The aim of this study was to determine firstly if there exist variations in fibrolysis among herbivore microbial ecosystems and secondly, the effect on fibre hydrolysis of compositing the most active systems with ruminal microbial ecosystem harvested from a Jersey cow. A literature review pointed to the complexity of carbohydrate (fibre) and how the physical and chemical nature of the forage carbohydrate can present barriers that hinder digestion in the rumen, especially its association with hemicelluloses, pectin, lignin and tannins. Fresh rumen fluid was collected from fistulated herbivores (Jersey cow and sheep) and faecal samples from non-fistulated herbivores (buffalo, horse, impala, camel, elephant, llama, sheep, wildebeest and elephant). Crude protein samples were precipitated with 60% ammonium sulfate. Sample activities were monitored and optimised by incubating with carboxymethyl cellulose (CMC) for 2 h at 39°C. The crude protein samples precipitated from the 11 herbivore microbial ecosystems were active. This was confirmed by an increase in enzyme specific activity with a decrease in total crude protein concentration. In vitro pH optimisation showed a broad range of activity for all ecosystems (4.5-8.0) but for the zebra, horse and elephant which peaked at pH 5. In experiment two (Chapter 4), seasonal variation of the enzymes (exocellulase, endocellulase, cellobiase and xylanase) were monitored through winter and summer. Enzyme specific activity of exocellulase, endocellulase, cellobiase and xylanase were determined by incubation with the specific substrates, crystalline cellulose, CMC, pNPG and xylan, respectively. The amount of reducing sugar released was used to determine the enzyme specific activity. Exocellulase analysis was suitable in winter while summer was preferred for carboxymethyl cellulase and xylanase due to their relative abundance. Cellobiase analysis did not depend on any particular season. Eleven herbivore microbial ecosystems were characterised according to their fibrolytic enzyme specific activities. Enzyme catalytic activities were calculated from kinetic parameters (Km and Vmax) obtained from Eisenthal and Cornish-Bowded plots (Chapter 5). Fibrolytic enzyme expression as well as their activities differed among the 11 ecosystems (P<O.OOOI). They were classified into three groups based on fibrolytic enzyme concentrations; group A with high enzyme concentrations (horse, impala, zebra, wildebeest and the elephant), group B with intermediate (cow, llama, camel, buffalo and giraffe) and group C with low enzyme concentrations (sheep). Exocellulase activity was reasonably correlated with endocellulase activity (r = 0.8978). Xylanase activity was also correlated with carboxymethyl cellulase actvity (r = 0.7104). Enzyme kinetic studies revealed that crude protein samples from the horse, zebra, wildebeest and elephant had the highest enzyme catalytic activities. Microbial or enzyme composite systems were created from the most active ecosystems (horse, wildebeest and zebra) in an attempt to improve the Jersey cow system. These systems were B (cow and horse), C (cow and wildebeest), D (cow and zebra) and E (cow, horse, zebra and wildebeest). The specific activities and enzyme efficiencies of these new systems were determined and compared with system A (cow). Microbial synergism of these systems was also investigated by measuring the amount of gas produced and true degradability (TD) after 72 h of incubation. The composite systems Band E were the most active fibrolytic enzyme systems while C and D were intermediate when compared to that of A. In vitro microbial synergism assays showed that systems B, D, and E had the highest potential of improving milky maize stover (MM) and nutral detergent fibre (NDF) fermentation and degradability in Jersey cows. It was concluded that: (i) fibrolytic and hemicellulolytic enzyme concentrations vary from one season to another with the changing forages; (ii) microbial fibrolytic activities vary among animals grazing on the same field or different geographical regions; and (iii) lastly microbial synergisms of active ecosystems have the potential of improving fibre hydrolysis. However, there is a need to conduct in vivo experimentation to determine the real potential of these in vitro observations. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.

