The objectives of the study were to determine somatic cell count (SCC) and evaluate the presence of pathogens (IMI – intramammary infection) in late lactation (LL), followed by the start (colostrum, CL) and approximate peak (established lactation, EL) of the next lactation, as well as to assess the possible transmission of IMI from lactation to lactation. The study was performed on a dairy farm in northern Slovakia. A total of 489 half udder milk samples (242, 80 and 167 in LL, CL and EL, respectively) were collected. Pathogens were identified using MALDI-TOF MS and PathoProof (the latter only in LL). SCC was determined only in LL and EL. Samples were divided according to SCC in four groups from lowest (SCC1 < 500 × 103 cells mL−1) to highest (SCC4 ≥ 2000 × 103 cells mL−1). SCC was higher in LL than in EL. The prevalence of pathogens identified using MALDI-TOF MS was 16.5, 38.8 and 12.6% in LL, CL and EL, respectively. Non-aureus staphylococci and mammaliicocci (NASM) were the most common isolated pathogens in goat milk and colostrum. Staphylococcus (S.) caprae and S. epidermidis species tended to cause persistent IMI in the next lactation. The identification of pathogens using PathoProof was higher than with MALDI-TOF MS. Of all the pathogens (n = 262) identified using PathoProof, the most common were Staphylococcus spp. (86.7%) of which 65.8% exhibited the β-lactamase gene. Additionally, Escherichia coli (4.2%), S. aureus (2.7%), Enterococcus spp. (2.3%), Streptococcus uberis (1.9%), Mycoplasma spp., Protetheca spp. (0.8% each), Arconabacterium pyogenes/Peptoniphilus indolicus and yeast (0.4% each) were also detected using PathoProof. Better identification of pathogen presence in samples with high SCC could contribute to the discussion about SCC as an indicator of subclinical mastitis in goats.

The weaning process negatively affects the haematological parameters and innate immune response of dairy calves, even when managed under an intensive milk program. Here we describe haematological and innate immunity changes in 47 Holstein calves aged 69-85 days subjected to a gradual weaning process. Blood samples were collected at six (D-6), four (D-4), and two (D-2) days before and on the weaning day (D0) for the phagocytosis assay and to measure the production of reactive oxygen species (ROS) after stimulation with Staphylococcus aureus, Escherichia coli, and Mannhemia haemolytica, in addition to total protein (TP), haptoglobin (Hp), and iron concentration. The highest mean neutrophil number was recorded at D-2. The absolute number of monocytes was initially high on D-6 and D-4 but declined as the calf progressed to weaning. The number of basophils decreased rapidly, reaching a low value on D-4, and remained low for the remainder of the study period. The TP, Hp, and Fe concentrations decreased. Overall, polymorphonuclear leukocyte phagocytosis activity induced by S. aureus and E. coli decreased from D-6 to D-2, indicating persistence of the low phagocytosis rate for S. aureus. ROS production was constant for all bacterial stimulations from D-6 to D-2, followed by an increase on D0. Phagocytosis and ROS production indicate that the weaning process dampens the innate immune response relative to exposure to these common pathogenic bacteria in dairy calves. Phagocytosis and the corresponding indicators of intracellular killing activities (ROS production and myeloperoxidase index) represent the most accepted core mechanisms for the early elimination of pathogenic microorganisms in calves. Despite a slow gradual weaning management system, the study concluded that intensive milk production programs contribute to innate immune response suppression during weaning.