Joel Filipe

Milk microbiome diversity and bacterial group prevalence in a comparison between healthy Holstein Friesian and Rendena cows

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.

A comparison study of the inflammatory response in Holstein Friesian versus a local cattle breed (Rendena)

The selective pressure for increased milk production brought about great difficulties in the adaptation of cows to their environment. However, not much is known about the biological mechanisms behind the relationship between genetic selection and higher risk of metabolic and infectious diseases (Oltenacu, P.A., and Broom, D.M., 2010). It is well known that during the calving period, high-yielding dairy cattle are more susceptible to common environmental stressors, affecting disease occurrence and milk production levels (Bach, A., 2011). In this study we compared innate immune response of 6 Holstein Friesian (HF) and 4 Rendena (R) cows reared in the same farm and under the same management conditions. Milk and blood samples were collected at dry-off (T1), 1 day after calving (T2), 7-10 days after calving (T3), and 30 days after calving (T4). Milk samples were subjected to measurement of the inflammation marker cathelicidin and assessment of different innate immune-related mediators; blood samples were used for the analysis of plasma metabolites indicators of systemic inflammation. HF cows showed a more severe systemic inflammatory response at T2 and T3 in comparison with R cows (fig.1). Concerning the milk protein abundance profile, higher levels in R cows were observed in the colostrum (T2). Moreover, at all time points HF showed higher levels of the inflammation marker cathelicidin in milk (fig.2). In addition, the expression of innate immune related genes were different in HF compared with R (fig.3). Our results suggest that HF cows develop a systemic and local mammary inflammatory response that confirms their higher susceptibility to disease compared with R cows. Our findings reveal that fundamental effector activities of innate immunity in the mammary gland could be included in the breeding programs of HF cows and suggest the spread of autochthonous cow farming in order to maintain the biodiversity, reduce the antibiotic consumption and production of high quality dairy products.

Diets with different lipid contents do not modify the neuronal membrane lipid raft profile in a scrapie murine model

UNLABELLED In Transmissible Spongiform Encephalopathies (TSEs), the localization of the prion protein in the neuronal membrane lipid rafts (LR) seems to play a role in sustaining the protein misfolding. Changes in membrane properties, due to altered lipid composition, affect their organization and interaction between lipids and protein therein, and consequently also membrane resident protein functionality; dietary polyunsaturated fatty acids (PUFAs), gangliosides and cholesterol seem to influence these processes. AIMS In this work, the influence of administration of different feed, able to change the composition of lipid membrane, on the clinical progression of prion disease was studied. MAIN METHODS The activity of three diets (hyperlipidic with 6% fats; hypolipidic with 0.1% fats; and purified with 4% fats) was tested in CD1 mouse model experimentally infected with RML scrapie strain. Presence and distribution of typical central nervous system (CNS) lesions and deposits of PrP(sc) were evaluated by histopathological analysis and immunohistochemistry. Analysis of lipids was performed in homogenate and insoluble brain fraction of the neuronal membrane rich in LR. KEY FINDINGS Results show that a diet with a different lipid level has not a significant role in the development of the scrapie disease. All infected mice fed with different diets died in the same time span. Histology, immunohistochemistry, and neuropathological analyses of the infected brains did not show significant differences between animals subjected to different diets. SIGNIFICANCE Independently of the diet, the infection induced a significant modification of the lipid composition in homogenates, and a less noticeable one in insoluble brain fraction.

Rumen fluid, a new diagnostic matrix in dairy cattle farms?

Production diseases of dairy cows are considered man-made problems caused by the inability of cows to achieve a sufficient feed energy intake (Mulligan, 2008). A correct management of production diseases demands early diagnostic and prognostic parameters, in order to improve the management system and reduce the prevalence of clinical cases (Ingvartsen, 2003). A previous study of our group indicated that forestomachs walls express immune receptors and cytokines, and the rumen liquor contains leukocytes able to produce IFN-γ (Trevisi, 2014). Our working hypothesis implied that ruminal fluids could be a source of diagnostic information for the identification of herds at risk for production diseases. We first demonstrated that the diet can influence the immune response in forestomachs. Diverse leukocyte populations at low concentrations and IFN-γ were revealed in some samples of rumen fluids, with a clear inhibition of the response observed in the animals fed the maize-supplemented diet, compared to a normal and a soy-supplemented diet. We better characterized the leukocytes subpopulations in the rumen liquor, isolating B cells, monocytes and γδT cells. Finally we performed a field survey in order to find correlation among the immune profile of the rumen liquor. Clinically healthy animals showed a farm specific immunologic pattern of the rumen liquor: low CD45 mRNA expression, low IFN-γ, few/absent B-cells. We can conclude that the epithelial cells of ruminant forestomachs can react to different stresses (metabolic, infectious, inflammatory) and the inflammatory response can be sustained by infiltrating leukocytes. Our data points into the idea that dairy farms could be ranked according to a risk score using the inflammatory markers in rumen fluids, in addition to the traditional analysis.