Failed transfer of passive immunity (FTPI) in dairy calves – which is often due to the low amount of colostrum provided within a few hours after birth – remains a crucial issue. Enabling dairy calves to nurse colostrum from their dams could be useful in increasing intake and thus avoiding FTPI, but further potential effects on the health and welfare of both calves and dams should also be considered. In this study, 107 calf-dam pairs from two Italian dairy farms were alternately assigned to one of the following colostrum provision methods (CPMs): ‘hand-fed method’ (HFM) – the calf was separated from the dam immediately after birth and colostrum was provided by nipple-bottle (n = 50); ‘nursing method’ (NM) – the calf nursed colostrum from the dam for the first 12 h of life without farmer assistance (n = 30); and ‘mixed method’ (MM) – the nursing calf received a supplementary colostrum meal by nipple-bottle (n = 27). Serum of calves (1 to 5 days of age) and samples of their first colostrum meal were analysed by electrophoresis to assess immunoglobulin (Ig) concentration. Additionally, behavioural indicators of separation distress (calf and dam vocalisations; calf refusal of the first meal after separation; undesirable dam behaviour at milking) in the following 24 h were recorded as binary variables (Yes/No), and the health status of calves (disease occurrence and mortality) and dams (postpartum disorders and mastitis occurrence) were monitored for the first 3 months of life and 7 days after parturition, respectively. The lowest FTPI occurrence (calf serum Ig concentration <10.0 g/l) was found in the MM (11.1%) and the HFM (22.0%) compared with the NM (60.0%) (P<0.05), and the highest percentage of calves with optimal transfer of passive immunity (serum Ig concentration ≥16.0 g/l) was observed in the MM (55.6%). The lowest calf–dam separation distress was observed in the HFM (P<0.05). The highest calf disease occurrence was recorded in the HFM (64.0%) and the lowest in the NM (33.3%), with an intermediate value for the MM (44.4%) (P<0.05). No effect of the CPM was observed on dam health or calf mortality (P>0.05). The results of this study indicated that providing calves with a supplementary colostrum meal in addition to nursing from the dam (MM) is truly effective in maximizing passive immunity transfer. Anyway, specific strategies should be studied to minimise calf-dam separation distress.

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INTRODUCTION: The early diagnosis of Mycobacterium avium subsp. paratuberculosis (MAP) is one of the current challenges of farmers and veterinarians. OBJECTIVES: This work aimed to investigated the changes in metabolic levels associated with natural MAP infection in infected and infectious dairy cattle METHODS: The study included sera from 23 infectious/seropositive, 10 infected but non-infectious/seronegative, and 26 negative animals. The samples were selected from a collection of samples gathered during a prospective study. The samples were analyzed by quantitative nuclear magnetic resonance (NMR) spectroscopy and routine blood chemistry. The blood indices and the 1H NMR data were concatenated by low-level data fusion, resulting in a unique global fingerprint. Afterwards, the merged dataset was statistically analyzed by the least absolute shrinkage and selection operator (LASSO), which is a shrinkage and selection method for supervised learning. Finally, pathways analysis was performed to get more insights on the possible dysregulated metabolic pathways.RESULTS: The LASSO model achieved, in cross-validation, an overall accuracy of 91.5% with high values of sensitivity and specificity in classifying correctly the negative, infected, and infectious animals. The pathway analysis revealed MAP-infected cattle have increased tyrosine metabolism and enhanced phenylalanine, tyrosine and tryptophan biosynthesis. The enhanced synthesis and degradation of ketone bodies was observed both in infected and infectious cattle.CONCLUSION: In conclusion, fusing data from multiple sources has proved to be useful in exploring the altered metabolic pathways in MAP infection and potentially predicting negative animals within paratuberculosis-infected herds.

The early diagnosis of Mycobacterium avium subsp. paratuberculosis (MAP) is one of the current challenges of farmers and veterinarians. This work aimed to investigate the changes in metabolic levels associated with natural MAP infection in infected and infectious dairy cattle. The study included sera from 23 infectious/seropositive, 10 infected but non-infectious/seronegative, and 26 negative Holstein Fresian cattle. The samples were selected from a collection of samples gathered during a prospective study. The samples were analyzed by quantitative nuclear magnetic resonance (NMR) spectroscopy and routine blood chemistry. The blood indices and the 1H NMR data were concatenated by low-level data fusion, resulting in a unique global fingerprint. Afterwards, the merged dataset was statistically analyzed by the least absolute shrinkage and selection operator (LASSO), which is a shrinkage and selection method for supervised learning. Finally, pathways analysis was performed to get more insights on the possible dysregulated metabolic pathways. The LASSO model achieved, in a 10 time repeated 5-fold cross-validation, an overall accuracy of 91.5% with high values of sensitivity and specificity in classifying correctly the negative, infected, and infectious animals. The pathway analysis revealed MAP-infected cattle have increased tyrosine metabolism and enhanced phenylalanine, tyrosine and tryptophan biosynthesis. The enhanced synthesis and degradation of ketone bodies was observed both in infected and infectious cattle. In conclusion, fusing data from multiple sources has proved to be useful in exploring the altered metabolic pathways in MAP infection and potentially diagnosing negative animals within paratuberculosis-infected herds.