A bactéria Listeria monocytogenes é reconhecida como um importante patógeno humano estando amplamente distribuída no ambiente e é responsável pela contaminação de alimentos crus e processados. O mecanismo de patogenicidade é determinado pela presença de genes no cromossomo da bactéria e entre eles estão os genes iap e hly que são essenciais para o mecanismo de invasão e atividade hemolítica do microorganismo, respectivamente. O obejtivo do presente estudo foi confirmar as cepas de L. monocytogenes usando a ténica de PCR para o gene hly e análise da variação nucleotídica do domínio central do gene iap, que é caracterizado pela presença de seqüências repetidas dos aminoácidos treonina e asparagina. Vinte e seis cepas de L. mnocytogenes, previamente isoladas de produtos lácteos e identificdas por métodos clássicos, se mostraram positivas para a PCR espécie-específico e então submetidas à determinação da seqüência nucleotídica. Os resultados mostraram variações na seqüência nucleotídica contendo substituições, inserções, deleções e um número de seqüências similares entre as cepas isoladas e a cepa controle EGD-e. Vinte e três cepas exibiram a mesma deleção que compreende 24 pares de bases dentro da seqüência de repetição e alterações similares na proteína traduzida. Apenas três cepas mostraram tamanhos diferentes de deleções e diferentes alterações na proteína. De acordo com estes resultados, a maioria das cepas apresentou uma característica molecular comum, diferentes da cepa padrão e este perfil predominante pode ser considerado como a característica das L. monocytogenes isoladas de produtos lácteos no Sul do Brasil. / The bacterium Listeria monocytogenes is recognized as an important human pathogen being omnipresent in the environment and is responsible for contamination in raw and processed foods. The mechanism of pathogenicity is established by presence of some genes on chromosome of bacteria between them, iap and hly genes that are essential to the invasion mechanism and hemolytic activity of microorganism, respectively. The aim of present study was confirm the strain L. monocytogenes using PCR to hly gene and analysis the nucleotide variability of central domain of iap gene characterized by the presence of similar sequences of threonine and asparagine amino acids. Twenty-six strains previously isolated from dairy products and classified by classic methods to L. monocytogenes were positive to specie-specific PCR and than submitted to nucleotide sequence determination. The results showed a sequence variation containing nucleotide substitutions, insertions, deletions and a number of repeated sequences among the isolates and control strain EGD-e. Twenty-three strains exhibited the same gap that includes a deletion of 24 base pairs inside of the repeated sequence and similar alterations in the translated protein. Just three strains showed different sizes of gaps and different protein alterations. According to these results, the majority strains displayed a common molecular characteristic different from the strain pattern and this predominant profile can be considerate as characteristic to L. monocytogenes isolated from dairy products in South Brazil.

A bactéria Listeria monocytogenes é reconhecida como um importante patógeno humano estando amplamente distribuída no ambiente e é responsável pela contaminação de alimentos crus e processados. O mecanismo de patogenicidade é determinado pela presença de genes no cromossomo da bactéria e entre eles estão os genes iap e hly que são essenciais para o mecanismo de invasão e atividade hemolítica do microorganismo, respectivamente. O obejtivo do presente estudo foi confirmar as cepas de L. monocytogenes usando a ténica de PCR para o gene hly e análise da variação nucleotídica do domínio central do gene iap, que é caracterizado pela presença de seqüências repetidas dos aminoácidos treonina e asparagina. Vinte e seis cepas de L. mnocytogenes, previamente isoladas de produtos lácteos e identificdas por métodos clássicos, se mostraram positivas para a PCR espécie-específico e então submetidas à determinação da seqüência nucleotídica. Os resultados mostraram variações na seqüência nucleotídica contendo substituições, inserções, deleções e um número de seqüências similares entre as cepas isoladas e a cepa controle EGD-e. Vinte e três cepas exibiram a mesma deleção que compreende 24 pares de bases dentro da seqüência de repetição e alterações similares na proteína traduzida. Apenas três cepas mostraram tamanhos diferentes de deleções e diferentes alterações na proteína. De acordo com estes resultados, a maioria das cepas apresentou uma característica molecular comum, diferentes da cepa padrão e este perfil predominante pode ser considerado como a característica das L. monocytogenes isoladas de produtos lácteos no Sul do Brasil. / The bacterium Listeria monocytogenes is recognized as an important human pathogen being omnipresent in the environment and is responsible for contamination in raw and processed foods. The mechanism of pathogenicity is established by presence of some genes on chromosome of bacteria between them, iap and hly genes that are essential to the invasion mechanism and hemolytic activity of microorganism, respectively. The aim of present study was confirm the strain L. monocytogenes using PCR to hly gene and analysis the nucleotide variability of central domain of iap gene characterized by the presence of similar sequences of threonine and asparagine amino acids. Twenty-six strains previously isolated from dairy products and classified by classic methods to L. monocytogenes were positive to specie-specific PCR and than submitted to nucleotide sequence determination. The results showed a sequence variation containing nucleotide substitutions, insertions, deletions and a number of repeated sequences among the isolates and control strain EGD-e. Twenty-three strains exhibited the same gap that includes a deletion of 24 base pairs inside of the repeated sequence and similar alterations in the translated protein. Just three strains showed different sizes of gaps and different protein alterations. According to these results, the majority strains displayed a common molecular characteristic different from the strain pattern and this predominant profile can be considerate as characteristic to L. monocytogenes isolated from dairy products in South Brazil.

