Os objetivos deste trabalho foram determinar o valor nutricional do farelo de canola (FC) com a adição de complexo multienzimático e avaliar a sua utilização em dietas para leitões na fase inicial (15-30 kg). Foram realizados dois experimentos, um de digestibilidade e outro de desempenho. No Experimento I foi conduzido um ensaio de digestibilidade total com 30 leitões machos castrados de linhagem comercial com peso inicial de 15,4±2,32 kg, distribuídos individualmente em gaiolas de metabolismo, em delineamento experimental de blocos inteiramente casualizado, com seis tratamentos, cinco repetições e um animal por unidade experimental. Os tratamentos consistiram de uma Ração Referência (RR) com e sem adição de complexo multienzimático (carboidrases e proteases) e Ração Referência (75%) + Farelo de Canola (25%) sem e com níveis crescentes (150, 240 e 330 ppm) de complexo multienzimático. Os coeficientes de digestibilidade dos nutrientes foram calculados para a obtenção dos nutrientes digestíveis do farelo de canola. O tratamento que apresentou maior valor de ED (3567 kcal/kg) e EM (3320 kcal/kg) na matéria natural para o farelo de canola foi a Ração Referência (75%) + Farelo de Canola (25%) com adição de 240 ppm de complexo multienzimático. No Experimento II foram utilizados 90 leitões de linhagem comercial de alto potencial genético, metade macho castrado e metade fêmea com 13,89±0,27 kg de peso médio inicial e 27,64± 0,9 kg de peso médio final, distribuídos em delineamento experimental em blocos casualizado com quatro níveis crescentes de inclusão de FC (7,5; 15; 22,5 e 30 %) e adição de 240 ppm de complexo multienzimático (carboidrases e protease), nove repetições e dois leitões por unidade experimental. Adicionalmente, foi formulada uma ração testemunha (0 % de inclusão de FC) e adição de 240 ppm de complexo multienzimático. A análise de regressão indicou que houve efeito (P≤0,05) quadrático do nível de inclusão do FC sobre o consumo diário de ração e a conversão alimentar, com melhor valor ao nível de 20% de FC. Os resultados sugerem que é viável a utilização de até 20% de farelo de canola, suplementado com complexo multienzimático na ração, sem prejuízos no desempenho e NUP de leitões na fase inicial. O estudo da viabilidade econômica indicou que a inclusão do farelo de canola suplementado com complexo multienzimático pode reduzir os custos com a alimentação, dependendo da relação de preços entre os ingredientes. / The objectives of this study were to determine the nutritional value of canola meal (CM) with the addition of multienzyme complex and evaluate its use in diets for starting piglets (15-30 kg). Two experiments, a digestibility and other performance were carried out. Experiment I, digestibility assays was carried out with 30 barrow pigs of commercial line with initial weight of 15.4 ± 2.32 kg, allotted individually in metabolism cages in experimental design of randomized blocks with six treatments, five replicates and one animal per experimental unit. The treatments consisted of a Reference Diet (RD) with and without addition of multienzyme complex (carbohydrases and protease) and Reference Diet (75%) + Canola Meal (25%) without and with increasing levels (150, 240 and 330 ppm) multienzyme complex. The nutrient digestibility coefficients were calculated to obtain the digestible nutrients that of canola meal. The treatment that showed higher DE (3567 kcal/kg) and ME (3320 kcal/kg) as fed basis for canola meal was the Reference Diet (75%) + Canola Meal (25%) with addition of 240 ppm multienzyme complex. In Experiment II it was used 90 piglets from a commercial line of high genetic potential, half castrated male and half female with 13.89 ± 0.27 kg initial weight and 27.64 ± 0.9 kg final average weight, over experimental randomized block design with four increasing levels of inclusion of CM (7.5, 15, 22.5 and 30%) and adding 240 ppm of multienzyme complex (carbohydrases and protease), nine replicates and two piglets per experimental unit. In addition, a control diet (0% of CM inclusion) and adding 240 ppm of multienzyme complex has been formulated. Regression analysis indicated that there was effect (P≤0,05) of the FC inclusion level on daily feed intake and feed conversion in the starting phase. The results suggest that it is feasible to use up to 20% of canola meal supplemented with multienzymatic complex in diet without impairing performance and PUN of starting piglets. The study of the economic viability indicated that the inclusion of canola meal supplemented with multienzyme complex can reduce the cost of feed, depending on the price relationship between the ingredients.

