No abstract

Dry and early lactation periods represent the most critical phases for udder health in cattle, especially in highly productive breeds, such as the Holstein Friesian (HF). On the other hand, some autochthonous cattle breeds, such as the Rendena (REN), have a lower prevalence of mastitis and other transition-related diseases. In this study, milk microbiota of 6 HF and 3 REN cows, all raised on the same farm under the same conditions, was compared. A special focus was placed on the transition period to define bacterial groups’ prevalence with a plausible effect on mammary gland health. Four time points (dry-off, 1 d, 7–10 d and 30 d after calving) were considered. Through 16S rRNA sequencing, we characterized the microbiota composition for 117 out of the 144 milk samples initially collected, keeping only the healthy quarters, in order to focus on physiological microbiome changes and avoid shifts due to suspected diseases. Microbial populations were very different in the two breeds along all the time points, with REN milk showing a significantly lower microbial biodiversity. The taxonomic profiles of both cosmopolitan and local breeds were dominated by Firmicutes, mostly represented by the Streptococcus genus, although in very different proportions (HF 27.5%, REN 68.6%). Large differences in HF and REN cows were, also, evident from the metabolic predictive analysis from microbiome data. Finally, only HF milk displayed significant changes in the microbial composition along the transition period, while REN maintained a more stable microbiota. In conclusion, in addition to the influence on the final characteristics of dairy products obtained from milk of the two breeds, differences in the milk microbiome might, also, have an impact on their mammary gland health.

No abstract

Immunostimulants represent a modern and promising tool in aquaculture, enhancing the resistance of cultured fish to disease and stress. This study investigated the effect of a combination of dietary glucans, alpha-tocopherol and ascorbic acid on the innate immune response of cultured sea bass (Dicentrarchus labrax). After 5 weeks of adaptation on a commercial diet containing 100 p.p.m. ascorbic acid and 200 p.p.m. alpha-tocopherol, sea bass were switched to a diet supplemented with 2% beta-1.3/beta-1.6 glucans and ascorbic acid and alpha-tocopherol at 500 p.p.m. The supplemented diet was given at 2% of body weight per day over a 2-week period, every 3 months. Plasma lysozyme concentration, content and distribution of major plasma proteins and complement activity were measured prior to feeding the supplemented diet and after 40 weeks. Alternative pathways of complement activation and lysozyme activity were both significantly enhanced in fish fed on glucans and elevated doses of vitamins. No significant differences were observed in protein content or in albumin/globulin ratio. Compared to lysozyme activity, which showed marked individual variation, complement-mediated haemolytic activity has been shown to be a more reliable indicator of sea bass immunocompetence. Further studies are in progress to clarify the effect of each dietary component on the innate immune response and disease resistance.

The aim of this study was to investigate the effects of long-distance road transport (19 h, from Poland to Italy) during 2 seasons (summer vs. winter) on clinical and hematological variables in calves. The environmental temperature range that could compromise the thermoregulation system (thermal stress) of the calves was tested. For the 7 Holstein calves in each transport, the BW and rectal temperature (RT) were measured, and blood samples were collected at the farm of origin, before loading at the transit center (T2), after unloading at the farm of destination (T3), and 1, 2, 3, and 4 d after arrival. The body temperature (BT) and heart rate (HR) were continuously monitored from T2 to T3. The data were statistically analyzed according to a mixed model that considered the fixed effects of transport (repeated measurements), season of journey, and their interaction. Within the observed temperature-humidity index (THI) range (30 to 80), effective thermoregulation allowed the calves to maintain their BT with small physiologic changes to prevent thermal stress, particularly in the summer. With no seasonal differences, the HR was greater at loading than unloading (120 vs. 115 beats per min; P = 0.012). As for the transport effect, the BW was less (P < 0.001) after unloading, and the RT was greater (P = 0.004). This effect was more marked in summer. The hematological variables indicated a moderate effect of transport on the hydration condition, reactive and muscular systems, and metabolism, although hematocrit (P = 0.004), erythrocytes, cortisol, NEFA, β-hydroxybutyrate, lactate, creatine kinase, lactate dehydrogenase, and aspartate aminotransferase activity (P < 0.001), and total protein (P = 0.007) were greater after unloading. This was confirmed by a moderate decrease in total leukocytes (P = 0.031) and glucose concentration (P = 0.002). The changes in the clinical variables were similar for both seasons even though in the summer, hematocrit (P < 0.001), urea (P = 0.008), and total protein (P = 0.010) increased and glucose concentration (P = 0.038) decreased. In conclusion, the data did not show a pronounced effect attributable to the season of the journey. Long-distance road transport leads to notable changes in clinical and hematological variables at the end of the journey. However, these variables remained within their physiological ranges and returned to basal values within a few days after the journey.

