1,721,076 research outputs found
Studio dei processi digestivi nei ruminanti e negli erbivori monogastrici in relazione ai rischi di turbe digestive e ad anomalie degli indici ematici di stati infiammatori
No full textPer studiare le ripercussioni metaboliche e produttive di alterazioni della funzionalità del digerente sono state condotte tre sperimentazioni. Nella prima sono state controllate le condizioni di acidosi ruminale in bovine di allevamenti commerciali: in essi non si sono riscontrati valori di ph capaci di indurre seri effetti negativi a livello digestivo-metabolico, ma certamente a rischio. In tali condizioni, i più bassi valori di ph ruminali sarebbero soprattutto indice di una maggiore ingestione di alimenti, favorita anche da migliori condizioni generali di salute delle bovine. Nella seconda sperimentazione, l'applicazione di stress acuti a bovine in lattazione ha prodotto un rallentamento nel transito ruminale, soprattutto in animali in lattazione avanzata, confermando la possibilità che lo stress acuto rappresenti un fattore di rischio per anomalie digestivo/fermentative. Nella terza prova, relativa alla funzionalità del grosso intestino di conigli esposti a diete con diversi livelli di amido, performance produttive leggermente più favorevoli si sono registrate con la dieta più alta in fibra digeribile. A fronte di analoghe caratteristiche del digerente tra le tesi, alcuni parametri ematici ,soprattutto con riferimento allo status ossidativo, hanno permesso di porre in evidenza un quadro metabolico più favorevole associato all'uso di diete meno amidacee.
Quindi, alterazioni dei processi fermentativi, possono avere conseguenze sul livello produttivo e sullo stato di salute dell'animale. Per una migliore interpretazione dei dati della funzionalità del digerente appare utile il supporto di taluni parametri ematici.Three experiments were carried out to study the metabolic and productive effects of some changes of the digestive functionality. In the first experiment, the degree of ruminal acidosis was controlled on dairy cows from commercial farms: the low observed ph values were indices of risks but not so low to have serious adverse effects at digestive-metabolic level. However in these circumstances, the lower ph would be especially indices of a greater feed intake, in turn favoured by a better general animal health. In the second experiment, the application of acute stress to lactating cows showed digesta rumen passage rate of digesta, especially in late lactation, confirming the possibility that the acute stress could be a risk factor for digestive abnormalities. In the third one, on the large intestine functionality of rabbits exposed to diets with different levels of starch, some slightly better performances were obtained with the diet richer in digestible fibre. Though main digestive traits were unaffected by treatments, some blood parameters, particularly those linked to the oxidative status, revealed a more favourable metabolic situation associated with the use of less starchy diets.
Hence, alteration of the fermentative processes may impair animal production and/or the animal health conditions. For a better interpretation of the parameters of the digestive system functionality the support of some specific blood parameters appears useful
Assessment of the innate immune response in the periparturient cow
No full textThe transition period is the most critical phase in the life of high yielding dairy cows. Within a few weeks, cows are submitted to many challenges (physiological, nutritional, psychological, management) that require prompt and effective adaptive responses. The immune system is involved in this process, and many changes of the cow's immune system components have been observed around calving. Cows are considered to be immunosuppressed in late lactation, and available data suggest that the immune system is dysregulated around parturition. Significant attention has been focused on modification of cellular functions (e.g. the reduction of phagocytosis and diapedesis), but growing interest concerns the components of the innate immune system, which often exhibits increased responses such as susceptibility to inflammatory events and the related acute phase response (APR). Systemic inflammation plays a significant role in early lactation, affects many liver functions and has been associated with the impairment of cow performance (i.e. reduced feed intake, milk yield, fertility, welfare). The assessment of variations in immune-metabolic indices offers opportunities to predict the onset of the health troubles and to anticipate the proper therapies needed to guarantee health, good welfare and fertility in the following lactation. The frequency of diseases (metabolic and infectious) before calving is rare, but several clues suggest that various metabolic and immune variations can begin during the dry period. Interesting preliminary results encourage this perspective and possible candidates are suggested
Immune system, inflammation and nutrition in dairy cattle
No full textGood health is essential for good performance and the welfare of dairy cows, and nutrition is an important component of good health. Health is influenced by the interaction between the innate adaptive components of the immune system and other factors, such as the local and systemic inflammatory response, which can sometimes be more harmful than useful. Therefore, for dairy cows, particularly those in the periparturient period, it is important to avoid, or reduce as much as possible, any kind of infectious, parasitic or metabolic disease and the associated inflammation. Such inflammation can impair cow performance by lowering milk yield, dry matter intake, fertility and energy efficiency, and can reduce liver function. Good nutrition is essential in maintaining a functional immune system, while also avoiding other causes of inflammation, such as tissue damage, and digestive and metabolic syndrome-related disorders. Provision of appropriate nutrients, such as antioxidants, omega-3 polyunsaturated fatty acids, conjugated linoleic acid and vitamin D can have anti-inflammatory effects. In the future, ways to reduce inflammation while maintaining a good immune defence must be developed and the susceptibility of the cow to diseases and inflammation evaluated. Ideally, we would be able to selectively breed for cows with a lower susceptibility to both diseases and inflammation
Evaluation of innate immune responses in bovine forestomachs
No full textPrevious studies had indicated an active role of bovine forestomachs in the response to digestive disorders as well as
to inflammatory and infectious processes in the gastro-intestinal (GI) tract and elsewhere. We investigated the
potential of bovine forestomachs to receive, amplify and produce mediators of the innate immune response. Indeed,
we detected the expression of TIR8 and other receptors and cytokines of the innate immune response, such as Tolllike
receptor (TLR)4, interleukin (IL)-1beta, IL-10 and Caspase-1 in the forestomach walls of healthy cows. Their
presence suggests an active role of forestomachs in inflammatory disorders of the GI tract and other body
compartments. We confirmed and further characterized the presence of leukocytes and cytokines in the rumen fluids.
