Thesis (DVSc (Production Animal Studies))--University of Pretoria, 2002. / Includes bibliographical references.

Orientador: Rafael Silvio Bonilha Pinheiro / Banca: Viviane Correira Santos / Banca: Jane Maria Bertocco Ezequiel / Resumo: A produção de volumosos para a alimentação animal através do sistema de integração lavoura-pecuária é uma alternativa para a recuperação de pastagens degradadas e para a produção de volumosos conservados de alta qualidade. Neste sistema, o consorcio de gramíneas com leguminosas pode ser uma estratégia para a produção de silagem, pois a fixação biológica de nitrogênio incrementa os teores e a disponibilidade desse nutriente no solo, consequentemente, melhorando o valor nutricional da silagem. Pesquisas em busca de alternativas para volumosos de melhor qualidade são fundamentais para a eficiência dos sistemas de produção de cordeiros, principalmente para o confinamento, pois a alimentação representa o maior custo neste sistema. O presente trabalho teve o objetivo de avaliar o efeito de volumosos, provindo de um sistema de integração lavoura-pecuária, sobre o desempenho, digestibilidade, produção de metano e dióxido de carbono entérico, comportamento ingestivo e a análise de custos da terminação de cordeiros ½ Dorper e ½ Santa Inês em confinamento, com dietas contendo concentrado e diferentes silagens (silagem de milho exclusivo, silagem de milho + Urochloa brizantha cv. Marandu e silagem de milho + Urochloa brizantha cv. Marandu + guandu-anão). O ganho médio diário (kg/dia), assim como o período em que os cordeiros permaneceram confinados, não foi influenciado pelas diferentes dietas. A utilização da silagem proveniente do consórcio do milho, Marandu e guandu-anão na dieta de cordeiros, proporcionou aumento no consumo de matéria seca (kg/dia) e acresceram os tempos dispendidos para ruminação, mastigação e distribuição da fibra fisicamente efetiva. As dietas mostraram rentabilidade favorável na terminação de cordeiros em confinamento; entretanto, o maior retorno econômico foi obtido com o sistema em que os animais foram alimentados com silagem... / Abstract: The production of forage to the feeding through the integrated crop-livestock system (ILP) is an alternative for the recovery of degraded pastures and the production of silage high quality. The consortium of grasses with legumes can be a strategy for the production of silage because the biological nitrogen fixation increases the levels and the availability of this nutrient in the soil, thus improving the nutritional value of the silage. Research in search of alternatives to bulky best quality are fundamental to the efficiency of sheep production systems, primarily for the confinement because food represents the largest cost in this system. The aimed of this study was to evaluate the effect of silage, coming from a crop-livestock integration system on performance, digestibility, production of CH4 and CO2 in vitro, feeding behavior and cost analysis termination lambs ½ Dorper ½ Santa Inês in feedlot, with diets consist of concentrated and different silages (corn silage; corn silage + Urochloa brizantha cv. Marandu and corn silage + Urochloa brizantha cv. Marandu + pigeon pea). Average daily gain (kg/day) and the period during which the lambs were confined, was not influenced by the different diets. The use of silage from corn consortium with Marandu and pigeon pea in the diet of lambs led to an increase in dry matter intake (kg/day) and further compounded the times spent for ruminating, chewing and distribution of physically effective fiber. Diets showed favorable profitability in finishing lambs in confinement; however, the greatest economic return was obtained with the system in which the animals were fed with silage corn. The diet containing corn silage in consortium with Marandu and pigeon pea provided increased crude protein intake (kg/day) compared to corn silage (0,273 and 0,238, respectively). The potential production of greenhouse gases, was lower for diets containing corn silage in consortium, ... / Mestre

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Typescript. / Digitized by Kansas Correctional Industries

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Typescript (photocopy). / Digitized by Kansas Correctional Industries