CAPES / Os altos custos com a ração na suinocultura é um dos fatores que mais afeta a atividade, além da fase de creche ser uma das fases mais críticas da produção. Frente a isso, os produtores procuram alimentos que garantam a eficiência da produção e a diminuição dos riscos desta fase. O uso de aditivos como as enzimas podem tornar os nutrientes das rações mais digestíveis e melhorar o desempenho zootécnico dos animais. O objetivo do presente trabalho foi avaliar um complexo multienzimático na dieta de leitões na fase inicial (15 a 30 kg). O experimento foi conduzido na Universidade Tecnológica Federal do Paraná, Campus Dois Vizinhos na Unidade de Ensino e Pesquisa da Suinocultura (UNEP). Foram quatro tratamentos, T1: Controle Negativo + Complexo Multiezimático (CME); T2: Controle Negativo; T3: Controle Positivo + CME e; T4: Controle Positivo. Foram utilizados 80 leitões, sendo 40 machos castrados e 40 fêmeas, de uma linhagem comercial, com peso inicial médio de 16,88kg+2,69kg, alojados em baias de alvenaria. Os animais foram pesados individualmente a cada semana para mensuração do ganho de peso, as rações fornecidas e as sobras foram pesadas para determinação do consumo de ração e conversão alimentar. O delineamento experimental foi de blocos casualizados, num esquema fatorial 2x2, sendo 2 dietas controles (positivo e negativo) e 2 níveis de enzimas adicionados à dieta (0 e 50 g/ton). Os dados de desempenho e parâmetros sanguíneos foram submetidos à análise de variância e os efeitos de tratamento foram comparados através de análise fatorial para avaliar os efeitos do CME. Por meio da média de peso obtida ao final do experimento, foram selecionados 40 animais, sendo dez por tratamento para coleta de 10 mL de sangue para análise de parâmetros sanguíneos. Para avaliação da viabilidade econômica foi levantado o preço das matériasprimas utilizadas para a obtenção dos custos das rações experimentais, a partir deles foi calculado o custo da ração por quilograma de peso vivo ganho, o Índice de Eficiência Econômica (IEE) e o Índice de Custo (IC). Os resultados demonstram que não houve diferença significativa dos tratamentos (P<0,05) sobre as variáveis de desempenho zootécnico e dos parâmetros sanguíneos de leitões na fase inicial. A viabilidade econômica foi melhor em dietas controle negativo suplementadas com CME quando comparadas as demais dietas experimentais. Portanto, podemos concluir que a suplementação de CME em dietas controle negativo não prejudica o desempenho zootécnico e saúde dos animais e reduz o custo de produção. / The high costs of pig breeding are one of the factors that most affect the activity, and the nursery phase is one of the most critical stages of production. Faced with this, producers seek food that ensures the efficiency of production and reduce the risks of this phase. The use of additives such as enzymes can make feed nutrients more digestible and improve animal performance. The objective of the present study was to evaluate a multienzymatic complex in the diet of piglets in the initial phase (15 to 30 kg). The experiment was conducted at the Universidade Tecnológica Federal do Paraná, Campus Dois Vizinhos, at the Swine research and Training Unit (UNEP). There were four treatments, T1: Negative Control + Complex Multiezimatic (CME); T2: Negative Control; T3: Positive Control + CME e; T4: Positive Control. A total of 80 piglets were used, 40 castrated males and 40 females from a commercial line, with a mean initial weight of 16.88 kg + 2.69 kg, housed in masonry bays. The animals were weighed individually each week to measure the weight gain, the rations provided and the leftovers were weighed for determination of feed intake and feed conversion. The experimental design was randomized blocks, in a 2x2 factorial scheme, two control diets (positive and negative) and two levels of enzymes added to the diet (0 and 50 g / t). Performance data and blood parameters were subjected to analysis of variance and treatment effects were compared through factorial analysis to evaluate the effects of CME. By means of the mean weight obtained at the end of the experiment, 40 animals were selected, of which 10 were used to collect 10 mL of blood for analysis of blood parameters. In order to evaluate the economic viability, the raw material used to obtain the experimental feed costs was calculated. The cost of the ration per kilogram of live weight gained, the Economic Efficiency Index (IEE) and the Index Of Cost (CI). The results showed that there was no significant difference of the treatments (P <0.05) on the variables of growth performance and the blood parameters of piglets in the initial phase. The economic viability was better in negative control diets supplemented with CME when compared to the other experimental diets. Therefore, we can conclude that supplementation of CME in negative control diets do not has negative effect on growth performance and health of animals and reduces the cost of production.

