The objective of the study was to determine the feed conversion efficiency (FCE), carcass characteristics, physico-chemical quality, fatty acid (FA) composition and shelf life of pork from pigs fed diets containing either 0% (T1), 2.5% (T2), 5% (T3) or 7.5% (T4) Moringa oleifera leaf meal (MOLM). Consumer health-related perceptions on pork and fatty acids were also investigated. Twenty four crossbred Large White x Landrace pigs of both sexes at 18 weeks of age and initially weighing 71.6 kg on average were housed individually and had ad libitum access to one of the four dietary treatments for a period of six weeks. Average daily feed intake (ADFI) and average daily gain (ADG) and feed conversion ratios (FCR) were calculated as an indication of FCE and pigs were slaughtered at an average live weight of 99.6 kg. Carcass traits such as back fat thickness (BFT), carcass temperatures and pH readings taken 45 minutes and 24 hours (pH45 and pHu) post mortem were recorded. M. longissimus thoracis et lumborum (LTL) samples were taken from each carcass for the determination of lightness (L*), redness (a*), yellowness (b*), thawing loss percentage (TL%), cooking loss percentage (CL%), Warner Bratzler Shear Force (WBSF), shelf life and FA composition. Furthermore a survey was conducted amongst 80 University of Fort Hare Students to determine their health-related perceptions on pork and fatty acids as well as their pork consumption frequency using questionnaires. The FCE of pigs fed on 0-5% MOLM (T1, T2 and T3) diets did not differ significantly, but the FCE of pigs fed 7.5% MOLM (T4) was significantly (p<0.05) reduced. No significant relationship was reported between inclusion of MOLM carcass characteristics and physico-chemical pork quality. There was however a significant improvement (p<0.05) in the shelf life of the pork from MOLM fed pigs in terms of colour and odour during 10 days of refrigerated storage (at 3±1°C). There was a significant (p<0.05) reduction in the total intramuscular fat (IMF) content and the saturated fatty acid (SFA) C18:0 (stearic acid) content and an overall non-significant (p>0.05) increase in the poly unsaturated fatty acid (PUFA) content of pork from MOLM fed pigs. The possible reason for this is that the feeding of MOLM was commenced when the pigs were at an advanced age and weight. The survey revealed that the majority of interviewed students consume fresh (39.7%) and processed (32.4%) pork two to three times a week, perceive pork to be generally healthy (70%) and the second most healthy meat type (39.5%). While the majority (55.4%) were aware of the health implications of FAs they did not know which FA classes pose more of a health risk (51.3%). In conclusion2.5% and 5% of MOLM in finisher pig feed did not negatively affect FCE, carcass characteristics or physico-chemical meat quality; significantly improved pork shelf life and reduced total IMF and SFA content of pork but 7.5% MOLM negatively affected FCE; and the majority of students perceive pork to be the second most healthy type of meat and are generally aware of the health implications of FAs.

Carbohydrates have variable digestibilities and metabolizable energy values in carnivorous fish. Simple sugars are generally more digestible than complex polysaccharides, and low levels of dietary carbohydrate may contribute more metabolizable energy than high levels. Two experiments were conducted to study the effects of dietary level and processing treatment of wheat starch on the digestibility of diets fed to sablefish (Anoplopoma fimbria), in different regions of the digestive tract. Moreover, an experiment was undertaken to determine if the dietary concentration of an indigestible external marker (chromic oxide) influenced its motility, relative to other ingredients in the ingesta, as it passed through the digestive tract. Lastly, a growth experiment was undertaken to compare the performance of sablefish fed formulated diets containing one of two levels of carbohydrate to that of fish fed a natural fish diet. The gastric evacuation of a formulated and a natural diet were also investigated. Apparent digestibility values for the nutrients in a formulated diet (containing 44.4% cooked wheat and 0.1% chromic oxide) fed to sablefish were noted to increase progressively from the anterior to the posterior regions of the intestinal tract. Within each region of the gut, the apparent digestibility values for most nutrients declined over three sample periods. Carbohydrate (nitrogen-free extract) digestibility down to the distal section of the intestine ranged from 51.0 to 82.8%. An experiment designed to assess the effect of carbohydrate treatment on the digestibility of four isonitrogenous, isocaloric diets met with partial failure. It was determined that the 1.0% chromic oxide marker flowed at a differential rate to the rest of the ingesta in the digestive tract, which violated the criteria for an effective marker. Consequently, diet digestibility was not determined in this experiment. Hepatic glycogen levels in fish receiving the dietary treatments were compared, and these values were used to estimate the relative availability (digestibility) of carbohydrate from the respective diets. According to this index, the sequence for digestibility was as follows: pregelatinized starch > cooked wheat > pregelatinized starch/cooked wheat > unprocessed wheat. Differential movement of chromic oxide relative to other ingesta was observed in sablefish fed on alternate days regardless of the dietary concentration of the indigestible marker (0.1 or 1.0%). It was surmised that the feeding protocol established the circumstances from which marker 'streaming' was observed in the results. Differential transport of Cr₂O₃ through the gut by ingested seawater was suggested as a possible mechanism for the phenomenon. Sablefish fed a natural fish diet had the highest growth rates, condition factors, liver lipid levels and the lowest feed conversion ratios and liver glycogen levels. Sablefish fed a diet containing 22.2% cooked wheat had a higher growth rate, condition factor, and a lower food conversion ratio, than those fed a diet containing 44.4% cooked wheat. Ingestion of the 44.4% cooked wheat diet resulted in the highest values for liver glycogen and hepatosomatic index. It was concluded that sablefish have a limited ability to metabolically utilize digestible carbohydrate and that most of the dietary non-protein energy should originate from high quality lipid for maximum protein sparing. / Science, Faculty of / Resources, Environment and Sustainability (IRES), Institute for / Graduate