No abstract

Many apparently healthy cows show marked inflammatory conditions around calving, associated with endocrine and metabolic changes. To prevent the above conditions, a low-dose, oral interferon-alpha (IFN-alpha) treatment was carried out on periparturient, multiparous dairy cows. In the first trial, 10 cows received 10 IU of IFN-alpha/kg of BW daily during the last 2 wk of pregnancy. In a second trial, 4 cows received 0.5 IU of IFN-alpha/kg of BW daily until d 5 of lactation. In both trials, a homogenous group of untreated dairy cows was used as control. All cows were monitored, during the month before and after calving, for health status, BCS, milk yield, and inflammatory, metabolic, immune, and hematological variables. Compared with control cows, IFN-alpha-treated animals showed in both trials a larger decrease of BCS along with decreased milk yield (P < 0.05), increased haptoglobin (P < 0.05) and ceruloplasmin, and a slower increase of negative acute phase proteins (albumin, cholesterol, paraoxonase, vitamin A) after calving. Interferon-alpha-treated animals also showed a larger decrease of plasma glucose and greater values of NEFA, beta-hydroxybutyrate, and reactive oxygen metabolites. There also was evidence of IL-6 and tumor necrosis factor-alpha responses in both groups before calving with a quick decrease thereafter. The IL-6 response appeared in some animals regardless of the IFN-alpha treatment. Results indicate that low-dose IFN-alpha can sustain an inflammatory response in dairy cows and cause notable metabolic changes. This outcome might be explained by the repeated and extended interaction of IFN-alpha at low doses with the oral lymphoid tissues during rumination, as suggested by the observed stability of the cytokine in the rumen milieu; the final inflammatory effect could thus be as large as that of high doses. In addition, the antiflogistic signal of IFN-alpha might be counteracted and inverted by lymphocytes detected in the rumen liquor.

African swine fever (ASF) is a devastating disease for which there is no vaccine. The ASF virus (ASFV) can infect dendritic cell (DC), but despite the critical role these cells play in induction of adaptive immunity, few studies investigated their response to ASFV infection. We characterized the in vitro interactions of porcine monocyte-derived DCs (moDC) with a virulent (22653/14), a low virulent (NH/P68) and an avirulent (BA71V) ASFV strain. At a high multiplicity of infection (MOI = 1), all three strains infected immature moDC. Maturation of moDC, with IFN-α/TNF-α, increased susceptibility to infection with 22653/14 and other virulent strains, but reduced susceptibility to NH/P68 and BA71V. The reduced moDC susceptibility to BA71V/NH/P68 was IFN-α mediated, whereas increased susceptibility to 22653/14 was induced by TNF-α. Using an MOI of 0.01, we observed that BA71V replicated less efficiently in moDC compared to the other isolates and we detected increased replication of NH/P68 compared to 22653/14. We observed that BA71V and NH/P68, but not 22653/14, downregulated expression of MHC class I on infected cells. All three strains decreased CD16 expression on moDC, whereas ASFV infection resulted in CD80/86 down-regulation and MHC class II DR up-regulation on mature moDC. None of the tested strains induced a strong cytokine response to ASFV and only modest IL-1α was released after BA71V infection. Overall our results revealed differences between strains and suggest that ASFV has evolved mechanisms to replicate covertly in inflammatory DC, which likely impairs the induction of an effective immune response.