Made available in DSpace on 2015-03-26T13:54:56Z (GMT). No. of bitstreams: 1 texto completo.pdf: 62641 bytes, checksum: a95abae0f8848a60ac3a88dc7e600185 (MD5) Previous issue date: 2006-02-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Sixty lactating sows, with differents parities orders, were used to evaluate the effect of digestible threonine levels on the productive and reproductive performance, during period of lactation of 16.14 days. The animals were assigned to a randomized completely design, with four treatments and fifteen replicates. The sow was considered the experimental unity. The experimental diets were consisted of four levels of digestible threonine, 0.608; 0.646; 0.684; 0.722%, corresponding the ratios of digestible threonine:digestible lysine of 64, 68, 72 and 76%, respectively. No effects of digestible threonine levels of diets on productive and reproductive performance of sows were observed The intake of digestible threonine increased linearly among treatments. No effects of treatments were observed for weight gain of piglets. It can be concluded that the level of 0.608% of digestible threonine, corresponding of digestible threonine:digestible lysine ratio of 64% attend the requirements of digestible threonine of lactation sows, during period of lactation of 16.14 days. / Sessenta matrizes em lactação, de diferentes ordens de parto, foram utilizadas para avaliar o efeito de níveis de treonina digestível sobre o desempenho produtivo e reprodutivo, durante um período de lactação de 16,14 dias. Os animais foram distribuídos em delineamento inteiramente casualizado, com quatro tratamentos, quinze repetições por tratamento, sendo a porca considerada a unidade experimental. As rações experimentais foram constituídas de quatro níveis de treonina digestível, 0,608; 0,646; 0,684; 0,722 correspondentes a relações com a lisina digestível de 64, 68, 72 e 74%, respectivamente. Não se observou efeito dos níveis de treonina digestível da ração sobre os parâmetros produtivos e reprodutivos das porcas em lactação. Houve efeito dos tratamentos sobre o consumo de treonina digestível, que aumentou de forma linear. O ganho de peso dos leitões não foi influenciado pelos tratamentos. Concluiu-se que o nível de 0,608%, correspondente a relação treonina digestível:lisina digestível de 64%, atende as exigências de treonina digestível para porcas durante um período de lactação de 16,14 dias.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Neste trabalho, cristais de treonina (C4H9NO3) nas formas L e D foram submetidos à anÃlises atravÃs da tÃcnica de espectroscopia Raman. Inicialmente realizou-se uma identificaÃÃo de todas as bandas Raman para as duas amostras por comparaÃÃo com dados de outros trabalhos de espectroscopia Raman em aminoÃcidos. Em uma segunda etapa obteve-se os espectros do material variando o parÃmetro termodinÃmico de pressÃo hidrostÃtica. Para a D-treonina a regiÃo espectral para os experimentos realizados em funÃÃo da pressÃo hidrostÃtica esteve no intervalo de frequÃncia entre aproximadamente 30 cm-1 e 600 cm-1 e a variaÃÃo da pressÃo entre 0,0 GPa e 8,5 GPa. Os resultados mostram que o cristal de D-treonina sofreu duas transiÃÃes de fase estruturais, primeiro no intervalo de pressÃo entre 1,9 e 2,4 GPa e a segunda no intervalo de pressÃo entre 5,1 e 6,0 GPa. Os cristais da forma L foram revistos atà a pressÃo de 27,0 GPa no intervalo de frequÃncia entre aproximadamente 50 cm-1 e 3300 cm-1. ModificaÃÃes associadas aos modos externos indicam que o material sofreu trÃs transiÃÃes de fase reversÃveis: a primeira em 1,6 GPa, a segunda em 9,2 GPa e uma terceira em 15,5 GPa. A comparaÃÃo com um trabalho anterior sobre o L-confÃrmero tambÃm à fornecida. / In this work, crystals threonine (C4H9NO3) in the forms L and D were subjected to analysis by Raman spectroscopy. Initially there was an attempt to identify all of the Raman bands for the two samples by comparison with data from other work Raman spectroscopy of amino acids. In a second step we obtained the spectra of the material by varying the thermodynamic parameter hydrostatic pressure. For the D-threonine spectral experiments for the hydrostatic pressure due region was in the range of frequencies between approximately 30 cm-1 and 600 cm-1 and the change in pressure between 0.0 GPa and 8.5 GPa. The results show that the crystal D-threonine undergone two structural phase transitions, the first pressure range between 1.9 and 2.4 GPa and the second pressure range between 5.1 and 6.0 GPa. The crystals of the L-form were reviewed by the pressure of 27.0 GPa in the frequency range between approximately 50 cm-1 and 3300 cm-1. Changes associated with the external modes indicate that the material suffered three reversible phase transitions: the first at 1.6 GPa, 9.2 GPa in the second and a third at 15.5 GPa. A compared with a previous work on L-conformer is also provided.

