection and animal welfare) appeal to consumers to a much lesser extent. However, these ethical and ecological factors influenced consumers differently across regions. British consumers emerged as the most receptive to PBDA. German respondents showed the highest sensitivity to animal welfare and environmental concerns in PBDA communication. Polish consumers, on the other hand, strongly believe in the exceptional health benefits and necessity of dairy in daily diets, which negatively affects their interest in PBDA. Notably, dairy is perceived more favourably than PBDAs on most attributes in all investigated countries.

Bovine mastitis caused by Staphylococcus aureus increases antimicrobial use and may compromise milk quality, yet genomic evidence from subtropical China remains limited. This study aimed to characterise the genomic epidemiology, antimicrobial non-susceptibility and functional risk tiers of dairy-associated S. aureus in northern Fujian, China. We analysed 59 S. aureus isolates recovered from 162 bulk-tank milk samples collected from 14 farms during 2023-2024, using whole-genome sequencing, MLST/spa typing and core-genome SNP phylogenetics, together with disc diffusion susceptibility testing (CLSI M100) and annotation of resistance, virulence and plasmid replicons (CARD, VFDB and PlasmidFinder). An unsupervised multivariate workflow (principal component analysis followed by K-means clustering) integrated genomic and phenotypic features to assign functional-risk tiers. Seven MLST and eight spa types were detected, dominated by ST1-t114/t127 (40.7%) and ST9784-t189 (20.3%). Livestock-associated MRSA ST59-t437 carrying SCCmec IV and IEC-D was detected in raw milk from this region for the first time. Overall, 45.8% of isolates were non-susceptible to at least one antimicrobial, most commonly penicillin and ampicillin (28.8% each). ST9784-t189 more frequently carried lnu(A) and pLNU4-like plasmid sequences and showed higher clindamycin non-susceptibility than other lineages. PCA/K-means grouped isolates into low-, medium- and high-risk tiers (76.3%, 15.3% and 8.4%, respectively); medium/high tiers showed higher multidrug non-susceptibility and a greater enterotoxin gene burden and were more often associated with plasmid replicons including pKH1 and pAMalpha1. This single-province pilot study provides a genomic baseline for dairy-associated S. aureus in subtropical China and suggests that unsupervised multivariate grouping may support risk-aware surveillance and milk-quality assurance; larger multi-region datasets are needed to assess generalisability.

Visual mobility scoring to detect lame dairy cattle can be subjective and inconsistent. This study assessed the reliability of visual mobility scores from multiple assessors, using different scoring methods (live vs. video) and experience levels to evaluate their influence on label quality for machine learning applications. We gathered data from two farms using the AHDB 4-point mobility scale and a simplified post-hoc dichotomised version, with both live and video assessments. Substantial within- and between-assessor variation was seen in scores, particularly for scores 0 and 1 (consistent with normal and slightly abnormal gaits, respectively). Assessors showed only fair (weighted kappa ≈ 0.33) score consistency when they scored the same animal in different ways (live vs. video). Post-hoc simplification of the four-level scores to a dichotomous score improved agreement but reduced granularity. Assessor experience had limited influence on agreement levels (P > 0.05), and increased video viewing frequency during the assessment process was associated with lower inter-assessor agreement (probability estimate = -0.49, P = 0.005), suggesting higher uncertainty in ambiguous cases. Qualitative feedback from assessor comments revealed that the speed of the animal affected their scoring decisions (β = -1.92, P = 0.007). These results highlight the difficulties in using subjective human scores as labels for machine learning training. To improve automatic lameness detection in dairy cattle, we need strategies to reduce this variation and use more definitive labels.