Four successive experiments were carried out to study the effects of different treatments on the nutritive quality of 4 samples of wheat. The treatments used were autoclaving, freezing, water-soaking, acid-soaking, boiling in water, and combinations of these treatments. Metabolizable energy values of the various samples of treated and untreated wheat were determined using 2-3 weeks old chickens. Nitrogen retention from diets containing the different wheat samples was also measured. Autoclaving of wheat samples for 60 min. at 15 lb pressure markedly increased the nutritive quality of wheat as measured by metabolizable energy values. Freezing at -4°C for 5 days resulted in significant improvement in the metabolizable energy value of the samples of wheat treated in this manner. Water- or acid-soaking did not improve the metabolizable energy values of the wheat samples. The different treatments did not affect the percentage nitrogen retention from diets containing the treated wheat. Prolonged heating (autoclaving for 90 min. and 120 min. at 15 lb pressure) reduced the energy values of wheat as well as the percentage nitrogen retention. / Land and Food Systems, Faculty of / Graduate

This investigation has analysed the impact on energy consumption for heating and cooling in UK housing stock, from the predicted future global warming effect, up to the 2080s. It was found that, up to the 2050s, it is likely that heating rather than cooling will remain the main source of energy use, in a pessimistic business-as-usual scenario. Micro-CHP (domestic scale combined heat and power plant) offers a medium term low carbon solution for the replacement of heating equipment. The operation of a micro-CHP unit in a time-of-use electricity tariff scenario for existing UK housing stock was simulated. The investigation analysed whether electrical export earnings could be increased by the use of feed forward control in comparison to a conventional control strategy of timed operation with optimised start, without serious compromise to fuel consumption. It has been found that the use of an auto-regressive model with exogenous input (ARX) model can adequately describe thermal characteristics of a typical house for a model based predictive controller. It was demonstrated that export earnings could be increased significantly without additional fuel consumption by accepting dynamic heating operation within a comfort range, rather than a static setpoint value. Compared to a conventional control strategy, overall CO2 emissions and peak network electricity demand were reduced. This approach increased electrical export earnings without additional fuel consumption during theoretical testing and has potential for further development. These finding confirm a positive case for utilising time-of-use electricity tariffs and could contribute significantly towards increasing the productivity of micro-CHP.