Orientador: Gabriel Forato Anhê / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-25T19:01:58Z (GMT). No. of bitstreams: 1 Araujo_ThiagoMatosFerreirade_D.pdf: 1239554 bytes, checksum: 87d5fc958173ca83a217021c9d866455 (MD5) Previous issue date: 2014 / Resumo: A obesidade é caracterizada pela deposição ectópica de gordura no fígado. Este acúmulo de gordura hepática (NAFLD) pode gerar consequências graves, como a hepatite não alcoólica (NASH), fator de ricos para carcino hepatocelular (HCC). A morte de hepatócitos, evento chave na evolução da NAFLD para NASH, é causada pelo excesso de nutrientes e é dependente do estresse de retículo endoplasmático (RE). O estresse no RE resulta no acúmulo de proteínas não processadas desencadeia a "unfolded protein response" (UPR), podendo gerar apoptose. A mTOR é formada basicamente por dois complexos: mTOR1 e mTOR2; ambos são sensíveis a nutrientes, a insulina e a rapamicina. O complexo mTOR2/Rictor catalisa a fosforilação da AKT, aumentando a sinalização da insulina. Deste modo, o objetivo deste trabalho foi avaliar a relação entre ativação da mTOR, do estresse de RE e da apoptose em hepatócito expostos a ácidos graxos livres. Observamos que a apoptose causada pelo palmitato ativa o estresse de RE de maneira tempo dependente. Não observamos alterações na fosforilação de proteínas alvo específicas para o complexo mTOR1. No entanto, a fosforilação geral da mTOR foi estimulada pelo palmitato. Altas doses de rapamicina inibiram a apoptose e do estresse de RE causado pelo palmitato, sugerindo a participação do complexo mTOR2. Estes resultados ainda foram confirmados pelo silenciamento gênico da Rictor. A fosforilação em serina 473 da AKT apresenta um caráter transitório, elevando-se em tempos que precedem morte e o estresse de RE, e diminuindo em tempos prolongados concomitantemente à apoptose. A inibição da AKT pelo "AKT inhibitor" gerou diminuição da apoptose, do estresse de RE e da incorporação lipídica na linhagem de hepatoma. Estes dados sugerem que a AKT, como alvo preferencial da mTOR2 é necessária para geração de morte e da UPR. A glicose (33.3mM) gera morte as células HepG2 e esta é inibida com baixas doses de rapamicina, mostrando possível atividade via mTOR1 nesta resposta. De outro modo, a frutose (4.5mM) que também desencadeia apoptose das células de hepatoma, tem seu efeito inibido por doses maiores de rapamicina, indicando atividade mTOR2 neste processo. No entanto, a possibilidade de diferentes monossacarídeos recrutarem complexos diferentes de mTOR para desencadear apoptose ainda precisa ser melhor explorada / Abstract: Obesity is characterized by fat ectopic deposition in liver. This hepatic fat accumulation our non-alcoholic fat liver disease (NAFLD) can have serious consequences such as non-alcoholic hepatitis (NASH), that is a factor to liver cancer. The cell death of hepatocytes is an important event in the development to NAFLD to NASH, all that are caused by excess nutrients and dependent of endoplasmic reticulum (ER) stress. The ER stress is caused by accumulation of unfolded proteins triggers the unfolded protein response (UPR), which mau cause apoptosis. mTOR is basically formed by two complexes: mTOR1 and mTOR2, both are sensitive to nutrients, insulin and rapamycin. The mTOR2/Rictor complex catalyse AKT phosphorylation increasing the insulin pathway. All together, the aim of this study was evaluate the relationship between mTOR, ER stress and apoptosis in liver cells exposed to free fatty acids. We observed that apoptosis caused by palmitate activates ER stress in a manner dependent on time. We din¿t observed changes in phosphorylation of specific target proteins to mTOR1 complex. However, a general phosphorylation of mTOR was stimulated by palmitate. High doses of rapamycin inhibited apoptosis and ER stress caused by palmitate, suggesting