Call number: LD2668 .T4 1978 B83 / Master of Science

Thesis (MScAgric)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: The purpose of this study was to determine the essential amino acid requirements of beef cattle under feedlot conditions through evaluation of the duodenal and whole empty body essential amino acid compositions. To define the ideal protein required for growth, the whole empty body essential amino acid compositions of 8 beef steers (Simmental and Hereford crosses) was investigated. The amino acid composition of the components (carcass, metabolic organs and residual fraction), was pooled relative to their respective mass and protein contribution, resulting in the calculated whole empty body amino acid composition: arginine 6.81; histidine 2.69; isoleucine 4.02; leucine 6.96; lysine 7.43; methionine 2.01; phenylalanine 4.03; threonine 4.01; valine 5.30; tryptophan 0.82. Variations in profiles were found between scientific reports, either indicating that ratios change with growth and implants or possibly through genotype. The present study's body amino acid ratios were used to estimate dietary amino acid requirements through evaluation of the duodenal essential amino acid compositions from three different maize based feedlot diets. Although there was a general increase in the biological value of protein after rumen fermentation, the duodenal essential amino acids in comparison with the whole empty body recorded deficient/unbalanced profiles of essential amino acids for growth. The chemical scores suggested that the first-to-thirdlimiting amino acids in the duodenal digesta of beef cattle, that received three different commercially available feedlot diets, were: histidine, lysine, methionine/arginine (Diet 1), histidine, arginine, lysine (Diet 2) and arginine, methionine, histidine (Diet 3). Thedisproportionate duodenal amino acid concentrations obtained from the three diets, emphasise the necessity to enhance the intestinal delivery of amino acid profiles through different undegradable protein sources, with the objective to maximise protein utilisation and obtain the genetic potential for optimal growth in feedlot cattle. When amino acid requirements and flows to the duodenum were simulated using the Cornell Net Carbohydrate and Protein system (CNCPS), predictions indicated that lysine amino acid flow was limiting the metabolizable allowable average daily gain in Diet 1 and 3. Predicted profiles indicated that the order of limitation was: lysine, arginine, histidine (Diet 1), lysine, arginine, histidine, methionine (Diet 2) and lysine, arginine, histidine (Diet 3). The predicted profiles were in accordance with observed duodenal values, except for methionine that was observed limiting in Diet 1 and 3; however, the sequence and extent of limitation varied. Results indicate that prediction models have potential in predicting requirements; however there are still limitations for use to accurately define requirements for particular EAA's. From the present study, it is clear that the protein accretion was constrained by quantity and/or disproportionality of amino acids available for absorption. Further research should therefore be directed towards obtaining a more desirable array of amino acids to the lower digestive tract that is digestible, absorbable and an economically viable option for the feedlot operator. / AFRIKAANSE OPSOMMING: Aminosuurbehoeftes van Voerkraalbeeste Volgens die Duodenale en Totale Lee Liggaam Essensiele Aminosuur Profiel: Die doel van hierdie studie was om die essensiele aminosuur vereistes van vleisbeeste onder voerkraal toestande te bepaal deur die evaluering van die duodenale en totale lee liggaam essensiele aminosuursamesteilings. Om die idea Ie proteiene wat vir groei benodig word te definieer, is 'n ondersoek ingestel na die totale lee liggaam essensiele aminosuursamesteilings van 8 vleisbees osse (Simmetailer en Hereford kruise). Die aminosuursamesteiling van die komponente (karkas, metaboliese organe en residuele fraksie), se massa en proteien bydrae is gebruik om die totale lee liggaam aminosuursamestelling 5005 volg te bereken: arginien 6.81; histidien 2.69; isoleusien 4.02; leusien 6.96; lisien 7.43; metionien 2.01; fenielalanien 4.03; treonien 4.01; valien 5.3; triptofaan 0.82. Variasies in profiele tussen wetenskaplike verslae is gevind. Dit dui daarop dat groei en inplantings of moontlik genotipe 'n invloed op profiele kan he. Die huidige studie se liggaam aminosuurverhoudings is gebruik om die dieet aminosuurbehoeftes te skat deur evaluering van die duodenale essensiele aminosuursamesteilings van drie verskiilende mielie-gebaseerde voerkraal diete. Alhoewel daar 'n algemene toe name in die biologiese waarde van die proteien na rumen fermentasie was, het die duodenale essensiele aminosure in vergelyking met die totale lee liggaam, ongebalanseerde profiele van essensiele aminosure vir groei getoon. Die chemiese teilings toon aan dat die eerste-tot-derde-beperkende aminosure in die duodenale inhoud van vleisbeeste wat drie verskillende kommersieel beskikbare voerkraal diete ontvang het, soos volg is: histidien, lisien, metionieniarginien (Dieet 1), histidien, arginien, lisien (Dieet 2) en arginien, metionien, histidien (Dieet 3). Die ongebalanseerde aminosuur konsentrasies wat in die duodenum van die drie dlete verkry is, beklemtoon die noodsaaklikheid om die intestinale lewering van aminosuurprofiele te verbeter deur verskillende nie-degradeerbare proteien bronne te voer. Die doelwit moet wees om proteien verbruik te optimaliseer en daardeur die genetiese potensiaal vir optimale groei in voerkraalbeeste te bereik. Met die simulering van aminosuurbehoeftes en vloei na die duodenum van die drie standaard voerkraal diete met behulp van die "Cornell Net Carbohydrate and Protein System" (CNCPS), het voorspellings gewys dat lisien aminosuurvloei die metaboliseerbare toelaatbare gemiddelde daaglikse toename in Dieet 1 en 3 beperk het. Voorspelde profiele wys dat die volgorde van beperking soos volg sou wees: lisien, arginien, histidien (Dieet 1), lisien, arginien, histidien, metionien (Dieet 2)' en lisien arginien, histidien (Dieet 3). Die voorspelde profiele was in ooreenstemming met die waargeneemde duodenale waardes, behalwe vir metionien wat beperkend was in Dieet 1 en 3; die volgorde en mate van beperking was egter verskillend. Resultate wys dat voorspellingsmodelle die potensiaal het om behoeftes te voorspel. Vir die akkurate definisie van behoeftes vir spesifieke essensiele aminosuure is daar egter nog beperkinge. Uit die huidige studie, is dit duidelik dat protetenneerleqqinq deur die hoeveelheid en/of oneweredigheid van geabsorbeerde aminosure beperk is. Verdere navorsing moet dus fokus op die verkryging van In meer geskikte profiel van aminosure wat verteerbaar, opneembaar en 'n ekonomiese lewensvatbare opsie vir die voerkraalbestuurder is.