Made available in DSpace on 2015-03-26T13:55:24Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1753652 bytes, checksum: 23724be0973af46287264619b5b0e719 (MD5) Previous issue date: 2014-07-10 / This is a data survey from the main commercial mineral supplements for dairy and beef cattle currently available in the Brazilian market. 307 products have been listed, from eight of the leading companies operating in Brazil. The products have been listed in six categories: ready-to-use for beef cattle ; ready-to-use for dairy cattle ; units to produce beef cattle concentrate ; units to produce dairy cattle concentrate ; premix , which must be added to NaCl; and protein salts n order to evaluate their minerals, vitamins, ionophores, yeast, urea and crude protein composition, and compare the mineral levels with the Brazilian legislation (IN12, 2004). The ready to use products do not fulfill the legal specifications for phosphorus level in all products. The same happens in some "premix" products in 1:1 dilution with NaCl, when indicated for dairy cattle. This mineral level is 64.9 % higher in products to produce dairy cattle concentrate , when compared with the same kind of products for beef cattle. The P average for protein salts category is 28.5 g/kg and in order to meet the legal specifications, the ingestion must be considered. When it comes to micro minerals the premix category does not comply with the specifications in Cu , Mn , Zn and Se in 1:1 dilution for dairy cattle. The ready to use category meets all minerals specifications for dairy cattle but it does not for beef cattle, only part of the mineral range. Dairy cattle products to produce concentrate have higher viimicrominerals levels than those used for beef cattle, and the protein salts have lower levels compensated by higher ingestion. The legislation does not detail all animal categories. This fact is associated with some other factors as the large territory and massive herd make the Brazilian market gather around the conditions to group an extensive range of products. Therefore, the current legislation itself is not able to mold products for each mineral supplements situation that can occur in all Brazilian production systems. / Foi realizado um levantamento de dados dos principais suplementos minerais voltados para a bovinocultura leiteira e de corte disponíveis atualmente no mercado brasileiro. Foram listados 307 produtos, de oito das principais empresas desse segmento no Brasil. Os produtos foram elencados em seis categorias: produtos prontos para utilização para gado de corte ; produtos prontos para utilização em gado leiteiro ; núcleos para fabricação de concentrado para gado de corte , núcleos para fabricação de concentrados para gado leiteiro; premix ou produtos a serem misturados ao NaCl; e proteinados. Objetivou-se agrupar as composições de minerais, vitaminas, ionóforos, levedura, ureia e proteína bruta, bem como comparar os níveis minerais dos produtos com a legislação pertinente (IN 12, 2004). Os níveis de P não atendem às especificações da legislação em todos os produtos prontos para uso. Na categoria premix , a diluição em 1:1 com o NaCl não atende à totalidade dos produtos quando a indicação é para bovinos leiteiros. Para os núcleos de fabricação de concentrado, os níveis desse mineral são 64,9% mais altos nos produtos destinados à pecuária leiteira do que nos produtos para corte. Nos proteinados, a média do P ficou em 28,5 g/kg, e seu atendimento às especificações do MAPA depende do consumo. Os teores de microminerais na categoria premix não atendem às especificações para os microminerais Cu, Mn, Zn e Se em diluição de 1:1 para bovinos de leite. Nos produtos prontos para uso em bovinos leiteiros, os níveis mínimos de micros atendem às vespecificações do MAPA; já nos produtos para bovinos de corte, esses níveis não são atendidos em todos os micros. Os núcleos para rações também possuem médias mais altas nos produtos para leite, em comparação aos de corte, e os proteinados possuem médias baixas fato compensado por maiores consumos. Observou-se que a legislação não discorre detalhadamente sobre todas as categorias de animais e que outros fatores, como grande extensão territorial e rebanho massivo, criaram situações para que o mercado brasileiro reunisse uma gama muito extensa de produtos. Assim, a legislação atual, por si só, não é capaz de moldar os produtos destinados à mineralização bovina para atender a todas as situações que ocorrem nos diversos sistemas de produção brasileiros.