the participation of the mTOR2 complex. These results were further confirmed by gene silencing of Rictor. The AKT phospholylation in serine 473 has a transitional character, rising in times that preceding cell death and ER stress, and decreasing concomitantly apoptosis in prolonged times. Inhibition of AKT by AKT inhibitor caused a decrease in apoptosis, ER stress and lipid incorporation in hepatoma cell line. These data suggest that AKT, preferential targets of mTOR2 is required for generation death and UPR. Glucose (33.3mM) generates HepG2 cell death and this is inhibited by low doses on rapamycin, showing possible mTOR1 activity. Otherwise, fructose (4.5mM) also triggers apoptosis of hepatoma cells; its effect is inhibited by higher doses of rapamycin, indicating mTOR2 activity in this process. However, the possibility of different monosaccharide recruit different complexes of mTOR to trigger apoptosis should be further explored / Doutorado / Farmacologia / Doutor em Farmacologia

Orientador: Gonçalo Amarante Guimarães Pereira / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-21T15:05:51Z (GMT). No. of bitstreams: 1 Almeida_GustavoPereirade_M.pdf: 7665145 bytes, checksum: 3fef8dc5d333834f8117015fea3b10ef (MD5) Previous issue date: 2012 / Resumo: A produção de energia por meio de fontes renováveis é uma exigência atual para se atingir uma economia sustentável. Os organismos fotossintetizantes surgem nesse contexto como ferramentas importantes na produção de compostos carbônicos ricos em energia, com destaque para microalgas em que tais compostos podem atingir até 80% do peso seco. Entretanto, um fator ainda desfavorável para sua utilização é o seu baixo rendimento na produção de biomassa. A espécie Chlamydomonas reinhardtii, por exemplo, é capaz de duplicar apenas algumas vezes durante 24 horas. As vias que controlam o crescimento celular, portanto, são alvos promissores para modificação genética. Dentre essas vias, à via de sinalização sensível à rapamicina aparece como um controlador central. Com o intuito de entender melhor como esse controle é exercido ao nível da expressão gênica global, foi utilizado a ferramenta de sequenciamento de RNA em larga escala para obtenção dos transcriptomas de culturas (sincronizadas) sob inibição dessa via e na condição controle, em oito momentos ao longo de um ciclo celular de 24h. O controle exercido por essa via sobre o metabolismo e sobre o ciclo celular foi o foco das análises. Foi encontrado que a inibição da via da TOR é capaz de gerar uma resposta de direcionamento parcial do metabolismo para a produção de TAG em detrimento de moléculas complexas como proteínas. Esse direcionamento foi considerado parcial devido à ocorrência concomitante de reações catabólicas. Outros dados obtidos sugerem que a via da TOR, além de regular o metabolismo de uma maneira geral e diversas funções celulares, também exerce influência sobre o progresso do ciclo celular e sua inibição resulta no atraso do desenvolvimento das fases do ciclo. Diversos fatores reguladores da transcrição envolvidos no desenvolvimento, no crescimento e na regulação do ciclo celular, foram encontrados diferencialmente expressos e constituem possíveis genes chave no controle do crescimento. Eles representam alvos em potencial para modificação genética com intuito de otimizar as taxas de crescimento na primeira etapa do sistema de produção. Na busca de alternativas aos processos atuais de indução do acúmulo de cadeias carbônicas, os efeitos da combinação rapamicina e via da TOR representam uma abordagem interessante para pesquisas futuras para viabilização da utilização de microalgas como fonte de energia. Este estudo possibilitou um melhor entendimento da atuação da via da TOR no crescimento e progresso do ciclo celular em C. reinhardtii ao nível de expressão gênica / Abstract: The energy production through renewable sources is an actual demand for achieving a sustainable economy. In this context, photosynthesizing organisms come to light as important tools for the production of energy-rich carbonic compounds, especially the microalgae, in which these compounds can reach up to 80% of the dry weight. However, an unfavorable factor for its utilization is the low yield of biomass production. The species Chlamydomonas reinhardtii, for instance, is capable of achieving only some duplication after 24 hours. The