Research for sustainable development is distinguished by its intended focus on socio-ecological systems, and its mandate to bring together the insights and strengths of multiple disciplines. The animal farming system is understudied in the causal inference literature, despite the increasingly apparent environmental and social costs of its industrial form. The flourishing climate-economy literature, largely motivated by impending changes in climate, rests on assumptions that limit the external validity of its findings, and thereby their relevance for the future. This dissertation sheds light on (i) factors that limit the sustainability of animal farming, and (ii) statistical assumptions that limit the relevance of findings for sustainable development, through three empirical analyses. Chapter 1 quantifies the marginal surface water pollution caused by swine feeding operations in the U.S., which suggests the sustainability of animal production requires reducing its concentration in space. Chapter 2 estimates the impacts of humid heat stress on cow milk yield, their potential alleviation through cooling technologies, and provides evidence against the common assumption of time separability of temperature effects in agricultural production. Chapter 3 shows how the standard linear regression model can generate highly misleading conclusions in the climate-conflict literature, and proposes an alternative framework for inference.

This study was designed to determine whether feeding an Aspergillus product would influence growth or feed utilization and intestinal mucosal cell function as indicated by uptake of methionine and glucose by isolated intestinal brush border membrane vesicles (BBMV). In Experiment 1, 24 weanling pigs were paired by sex, BW, and litter and were allotted, within pairs, to either an 18% CP corn-soy diet (control) or the same diet supplemented (.15%) with an Aspergillus product. There were no differences (P > .05) in ADG, daily feed intake, or feed/gain between the two groups. In Experiment 2, 24 weanling wether lambs were paired by BW and were randomly assigned within pair to a 14% CP diet containing 61.1 % cracked corn, 17.3% soybean meal, and 15% ground orchard grass hay (control) or the same diet fortified (.07%) with an Aspergillus product. There were no differences (P > .05) in ADG, daily feed intake, or feed/gain between the two groups. Enrichment of alkaline phosphatase in BBMV used in transport studies were 12.7-fold higher in pigs and 5.6-fold higher in lambs over the original homogenate. / Ph. D.

Thesis (M. Tech.) -- Central University of Technology, Free State, 2010 / This study evaluated the effects of two bacterial inoculants on the fermentation quality and aerobic stability of ensiled potato hash (PH) and on digestibility, growth performance and carcass characteristics of growing pigs fed the ensiled PH. In the first experiment, 700 grams of PH, was mixed with 300g wheat bran (as is basis) and ensiled in 1.5 litre anaerobic jars. The mixture had a dry matter (DM) of 41.3 g/kg, 78.05 g/kg DM of water-soluble carbohydrates (WSC) and a pH of 6.87 at day 0 and was treated with Bonsilage forte, BF, a heterofermentative LAB, Lalsil Fresh lactobacillus bachneri, LFLB, a homofermentative LAB or without LAB inoculant (control). Triplicate samples per treatment were collected on days 0, 3, 10, 21 and 45 post-ensiling and analysed for DM, WSC, pH, lactic acid (LA), acetic acid (AA), butyric acid (BA), propionic acid (PA) and ammonia-N. On day 45, the silage was subjected to aerobic exposure for 5 days and CO2 production was measured. In the second and third experiments, potato hash-wheat bran mixtures of 7:3 ratio were produced and ensiled in 210 litre drums that were kept at a 250C environment. The second experiment involved an apparent nutrients digestibility study using 30 female (Large White x Landrace crossbred) pigs (30 2 kg live weight), which were selected and housed individually. A cross-over design was applied with two periods and 30 animals fed 10 diets. Three pigs were given one diet per period. The diets were: commercial feed (control); 20, 40, and 60% dietary inclusion of