322 research outputs found

    Contribution of macrophages to plasmin activity in ewe bulk milk

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    A total of 225 bulk sheep milk samples were collected throughout lactation to assess the contribution of macrophages to the regulation of the plasmin/plasminogen system. Samples were analyzed for composition, milk renneting parameters, and for activities of plasmin (PL), plasminogen (PG) and plasminogen activators (PA). Isolation of macrophages from milk was performed using a magnetic positive separation; separated cells were lysed and activity of urokinase-PA was determined. PL activity in milk decreased during lactation (P < 0.001). The reduction in plasmin activity recorded in the mid and late lactation milk matched with the increase in PG/PL ratio (P < 0.001). The activity of PA increased throughout lactation (P < 0.001), the highest value being recorded in the late lactation milk.The amount of isolated and concentrated macrophages was higher in early and mid lactation milk than in late lactation milk (P < 0.01). Stage of lactation did not influence the activity of u-PA detected in isolated macrophages. The activity of u-PA associated with macrophages was lower than total PA activity detected in milk. Our results lend support to the hypothesis that in ewe bulk milk from healthy flocks macrophages only slightly contributed to the activation of plasmin/plasminogen system

    Contribution of macrophages to proteolysis and plasmin activity in ewe bulk milk.

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    A total of 225 bulk sheep milk samples were collected from 5 intensively managed flocks during early, mid, and late lactation to assess the contribution of macrophages to the regulation of the plasmin-plasminogen system. Samples were analyzed for composition, somatic cell counts, milk renneting characteristics, and for plasmin (PL), plasminogen (PG), and plasminogen activators (PA) activities. Isolation of macrophages from milk was performed using a magnetic positive separation and mouse antiovine macrophage antibody; separated cells were lysed by several freeze-thaw cycles, and activity of urokinase PA (u-PA) was determined. Plasmin activity decreased during lactation (42.06 +/- 0.66, early; 31.29 +/- 0.66, mid; 28.19 +/- 0.66 U/mL, late). The reduction in PL activity recorded in the mid and late lactation milk matched the increase in PG:PL ratio. The activity of PA increased throughout lactation; the highest value being recorded in the late lactation milk (260.20 +/- 8.66 U/mL). Counts of isolated and concentrated macrophages were higher in early and mid lactation milk (3.89 +/- 0.08 and 3.98 +/- 0.08 log10 cells/mL, respectively) than in late lactation milk (3.42 +/- 0.08 log10 cells/mL). Stage of lactation did not influence the activity of u-PA detected in isolated macrophages. The activity of u-PA associated with isolated milk macrophages only minimally contributed to total PA activity detected in milk. Proteolytic enzymes, associated with isolated macrophages, act on alpha-casein hydrolysis, as shown by urea-PAGE electrophoresis analysis. Somatic cell counts did not exceed 600,000 cells/mL, and this threshold can be considered a good index of health status of the flock and of the ability of milk to being processed. Our results lend support to the hypothesis that macrophages in ewe bulk milk from healthy flocks only slightly contribute to the activation of the PL-PG system

    Relationship between cortisol response to stress and behavior, immune profile, and production performance of dairy ewes.

