Gastrointestinal (GI) barrier integrity is essential for nutrient absorption, health, and production efficiency in dairy cattle. Nonsteroidal anti-inflammatory drugs (NSAID) reduce prostaglandin synthesis and may compromise mucosal defenses, increasing intestinal permeability. This exploratory study characterized tissue-specific transcriptional responses to NSAID-induced barrier dysfunction in dairy heifers. Eight 13-mo-old heifers were assigned to control (n = 4) or aspirin-treated (n = 4) groups. Aspirin was administered at 100 mg/kg BW every 12 h for 4 d (d 4–7). On d 13, animals were euthanized and epithelial tissues from the rumen, small intestine, colon, and liver were collected at slaughter for RNA sequencing. A total of 370 differentially expressed genes were detected, with 355 localized to the colon, indicating a concentrated response in this tissue. Enriched pathways included cell adhesion, ion transport, extracellular matrix-receptor interaction, and PI3K-Akt signaling, suggesting activation of epithelial repair and extracellular matrix remodeling processes. These observations, though limited by sample size, highlight transcriptional changes in colon tissue following NSAID administration and provide preliminary insight into molecular pathways potentially involved in barrier dysfunction in dairy cattle.
There is increased interest in Salmonella Dublin surveillance on dairy farms using either milk or serum samples from individual lactating cows. In practice, sample selection is often based on convenience, and results from milk and serum are frequently used interchangeably. The objective of this cross-sectional diagnostic accuracy study was to evaluate agreement between milk and serum results from individual lactating cows using a commercial antibody ELISA (PrioCHECK S. Dublin Strip Kit; Thermo Fisher Scientific). Milk and serum were collected from 422 lactating cows on 6 dairy farms in British Columbia, Canada. Agreement between milk and serum ELISA percent positivity (PP) was assessed using Lin's concordance correlation coefficient (CCC) and Bland–Altman analysis. Categorical agreement was evaluated using Cohen's kappa, and Youden's index used to identify optimal cut points. There was moderate agreement between milk and serum PP values (CCC = 0.67, 95% CI 0.63–0.71). Using milk at a reference cut point of 35 PP, the optimal serum cut point identified by Youden's index was 1.44 PP, yielding sensitivity of 87.57% and specificity of 89.24%. In contrast, when serum at 35 PP was used as the reference, the optimal cut point for milk was 58.84 PP, producing sensitivity of 95.12% and specificity of 90.29%. Cohen's kappa coefficients indicated fair agreement using a cut point of 35 PP for both milk and serum (κ = 0.36, 95% CI 0.28–0.45), moderate agreement using a milk cut point of 35 PP with serum cut points of 15 PP (κ = 0.57, 95% CI 0.48–0.66) or 1.4 PP (κ = 0.61, 95% CI 0.50–0.65), and substantial agreement using a milk cut point of 58.84 PP and a serum cut point of 35 PP (κ = 0.74, 95% CI 0.67–0.81). A mixed linear regression model was used to investigate the effects of lactation number, DIM, and SCC at sampling on the difference between milk and serum PP, with herd as a random effect. Compared with cows in their first lactation, cows in lactation ≥3 had larger discrepancies between paired PP (β = 6.15; 95% CI 0.65–11.65). Larger differences between milk and serum PP were also associated with SCC between 200,000 and 400,000 cells/mL (β = 11.80, 95% CI 4.92–18.67) and >400,000 cells/mL (β = 8.51, 95% CI 1.82–15.21) compared with SCC ≤100,000 cells/mL. The results suggest that milk and serum ELISA should not be used interchangeably and that meaningful agreement depends on the cut points applied.