potato hash silage (untreated potato hash silage, UPHS; Lalsil Fresh treated potato hash silage, LFLBPHS, and Bonsilage forte treated potato hash silage, BFPHS). Each experimental period lasted for eleven days with seven days being for adaptation to each diet and four days for collection of faeces before crossing over to the next treatment. Pigs were fed twice per day at 8:00 and 15:00, with the daily allowance equally divided between the two meals. Faecal samples were weighed and 10% of the total collection was taken and kept in a freezer at -180C. Prior to chemical analysis, individual samples of faeces were thawed and pooled for pigs within periods. Water was made available at all times through drinking nipples. The third experiment was a pig growth study using sixty-four crossbred pigs (Large White x Landrace) consisting of 32 males and 32 females (30.4±2.3kg live weight). The pigs were randomly allocated to four diets in a 4 x 2 (treatment x sex) factorial experiment in a completely randomised design. The diets contained up to 40% potato hash silage (PHS) and were: control (commercial diet - no silage), UPHS, BFPHS and LFLBPHS. Each experimental unit consisted of two pigs and each treatment was replicated 8 times. Pigs were fed on one of the four diets until they reached a slaughtering weight of 60 kg. Warm carcass weights were determined immediately after slaughter. After an overnight chill storage at 4.30C, cold carcass weights were determined. Carcass length was taken on hanging carcasses by measuring from the pelvic bone to the first thoracic vertebra, using a measuring tape. Backfat thickness was also taken on cold carcass at P2 (45 mm from midsection) between the 3rd and 4th rib on the left side of the pigs. Drip loss was also calculated for hanging carcasses by determining the weight loss after the overnight chill. Results from experiment 1 showed that both inoculants (LFLB and BF) reduced (P<0.05) the silage pH while increasing the LA content of silage compared to the control. The concentrations of propionic acid, butyric acid and ammonia-N were not affected by inoculation. When exposed to air, BF and LFLB reduced (P<0.05) CO2 production compared to the control. Results of the second experiment showed that daily intakes of organic matter (OM), crude protein (CP), ether extract (EE), acid detergent fibre (ADF), neutral detergent fibre(NDF), and gross energy (GE) were different (P<0.05) between diets. There were no differences (P<0.05) in digestibility of DM, EE, and DE among the treatments. However, diets containing 60% PHS had lower (P<0.05) NDF and ADF digestibility compared to diets containing less PHS. Furthermore, pigs on the control diet had higher (P<0.05) final body weight, average daily gain (ADG) and better feed conversion ratio (FCR) compared to those fed on other diets. Results of the third experiment showed that, pigs that were fed the control diet had higher (P<0.05) slaughter weight than pigs that were fed on diets containing PHS. There were no differences (P>0.05) on warm and carcass weight between diets containing PHS. Control had higher (P<0.05) dressing percentage than the other treatments. Drip loss percentage, backfat thickness, gastrointestinal tract (GIT), lungs and heart did not differ (P<0.05) between treatments. The effects of gender was not significant within treatments on slaughter weight, warm and cold carcass weights, dressing percentage, carcass length, backfat thickness, drip loss, GIT, lungs and heart. There were no gender by diet interactions (P>0.05) on warm carcass weights, cold carcass weights, drip loss percentage, carcass length, backfat, intergastral, lungs and heart. However, gender by diet interaction (P<0.05) occured on slaughter weight and dressing percentage. It was concluded that, inoculation improved both the fermentation and aerobic stability of PHS. Furthermore, there was no advantage in using LAB inoculants in ensiling potato hash on the growth performance or meat characteristics of growing pigs. However, further work is needed to evaluate the effects of higher dietary inclusion levels (> 60 %) of PHS on pig growth and reproductive performance.