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    The existence of a relationship between cortisol levels, after an acute stress, and behavioral activities, immunological profile, and production performance in sheep was studied. An initial flock of 30 Comisana ewes was involved in the experiment, and each of the 30 ewes was individually subjected to an isolation test in a novel environment. Subsequently, from the initial flock, 2 groups of 8 Comisana ewes were each retrospectively selected, and the animals were divided, according to their cortisol concentration 10 min after the isolation test, into high cortisol (HC) ewes, having a peak of cortisol concentration >90 ng/mL (average: 119.3 ng/mL +/- 11.8), and low cortisol (LC) ewes having a peak of cortisol concentration <80 ng/mL (average: 52.4+/-11.8). During the isolation test, the behavior of each animal was video-recorded and behavioral activities were registered. Blood samples were collected before the isolation test, immediately after the test (10 min), and at 60, 120, 300 min, 24 h, and 48 h after the test to evaluate percentages of T-helper (CD4(+)) and T-cytotoxic (CD8(+)) cells, CD4(+)/CD8(+) ratio, and IL-1beta and IL-6 levels. The ewes were milked for 3 d after the isolation test to determine cortisol levels and IL-1beta and IL-6 concentrations in whey. Milk yield was recorded at each milking, and milk samples were analyzed for pH, nutritional parameters, renneting properties, and somatic cell count. During the isolation test, HC ewes exhibited a shorter duration of movement and fewer bleats than LC ewes. The average plasma IL-1beta concentration was higher in HC than in LC ewes. The average whey IL-1beta and IL-6 concentrations were higher in whey from HC ewes than in LC ewes. A positive correlation emerged between plasma and whey IL-1beta concentrations. The average CD4(+)/CD8(+) ratio in blood was lower in HC than in LC ewes. Time from isolation affected the CD4(+)/CD8(+) ratio: at 120 min, the CD4(+)/CD8(+) ratio increased compared with that at 10 min after isolation and then decreased until 300 min after isolation. On average, ewes with low cortisol concentrations showed higher milk production and lower SCC than ewes with high cortisol concentrations. Results suggest that plasma cortisol concentration is connected to the behavioral response and immune competence of dairy ewes and cytokine concentrations. Both whey IL-1beta and IL-6 can be considered reliable indicators of the magnitude of hypothalamic-pituitary-adrenal axis activation. The stress-induced changes in CD4(+)/CD8(+) ratio are critical for controlling disease incidence and planning appropriate vaccination programs. High reactivity of the hypothalamic-pituitary-adrenal axis is also associated with a reduction in milk production and an increased predisposition to develop intramammary inflammatory processes

    Effect of solar radiation and flaxseed supplementation on milk production and fatty acid profile of lactating ewes under high ambient temperature

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    Abstract The objectives of this study were to evaluate the effects of protection from solar radiation and whole flaxseed supplementation on milk yield and milk fatty acid profile in lactating ewes exposed to high ambient temperature. The experiment was conducted during summer and involved 40 ewes divided into 4 groups. The ewes were either exposed (not offered shade) or protected from solar radiation (offered shade). For each solar radiation treatment, ewes were supplemented with whole flaxseed or not. Milk samples from each ewe were collected at the morning and afternoon milking every week, and analyzed for pH, total protein, casein, fat, and lactose content, somatic cell count, and renneting parameters (clotting time, rate of clot formation, and clot firmness after 30min). At the beginning of the experiment, and then at d 23 and 44, milk samples were analyzed for milk fatty acids using gas chromatography. Flaxseed supplementation significantly increased milk yield, fat, protein, and casein yields, and somatic cell count, and increased fat and lactose contents of milk. A decrease of saturated fatty acids from C6:0 to C16:0 and an increase of C18:1 trans -11 and C18:2 cis- 9, trans -11 was observed in milk from flaxseed-supplemented ewes. Flaxseed supplementation decreased saturated fatty acids content and increased total monounsaturated fatty acids content, the total content of isomers of conjugated linoleic acid, and polyunsaturated fatty acids content in milk. Flaxseed also increased the α-linolenic acid content of milk. As a result, milk from supplemented groups showed an increase in n-3 fatty acid content. Flaxseed supplementation decreased short-chain and medium-chain fatty acids, and increased long-chain fatty acid content of milk. On average, flaxseed supplementation increased the C18:2 cis -9, trans -11/C18:1 trans -11 Δ 9 -desaturase index starting from d 23 of the experiment, in correspondence with the highest C18:2 cis -9, trans -11 content of milk from flaxseed-supplemented ewes. Flaxseed decreased atherogenic and thrombogenic indices of milk. Protection from solar radiation during summer did not improve yield and composition of ewe milk. Nevertheless, milk from ewes exposed to solar radiation showed decreased long-chain fatty acid and polyunsaturated fatty acids contents, and in particular, decreased vaccenic acid, rumenic acid, and total conjugated linoleic acid contents

    Development of affinity to the stockperson in lambs from two breeds

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    Analyzing the potential biological determinants of autism spectrum disorder: From neuroinflammation to the kynurenine pathway