This study was designed to provide information on some of the factors affecting voluntary consumption and digestibility of forages by sheep. A wet sieving procedure was used to determine particle size distribution in the reticulo-rumen, omasum and abomasum of sheep fed 100 % prebloom alfalfa or 100 % second-cut Altai wild ryegrass hays or mixtures of these with tall wheatgrass or Altai wild ryegrass straws. The study also compared second-cut Altai wild ryegrass and prebloom alfalfa as components in an all forage diet for sheep. Each diet was fed ad libitum to eight Romanov x Western whiteface wether lambs weighing 22 to 25 kg during the intake and digestibility trials. For the determination of particle size distribution, the animals were slaughtered at 12, 24, 36, and 48 hours after feed removal and the contents of the reticulo-rumen, omasum and abomasum sampled. Five different methods of describing digesta particle size distribution were compared as to their ability to predict voluntary intake and digestibility of the forages by sheep. The best method for expressing particle size distribution in the reticulo-rumen in terms of ability to predict dry matter digestibility (DMD) was the proportion of soluble dry matter in total dry matter (PSDM). A significant (P< 0.05) correlation (r = 0.84) between PSDM and dry matter digestibility, 12 hours after feed removal was obtained. PSDM in omasal digesta 24 hours after feed removal was also highly correlated with DMD and energy digestibility (r = 0.97, 0.91, respectively). Very high correlations were obtained between PSDM in abomasal digesta 24 hours after feed removal and digestibility of cellulose, NDF and ADF (r = 0.99, 0.97 and 0.97 respectively). The proportion of particles less than 1mm to the total particles (PIP) in the reticulo-rumen gave the most consistent correlations with intake of dry matter and energy. Voluntary intake of dry matter by the animals on the alfalfa-based diets were significantly higher (P< 0.05) than those on the second-cut Altai wild ryegrass-based diets. However, the apparent digestibility coefficients of the proximate fractions in the Altai wild ryegrass diets were significantly higher (P< 0.05) than those of diets containing alfalfa. Daily intake of digestible energy by animals on 100 % alfalfa was not significantly different from that of animals on 100 % second-cut Altai wild ryegrass. The difference between their respective combinations with tall wheatgrass and Altai wild ryegrass straws were also not significant. It was concluded that PIP and PSDM are indeces based on biologically significant fractions and may therefore have greater relevance than purely mathematical or statistical descriptions of particle size distribution in digesta. In this regard, the relationship between PSDM and digestibility and, PIP and intake are consistent with published theory and can be used in mathematical models to examine control processes in feed intake, rate of passage and digestion. The study also indicated that second-cut Altai wild ryegrass harvested at the prebloom stage can be used as a substitute for alfalfa in an all-forage diet for winter feeding of sheep. / Land and Food Systems, Faculty of / Graduate

Formaldehyde treatment of dietary protein to reduce its degradation in the rumen has been reported to be beneficial in some instances. Four levels of formaldehyde (0.0%, 0.8%, 1.0% and 1.2% on an air dry basis) were applied to a dehydrated and hammermilled grass-clover forage. In vitro nitrogen digestibility and ammonia-nitrogen production at *the microbial stage of incubation were reduced significantly (p < 0.05) as the level of formaldehyde was increased. Nitrogen digestibility for the combined microbial and acid-pepsin stages of incubation was significantly (p < 0.05) reduced only at the 1.2% level of formaldehyde application compared to the untreated forage. Ram lambs ranging in body weights of 29kg to 36kg were then used in studies of nitrogen and carbohydrate metabolism. One percent formaldehyde was applied to the grass-clover forage. Each of the five diets (14% C.P. on D.M. basis) contained 50% grass-clover forage, 38% cassava, 11% barley and 1% sheep mineral premix on a dry matter basis. Diet one contained the untreated forage while the others contained the formaldehyde treated forage. Diets three and five were supplemented with isovaleric acid (3.0g/Kg diet) and isobutyric acid (2.3g/Kg diet). Diets four and five were supplemented with sulphur in the form of sodium sulphate. The apparent digestibility coefficients of acid-detergent fibre and cellulose were increased significantly (p < 0.05) by formaldehyde treatment of the forage. The apparent digestibility coefficient of nitrogen was significantly (p < 0.05) depressed by formaldehyde treatment of the forage except for the diet supplemented with VFAS (diet three). The apparent digestibility coefficients of dry matter and organic matter were not affected significantly (p > 0.05). Ruminal fluid levels of isovaleric and isobutyric acids were significantly (p < 0.05) higher for animals fed diet three than for animals fed diets two and four. Formaldehyde treatment of the forage resulted in significantly (p < 0.05) higher levels of valeric acid and lower levels of ammonia in ruminal fluid. Ruminal fluid levels of total volatile fatty acids, acetic, propionic and butyric acids and rumen pH were not affected significantly (p < 0.05) by formaldehyde treatment of the forage. The ratio of microbial protein-nitrogen (estimated from RNA-N) to total abomasal digesta nitrogen was significantly (p < 0.05) decreased by formaldehyde treatment of the forage except for the diet supplemented with VFAS (diet three). The concentration of non-protein-nitrogen in abomasal digesta was significantly (p < 0.05) reduced by formaldehyde treatment of the forage. Abomasal digesta pH, concentration of total nitrogen, RNA-N, microbial protein-nitrogen, acid-detergent fibre, and cellulose were not affected. The reduction in the ratio of microbial protein-nitrogen to total abomasal digesta nitrogen and non-protein-nitrogen by formaldehyde treatment of the forage suggests that the treatment reduced microbial degradation of dietary protein except perhaps for the diet supplemented with VFAS (diet three). Nitrogen balance was significantly (p < 0.05) improved by formaldehyde treatment of the forage except for the sulphur supplemented diets. Sulphur supplementation tended to offset the beneficial effects of formaldehyde protection of the forage protein. Supplementation with VFAS did not further enhance nitrogen utilization. Formaldehyde treatment of the forage significantly (p < 0.05) improved sulphur balance except for the diet supplemented with both sulphur and VFAS (diet five). Daily feed intake and urine output per unit metabolic body size and growth rate over a seventeen-day period were not significantly (p < 0.05) affected by formaldehyde treatment of the forage. The flow of total digesta, organic matter, dry matter, acid-detergent fibre, cellulose and total nitrogen through the duodenum for a 24-hour period was markedly higher for the diets containing the formaldehyde treated forage. The flow of microbial protein-nitrogen and non-protein-nitrogen however was markedly depressed by formaldehyde treatment of the forage. A sheep fitted with a duodenal re-entrant cannula was used for this study. / Land and Food Systems, Faculty of / Graduate