Made available in DSpace on 2015-03-26T13:55:25Z (GMT). No. of bitstreams: 1 texto completo.pdf: 840074 bytes, checksum: f585a1e0847e000c0f9ccf71f306abb8 (MD5) Previous issue date: 2014-07-22 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / This work was developed in order to evaluate the feed intake, digestibility and performance of crossbred cattle fed in confinement at different frequencies with diets containing different levels of calcium and phosphorus; determine the nutritional requirements of energy, protein and macro minerals; and evaluate the effects on consumption estimates when reducing the number of samples of leftovers for laboratory analyses by grouping these samples in the total period of the confinement. For that were used 32 1&#8260;2 crossbred Gir x Holstein barrows, with mean 377.46 ± 49.4 kg of initial body weight. Initially, four animals were slaughtered and used as a reference to estimate the initial empty body weight (EBW) of the remaining animals in the experiment. 24 animals were used in a completely randomized factorial 2x3x2 design with two concentrate diet levels (30 and 60%), three frequency (full diet fed in the morning, at 8:00 am; roughage provided in its entirety in the morning and concentrate divided into twice, at 8:00 and at 16:00 hours; and feeding roughage and concentrate divided into two equal portions per day) and diets with or without inorganic sources of calcium and phosphorus. The four other animals were fed daily at maintenance level (1.1% body weight on dry matter). The roughage used was crushed sugar cane. At the end of 84 days all animals were slaughtered and samples from the carcasses and not carcass constituents were taken to determinate composition. Chapter 1: The dry matter (DM) and nutrients were not affected (P> 0.05) by feeding frequencies but were higher (P <0.05) for diets with 60% of concentrate. Supplementation with dicalcium phosphate affected only the consumption of phosphorus that was higher for supplemented diets. There was no effect of feeding frequency, supplementation with dicalcium phosphate or their interactions (P> 0.05) on the digestibility of diets constituents. Higher levels of concentrate provided higher average of daily gains and income from hot and cold carcass. In Chapter 2: The net (NEm) and metabolizable energy (MEm) requirements for maintenance were obtained by relating heat production (CP) and metabolizable energy intake (MEI) while the energy requirements for weight gain (NEg ) and net protein requirements for weight gain were obtained as a function of EBW and empty body weight gain (EBWG). The daily requirements of metabolizable and net energy for maintenance were 86.48 and 126.15 kcal / PCVZ 0.75 respectively. The requirements for net energy gain can be obtained by the equation: NEg = 0.0568 ± 0.0025 × × PCVZ0,75 GPCVZ1,095. The efficiency of use of metabolizable energy for maintenance and gain are 64 and 29.68%, respectively. The metabolizable protein requirement for maintenance is 4.14 g / BW 0.75. The net protein requirements for weight gain can be obtained through the equation PLg = 236.36 ± 30.06 × EBW - 19.84 ± 6.14 × ER. Third chapter: The relationship between the consumption of each mineral and it retention was expressed as a linear equation, and the intercept considered the requirement for maintenance of the mineral. Using the samples of the carcass and no carcass were determined the proportion of each mineral, determining the body content for each mineral expressed as a function of EBW. No variations in daily fecal and urinary excretions of phosphorus according to the supplementation with dicalcium phosphate were found. The absence of dicalcium phosphate supplementation in cattle diets in the finishing phase implies lower retention of calcium and phosphorus in the carcass. The absorption coefficients were 83.34, 77.21, 82.57, 40.27 and 92.25% for calcium, phosphorus, sodium, magnesium and potassium, respectively. The net daily maintenance requirements are 28.18, 10.31, 50.11, 25.86, and 91.67 mg / EBW for calcium, phosphorus, magnesium, sodium and potassium, respectively. Net requirements for calcium, phosphorus, magnesium, sodium and potassium for weight gain can be calculated respectively by the equations: Ca = × EBW (EBW-51.77 × 0.3023); P = EBWG × (30.87 × EBW-3459); EBW = mg × (0.865 × EBW-0.2133); In EBW = × (6.517 × EBW-0.3483); EBW = K × (4.06 × EBW-0.1875). It is concluded that the intake, digestibility of nutrients and performance were not affected by the feeding frequencies adopted or by the levels of calcium and phosphorus added, but were improved with increasing level of concentrate. About the sampling of leftovers, it is recommended to make a single composite sample for 84 days of confinement. The values and equations obtained for the requirements of crossbred Holstein × Zebu differs from that obtained by Br- Corte (2010), emphasizing that the number of animals with similar characteristics like those used are a small part of the database of this system. / O presente trabalho foi desenvolvido com os objetivos de avaliar o consumo, a digestibilidade e o desempenho de bovinos mestiços em confinamento alimentados em diferentes frequências de alimentação com dietas contendo diferentes níveis de cálcio e fósforo; determinar suas exigências nutricionais de energia, proteína e macrominerais; e avaliar o efeito da redução do número de amostras destinadas às análises laboratoriais de sobras pelo agrupamento dessas amostras no período total do confinamento, sobre as estimativas de consumo. Foram utilizados 32 animais mestiços 1&#8260;2 Zebu x Holandês, machos, castrados, com peso corporal médio inicial de 377,46±49,4 kg. Inicialmente, quatro animais foram abatidos e tomados como referência para estimar o peso de corpo vazio (PCVZ) inicial dos animais remanescentes no experimento. 