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    Autism Spectrum Disorder (ASD) etiopathogenesis is still unclear and no effective preventive and treatment measures have been identified. Research has focused on the potential role of neuroinflammation and the Kynurenine pathway; here we review the nature of these interactions. Pre-natal or neonatal infections would induce microglial activation, with secondary consequences on behavior, cognition and neurotransmitter networks. Peripherally, higher levels of pro-inflammatory cytokines and anti-brain antibodies have been identified. Increased frequency of autoimmune diseases, allergies, and recurring infections have been demonstrated both in autistic patients and in their relatives. Genetic studies have also identified some important polymorphisms in chromosome loci related to the human leukocyte antigen (HLA) system. The persistence of immune-inflammatory deregulation would lead to mitochondrial dysfunction and oxidative stress, creating a self-sustaining cytotoxic loop. Chronic inflammation activates the Kynurenine pathway with an increase in neurotoxic metabolites and excitotoxicity, causing long-term changes in the glutamatergic system, trophic support and synaptic function. Furthermore, overactivation of the Kynurenine branch induces depletion of melatonin and serotonin, worsening ASD symptoms. Thus, in genetically predisposed subjects, aberrant neurodevelopment may derive from a complex interplay between inflammatory processes, mitochondrial dysfunction, oxidative stress and Kynurenine pathway overexpression. To validate this hypothesis a new translational research approach is necessary

    Molecular Coancestry and Classical Genetic Distances Depict Different Patterns of Relationship Among Sheep Breeds from Southern Italy

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    Several molecular-based parameters, such as similarity indexes, can be adopted to optimize the management of genetic diversity in conservation programmes. From simulated data, Oliehoek et al. (2006) showed that molecular coancestry (Toro et al., 2002) is, among the possible relatedness estimators, the one that performs better in structured populations, such as populations in need of conservation usually are. Several studies have, therefore, proposed the use of molecular coancestry coefficients as a measure of genetic variability and as a useful tool for conservation of endangered breeds (Ciampolini et al., 2007; Glowatzki-Mullis et al., 2009). Here we report the results obtained evaluating within- and between-breed molecular coancestry (Toro et al., 2002), together with other classical genetic parameters, for two insular sheep breeds (Sarda from Sardinia and Comisana from Sicily), recently spread almost all over Italy, and for five local rare sheep breeds from Southern Italy

    Analisi della variabilità genetica della razza Gentile di Puglia mediante microsatelliti

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    La razza Gentile di Puglia conta circa 2813 soggetti allevati in 29 aziende distribuite sui territori di Puglia, Abruzzo, Calabria e Molise (dati Asso.Na.Pa del 2006); da decenni si sta verificando una costante e preoccupante contrazione numerica degli esemplari appartenenti alla razza. La pecora Gentile presenta una produzione di latte modesta in termini quantitativi, sebbene l’elevato contenuto in grasso e proteine lo rendano particolarmente idoneo alla lavorazione casearia. In tale contesto la caratterizzazione genetica della razza Gentile di Puglia, attraverso lo studio della variabilità genetica con approccio di tipo molecolare, potrebbe rappresentare un valido strumento per la sal- vaguardia della razza e per la valorizzazione delle sue produzioni

    Functional Properties of Meat in Athletes’ Performance and Recovery

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    Physical activity (PA) and sport play an essential role in promoting body development and maintaining optimal health status both in the short and long term. Despite the benefits, a long-lasting heavy training can promote several detrimental physiological changes, including transitory immune system malfunction, increased inflammation, and oxidative stress, which manifest as exercise-induced muscle damages (EIMDs). Meat and derived products represent a very good source of bioactive molecules such as proteins, lipids, amino acids, vitamins, and minerals. Bioactive molecules represent dietary compounds that can interact with one or more components of live tissue, resulting in a wide range of possible health consequences such as immune-modulating, antihypertensive, antimicrobial, and antioxidative activities. The health benefits of meat have been well established and have been extensively reviewed elsewhere, although a growing number of studies found a significant positive effect of meat molecules on exercise performance and recovery of muscle function. Based on the limited research, meat could be an effective post-exercise food that results in favorable muscle protein synthesis and metabolic performance
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