MSCAGR (Animal Science) / Department of Animal Science / The aim of the study was to investigate the effects of feed withdrawal and strain on laying performance and egg quality of White and Brown Hy-line layers. Fifty four hens for each strain (White Hy-Line and Brown Hy-line) aged 18 weeks (point of laying stage) were used in the investigation. Feed withdrawal had no effect (P>0.05) on laying performance, mortality rate, egg internal and external quality, but significantly affected (P<0.01) average feed intake, body weight, small and extra-large eggs percentages. Hens under ad libitum consumed more feed than hens under four hours and eight hours feed withdrawal. High body weight was observed on ad libitum fed hens, intermediate on eight hours feed withdrawn hens and lower at four hours feed withdrawn hens. High percentage of small graded eggs was observed on four hours feed withdrawn hens, intermediate on eight hours feed withdrawn hens and lower on ad libitum fed hens. High percentage of extra-large graded eggs was observed on ad libitum fed hens, intermediate on eight hours feed withdrawn hens and lower four hours feed withdrawn hens. Strain had a significant effect on average egg weight, median egg weight, albumen weight, extra-small, small, medium and large graded eggs percentages (P<0.01) and on body weight, egg height , egg width, average egg shell colour (P<0.05). Strain did not affect (P>0.05) average feed intake, body weight change, egg output, feed conversion ratio, mortality rate, egg shell breaking force, albumen height, yolk height, yolk weight, extra-large and jumbo graded eggs percentage. Brown Hy-Line layers had high average egg weight, median egg weight, egg height, egg width, and average egg shell colour and albumen weight than White Hy-Line layers. Small sized eggs percentage and body weight were high on White Hy-Line layers compared to Brown Hy-Line layers. Medium and large sized eggs were high on Brown Hy-Line layers than White Hy-Lines. Feed withdrawal by strain interaction effect was observed on body weight, average egg weight and median egg weight, albumen weight and egg height, percentage of small, medium and large graded eggs (P<0.05). Brown Hy-Line hens under eight hours feed withdrawal had high egg weight, median egg weight, egg height, albumen weight and under eight hours feed withdrawn White Hy-Line hens had lower albumen height compared to other interactions. In all interactions White Hy-Line had high percentage of small graded eggs whereas Brown Hy-line had high percentage of large and medium graded eggs. / NRF