24 animais foram distribuídos em delineamento inteiramente casualizado em esquema fatorial 2x3x2, com dois níveis de concentrado (30 e 60%), três frequências de alimentação (alimentação completa fornecida pela manhã, às 8:00 horas; volumoso fornecido em sua totalidade pela manhã e concentrado dividido em duas vezes, às 8:00 e às 16:00 horas; e alimentação volumosa e concentrada dividida em duas porções iguais ao dia) e dietas contendo ou não fontes inorgânicas de cálcio e fósforo. Os outros quatro animais foram alimentados diariamente ao nível de mantença, (1,1% do peso corporal em matéria seca). O volumoso foi a cana de açúcar triturada. Ao final de 84 dias, todos os animais foram abatidos, e a partir das amostras de carcaça e dos constituintes não carcaça foi determinada a composição corporal. No capítulo 1: Os consumos de matéria seca (MS) e dos nutrientes não foram afetados (P>0,05) pelas frequências de alimentação, mas foram superiores (P<0,05) para as dietas com 60% de concentrado. A suplementação com fosfato bicálcico afetou apenas o consumo de fósforo, superior para as dietas suplementadas. Não houve efeito da frequência de alimentação, nem da suplementação com fosfato bicálcico ou das suas interações (P>0,05) sobre as digestibilidades dos constituintes das dietas. Maiores níveis de concentrado proporcionaram maiores ganhos médios diários e rendimentos de carcaça quente e fria. No capitulo 2: As exigências de energia líquida (ELm) e metabolizável para mantença (EMm) foram obtidas relacionando a produção de calor (PC) e o consumo de energia metabolizável (CEM), enquanto as exigências de energia para ganho de peso (ELg) e as exigências líquidas de proteína para ganho foram obtidas em função do PCVZ e do ganho de peso de corpo vazio (GPCVZ). As exigências diárias de energia líquida e metabolizável para mantença foram de 86,48 e 126,15 kcal/PCVZ 0,75, respectivamente. As exigências de energia líquida para ganho podem ser obtidas pela equação: ELg = 0,0568±0,0025 × PCVZ0,75 × GPCVZ1,095. As eficiências de uso da energia metabolizável para mantença e para ganho são de 64 e 29,68%, respectivamente. As exigências de proteína metabolizável para mantença é de 4,14 g/PC0,75. As exigências liquidas de proteína para ganho de peso podem ser obtidas através da equação PLg = 236,36±30,06 × GPCVZ 19,84±6,14 × ER.. No terceiro capítulo: A relação entre o consumo de cada mineral e sua retenção foi expressa a partir de uma equação linear, sendo o intercepto considerado a exigência de mantença do mineral. Nas amostras de carcaça e não carcaça foram determinados a proporção de cada mineral, determinando- se assim o conteúdo corporal para cada um dos minerais, expressos em função do PCVZ. Não foram encontradas variações nas excreções fecal e urinária diárias de fósforo em função da suplementação com fosfato bicálcico. A ausência suplementação de fosfato bicálcico em dietas para bovinos em fase de terminação implica em menor retenção de cálcio e fósforo na carcaça. Os coeficientes de absorção foram de 83,34, 77,21, 82,57, 40,27 e 92,25% para cálcio, fósforo, magnésio sódio e potássio, respectivamente. As exigências líquidas diárias de mantença são de 28,18, 10,31, 50,11, 25,86, e 91,67 mg/PCVZ para cálcio, fósforo, magnésio, sódio e potássio, respectivamente. As exigências líquidas de cálcio, fósforo, magnésio, sódio e potássio para ganho de peso podem ser calculadas respectivamente pelas equações: Ca = GPCVZ × (51,77 × PCVZ-0,3023) ; P = GPCVZ × (30,87 × PCVZ-3459); Mg = GPCVZ × (0,865 × PCVZ-0,2133) ; Na = GPCVZ × (6,517 × PCVZ-0,3483); K = GPCVZ × (4,06 × PCVZ-0,1875). Conclui-se que o consumo, a digestibilidade dos nutrientes e o desempenho não foram afetados pelas frequências de alimentação adotadas nem pelos níveis de cálcio e fósforo, contudo foram melhorados com o aumento do nível de concentrado. Quanto à amostragem de sobras, recomenda-se fazer uma única amostra composta para 84 dias de confinamento. Os valores e equações obtidos para as exigências de animais mestiços Holandês × Gir diferem das obtidas pelo Br-Corte (2010), ressaltando- se que o número de animais com características semelhantes aos utilizados constituem pequena parte do banco de dados desse sistema.