pathways that control cell growth are therefore promising targets for genetic modification. Among them, the rapamycin-sensitive signaling pathway emerges as a central controller. With the aim of better understanding how this control is fulfilled by the means of global gene expression, the high throughput RNA sequencing technology was used. With it, the synchronized cultures transcriptome under the inhibition of this pathway and in the control condition, of eight points during a cellular cycle of 24 hours, were obtained. The metabolism and the cell cycle control by the TOR pathway was the main focus of the analysis. It was found that the inhibition of this pathway is capable to partially draw the metabolism towards TAG production to the detriment of producing more complex chains as proteins. This directing was considered partial due to the concomitant occurrence of catabolic reactions. Other data suggested that the TOR pathway, apart from the metabolism regulation in a general way and regulation of many other cellular functions, also influence the cell cycle progression and its inhibition retards the development of cell phases. Several transcription regulators involved in development, growth and cell cycle regulation were found out to be differentially expressed and are likely to constitute key genes in growth control. They represent potential targets for genetic modification aiming the optimization of growth rate in the first step of the production system. In the search for alternatives to the current process of inducing carbon chain accumulation, the effects of the combination between rapamycin and TOR pathway represent an interesting approach for future research intending to turn the utilization of microalgae as an energy source into a feasible option. This study enabled a better understanding of the role of the TOR pathway in growth and cell cycle progression of C. reinhardtii at the level of gene expression / Mestrado / Genetica de Microorganismos / Mestre em Genética e Biologia Molecular

Thesis (M.Sc. (Animal Production)) --University of Limpopo, 2019 / Two experiments were conducted to determine the effect of dietary threonine level on production performance and carcass characteristics of Ross 308 broiler chickens. In each experiment the diets were isocaloric and isonitrogenous but with different dietary threonine levels.The first part of the study determined the effect of dietary threonine level on feed intake, growth rate, mortality and carcass characteristics of Ross 308 broiler chickens aged between Day 1-21. A total of 150 unsexed day-old chicks were used in a complete randomized design having 5 treatments (6.4, 7.5, 8, 8.5 and 9g of threonine/kg DM feed), replicated three times and having ten chickens per replicate. The second part of the study determined the effect of dietary threonine level on feed intake, digestibility, growth rate, mortality and carcass characteristics of male Ross 308 broiler chickens aged between Day 22-42. Seventy-five male chickens were used in a complete randomized design having 5 treatments (6.4, 7.5, 8, 8.5 and 9g of threonine/kg DM feed), replicated three times and having five chickens per replicate. A quadratic regression model was used to determine the optimal productivity of the chickens while a General Linear Model (GLM) procedures for the statistical analysis of variance was used to detect dietary treatment effects. Where there were significant differences (P<0.05), Turkey’s honestly significant difference test (HSD) was used for mean separation. The chickens were slaughtered at the ages of 21 and 42 days for Experiments 1 and 2, respectively, following ethical standards as recommended by the University of Limpopo Animal Research Ethics Committee (AREC/12/2017: PG). Two chickens per replicate for both studies were slaughtered for the determination of carcass characteristics (carcass and organ weights, gut organ digesta pH and gastro-intestinal length measurements). Dietary threonine levels used in this experiment affected (P<0.05) feed intake, growth rate, live weight, metabolisable energy (ME) intake, nitrogen retention, feed conversion ratio and gut organ weights and lengths of unsexed Ross 308 broiler chickens aged 21 days. Dietary threonine level did not affect (P>0.05) diet digestibility. Feed conversion ratio, pH of the proventriculus digesta, gut intestine