The protein profile of milk is an increasingly important research topic in relation to the technological properties of milk for cheese-making and value of it for human nutrition. Goats are a valuable source of milk worldwide, but there is no precise and rapid method for the simultaneous identification and quantification of the genetic variants of the major protein fractions. In this study we devised a method for the rapid identification and quantification of the main genetic variants of α_S1-, α_S2-, β- and κ- caseins, and of α-lactalbumin and β-lactoglobulin (whey proteins) in caprine milk using an HPLC-UV reverse-phase C8 column. The R² of the calibration equations was > 0.99 for all 15 protein fractions identified. A total of 520 milk samples were taken from 260 goats (in duplicates) of 6 different breeds reared on 22 farms operating different farming systems, ranging from traditional/extensive to modern/intensive, and analyzed them to externally validate the method. Milk samples from DNA-genotyped goats were used to identify the genetic variants of the caseins. Compared with other studies, with our method we were able to separate the main genetic variant of caseins within a total run time of 24 min and with a repeatability > 92% for all fractions except for the C variant of κ-casein. Farms were found to be the major source of the variability in the contents of true proteins (56.1% of total variance), true caseins (48.6%), κ-casein C (50.6%) and whey proteins (52.9-62.9%) in goats' milk, whereas individual goat within farm was the most important source of variability in the contents of individual caseins and their genetic variants (53.9% to 94.7%).

Understanding the relationship between microbial community alterations and disease can provide valuable insights for improving diagnostics, prevention, and treatment strategies. This study used 16S rRNA amplicon sequencing to investigate and compare microbial diversity in the milk and feces of Holstein cows with subclinical mastitis caused by Streptococcus agalactiae and Prototheca spp. with that of healthy cows. A bacteriological screening identified 50 Holstein cows reared in a commercial dairy farm and classified into 3 experimental groups: (1) animals negative at the bacteriological examination with no history of subclinical mastitis (HLTH; n = 16), (2) animals positive at the bacteriological examination for either Streptococcus agalactiae (STRP; n = 22) or Prototheca spp. (PRTH; n = 12). The milk microbiota showed significant pathogen-specific alterations, with increased Firmicutes in STRP cows (55.6%) and Cyanobacteria in PRTH cows (17.3%), compared with healthy cows (39.2% and 0.7%, respectively). Alpha diversity (observed amplicon sequence variants, Shannon, and evenness indices) was significantly lower in infected cows, confirming a microbial imbalance. Beta diversity analysis (PERMANOVA) revealed significant differences in microbial composition between healthy and infected cows, but no significant differences in fecal microbiota composition. Differential abundance analysis identified Streptococcus (log₂fold change [FC] = 7.3) as the most enriched taxon in STRP cows and Cyanobacteria (log₂FC = 8.9) as the most enriched in PRTH cows in milk matrix, while Macrococcus caseolyticus was significantly reduced in both infected groups (log₂FC = -4.5). These findings suggest that subclinical mastitis leads to significant shifts in the milk microbiota but does not alter the fecal microbiome, supporting a localized rather than systemic microbial response. This study provides novel insights into the microbial dynamics of subclinical mastitis and potential biomarkers for disease monitoring.

In the Trentino Alto Adige region, disposal of grape stalks (GS) represents a major cost for wineries, despite their content of phenolic and tannin-rich compounds with potential functional value in ruminant nutrition. This study evaluated whether dietary GS supplementation could influence milk microbiota and cheese quality, supporting local circular-economy strategies. GS from three red cultivars (L-GS, CS-GS, M-GS) were dried, milled, and assessed for safety; their average total polyphenol content was approximately 15 g/kg DM. 3 Holstein cows underwent a 7-week trial consisting of alternating control (CTRL) and GS-supplemented periods (2% DM). Weekly milk samples (n = 21) and corresponding mini-cheeses (n = 21) were analyzed. GS supplementation did not affect milk coliforms (2.3–2.5 log CFU/mL), while total mesophilic counts were significantly lower in M-GS (2.8 ± 0.46 log CFU/mL) than in CTRL (4.5 ± 0.71; p < 0.05). Acinetobacter dominated the milk microbiota but decreased from 34.0% in CTRL to 18.0% in L-GS. Cheese total polyphenols were highest in CS-GS (224 ± 34 mg/kg). ¹H-NMR and VOCs profiling indicated cultivar-dependent shifts in carbohydrate-related metabolites and short-chain fatty acids. Overall, GS supplementation subtly modulated cheese biochemical and aromatic traits without impairing technological performance, supporting the valorization of winery by-products within integrated dairy-viticulture systems.