Two experiments were conducted in NEAVI ( Center for Studies in Poultry ) located in the Central Animal Laboratory of the Federal University of Sergipe , in order to develop a practical and inexpensive technology for the production of shrimp waste meal, as well as evaluating the content of digestible amino acids and their energy values . This study aimed to determine drying times in different proportions of shrimp waste . 35 and 50 kg of shrimp waste , in duplicate , totaling 40.70 and 100 kg , respectively, the amounts of 20 were allocated into six platforms . The time taken to dryness the residue was 35 , 45 and 55 hours, respectively. Chemical composition of shrimp head meal ( FRC ) was also evaluated and the following results were obtained : 90.7 % dry matter , crude protein 39.3 % , ether extract 5.8% , calcium 11.3 % , phosphorus 2.23 % calcium and 1 , 47 % and shrimp waste flour showed values of 89.0 % for dry matter , 32.6 % crude protein , 3.9% for fat , 9 , 87 % for calcium, phosphorus and 2.22 % to 1.53 % for sódio.No first experiment we determined the digestibility of amino acids using the method of ileal collection with 180 broiler chicks , 28 days old , distributed in a completely randomized experimental design , divided into 3 treatments with 6 replicates and 10 birds per experimental unit . The experimental diets were composed of free protein diet with 0 , 5, 10 and 15% inclusion of FRC . The best coefficients were obtained with the 10% level of inclusion for methionine ( 81.2 % ) , cystine ( 58.6 % ) , methionine + cystine ( 73.1 % ) , lysine ( 82.4 % ) and threonine ( 53.3 %). The second experiment determined the coefficients of metabolization of DM, CP , N , Gord , Ca and P and the apparent metabolizable energy (AME ) and apparent metabolizable energy corrected for nitrogen balance ( AMEn ) of test diets and food . The method of total excreta collection with 180 broiler chicks of cobb trademark , aged 16-26 days old was used . The completely randomized design with 5 treatments and 6 replicates 6 birds per experimental unit was used . The FRC was included in a reference diet at levels of 0 , 5 , 10 , 15 and 20 % . The chicks were housed in metal cage with trays to collect excreta . A significant influence of the inclusion levels of CRP (P <0.05 ) in the level of 10% was higher in the following factors : dry matter was obtained 73.27% and 76.37 % crude protein . The coefficient of metabolizable ether extract was higher in the inclusions of iv 15 % with coefficients of 95.48 % and 20 % which was 96.59 % . Nitrogen retention was higher in higher levels of inclusion of FRC 10 , 15 and 20 % , which did not differ , obtaining values of 74.3 , 77.0 and 76.9 % , respectively . No statistical difference was observed in the coefficients metabolization of calcium and phosphorus . The AME and AMEn were significantly affected by the inclusion of FRC , as was increased to include these variables suffered diminishing effect on their values . The best level was 10% which presented values of AME 2325.1 Kcal / Kg and AMEn 1827.5 Kcal / Kg for flour of shrimp waste . / Dois experimentos foram realizados no NEAVI ( Núcleo de Estudos em Avicultura) localizado no Biotério Central da Universidade Federal de Sergipe, a fim de desenvolver uma tecnologia prática e barata para a produção da farinha de resíduo de camarão, bem como avaliar o conteúdo de aminoácidos digestíveis e seus valores energéticos. Objetivou-se a determinação dos tempos de secagem em diferentes proporções de resíduo de camarão. Foram alocadas em seis plataformas as quantidades de 20; 35 e 50 kg de resíduo de camarão, em duplicata, totalizando 40,70 e 100 kg, respectivamente. O tempo levado para secagem do resíduo foi de 35, 45 e 55 horas, respectivamente. Também foi avaliada composição química da farinha de cabeça de camarão (FRC) e foram obtidos os seguintes resultados: matéria seca de 90,7%; proteína bruta de 39,3%, extrato etéreo de 5,8%, cálcio de 11,3%, fósforo de 2,23% e cálcio de 1, 47% e a farinha de resíduo de camarão apresentou valores de 89,0% para matéria seca, 32,6% para proteína bruta, 3,9% para extrato etéreo, 9,87% para cálcio, 2,22% para fósforo e 1,53% para sódio.No primeiro experimento foram determinados os coeficientes de digestibilidade dos aminoácidos utilizando-se o método de coleta ileal com 180 pintos de corte, com 28 dias de idade, distribuídos em um delineamento experimental inteiramente casualizado, distribuídos em 3 tratamentos, com 10 repetições e 6 aves por unidade experimental. As dietas experimentais foram compostas por dieta isenta de proteína com 0, 5, 10 e 15% de inclusão de FRC. Os melhores coeficientes foram obtidos com o nível de 10% de inclusão para metionina (81,2%), cistina (58,6%), metionina+cistina (73,1%), lisina (82,4%) e treonina (53,3%). No segundo experimento foram determinados os coeficientes de metabolizabilidade de MS, PB, N, Gord, Ca e P e os valores de energia metabolizável aparente (EMA) e energia metabolizável aparente corrigida pelo balanço de nitrogênio (EMAn) das dietas teste e do alimento. Foi utilizado o método de coleta total de excretas com 180 pintos de corte de marca comercial cobb, com idade de 16 a 26 dias de idade. Foi utilizado o delineamento experimental inteiramente casualizado em 5 tratamentos com 6 repetições e 6 aves por unidade experimental. A FRC foi incluída em uma dieta referência nos níveis de 0, 5, 10, 15 e 20%. Os pintos foram alojados em baterias metálicas com ii bandejas para a coleta de excretas. Houve influência significativa dos níveis de inclusão da FRC (P<0,05), em que o nível de 10% mostrou-se superior nos seguintes coeficientes: de matéria seca obteve-se 73,27% e proteína bruta com 76,37%. O coeficiente de metabolizabilidade do extrato etéreo foi maior nas inclusões de 15% com coeficientes de 95,48% e 20% que foi de 96,59%. A retenção de nitrogênio foi superior nos maiores níveis de inclusão de FRC 10, 15 e 20%, que não diferiram entre si, obtendo valores de 74,3; 77,0 e 76,9%; respectivamente. Não foi observada diferença estatística nos coeficientes de metabolizabilidade de cálcio e fósforo. A EMA e EMAn foram afetadas significativamente pela inclusão de FRC, conforme aumentou-se a inclusão, essas variáveis sofreram efeito decrescente em seus valores. O melhor nível de inclusão foi o de 10% que apresentou valores de EMA de 2325,1 Kcal/Kg e de EMAn 1827,5 Kcal/Kg para a farinha de resíduo de camarão.

