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Pressure aimed at reducing the use of antibiotics in livestock is steadily increasing. In 2022, the prophylactic use of antibiotics for preventive purposes will be banned in the European Union (EU), including blanket therapy at dry-off. The objective of this study was to evaluate the short- and long-term effects of selectively treating cows with low somatic cell count (SCC) at dry-off using internal teat sealant with or without antibiotic therapy on udder health, milk production, metabolic, and inflammatory conditions through the next lactation. Fifteen Holstein dairy cows without intramammary infections and with SCC less than 200×103 cells/mL at dry-off were enrolled in the study. Cows were abruptly dried off and treated either with antibiotic plus teat sealant (AB) or with teat sealant only (TS). Milk and blood samples were collected on scheduled days from 10 days before dry-off to 28 days after calving. Milk composition and both inflammatory and metabolic profiles were assessed. Fertility and milk production were recorded during the previous and subsequent lactation. Rumination time was monitored from three weeks before dry-off to four weeks after calving. Data were analyzed with PROC MIXED and PROC GLM of SAS software. Total milk production, reproductive performance, rumination time, and mastitis incidence did not differ between groups. Milk yield during the first 120 days after calving was not affected by treatment. Milk composition and SCC were not affected during the first month. Compared with AB, TS had lower plasma calcium at -47 days from calving, gamma-glutamyl transferase at –50, –47, and –42, tocopherol at –65, –50, and –47, and alkaline phosphatase at 3 days from calving. Overall, both metabolic and inflammatory statuses were similar between AB and TS cows with only small transient differences. With the perspective of reducing antibiotic usage in dairy farms, internal teat sealant could be used alone in healthy cows with low SCC with no relevant effect

Paratuberculosis is an infectious disease of ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP). MAP is an intracellular pathogen with a possible zoonotic potential since it has been successfully isolated from the intestine and blood of Crohn’s disease patients.Since no cure is available, after the detection of the disease, animal culling is the sole applicable containment strategy. However, the difficult detection of the disease in its subclinical form, facilitates its spread raising the need for the development of effective diagnosis and vaccination strategies. The prompt identification and isolation of the infected animals in the subclinical stage would prevent the spread of the infection.In the present study, an immunoinformatic approach has been used to investigate the immunogenic properties of 10 MAP proteins. These proteins were chosen according to a previously published immunoproteomics approach. For each previously-described immunoreactive protein, we predicted the epitopes capable of eliciting an immune response by binding both B-cells and/or class I MHC antigens. The retrieved peptide sequences were analyzed for their specificity and cross-reactivity. The final aim is to employ the discovered peptides sequences as a filtered library useful for early-stage diagnosis and/or to be used in novel multi-subunit or recombinant vaccine formulations.

Mycobacterium avium subsp. paratuberculosis (MAP) is the cause of a chronic enteritis of ruminants (bovine paratuberculosis (PTB)-Johne's disease) that is associated with enormous worldwide economic losses for the animal production. Diagnosis is based on observation of clinical signs, the detection of antibodies in milk or serum, or evaluation of bacterial culture from feces. The limit of these methods is that they are not able to detect the disease in the subclinical stage and are applicable only when the disease is already advanced. For this reason, the main purpose of this study is to use the MAP proteome to detect novel immunoreactive proteins that may be helpful for PTB diagnoses. 2DE and 2D immunoblotting of MAP proteins were performed using sera of control cattle and PTB-infected cattle in order to highlight the specific immunoreactive proteins. Among the assigned identifiers to immunoreactive spots it was found that most of them correspond to surface-located proteins while three of them have never been described before as antigens. The identification of these proteins improves scientific knowledge that could be useful for PTB diagnoses. The sequence of the identified protein can be used for the synthesis of immunoreactive peptides that could be screened for their immunoreaction against bovine sera infected with MAP. All MS data have been deposited in the ProteomeXchange consortium with identifier PXD001159 and DOI 10.6019/PXD001159.