Thesis (M. Tech. Agriculture) -- Central University of Technology, Free state, 2012 / The eight-week study was conducted to evaluate the effects of rearing system (indoor vs. outdoor) and energy level on digestibility, growth performance and on the carcass characteristics and visceral organs of pigs. A total of 48 Large Whites (LW) X Landrace (LR) male grower pigs were randomly selected at average weights of 27 ± 4.6.kg and divided into two equal groups that were either raised indoors or outdoors. Within each rearing system, half the pigs were fed on a diet formulated to contain either a normal energy level (14 MJ DE/kg) or high energy level (16.1 MJ DE/kg) resulting in a 2 X 2 factorial design. The pigs were fed ad libitum and water was freely available. Pigs were housed in pairs and each indoor and outdoor pig was offered a space allowance of 0.51 and 13.5 m2 respectively. Indoor pigs were raised in a temperature controlled house consisting of a concrete floor pen while outdoor pigs were on a pasture that predominantly consisted of Kikuyu. Movable gates were used to construct outdoor camps and empty feed bags were used to construct a shade for use as shelter. Faecal collection for digestibility determination took place during week 7 while the growth performance trial was still in progress. Chromium oxide was used to evaluate digestibility and faeces were grabbed before they fell to the ground and sampled. With the exception of ether extracts (EE), the digestibilities of crude protein (CP), digestible energy (DE), crude fibre (CF), neutral detergent fibre (NDF), acid detergent fibre (ADF) and organic matter (OM) were reduced (P <0.05) by rearing pigs outdoors. EE followed the same trend. Feeding the high energy (HE) diet significantly (P >0.05) improved the digestibilities of all the nutrients except for CP. There were no significant interactions (P>0.05) between rearing system and diet for the digestibility of nutrients. Daily gains were similar (P >0.05) between indoor and outdoor pigs. Daily feed intakes and conversions were significantly (P <0.05) lower in indoor pigs. There were no significant (P >0.05) differences between the daily gains and feed conversions of pigs fed either the normal energy (NE) or the HE diet. Indoor pigs fed the HE diet had lower (P < 0.05) feed intakes compared to pigs on the other treatments. In general, average daily feed intakes (ADFI) of the HE fed pigs were significantly (P <0.05) lower than those of the NE fed pigs. The carcass measurements of the indoor and outdoor pigs were similar. The gastro-intestinal tract (GIT) and the liver weights of the outdoor reared pigs were significantly (P <0.05) heavier than those of the indoor reared pigs. Feeding the HE diet led to significantly (P <0.05) higher carcass weights and dressing percentages. Interactive effects (P <0.05) of diet and rearing system were found for lean meat percentage (Lean P) and eye muscle area (EMA). Indoor pigs fed on the NE diet had higher Lean P and EMA while an opposite effect was obtained in the outdoor system. The liver of the NE diet fed pigs was significantly (P < 0.05) heavier than that of the pigs fed the HE diet. It can be concluded that with regard to growth performance and carcass characteristics, the NE and HE diets are respectively best suited for the indoor and outdoor rearing of pigs.

Thesis (MScAgric)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: The world demand for animal proteins and profit-driven production has led to producing animal proteins intensively. Intensive pork production systems have traditionally had a poor image with the public, because these production systems are associated with environmental pollution. Currently, pigs are produced on highly specialised farms, and are fed concentrated (often imported) pig feed. The resulting higher production and higher animal densities contribute to an increased pollution of water, soil and air. The aim of this study is to determine the energy balance and emissions of three case studies, and to compare these results with their financial performance. The impacts will be recorded in the following impact categories: global warming potential (GWP), acidification potential (AP), eutrophication potential (EP) and Energy Use (EU). The case studies are three typical South African pig production facilities selected by the South African pork producer’s organisation (SAPPO). The production inputs, from the feed acquisition to the delivery of one kg of pig at the farm gate, were included. The three farms are located in different areas in South Africa, namely KwaZulu-Natal province (Case study 1), North-West province (Case study 2) and Western Cape province (Case study 3). The functional unit (FU) for this study is defined as 1 kg of South African pig (live-weight) at the farm gate. This study found that the GWP/FU of Case study 2 is 4 and 2 % higher than Case studies 1 and 3 respectively. The EP/FU of Case study 1 is 9 and 6 % higher than Case studies 2 and 3 respectively. The AP/FU of Case study 1 is 4 and 5 % higher than Case studies 2 and 3 respectively. The EU/FU of Case study 3 is 45 % and 16 % higher than Case studies 1 and 2 respectively. The major activities that contributed to the environmental impact categories were the slurry management activity, followed by electricity usage. The financial and environmental performance comparison did show deviations. Therefore, it is recommended that environmental and financial performance measurements be made, in order to create a true reflection of the impacts. The potential for improvement in financial and environmental performance proved to be significant in the productivity of the sow herd, as well as in the management of the piglets. The location of the production facility does not claim to hold have significant environmental or financial implications. Management of the emissions produced by piggeries can offset the impact of the piggery's location. / AFRIKAANSE OPSOMMING: Nie beskikbaar.