In particular, T and B lymphocytes and myeloid lineage cells were detected in the ruminal content of both rumenfistulated
heifers and diseased cows. Also, leukocyte infiltration was modulated by feeding disorders: an acidogenic
diet based on daily supplements of maize was shown to inhibit leukocyte accumulation, as opposed to a control, haybased
diet, with or without a soy flour (protein) supplement. A survey of 11 dairy farms indicated that low-stress diets
and management were correlated with low levels of CD45 gene expression and B cell infiltration in rumen fluids, such
as in the “control farm”. In other farms, the rumen fluids of dairy cows showed increased levels of CD45 gene
expression and numbers of leukocytes of different lineages (B-cells, T-cells, myeloid cells). This latter pattern of
infiltration was correlated with an increased prevalence of inflammatory markers (positive and negative acute phase
responses). On the whole, our results indicate that bovine forestomachs can receive and amplify signals for the
immune cells infiltrating the rumen content and oral lymphoid tissues. Owing to the above, the examination of the
rumen fluid could be a novel and useful diagnostic tool to support the clinical inspections of cattle herds
Acute mammary and liver transcriptome responses after an intramammary Escherichia coli lipopolysaccharide challenge in postpartal dairy cows
No full textThe study investigated the effect of an intramammary lipopolysaccharide (LPS) challenge on the bovine mammary and liver transcriptome and its consequences on metabolic biomarkers and liver tissue composition. At 7days of lactation, 7 cows served as controls (CTR) and 7 cows (LPS) received an intramammary Escherichia coli LPS challenge. The mammary and liver tissues for transcriptomic profiling were biopsied at 2.5h from challenge. Liver composition was evaluated at 2.5h and 7days after challenge, and blood biomarkers were analyzed at 2, 3, 7 and 14days from challenge. In mammary tissue, the LPS challenge resulted in 189 differentially expressed genes (DEG), with 20 down-regulated and 169 up-regulated. In liver tissue, there were 107 DEG in LPS compared with CTR with 42 down-regulated and 65 up-regulated. In mammary, bioinformatics analysis highlighted that LPS led to activation of NOD-like receptor signaling, Toll-like receptor signaling, RIG-I-like receptor signaling and apoptosis pathways. In liver, LPS resulted in an overall inhibition of fatty acid elongation in mitochondria and activation of the p53 signaling pathway. The LPS challenge induced changes in liver lipid composition, a systemic inflammation (rise of blood ceruloplasmin and bilirubin), and an increase in body fat mobilization. The data suggest that cells within the inflamed mammary gland respond by activating mechanisms of pathogen recognition. However, in the liver the response likely depends on mediators originating from the udder that affect liver functionality and specifically fatty acid metabolism (beta-oxidation, ketogenesis, and lipoprotein synthesis)
Simple method to evaluate feeds and diets within the models of welfare assessment in dairy farms.
No full textA novel index to quickly assess the severity and the consequences of the inflammatory status in the periparturient dairy cow
No full textUnder intensive culture conditions, fish are subjected to
increased stress that has negative impacts on the fish overall
performance. Though good management practices contributes to
reduce stressor effects, the possible role of the diet quality in
modulating acute stress response has been poorly investigated
in fish. The objective of this study was to evaluate the modulation
of acute stress response by different diets in marbled trout,
Salmo marmoratus. Twelve groups of trout fingerlings (150 mg
ABW) each consisting of 1000 specimens were randomly allotted
in triplicate to four commercial trout diets (S, B, D, V) differing
in ingredient and nutrient composition (12-20% lipid and 51-59%
protein). Fish groups, kept under controlled rearing conditions
(water temperature 8.5-10°C) in a flow-through rearing tank system,
were fed over 148 days at 3% body weight/d-1 in two daily
meals. At the end of the trial one group of fish per diet was subjected
to a standardized protocol of disturbance simulating an acute transportation stress (1 hour at 4.5 fish/L) and sampled 1
h after exposure. The fish remaining in the tanks were used as
controls. Modulatory effects of dietary treatments were evaluated
by means of cortisol level measured by RIA in plasma, fins and
skin mucus and associated to the growth performance and mortality
observed in the feeding trial. Diet B resulted in the poorest
survival (59.2 vs 70.0%, P<0.05) and in the lowest weight gain
relative to all the other diets which gave rise to similar responses
(703 vs 1100% IBW, P<0.05). Moreover, fish fed diet B showed
the highest cortisol burst after transportation in all matrices (4-
12 folds higher than controls), such an increment being an
adverse response against the stressor. Cortisol significantly
increased in all matrices after the transportation stress
(P<0.01), but only in plasma a significant effect of the past diet
(P<0.05) has be detected. The results showed that a poor diet,
beyond reducing growth and survival, can also affect fish acute
stress response and that cortisol levels measured in non-invasive
matrices such fins or skin mucus proved reliable to study acute
stress response in marbled trout
Adrenal response to ACTH challenge in early lactating dairy cows characterized by different inflammatory conditions.