Bacterial spores, which are found in raw milk and are able to survive high temperature, short time pasteurization, are a well-documented concern for dairy product spoilage. Due to their resistance and propensity to occupy environmental niches, bacterial spores may also be found in food processing environments, ultimately leading to introduction into processed dairy products through cross-contamination, although few studies have investigated the presence of dairy-relevant spores in processing environments. Here, we aim to enumerate and identify predominant bacterial spores isolated from 14 environmental sites in a dairy processing facility over 3 independent sampling events. To that end, mesophilic spore tests (i.e., mesophilic spore count and mesophilic most probable number spore test) were performed on the environmental sponge samples (n = 42). Sponges collected from the processing facility were heat treated at 80°C for 12 min, followed by both a most probable number technique to enumerate low-level contamination, as well as pour plating on standard methods agar to evaluate a broad range of potential spore levels. The mean spore count across the 14 environmental sites ranged from −1.34 log most probable number/mL to 3.86 log cfu/mL with SD of 1.47 log cfu/mL, demonstrating large differences across sites in both concentration and variability. General purpose tables and a microthermics benchtop had the highest mean spore counts, whereas the exterior of the spray dryer powder nozzle and the exterior of the HTST pasteurizer showed the lowest mean spore counts. Isolates representing unique colony morphologies were characterized using rpoB gene sequencing. The 133 isolates successfully sequenced comprised 14 genera, 42 species, and 55 unique rpoB allelic types, including 53 isolates that represented 25 new allelic types not previously described. The most common genera isolated were Bacillus and Paenibacillus, representing 34.6% and 22.6% of the isolates, respectively. Other genera included Cytobacillus (15.8%), Niallia (8.3%), and others (18.8%). Of the Bacillus isolated from the processing environment, Bacillus subtilis s.l. Clade1 and Bacillus cereus group were the most commonly isolated. Further, we observed sporeformers with the same rpoB allelic types over multiple sampling events from the same sites, suggesting putative persistence in the processing environment. Overall, our results indicate that dairy processing environments may harbor spores of relevance to dairy product quality and safety. Future studies should further examine spores in processing environments and develop strategies to prevent their introduction into dairy products to reduce food waste, extend product shelf life, and reduce risk to public health.
This study examined consumer responses to local and regional dairy brands in Tennessee, including their progression through a 4-stage marketing funnel (brand awareness, purchase intent, repurchase likelihood, and recommendation likelihood) when considering 7 dairy brands (6 real, 1 hypothetical). Using an in-person survey, we found that brand awareness represented the binding constraint for local small creameries, with brand awareness rates below 10%, whereas awareness was 93% for the established regional brand. Engagement with farm-direct retail channels and approval of local food buying promoted local dairy brand awareness and initial purchase likelihood for those products. Conditional on purchase, perceived quality emerged as the dominant driver of both repurchase and recommendation intentions. The local brand exhibited significantly higher recommendation likelihood than purchasers of the regional brand, suggesting word-of-mouth advocacy among engaged consumers. Closing the awareness gap represents the major challenge for regional and local dairy brands.
Automatic milking systems (AMS) can provide dairy cattle with agency over milking frequency, including when they transition from lactation to the dry period. The aim of this observational pilot study was to determine whether dairy cows would dry off voluntarily and to characterize self-milking behavior in late lactation. Holstein dairy cows (n = 15; 12 multiparous, 3 primiparous) were enrolled in a voluntary dry-off procedure in late lactation (mean ± SD: 74 ± 3 d days before expected calving) in which they no longer received concentrate in the AMS and were not fetched for milking. Cows were considered dry if they did not visit the AMS for 72 h or produced <4.5 kg milk/d for 3 d consecutively. If cows did not dry off by 40 d before expected calving, they were dried off by farm intervention. Twelve cows met the voluntary dry-off criteria 20.3 ± 8.0 d after enrollment (range: 10–32 d). From enrollment to the last day of milking, daily milk yield was reduced by 46.6% ± 18.9%, and the time between AMS visits increased from 9.6 ± 1.7 h to 25.1 ± 5.3 h. Daily milk yield had a high negative correlation with the interval between milkings, with higher daily milk yield corresponding to shorter intervals between visits. Additionally, cows with a greater percent reduction in milk yield by 9 d after enrollment and cows with more variable daily milk yield met the dry-off criteria earlier. This pilot study suggests that cows can reduce milking voluntarily, which may improve their agency and welfare. However, if cows are allowed to reduce milkings voluntarily, they still require monitoring during late lactation to ensure proper progression into the dry period.