Passive millimeter-wave (PMMW) imaging is a technique that allows the detection of inherent millimeter-wave radiation emitted by bodies. Since different bodies with varying properties emit unequal power intensities, a contrast can be established to detect their presence. The advantage of this imaging scheme over other techniques, such as optical and infrared imaging, is its ability to operate under all weather conditions. This is because the relatively long wavelengths of millimeter-waves, as compared to visible light, penetrate through clouds, fog, and sandstorms. The core of a PMMW camera is an antenna, which receives the electromagnetic radiation from a scene. Because PMMW systems require high gains to operate, large antenna arrays are typically employed. This mandatory increase of antenna elements is associated with a large feeding network. Therefore, PMMW cameras usually have a big profile. In this work, two enabling technologies, namely, Substrate integrated Waveguide (SIW) and Low Temperature Co-fired Ceramic (LTCC), are coupled with an innovative design to miniaturize the passive front-end. The two technologies synergize very well with the shielded characteristics of SIW and the high density multilayer integration of LTCC. The proposed design involves a novel multilayer power divider, which is incorporated in a folded feed network structure by moving between layers. The end result is an efficient feeding network, which footprint is least affected by an increase in array size. This is because the addition of more elements is accommodated by a vertical expansion rather than a lateral one. To characterize the feed network, an antenna array has been designed and integrated through efficient transitions.The complete structure has been simulated and fabricated. The results demonstrate an excellent performance, manifesting in a gain of 20 dBi and a bandwidth of more than 11.4% at 35 GHz. These values satisfy the general requirements of a PMMW system.

Single nucleotide polymorphism (SNP) methodology is being used as a means to determine genetic merit in beef cattle by interrogating animal genomes and associating the findings with performance traits. The ability to predict future trait performance is highly attractive to beef cattle producers as they can make important management and financial decisions earlier and with more certainty. To fully realize the potential of SNP testing technology the methodology must be vetted to assure producer confidence. The purpose of this project is to assess three sources of information for beef cattle trait assessment. These information sources are: SNP testing, Expected Progeny Differences (EPDs) and direct animal measures. To conduct this study, young beef bulls (n=181) consigned to the SIU Beef Evaluation Station were utilized in an 84-day period to obtain direct measures. The SIU Beef Evaluation Station uses the Calan-Broadbent confinement feeding system which allows researchers to monitor individual animal feed intake and weight gain. Feed efficiency traits are important to the cattle industry since feed is generally among the largest input cost to producers. The evaluation of bulls also assesses reproductive and carcass traits which are also important to the producer’s financial success.Individual animal performance information was sent to the bull’s respective breed association for determination of EPD’s. Blood samples were submitted to a commercial company for SNP testing (Igentiy Gold and Igenity Beef Profile, Neogen, Lincoln, NE). Data was analyzed using pairwise comparisons by source of information. Pearson correlations were used to determine the direction and the strength for sources of information to vary together. Data was determined to be correlated when the correlation coefficient was 0.3 < r < - 0.3. No correlation was observed between RFISIU :RFINEO (r = 0.042), RFINEO:F/GSIU (r = - 0.09), RFISIU:ADGNEO (r = 0.091), RFISIU:ADGSIU (r = - 0.039), RFINEO:ADGNEO (r = 0.236), BWNEO:BWSIU (r = 0.115), FRAMESIU:BWSIU (r = 0.111), FRAMESIU:BWEPD (r = 0.159), FRAMESIU:ADGSIU (r = 0.148), FRAMESIU:ADGNEO (r = -0.005), BWSIU:BWEPD (r = 0.256), and BWNEO:BWEPD (r = 0.226). Correlations were observed between RFISIU:F/GSIU (r = 0.455), ADGSIU :ADGNEO (r = 0.353), and FRAMESIU:BWNEO (r = 0.326).This study determined that beef bulls should continue to be performance tested due to discrepancies between sources of information for key animal performance traits. Assessment of SNPs used in the commercial test should continue.

Formulations for analysis of printed antenna structures are derived and compared, to determine one to implemented in SuperNEC based on the efficiency of its numerical solution in terms of memory usage and solution time. SuperNEC is a software application for computing the response of electromagnetic structures to electromagnetic fields. SuperNEC cannot be used for simulation of printed antenna structures. This is because the formulation that is implemented in SuperNEC does not account for the effect of the substrates that the radiating elements of the antenna structure are printed on, and it is also not intended for antenna structures whose radiating elements are surfaces. Two MoM (Method of Moments) formulations and a FEM (Finite Element Method)-MoM formulation are presented, together with different models for the antenna feed. The FEM-MoM formulation is selected for implementation in SuperNEC because it is argued that it is likely to be more memory efficient when compared to the MoM formulations, and also that less time is required to fill the matrices resulting from the numerical solution of the formulation. The formulation is implemented in a stand alone software application, which will be integrated into SuperNEC. Numerical results that are computed using the software application are presented to illustrate correct implementation of the formulation. The results are compared to: an exact solution, results from another publication, and results computed using a different formulation. Good agreement is obtained in each case.