This study aimed to assess the productivity and profitability of Iranian Holstein dairy herds by utilizing technical-economic indices, particularly in light of fluctuations of milk and feed prices. The dataset comprised 2,890,994 test day records from 190,900 cows across 93 Holstein dairy herds in Isfahan province, covering agricultural years from 2016 to 2022. To evaluate the effects of production levels and lactation stages on investigated indices, a two-way ANOVA analysis using SAS software was used. The results revealed that the average daily milk income was US $9.37 ± 3.63 per cow, while the average of feed cost was $3.97 ± 1.70 per cow. The mean of income over feed cost (IOFC) was estimated at $5.40 ± 2.41, with a range from $1.12 to18.06. Notably, with an average income equal to feed cost (IEFC) of 16.8 kg, farmers need approximately 42% of their produced milk to cover feed costs. The results of this research indicated that only 1% of the milk-to-feed price ratio (MFPR) exceeded 3.0, suggesting that higher milk production at this level is indeed profitable. Additionally, the money-corrected milk (MCM) yield was found to be 1.5% higher than the standard milk yield. The IOFC exhibited a positive and relatively strong correlation with various factors: 0.92 with milk income, 0.75 with MCM, 0.55 with feed costs and 0.22 with IEFC. Furthermore, the production levels and lactation stages significantly impacted the measures studied (P < 0.01). Interestingly, the second-parity cows with medium milk production emerged as the most profitable due to quality bonuses associated with higher milk prices. This highlights how increasing rewards and penalties related to milk quality provide incentives to farmers to focus on improving milk quality rather than merely increasing volume.

Weaning is a significant event in the life of Sahiwal calves, often leading to notable behavioural and emotional changes. This study aimed to investigate the effects of dam-calf contact on behavioural responses and adaptability in Sahiwal calves, focusing on fear responses, social interactions and reactivity to humans. A total of 16 newborn calves were assigned to 2 rearing systems: fenceline mother-calf contact (FMC) and separated mother-calf (SM), with 8 calves in each group. The FMC group received natural suckling and fenceline contact with their dams, while the SM group was separated at birth and fed via nipple bottles. Behavioural assessments were conducted through a series of tests, including social reactivity tests, social preference tests, umbrella-based fear elicitation and interaction with a familiar human. Key behavioural parameters such as time spent idle, exploratory behaviour, escape attempts, vocalizations, latency to resume feeding and preference for conspecifics or humans were recorded. Data were statistically analysed using independent t-tests to compare behavioural responses between groups. The results revealed distinct behavioural differences between the FMC and SM calves, indicating that dam contact influences social behaviour, reduces fearfulness and improves calves' adaptability to novel or stressful situations.

This study focuses on the carriage and antibiotic-susceptibility profiles of Gram-positive bacteria in dromedary camel milk. A total of 103 milk samples were collected from apparently healthy female dromedaries in southern Tunisia. Bacterial growth was observed only in 82 of these samples, yielding 86 Gram-positive bacterial isolates. Staphylococcus was the most frequently isolated genus (54/86, 62.8%) with 13% of coagulase-positive staphylococci (CoPS) represented by S. aureus and S. intermedius and 87% of coagulase-negative staphylococci (CoNS) (n = 47) identified as S. simulans, S. xylosus, S. warneri, S. hominus1, S. capitis, S. sciuri and S. equorum. Cellulomonas spp. (16, 18.6%), Lactococcus lactis subsp. lactis (8, 9.3%), Aerococcus viridans (7, 8.5%) and Kocuria rosea (1, 1.1%) were also identified. Staphylococcus species showed the highest resistance to chloramphenicol (50% of samples), followed by clindamycin (42.6% of samples), neomycin and nalidixic acid (40.7% each). No resistance genes were detected for the low levels of resistance to penicillin, oxacillin and cefoxitin. Cellulomonas spp., L. lactis subsp. lactis and A. viridans isolates exhibited moderate frequency of resistance, particularly to aminoglycosides and tetracycline. However, resistances to sulphonamide-trimethoprim, ciprofloxacin, nitrofurantoin, tylosin and rifampicin were rarely detected. Multidrug-resistant (MDR) bacteria were identified in 11.7% of the total isolates, with the higher rates observed for L. lactis subsp. lactis (25% of samples), A. viridans (14.2% of samples) and Cellulomonas spp. (6.25%), while 11% of Staphylococcus isolates were MDR, significantly more in CoPS (28.5%) than CoNS (8.5%). Additionally, MDR rate was higher in older female (p = 0.042) and those raised alongside ruminants (p = 0.030). All tested MDR bacteria exhibited significant combinations of resistance genes, including aph3-IIIa and ant6-Ia for aminoglycosides, cat(pC221) for chloramphenicol, ermA for erythromycin and clindamycin, tetK for tetracycline and drfA for trimethoprim-sulphonamide. Further, comprehensive studies are needed to understand MDR bacteria emergence within camel milk.