Orientador: Dirlei Antônio Berto / Coorientador: Messias Alves da Trindade Neto / Banca: Ana Silvia Alves Meira Tavares Moura / Banca : José Roberto Sartori / Banca: Maria Cristina Thomaz / Banca: Alexandre de Oliveira Teixeira / Resumo: Objetivou-se estimar o melhor nível de lisina digestível e sua relação com a energia metabolizável em dietas de suínos dos 50 aos 70 kg de peso vivo. Para tanto, foram realizados dois ensaios de desempenho, um com 72 machos castrados e outro com 72 fêmeas, com pesos médios iniciais de 49,75±0,41 kg e de 46,05±0,38 kg, respectivamente. O delineamento experimental usado nestes experimentos foi em blocos ao acaso com seis tratamentos, seis repetições e dois animais por unidade experimental (baia). No final dos experimentos mediu-se área de olho de lombo e espessura de toucinho na 10ª costela, por meio de ultrassonografia, em todos os animais. Também colheu-se sangue para leucograma de quatro animais dentro de cada tratamento, de forma aleatória, totalizando 24 machos castrados e 24 fêmeas, considerando delineamento inteiramente ao acaso, com quatro repetições por sexo e o animal era a unidade experimental. Os tratamentos foram 7,00; 8,00; 9,00; 10,00; 11,00 e 12,00 g de lisina digestível/kg de ração que continham 14,25 MJ de energia metabolizável/kg de ração e, em média, 160,92 g de proteína bruta/kg de ração. Realizou-se também um ensaio de digestibilidade e metabolismo, com 12 machos castrados e 12 fêmeas, em que foram avaliadas quatro dietas (7,00; 9,00; 10,00 e 12,00 g de lisina digestível/kg de ração), com três repetições e um animal por unidade experimental (gaiola). No ensaio de desempenho das fêmeas observou-se aumento linear na conversão alimentar, no consumo de proteína bruta (g/dia) e na eficiência de proteína bruta no período experimental de 0 a 16 dias. No período experimental de 0 a 32 dias observou-se aumento linear no consumo de proteína bruta (g/dia) e na eficiência de proteína bruta, bem como efeito quadrático no ganho de peso relativo (%) e na... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study aimed to estimate the optimum level of lysine and its relation to metabolizable energy in diets for pigs from 70 to 100 kg live weight. For this, were two performance tests, one with 72 barrows and other with 72 females, with average initial weight 76.86 ± 0.90 kg and 76.92 ± 0.96 kg, respectively, the experimental design was a randomized block with six treatments and six replicates of two animals per experimental unit (pen). At the end the experiments was measured loin eye area and backfat thickness at the 10th rib by means of ultrasound in all animals. Also picked up blood WBC to four animals in each treatment, totaling 24 males castrated and 24 female maturation, being considered the completely randomized design, with four replications for sex and the animal was the experimental unit. After fasting for 12 hours, were chosen at random, 24 castrated males and 24 females (four per treatment), which were sent to slaughter in the abattoir for commercial Ratings and carcass boning. The treatments were 7.00, 8.00, 9.00, 10.00, 11.00 and 12.00 g of lysine per kg diet containing 14.25 MJ of ME per kg feed and on average 155.20 g crude protein per kg feed. In assay digestibility and metabolism were used 12 castrated males and 12 females, with evaluation of four diets (7.00, 8.00, 11.00 and 12.00 g of lysine / kg) with three replicates and one animal per experimental unit (cage). In the performance test females observed linear... (Complete abstract click electronic access below) / Doutor

Three experiments were designed to find the most efficient and cost-effective method of meeting the changing amino acid requirements of male and female pigs during the growing period, using the minimum number of feeds. Trial one involved 144, and trial two 192 commercial crossbred (Landrace x Large White) pigs, eight to a pen, with sexes separate. Trial three involved 24 commercial crossbred (Landrace x Large White) pigs and 24 Dalland pigs each penned separately. The amino acid requirements (g/d) for the pigs in all three trials were determined for male and female Landrace x Large White pigs, respectively, using the Pig Growth Model (EFO Software Natal, 1995). Parameter values used for males and females were: growth rate (B, Id) 0.0107 and 0.0120; protein at maturity (Pmat, kg) 39.0 and 28.0; and lipid at maturity (Lpmat, kg) 2.60 and 3.89 respectively. In trials 1 and 2 two iso-energetic (DE 13.8 