Fiber-rich (HF) diets are typically supplemented with enzymes to improve their nutritive value and to offset their negative effects on pig growth. However, studies on enzyme effect in pigs have yielded inconsistent results on nutrient digestibility and growth. Although the inconsistencies observed could be explained by differences in substrate and experimental conditions and enzyme characteristics among studies, how enzymes influence metabolic and physiological responses in pigs is still not clear. Therefore, three experiments were conducted, using 3 dietary treatments (control, HF and HF diet supplemented with enzymes), to elucidate the effects of supplementing an HF diet with enzymes in growing pigs. Experiment one investigated HF and enzyme supplementation on energy and nutrient digestibility, digesta volatile fatty acid (VFA) concentrations, and gut microbial profile in pigs. Compared with the HF diet, enzymes improved dry matter, starch, energy and some amino acid (AA), but not nitrogen digestibility. Further, the enzymes stimulated the growth of gut bacterial groups, which have xylanolytic and cellulolytic properties in the HF-fed pigs, but enzymes did not influence digesta VFA concentration or fiber fermentation. Experiment 2 evaluated the effects of enzyme supplementation on growth performance, glucose uptake in jejunum tissue samples mounted in Ussing chambers, and intestinal nutrient transporter mRNA levels in pigs. Diet had no effect on feed intake and jejunal glucose uptake. The enzymes influenced nutrient transporter mRNA levels but did not improve pig growth rate and feed efficiency relative to the HF diet. The third experiment investigated the effect of supplementing the HF diet with enzymes on postprandial portal vein-drained viscera (PDV) nutrient fluxes and energy expenditure (measured as O2 consumption) by the PDV and whole-animal in pigs. Diet had no effect on energy expenditure. The HF diet reduced portal glucose, VFA and essential AA absorption and insulin production. Enzyme supplementation improved portal glucose and VFA absorption, but not essential AA absorption and insulin production. Overall, improvements in nutrient utilization due to enzyme supplementation did not improve the growth rate of pigs, which appears to be due to the lack of enzyme effect on essential AA and energy use by the PDV and insulin production / October 2016

Magister Scientiae - MSc (Chemistry) / Nanoscience and nanotechnology are known to be interdisciplinary, crossing and combining various fields and disciplines in pursuit of desirable outcomes. This has brought about applications of nanoscience and nanotechnology in multitudes of industries, spanning from the health, pharmaceutical to industrial industry. Within the health industry, the medical field has seen much advancement through nanoscience and nanotechnology. The importance of finding cures to diseases is top priorities within the medical field, along with advancements in understanding and diagnosing diseases. Due to these outcomes, we see the emergence of imaging techniques playing a crucial role. The work covered in this thesis looks at a prospective luminescent agent applicable in the medical field for bio-imaging, but also at a possible phthalocyanine sensitizer for treatment of cancer through photodynamic therapy. Another area where nanoscience and nanotechnology are found is in industry, where nanoparticles are utilised as catalysts in many synthetic reactions. Highly desirable catalysts in industry are those involved in oxidative reactions where we explore a metal nanoparticle catalyst within this work.

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