No full textProinflammatory cytokine profile during transition period of dairy cows
No full textProinflammatory cytokines (PIC) are crucial regulators of the immune function and mediate the acute phase response
(APR). Information available on the pattern of changes of PIC production in transition period of dairy cows are
fragmentary as well as their consequences on metabolism and health conditions. To verify the potential relevance of
the PIC level with health status of periparturient dairy cows, the changes of the plasma IL-1β and IL-6 have been investigated in 21 Holstein-Friesian cows from 4 weeks before to 4 weeks after parturition. Besides PIC concentrations
and health status, cows were monitored for dry matter intake (DMI), milk yield, body condition score and a wide
metabolic profile. The overall PIC production was higher during dry period compared the first month of lactation, but
showed a high variability among the cows. Thus cows were retrospectively divided in 3 groups according to the
concentrations of IL-1β before parturition and designated as up (UPIL), intermediate (INIL) and low (LOIL) IL-1β group.
The concentrations of IL-1β were 43.4 pg/ml, 78.7 pg/ml and 205.8 pg/ml for LOIL, INIL and UPIL, respectively (P
<0.01). The level of IL-6 is well related to the grouping based on IL-1β (P<0.01) and showed a similar pattern of
changes in transition period. UPIL group had worse health status, lower DMI, more body reserves lost, less milk
production and lower plasma albumin compared to INIL and LOIL. The UPIL cows also showed a more severe APR after
calving, as suggested by the marked increase of haptoglobin and the decrease of Zn (index of metallothionein) and
albumin during the first week of lactation (P< 0.05). Our results demonstrate a high variability of the levels of PIC in
late pregnant cows and the good relation among the high levels of PIC with health troubles (clinical and subclinical)
after calving. Thus, PIC levels could be used as prognostic markers for a risky transition period
Relation of inflammation and liver function with the plasma cortisol response to ACTH in early lactating dairy cows
No full textIn this study we examined the relationship between cortisol and inflammatory status in early lactating dairy cows after a stimulation test of the adrenal cortex. Twenty-four cows were grouped into quartiles (6 cows per each quartile) in accordance with the liver activity index (based on plasma concentration of negative acute phase proteins in early lactation); the quartiles were lower (LO; cows with the lowest liver functionality), intermediate lower, intermediate upper, and upper (UP; cows with the highest liver functionality). Each cow was injected i.v. with 20 μg of a synthetic analog of ACTH at 35 d in milk (DIM). Blood samples were taken to assess inflammatory status, and at 0, 30, and 60 min after ACTH challenge to measure total cortisol. The free cortisol fraction was analyzed in the LO and UP quartiles and the bound cortisol fraction was estimated as the difference between total and free cortisol. The LO, in comparison with the other quartiles, suffered a more severe inflammatory status, with the highest values of haptoglobin, reactive oxygen metabolites, and total nitric oxide metabolites and the lowest concentration of direct or indirect markers of negative acute phase proteins. The cows in the LO quartile had the highest values of plasma nonesterified fatty acids and β-hydroxybutyrate at 7 DIM, suggesting a more severe body lipid mobilization. The LO quartile cows showed the highest frequency of health problems and the lowest milk yield in the first 35 DIM. Thirty minutes after the ACTH treatment, the concentration of total cortisol was lower in LO in comparison to other groups. Similarly, the bound cortisol fraction was lower in LO versus UP. The adrenal response appeared inversely related with health status after calving (e.g., lower in LO cows, experiencing the most severe inflammatory status). The lower increase in cortisol after the ACTH challenge in cows with greater inflammation (LO quartile) seems a consequence of the lower availability of cortisol-binding globulin synthetized by the liver, but other mechanisms can be involved (e.g., rate of cortisol production, secretion, and metabolic clearance). Our data provide evidence that inflammation and metabolic changes reduce the concentration of circulating plasma cortisol during an acute stress. Hence, the acute phase response in dairy cows should be taken into account to interpret the results obtained from stimulation tests of the adrenal cortex. © 2013 American Dairy Science Association
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