Two metabolism trials were conducted with 15 wethers surgically equipped with duodenal and ileal cannulas to study the absorption of P and certain other minerals from swine waste and broiler litter. The effect of source and level of P on rumen cellulytic bacterial populations was also determined. Animals were fed a low P basal diet until serum inorganic P averaged 5.5 mg/dl, then randomly assigned to the following diets: low P basal alone, or supplemented with swine waste, broiler litter, dicalcium phosphate, or soybean meal. Trials consisted of a 7-d preliminary period, a 7-d collection of urine and feces and a 6-d sampling of duodenal and ileal digesta, and feces. Animals fed the waste diets tended to absorb more P than those fed the conventional supplements. Calculated by difference, sheep absorbed more P from swine waste and broiler litter than from dicalcium phosphate and soybean meal (P< .1). Less Ca was absorbed from the waste diets than from the conventionally supplemented diets (P< .05). Expressed as g/d, there was no difference in Mg absorption between waste and conventional diets. Sheep fed waste tended to digest more dry matter and a higher percentage of ADF in the large intestine. Lignin was primarily digested in the large intestine of all sheep. More cellulytic bacteria were isolated from the rumen of sheep fed the supplemented diets (P< .05). Both P intake and P recycling appear to be important influences on cellulytic bacteria in the rumen. Both broiler litter and swine waste appear to be good sources of P and Mg for ruminants. / Ph. D.

Call number: LD2668 .T4 1963 S56 / Master of Science

Call number: LD2668 .T4 1979 O43 / Master of Science

Call number: LD2668 .T4 1984 S876 / Master of Science

Thesis (MSc)--Stellenbosch University, 2001. / ENGLISH ABSTRACT: The use of fungal enzymes as ruminant feed digestibility enhancers was investigated. Currently, ruminants may not digest 38 to 80 % of fibrous forages' content. A renewed interest in the potential of feed enzymes for ruminants was prompted by the high costs of livestock production, together with the availability of newer enzyme preparations. Direct application of enzyme preparations can improve in vitro dry matter (DM) and neutral detergent fibre (NDF) degradation, indicating that direct-fed fibrolytic enzymes may be effective in enhancing in vivo digestion of forages. Two commercial enzyme products, Fibrozyme and Celluclast, and fungal extracellular enzyme extracts from Aureobasidium pullulans, Trichoderma reesei, Aspergillus aculeatus, and Thermomyces lanuginosus were evaluated for enhancing in vitro feed digestibility. Fibrozyme addition to both wheat straw and lucerne hay did not improve their in vitro digestibilities, even after a two hour pre-incubation period. The four fungal enzyme extracts did not enhance wheat straw's digestibility, but marginal increases were evident for lucerne hay. Celluclast addition resulted in marginal increases in the digestibility of both oat hay and oat silage, with no enhanced effect on lucerne hay and NaOH-treated wheat straw. No relationship could be found between the level of enzyme activity and the degree of feed digestion in the in vitro assay. Enzyme hydrolysis with Celluclast, in the absence of rumen fluid, gave more conclusive results. All the feed samples tested showed a positive response to