Thesis (M.S.)--University of Wisconsin--Madison, 1961. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 76-82).

5-Isopropyltropolone(gamma-thujaplicin) is one of the three isomeric isopropyltropolones found in the heartwood of western red cedar(Thuja plicata D. Don). The tropolones as a class have been shown to be inhibitors of the enzyme catechol-O-methyltransferase(COMT). The effect of this tropolone on the responses of the isolated guinea-pig atria to a number of sympathomimetic amines has been studied. Gamma-thujaplicin was used in the form of water soluble sodium salt(T-Na). T-Na itself was found to possess a slow but prolonged stimulating effect on the atria. In the presence of T-Na greater than 0.4 mcg./ml, both the positive inotropic and chronotropic effects of all of the sympathomimetic amines studied were increased. In the case of the short acting catechol amines, prolongation of these responses was also produced. The effect of T-Na on the responses to the adrenergic amines was compared with that of cocaine and ethylenedxa-minetetraacetic acid(EDTA). Potentiation of the responses to the adrenergic stimuli by T-Na and the last two agents appeared to follow a similar dose-response pattern although T-Na was twice as potent. Potentiation by T-Na of responses to the direct acting catechol amines was not affected by reserpinization. When used in place of EDTA for the repletion of norepinephrine stores in reserpinized atria, T-Na has been proved to be more effective than the former agent in retarding the oxidation of norepinephrine. The effect of histamine on the isolated atria was also studied. In a low concentration (0.2-0. 4mcg/ml) histamine stimulated the atria to a prolonged response that can only be terminated by changing the bathing fluid. The response of the atria to histamine was neither affected by the presence of a high concentration of antihistamine (3mcg./ml), nor was it blocked by the pre-addition of a beta-receptor blocking agent. Cocaine and pyrogallol had no effect on the histamine induced response. Therefore it is not likely that norepinephrine is involved in the response of the atria to histamine. In the presence of T-Na, however, the response to histamine was increased in the normal preparation, but T-Na had little or no effect on the histamine induced response in reserpinized atria. These results together with the fact that EDTA potentiated the action of sympathomimetic amines in a similar manner to T-Na do not support the assumption that T-Na potentiation of adrenergic responses is due to COMT inhibition. It would appear that T-Na produces like EDTA, a non-specific sensitization of the atria muscle. This mechanism is not clear and no evidence has been found to indicate that it is due to a general depletion of ions as a result of the chelating action of these compounds. / Pharmaceutical Sciences, Faculty of / Graduate

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Pigs exposed to elevated ambient temperatures exhibit reduced average daily gain, alterations in muscle and fat deposition during growth phases, and decreased overall health. Negative aspects of gastrointestinal (GI) function, integrity and permeability also result from hyperthermia. Saccharin-based artificial sweeteners have the potential to ameliorate the negative effects of heat stress (HS) by increasing GI GLP-2 production while capsicum oleoresin has been shown to reduce inflammatory response. Study objectives were to examine the effects of two artificial sweeteners, neohesperidin dihydrochalcone and saccharin, in combination with capsicum oleoresin (TakTik Sweet Heat , Pancosma, SA) on growth performance of pigs. Forty-eight pigs (12 weeks of age, 47.3 ± 7.6kg) were assigned to six treatments: thermal neutral conditions (21°C) fed ad libitum with (TN+) or without supplement (TN-), heat stress (35°C) fed ad libitum with (HS+) or without supplement (HS-), and thermal neutral conditions pair-fed to HS intake with (PFTN+) or without supplement (PFTN-). Dietary supplementation began 2 days prior to the 3-day environmental treatment period. Body weight was recorded on day -1 and day 3 relative to start of environmental treatment. Body temperature (BT) and respiration rate (RR) were measured thrice daily and feed intake (FI) were recorded daily. Blood samples were collected on day -1 and day 3 to determine metabolite profiles and immune response. Following sacrifice, sections of duodenum, ileum, and colon were collected for histology. Pigs in HS conditions had increased average BT and RR (~2.7-fold) compared to TN and PFTN groups (P<0.01). Irrespective of day, HS+ animals had increased respiration rates when compared to HS- animals (P<0.04). Heat stress decreased FI compared to TN groups. Regardless of treatment, supplement increased feed efficiency by 0.12kg (P<0.04). Circulating glucose concentration tended to decrease in HS+ and PFTN+ pigs compared to non-supplemented treatments (P=0.1). Circulating insulin increased in HS compared to PFTN (P<0.04), but did not differ from TN. Lymphocyte count tended to be decrease in HS compared to PFTN and TN (P=0.052). Monocyte count increased during HS compared to PFTN (P=0.01), but HS and TN did not differ. Supplement increased basophil count (P<0.03), irrespective of treatment. Ileal villus height tended to decrease during HS and PFTN compared to TN (P<0.08). Duodenal and colon villus height nor duodenal, ileal and colon crypt cell depth did not differ between groups. Overall, TakTik Sweet Heat supplementation increases pig feed efficiency and may improve immune response. / Master of Science

Breast milk remains the optimum vehicle to deliver high quality nutrients, including oligosaccharides, in quantities sufficient to sustain normal growth, however, it is currently unknown whether the addition of prebiotics to infant formula would alter neonate growth and development. The objective of this study was to determine the effect of Galactooligosaccharides (GOS) and Fructooligosaccharides (FOS) supplementation in nursery pig diets on growth and efficiency of food utilization. Forty-eight 4-day old crossbred pigs (1.628 ± .037 Kg BW) were randomly assigned to 1 of 8 diets: 1) milk-based formula containing Type 2 GOS and Type 1 FOS (4 + 1 g/L); 2) soy-based formula containing Type 1 FOS (3g/L); 3) milk-based formula with no prebiotic added; 4) milk-based formula containing Type 2 GOS only (5g/L); 5) milk-based formula containing Type 1 GOS only (5g/L); 6) milk-based formula containing Type 2 GOS and Type 2 FOS (4 + 1 g/L); 7) milk-based formula containing Type 1 GOS and Type 1 FOS (4 + 1 g/L); 8) soy-based formula with no prebiotic added. Diets were isonitrogenous, isocaloric and fed at 250 mL/kg body for a 2-week period. At sacrifice, blood and tissue samples were collected for analysis. A diet by time interaction (P < 0.001) indicated a smaller rate of accretion in bone mineral content for soy-based diets. Total bacteria and lactobacillus were significantly affected by treatment (P < 0.001). In conclusion, the addition of GOS and FOS to formula does not appear to alter growth however, the gut microbiota was significantly modified. / Master of Science

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Housing pigs in large pens using a floor base of deep litter has been developed as an alternative to conventional, indoor, intensive methods. Deep-litter, group housing systems are cheaper to establish and are perceived as being more “welfare and environmentally friendly” for pigs compared to conventional intensive systems. However, recent industry records have shown that pigs housed in deep-litter systems have growth performance problems. In general, pigs are 10 percent less efficient in converting feed to live weight gain, are 1 to 2 mm fatter and exhibit more carcass damage (carcass bruising and non-infectious arthritis stifle joint damage) compared to conventionally housed pigs. It is possible that the growth performance problems in deep-litter systems are largely behavioural and possibly stress related, and pose a barrier to adoption of these systems by industry. This PhD program examined the social and feeding behaviour of entire male growing pigs in deep-litter systems in relation to growth performance and stress physiology.

Call number: LD2668 .T4 1962 W87