The movement of salts in soils following application of feedlot wastes was studied experimentally and theoretically. The objectives of the study were (1) to evaluate the movement of salts in the soil following heavy application of animal wastes as related to the aggregate sizes of manure and water management practices and (2) to develop a mathematical model to predict the movement of salts within the soil and manure mixture. In the experimental study, air dried manure was formed into three distinct sizes, small (to pass 40 mesh sieve), medium (0.9 am in diameter, 1.2 cm in length), and large (1.8 cm in diameter, 1.8 cm in length). Soil columns of 15 cm inside diameter were packed with 30 cm of a soil-manure mixture over a 10 cm depth of soil. The manure application rate was equivalent to 100 metric tons/ha calculated on the basis of the cross-sectional area of the column. A total of five pore volumes of water was passed through the soil under continuous and intermittent water applications. The leachates were collected in 1/2 pore volume increments and the volume, EC, and pH determined immediately. Within 48 hours of the sampling, the leachates were analyzed for Na, K, Ca, Mg, Cl, and five trace elements (Fe, Mn, Zn, Cu, and Ni). The EC of the leachate for the first 1/2 pore volume was significantly (1% level) highest for the small-sized aggregates and the lowest for the large aggregate treatments under both moisture regimes. During the second increment, the order was reversed. In the later water applications, the EC for small aggregates was higher than the other sizes. There were no significant differences between the EC of the leachate from medium and large aggregate treatments during the later periods under either water treatments. Under both moisture regimes, the amount of Na removed from small aggregates decreased more rapidly than the other sizes. More than 90% of the total Na added to the system by manure was removed from the small aggregate treatment. In contrast, the highest amount of K removed (895 mg from small-sized aggregates under continuous leaching' represents about 35% of the total amount present In the manure applied. More Ca was removed from the small-sized aggregate treatments under both moisture regimes than was added by manure application. As for Mg the pattern of the removal was similar to that of Ca. No Cl was detected in the leachate after the fifth 1/2 pore volume was displaced. A mathematical model was developed to predict the movement of readily soluble ions such as Na, K, and Cl from different aggregate sizes of manure. The theoretical curves were compared with earlier experimental data and the parameters appearing in the mathematical equation were estimated. The results for Cl, Na, and K are presented graphically, and the estimated parameters as well as the values of the square roots of the sum of the squares between the theoretical and experimental values as percentage of the sum of the experimental values (SSR) are reported. From the low value of SSR's, it is evident that the model can predict the movement of the readily soluble ions from different aggregate sizes of manure quite accurately. A discussion on the suitability of the model for different sizes of manure aggregates and also a comparison between two different procedures to fit the model to the experimental data are given. In addition, a three phase theoretical model was developed to describe the movement of readily soluble ions from a soil-manure-water system. Experimental data were used in testing the model. The results for Na, K, and Cl are presented graphically. Estimated parameters for the experimental system and the values of SSR are presented. This model also can predict the movement of readily soluble ions from a soil-manure-water system.