MJ/kg) basal feeds were formulated; Basal A being a high crude protein (CP) (347g CP/kg) feed designed to meet the amino acid requirements of a male at 20 kg liveweight, while Basal B was a low protein feed (l34g CP/kg) designed to meet the amino acid requirements of a female at 88 kg, thus providing for the most- and the least-demanding pigs on the trial. In the third trial, two iso-energetic (DE 13.8 MJ/kg) basal feeds were again formulated; Basal A being a high crude protein (CP) (347g CP/kg) feed designed to be 20% higher than the amino acid requirements of a male at 20 kg liveweight, while Basal B was a low protein feed (l34g CP/kg) designed to be 20% lower than the amino acid requirements of a female at 88 kg, once again providing for the most- and the least-demanding pigs on the trial. Trials 1 and 2 began when the median weight of pigs in each pen reached 20kg, and were terminated at a pen median of 85 kg liveweight. In the third trial each pig was started on trial when it reached 20kg and was terminated at a weight of 85kg. The first trial involved a phase feeding schedule (20-40, 40-60 and 60-85kg liveweight). The two basal feeds were blended in different proportions to create three feeds per phase: lysine contents in each of the phases in Treatment 1 (TI) were: 11, 8.68 and 7.26g/kg; in T2 they were 9.93, 7.58 and 6.24g/kg; and in T3, 8.85, 6.48 and 5.22g/kg. From the analysis it was established that ADO and time to reach 85kg were the only variables to show significance. ADO exhibited a significant sex x treatment interaction. There were significant differences between treatments for time taken to reach slaughter weight. In addition to a treatment effect there was a sex x treatment interaction for time to slaughter weight. It was expected that males on Tl and females on T3 would exhibit the most efficient performance for their respective sex since these treatments were specifically formulated to meet their requirements. Midway through the trial the pigs contracted enteritis, this affecting the outcome of the trial by inhibiting the potential growth of the pigs. The results of the trial indicated that dietary protein level affected the time taken to reach slaughter weight. This led to the second trial where four treatments were applied. Three of the four treatments followed a fixed feeding schedule, making use of the two basal feeds and a 1: 1 blend of these. The fourth treatment followed a phase feeding schedule, differing between the males (20-65, 65-75 and 75-85 kg liveweight) and the females (20-35, 35-75 and 75-85 kg liveweight). This treatment also made use of the two basal feeds and a 1: 1 blend of these. From the analysis it was found that there were no significant effects of sex and no interactions between feeding treatments and sex; however, ADO, FI, FCE, back fat thickness, time taken to reach 85kg and cost/kg gain were all significantly affected by the feeding treatments. Carcass lean, carcass lipid and total body lipid were also significantly affected by the feeding treatment. This trial was conducted to determine the extent to which differences in growth rate, food intake and carcass lipid could be altered by dietary means. The effect of the level of feed protein was once again shown to be of importance when feeding growing pigs. The third trial was designed to test the efficiency with which two strains make use of the dietary protein supplied. Three treatments were applied: Tl was a choice-feeding treatment in which the pigs were offered the two basal feeds simultaneously. T2 and T3 followed a phase feeding schedule (20-40, 40-60 and 60-85kg liveweight). The two basal feeds were blended in various proportions to create three feeds per phase: the lysine contents in each of the phases in T2 were: 12.2, 10.0 and 7.26g/kg; and in T3 8.1, 6.7 and 5.1g/kg. There were significant sex effects as well as strain x feeding treatment interactions. All variables, ADG, FI, FCE, time taken to reach 85kg and cost/kg gain, with the exception of back fat thickness, showed significance. It was expected that the Dalland strain would perform better than the Cross strain; however, this was not the case, indicating the need for further research into the possibility of feeding according to the genetic makeup of the animal. The importance of meeting the amino acid requirements of the growing pig was evident when summarising the results of the three trials reported here. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.