length and caecum length of unsexed broiler chickens were optimized at different dietary threonine levels of 9.6, 8.5, 6.6 and 8.4 g/kg DM, respectively. Dietary threonine levels had an effect (P<0.05) on feed intake, diet digestibility, metabolizable energy, live weight, proventriculus pH values, GIT length, gut organ and carcass organ weights of male Ross 308 broiler chickens between 22 to 42 days of age. Proventriculus and large intestine weights were optimized at different dietary threonine levels of 7.5 and 9.1 g/kg DM feed, respectively. Dietary threonine level did not affect (P>0.05) growth rate, feed conversion ratio of male Ross 308 broiler chickens between 22 to 42 days of age. It is concluded that dietary threonine levels used in this study affected production performance of younger broilers (Day 1-21) more than that of older birds (Day 22-42). However, production variables were optimized at different dietary threonine levels. This has implication on diet formulation for the chickens and no linear response could be established / National Research Foundation (NRF), and the Department of Agriculture, Forestry and Fisheries (DAFF)

(M.Sc. (Animal Production)) -- University of Limpopo, 2014 / Two experiments were conducted to determine the effect of dietary threonine level on productivity and carcass characteristics of indigenous Venda chickens. In each experiment the diets were isocaloric and isonitrogenous but with different dietary threonine levels. A complete randomized design was used in both experiments, the starter (1-7 weeks old unsexed chickens) and finisher (8-13 weeks old female chickens) experiments. The treatments were CT4 (4 g of threonine/kg DM), CT5 (5 g of threonine/kg DM), CT6 (6 g of threonine/kg DM), CT7 (7 g of threonine/kg DM) and CT8 (8 g of threonine/kg DM). A quadratic type of equation was used to determine dietary threonine levels for optimal feed intake, growth rate, feed conversion ratio, live weight, metabolisable energy intake and nitrogen retention of unsexed Venda chickens aged one to seven weeks. Dietary threonine level affected (P<0.05) feed intake, growth rate, feed conversion ratio, live weight, metabolisable energy and nitrogen retention. However, feed intake, growth rate, feed conversion ratio, live weight, metabolisable energy and nitrogen retention of indigenous Venda chickens were optimized at different dietary threonine levels of 6.218, 6.437, 6.331, 6.655, 5.979 and 6.158 g/kg DM feed, respectively. Dietary threonine level did not affect (P>0.05) mortality rate of the chickens. The treatments for the second experiment were FT4 (4 g of threonine/kg DM), FT5 (5 g of threonine/kg DM), FT6 (6 g of threonine/kg DM), FT7 (7 g of threonine/kg DM) and FT8 (8 g of threonine/kg DM). Dietary threonine level had effect (P<0.05) on feed intake, growth rate, feed conversion ratio, live weight, metabolisable energy and nitrogen retention of female Venda chickens aged eight to 13 weeks. Feed intake, growth rate, feed conversion ratio, live weight, metabolisable energy intake and nitrogen retention of chickens were optimized at dietary threonine levels of 6.054, 6.142, 6.442, 6.201, 5.72 and 6.088 g/kg DM, respectively. However, dietary threonine level had no effect (P>0.05) on pH values of crop, proventriculus, gizzard, small intestine, large intestine and caecum of female Venda chickens aged 91 days. Carcass weights of female Venda chickens were affected (P<0.05) by dietary threonine level. Carcass, breast, drumstick, thigh, gizzard and liver weights of female Venda chickens aged 91 days were optimized at dietary threonine levels of 6.183, 6.201, 5.712, 5.847, 4.820 and 6.180 g/kg DM, respectively. Dietary threonine level v had effect (P<0.05) on crude protein and threonine contents of female Venda chicken meat. Meat crude protein and threonine contents of female Venda chickens aged 91 days were optimized at dietary threonine levels of 5.9 and 5.7 g/kg DM, respectively. Dietary threonine level had no effect (P>0.05) on meat flavour, tenderness and juiciness of female Venda chickens. However, meat flavour, tenderness and juiciness of female Venda chickens aged 91 days were optimized at dietary threonine levels of 5.977, 6.103 and 5.977 g/kg DM, respectively. No chicken deaths were observed. / National Research Foundation (NRF)

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