68 research outputs found

    Do changes of pen and penmate affect the behaviour of heifers?

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    We wanted to investigate if relocation affects behaviour of dairy heifers. In the study 32 Holstein heifers were housed in pairs until they were 13 months old. 16 heifers stayed in the same pen with the same penmate (control). The pen and penmates of 16 heifers were changed 16 times between 11 and 13 months of age

    Natural deep eutectic solvents as thermostabilizer for Humicola insolens cutinase

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    As a new generation of green solvents, deep eutectic solvents (DESs) are considered a promising alternative to current harsh organic solvents and find application in many chemical processing methods such as extraction and synthesis. DESs, normally formed by two or more components via various hydrogen bond interactions, offer high potential as medium for biocatalysis reactions where they can improve efficiency by enhancing substrate solubility and the activity and stability of the enzymes. In the current study, the stabilization of Humicola insolens cutinase (HiC) in natural deep eutectic solvents (NADESs) was assessed. The best hydrogen bond donor among sorbitol, xylitol, erythritol, glycerol and ethylene glycol, and the best acceptor among betaine, choline chloride, choline acetate, choline dihydrogen citrate and tetramethylammonium chloride, were selected, evaluating binding energies and molecular orientations through molecular docking simulations, and finally used to prepare NADES aqueous solutions. The effects of component ratio and NADES concentration on HiC thermostability at 90 degrees C were also investigated. The choline dihydrogen citrate:xylitol, in a 1:1 ratio with a 20 wt% concentration, was selected as the best combination in stabilizing HiC, increasing its half-life three-fold

    Adrenocorticotropic hormone and cortisol in calves after corticotropin-releasing hormone

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    The aim for this study was to analyze responsiveness of the hypothalamo-pituitary-adrenocortical axis to exogenous bovine corticotropin-releasing hormone (bCRH) in calves. Two dose-response studies were carried out, using either bCRH alone (dose rates of 0, .01, .03, and .1 μg bCRH/kg live weight) or in combination with arginine-vasopressin (bCRH:AVP, 0:0, .1:.05, .5:.25, and 1:.5 μg kg live weight). The bCRH was administered i.v. to calves (n = 5 to 7 per dose) housed individually or in groups. Serial blood samples were obtained from before to 300 min after injection and analyzed for plasma ACTH and cortisol concentrations. The lowest bCRH dose that produced a response in all calves was .1 μg/kg. In the experiment using bCRH with AVP, increasing the bCRH dose from .1 to 1 μg/kg resulted in an increase in peak ACTH concentration (321 vs 2,003 pg/mL) but did not significantly affect the peak cortisol concentration (37 vs 40 ng/mL). The time to reach the peak cortisol concentration increased with the dose of bCRH with AVP (from 38 to 111 min). The ACTH and cortisol concentrations determined at any time between 20 and 90 min after bCRH injection were correlated to the integrated responses calculated as areas under the ACTH and the cortisol curves (r between .61 and .99, P < .05). In comparison with results from studies in humans, pigs, and sheep, our data showed that the pituitary of calves seems less sensitive to CRH than that of other mammals, despite a greater capacity to produce ACTH. Moreover, the calf's adrenals seem to have a lower capacity to produce cortisol than adrenals of other mammals. As in other species, it seems that AVP enhances the release of ACTH and cortisol. For CRH challenge to be used in calves, we suggest injecting at least .1 μg of bCRH/kg live weight either with or without AVP and taking several blood samples before injection and between 20 and 90 min after injection

    Adrenocorticotropic hormone and cortisol in calves after corticotropin-releasing hormone

    No full text
    The aim for this study was to analyze responsiveness of the hypothalamo-pituitary-adrenocortical axis to exogenous bovine corticotropin-releasing hormone (bCRH) in calves. Two dose-response studies were carried out, using either bCRH alone (dose rates of 0, .01, .03, and .1 μg bCRH/kg live weight) or in combination with arginine-vasopressin (bCRH:AVP, 0:0, .1:.05, .5:.25, and 1:.5 μg kg live weight). The bCRH was administered i.v. to calves (n = 5 to 7 per dose) housed individually or in groups. Serial blood samples were obtained from before to 300 min after injection and analyzed for plasma ACTH and cortisol concentrations. The lowest bCRH dose that produced a response in all calves was .1 μg/kg. In the experiment using bCRH with AVP, increasing the bCRH dose from .1 to 1 μg/kg resulted in an increase in peak ACTH concentration (321 vs 2,003 pg/mL) but did not significantly affect the peak cortisol concentration (37 vs 40 ng/mL). The time to reach the peak cortisol concentration increased with the dose of bCRH with AVP (from 38 to 111 min). The ACTH and cortisol concentrations determined at any time between 20 and 90 min after bCRH injection were correlated to the integrated responses calculated as areas under the ACTH and the cortisol curves (r between .61 and .99, P < .05). In comparison with results from studies in humans, pigs, and sheep, our data showed that the pituitary of calves seems less sensitive to CRH than that of other mammals, despite a greater capacity to produce ACTH. Moreover, the calf's adrenals seem to have a lower capacity to produce cortisol than adrenals of other mammals. As in other species, it seems that AVP enhances the release of ACTH and cortisol. For CRH challenge to be used in calves, we suggest injecting at least .1 μg of bCRH/kg live weight either with or without AVP and taking several blood samples before injection and between 20 and 90 min after injection

    Is repeated regrouping stressful for heifers?

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    Is repeated regrouping stressful for heifers?

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    Rheology and differential scanning calorimetry used for the detection of drug crystallisation in drug-in-adhesive layers

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    Very few physical or theoretical models have been developed to assist with product development for oral colonic drug delivery. The aim here is to develop a theoretical mathematical model to describe the geometry of the colon and the fluid flows within it. This is part of a project which aims to predict the distribution and residence time of dosage forms in the colon e.g. whether they will reach the mucosal layer of the colon wall
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