This study was conducted to determine the influence of factors on the efficiency of protein utilization and the rate of lipid deposition and withdrawal in growing pigs. Two experiments were conducted in total. The first experiment involved fifty-two crossbred entire Large White x Landrace male pigs, individually penned, which were used to test the proposition that the efficiency of protein utilisation is influenced by the body composition of the pig at the start of the trial. The experiment was divided into two phases: in the first period, starting at 20kg liveweight, when 3 pigs were slaughtered to determine the initial body composition of the pigs on the trial, the remaining 48 pigs were divided into three groups, two of which were fed ad libitum, with 11 pigs being offered a feed high in crude protein (HP, 1979 CP/kg) and 19 pigs being offered a low CP (LP, 166g/kg) feed. The remaining 19 pigs were fed HP on a restricted basis; the daily allowance being 0.7 of the mean intake of those pigs fed HP ad libitum. The objective of this initial period was to create three groups of pigs differing in body lipid content. As each pig achieved a protein weight of approximately 5.9kg, predicted to occur when the pigs on the three treatments reached live weights of 35, 39 and 34kg respectively, the pig entered phase 2 of the trial. At this stage three pigs from each treatment (a total of 9 pigs) were slaughtered for carcass analysis, the protein contents being approximately 5.9kg, and lipid contents being 85,98 and 87g/kg for the 3 treatments respectively. During phase 2, the 8 pigs fed HP in phase 1 continued to be fed HP in phase 2; 8 pigs were chosen at random from those fed LP in phase 1 and were allocated the high CP basal feed, while the remaining 8 were given LP; and 8 of the pigs feed-restricted in phase 1 were randomly chosen and fed HP, while the remaining 8 were given LP. All pigs were fed ad libitum during phase 2. Four pigs from each treatment in phase 2 were slaughtered after 1 week and the remaining 4 a week later for analysis of body composition In the first week of the second phase of the trial protein gain was highest (264g/d) on the pigs previously restricted and then fed HP, followed by those previously fed LP and then HP (242g/d), with pigs previously restricted and then fed LP depositing the least amount of protein (192g/d). Pigs fed LP or HP throughout, had protein gains of 217 and 210g/d, respectively. Efficiencies of utilization of dietary protein did not differ significantly between treatments, however, the highest being measured in pigs fed LP throughout (461g/kg), followed in order by those fed LP and then HP (457g/kg), those fed HP throughout (404g/kg), those previously restricted and then fed LP (394g/kg), with those previously restricted and then fed HP being the least efficient (372g/kg). The second experiment involved twenty-six male and twenty-six female crossbred Large White x Landrace pigs, individually penned, which were used to determine the maximum rate at which growing pigs can gain lipid. The experiment was divided into three phases: In the first, starting at 20kg live weight (56 days old), when two males and 2 females were slaughtered to determine the initial body composition of the pigs on the trial, the remaining 24 males and 24 females were randomly allocated to their various treatments. The treatments consisted of a feed high in crude protein (H, 197g/kg), a feed low in CP (L, 166g/kg) and three blends, namely 5OH/5OL (180g/kg) (male diet), 30H/70L (167g/kg) (both male and female diets) and 20H/80L (162g/kg) (female diet). Six pigs from each sex were allocated to each treatment. The EFG Pig Growth Model was used to determine the fat contents (lipid index) on the two feeds available and the three blends, to estimate the best times to sample pigs. It was estimated that phase 1 would terminate at 63 d, phase 2 at 70 d and phase 3 at 77 d of age. At the end of each phase two pigs from each sex and treatment were slaughtered. The lipid contents differed significantly between treatments at the end of phase 2 for the male pigs, with the highest being measured in pigs fed L (108g/kg), followed in order by those fed 70L/30H (86g/kg), those fed 5OL/5OH (74g/kg), and those fed H (68g/kg) with the least lipid content. The lipid contents of the female pigs were highly significantly different at the end of phase 3, with the highest being measured in pigs fed L (147g/kg), followed in order by those fed 80L/20H (124g/kg), those fed 70L/3OH (116g/kg) and the least lipid content from those fed H (115g/kg). As estimated by the EFG Pig Growth Model, the male and female pigs fed L treatment had the highest lipid content and those fed H treatment, achieving their target rate of lipid deposition, with the lowest lipid content. This study indicates that the response in protein gain and in efficiency of utilization of protein of pigs to a given feed is dependent on the amount and quality of the feed given to the animals previously. Also, the maximum rate of lipid deposition can be achieved by monitoring the changes in lipid deposition over a period of time, which enables an enhanced understanding of the theory of food intake regulation in a growing pig. As a result, accurate changes can be made when designing a phase-feeding program for growing pigs. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.