Celluclast addition, even the less digestible feeds, namely sugarcane bagasse and wheat straw. In vitro results show that the assays were unsuccessful, because almost all of the experiments conducted showed inconclusive results. Alternative feed evaluation assays, which include the in vivo, in sacco and in situ methods of analysis, as well as gas production measurement and in vitro analysis with the DAISyII system, should be evaluated. A more detailed study of feed digestibility should be motivated by determining which feeds are hydrolysable, their chemical composition, i.e. how accessible the feeds are, and also evaluation of feed mixtures. The enzyme supplements also need to be evaluated for optimum temperature and pH, as well as the compilation of enzyme cocktails. / AFRIKAANSE OPSOMMING: Die gebruik van swamensieme om die verteerbaarheid van herkouervoere te verhoog, is ondersoek. Tussen 38 en 80 % van veselagtige voere se inhoud is tans onverteerbaar. 'n Hernieude belangstelling in die potensiaal van voerensieme vir herkouers word deur die hoë koste van veeproduksie, asook die beskikbaarheid van nuwe ensiempreparate gedryf Direkte byvoeging van ensiempreparate kan die in vitro droëmateriaal (DM) en neutrale onoplosbare vesel (NOV) vertering verbeter, wat daarop dui dat fibrolitiese ensieme wat direk gevoer word, effektief mag wees tydens die in vivo vertering van voer. Twee kommersiële ensiemprodukte, Fibrozyme en Celluclast, en die vier ekstrasellulêre ensieme van vier swamme, naamlik Aureobasidium pullulans, Trichoderma reesei, Aspergillus aculeatus, en Thermomyces lanuginosus is vir hul vermoë om die in vitro verteerbaarheid van voere te verbeter getoets. Byvoeging van Fibrozyme by beide koringstrooi en lusernhooi het geen verbetering in hulonderskeie in vitro verteerbaarheid tot gevolg gehad nie, selfs nie eens na 'n twee uur vooraf inkubasieperiode nie. Koringstrooi se verteerbaarheid is nie verbeter deur die byvoeging van die vier swam-ensiempreparate nie, maar 'n minimale verbetering is wel waargeneem in die verteerbaarheid van lusernhooi. Byvoeging van Celluclast het 'n minimale verbetering in beide hawerhooi en hawerkuilvoer se verteerbaarheid tot gevolg gehad, maar geen effek op lusernhooi of NaOH-behandelde koringstrooi se verteerbaarheid nie. Geen verwantskap is tussen die vlak van ensiemaktiwiteit en die mate van vertering tydens die in vitro toets gevind nie. Ensiematiese afbraak met Celluclast, in die afwesigheid van rumenvloeistof, het meer konkrete resultate gelewer. Al die voermonsters het 'n positiewe respons op die byvoeging van Celluclast getoon, selfs ook die minder verteerbare voere, nl. suikerrietbagasse en koringstrooi. In die wyer konteks was die resulate van die in vitro verteringstoetse egter onbeduidend as gevolg van groot variasie in die metings. Alternatiewe voerontledingstoetse, wat moontlik beter resultate mag lewer, sluit in in vivo, in sacco en in situ analises, asook die meting van gasproduksie en in vitro analise met die DAISyII sisteem. 'n Meer uitgebreide studie van voerverteerbaarheid wat die bepaling van die afbraak van voere, hul chemiese samestelling, met ander woorde toeganklikheid van voere, en die ondersoek van voermengsels behels, behoort aandag te geniet. Die ensiemmengsels behoort ook ten opsigte van samestelling, optimum temperatuur en pH ondersoek teword.