The integration of phenotypic, genomic and pedigree data into a single-step model for predicting genomically enhanced estimated breeding values (GEBVs) has become crucial for the accurate genetic evaluation of dairy cattle. This study compared two widely used software implementations, MiXBLUP and BLUPF90IOD3, for the prediction of breeding values using the single-step G-BLUP model based on data from the Polish national evaluation for stature. Four core animal sets were tested, which differed in the selection of bulls and cows. The GEBVs were predicted and validated using different subsets of the population. Both software packages resulted in high correlations (0.89 and 0.97) between full and truncated dataset predictions and similar validation performance, with MiXBLUP exhibiting slightly greater consistency across different sets of core animals. The ranking of the top 50 bulls remained stable across the implementations. This study concludes that both software implementations provide comparable GEBV predictions, suggesting that software choice should consider computational efficiency, cost and modeling flexibility, with MiXBLUP offering additional options for GEBV estimation.

The aim of the experiment reported in this research paper was to determine the influence of the bovine appeasing substance (BAS) on milk yield, energy metabolism, inflammation, and stress in cows during the transition period. Twenty-four multiparous Holstein cows (day 28 pre-partum to 21 postpartum) were distributed randomly into two groups: control (n = 12) and BAS (Secure Cattle®; n = 12). Each animal was administered 5 mL of the product on days 28 and 14 pre-partum and on the day of calving. The feed intake was assessed using automated, individual feeders and the milk yield was determined electronically. Six milk samples were obtained from each animal, which were analyzed for chemical composition and somatic cell count. Six blood samples were obtained per animal for future biochemical analyses (free fatty acids, beta hydroxybutyrate, cortisol, myeloperoxidase and paraoxonase 1). The statistical analyses were conducted with the JMP Pro 14 software, with P ≤ 0.05 being considered as statistical significance. BAS-treated cows showed higher milk yield than controls. Dry matter intake (DMI) during the pre- and postpartum periods was greater for the control than treated group. The BAS group exhibited reduced plasma cortisol postpartum. In conclusion, cows treated with BAS showed higher milk yield, lower DMI, and reduced plasma cortisol concentrations than controls.

The aim of this review is to quantify the strength of evidence for the efficacy of exogenous enzymes (EE) in dairy calf rearing, by systematically identifying, consolidating and discussing existing research on the subject. This review identified 17 articles that measured the effect of EE alone or in combination with another treatment on indicator variables for calf performance, behaviour, health or environmental output; 15 studies realised a positive effect of enzyme supplementation on at least one variable, and one study realised a negative effect of treatment on body parameters. Inconsistent results were noted for effects of EE on growth and feed efficiency. Studies that combined EE with another treatment, did not tend to find performance improvements compared to stand-alone treatments. However, several studies were underpowered which could have limited their ability to detect effects on primary response variables. All papers that measured digestibility found an increase in fibre digestibility from enzyme treatment; however, this did not always result in improved feed efficiency or growth. Reductions in non-nutritive oral behaviour, increased resting time and rumination, were observed in studies measuring calf behaviour, as were enhanced rumen development and reduced cost of calf rearing; suggesting that EE could enhance calf health and welfare, whilst having additional advantages for rearing economics. Future research into the efficacy of EE in dairy calves is worth pursuing. However, a targeted and evidence-based approach to experimental design is required, with due consideration given to enzyme actions and interactions, as well as robust power analysis for sample size.