Thesis (MScAgric)--Stellenbosch University, 2008. / ENGLISH ABSTRACT: Two in vitro experiments were conducted to evaluate the effect of exogenous fibrolytic enzyme application on dry matter (DM) and neutral detergent fibre (NDF) degradation and gas production (GP) of mature forages and forage-concentrate mixtures. The forages used in the first experiment were lucerne hay (LH), oat hay (OH) and wheat straw (WS). The same forages were used in the second experiment, but they were mixed with a concentrate feed to make three mixtures consisting of 80% (HC), 50% (MC) or 20% (LC) concentrate. The extracellular enzyme fraction (supernatant) of a fungal strain, ABO 374, was used as feed additive. The supernatant was used in a fresh (SU-ABO374) or lyophilized (CSIR-ABO374) form, the latter being reconstituted with water immediately before application. The liquid supernatants were applied to the incubation medium and not directly to the substrate, at a rate equivalent to 7.5 ml/kg feed DM. In the control treatments of both experiments, water was used instead of the liquid supernatants. For the DM and NDF degradability trials in both experiments, 500 mg forage samples were weighed into 50 x 50 mm dacron bags which were incubated anaerobically at 39ºC in 1.4L of a rumen liquid inoculated buffered medium in 2L fermentation jars. Bags from all treatments were removed after 2, 4, 8, 12, 24, 48, 72 and 96 h of incubation. For the gas production determinations, 500 mg of the respective substrate samples were weighed into 120 ml glass vials which were incubated for 96 h in 40 ml inoculated medium to which 0.5 ml of the respective enzyme solutions were added. Gas pressure was recorded manually with a digital pressure gauge after 2, 4, 8, 12, 24, 48, 72 and 96 h and pressure was converted to volume with a predetermined regression. The 96 h substrate residues were washed, dried, weighed and analyzed for NDF and OM. In both experiments the substrates differed in terms of DM and NDF degradability and gas production rates, but the enzyme treatments had no effect. The lack of response to enzyme application was ascribed to a number of factors, including the fact that enzyme application was into the incubation medium and not directly onto the substrates and also that no significant pre-incubation interaction time was allowed. The same preparations gave positive results in previous trials where they were applied directly onto the substrates and where a pre-incubation interaction time of 16 hours was allowed. (Key words: Exogenous enzymes, forages, concentrate based diets, DM and NDF degradation, gas production ) / AFRIKAANSE OPSOMMING: Die invloed van eksogene fibrolitiese ensieme op in vitro fermentasiekinetika van ruvoer- en gemengde voersubstrate. Twee in vitro-experimente is uitgevoer om die invloed van eksogene fibrolitiese ensieme op droëmateriaal (DM) en neutraal-onoplosbare vesel (NDF) degradering en gasproduksie (GP) van volwasse ruvoersubstrate en ruvoer-kragvoermengsels te bepaal. Ruvoere in die eerste eksperiment was lusernhooi (LH), hawerhooi (HH) en koringstrooi (KS). Dieselfde ruvoere is in die tweede eksperiment gebruik, maar hulle is met ‘n kragvoer gemeng om drie mengsels te maak, bestaande uit 80% (HK), 50% (MK) of 20% (LK) kragvoer. Die ekstrasellulêre ensiemfraksie (supernatant) van ‘n fungiale stam, ABO 374, is as ‘n voertoedieningsmiddel gebruik. Die supernatant is is in ‘n vars (SU-ABO374) of gevriesdroogde (WNNR-ABO374) vorm gebruik, waar laasgenoemde onmiddellik voor toediening gerekonstitueer is. Die vloeistof-supernatante is nie direk op die substrate gevoeg nie, maar tot die inkubasiemedium gevoeg, teen ‘n hoeveelheid ekwivalent aan 7.5 ml/kg voer DM. In die kontrolebehandeling van beide eksperimente, is water in plaas van die vloeistofsupernatante gebruik. Vir die DM- en NDF-degraderingsproewe in beide eksperimente, is 500 mg van die onderskeie ruvoere in 50 x 50 mm dacronsakkies geweeg wat anaerobies by 39ºC geïnkubeer is in 1.4L van ‘n rumenvloeistof-geïnokkuleerde medium in 2L fermentasieflesse. Vir alle behandelings is sakkies na 2, 4, 8, 12, 24, 48, 72 en 96 h inkubasie verwyder. Vir gasproduksiebepalings is 500 mg van die onderskeie substraatmonsters in 120 ml glasbotteltjies geweeg en vir 96 h in 40 ml geïnokkuleerde medium geïnkubeer waarin 0.5 ml van die onderskeie ensiemoplossings gevoeg is. Gasdruk is na 2, 4, 8, 12, 24, 48, 72 en 96 h bepaal met behulp van ‘n digitale drukmeter en druk is met behulp van ‘n voorafbepaalde regressie na volume omgeskakel. Die 96 h substraatresidue is gewas, gedroog, geweeg en ontleed vir NDF en OM. In beide eksperimente het die substrate verskil ten opsigte van DM- en NDF-degradeerbaarheid en gasproduksietempo’s, maar die ensiembehandelings het geen invloed gehad nie. Die gebrek aan respons is aan verskeie faktore toegeskryf, insluitend die feit dat ensiemtoediening in die inkubasiemedium toegedien is en nie direk op die substrate nie, asook die feit dat daar nie ‘n noemenswaardige pre-inkubasie interaksietyd toegalaat is nie. Dieselfde ensiempreparate het positiewe resultate gelewer in vorige proewe waar dit direk op die substraat toegedien is en waar ‘n pre-inkubasie interaksietyd van 16 ure toegelaat is. (Sleutelwoorde: Eksogene ensieme, ruvoere, kragvoerdiëte, DM- en NDF-degradering, gasproduksie)