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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Par?metros de adaptabilidade e estabilidade para produ??o de gr?os, teores de prote?nas e minerais em feij?o-caupi (vigna unguiculata (l.) walp.) no semi?rido brasileiro

Da Silva, Danillo Oleg?rio Matos 16 March 2018 (has links)
Submitted by Verena Pereira (verenagoncalves@uefs.br) on 2018-07-17T21:59:57Z No. of bitstreams: 1 Tese Final_ Danillo Olegario.pdf: 8604713 bytes, checksum: 2e0a9905d4de264fbbd3a8997c3babb3 (MD5) / Made available in DSpace on 2018-07-17T21:59:57Z (GMT). No. of bitstreams: 1 Tese Final_ Danillo Olegario.pdf: 8604713 bytes, checksum: 2e0a9905d4de264fbbd3a8997c3babb3 (MD5) Previous issue date: 2018-03-16 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The goals of this work were to compare and evaluate statistical methods of analysis of adaptability and stability for total protein, minerals and grain yield in cowpea lines, as well as retention of these nutrients after cooking to enable recommendation and registration of new cultivars for the Brazilian semiarid. Forty-four genotypes, distributed in two experiments of different population densities, were evaluated in seven environments, in the states of Bahia, Cear?, Pernambuco and Piau?. Initially, a comparison was made of ten statistical methods of adaptability and stability using only the production data. Spearman correlation coefficients were estimated between the methods. For the assessments of adaptability and stability of the genotypes the methods of Eberhart and Russell, Lin and Binns and the Model of main additive effects and multiplicative interaction - AMMI were applied. To evaluate the effect of cooking, 24 genotypes were used, including ten lines, five commercial cultivars and nine landraces maintained by farmers. The seed protein content was quantified through the Kjeldahl method. and the minerals by the AOAC standard procedure. The statistical analyzes for the experimental designs were performed in the SAS by the GLM procedure. The AMMI method is most suitable due to the graphical arrangement of both the genotypes and the environments and high correlation with others evaluated methods. The use of highly correlated methods is not recommended, as in the cases of Plaisted and Peterson and Wricke and the methods of Annicchiarico and Lin and Binnsthat show strong association and produce similar genotypic classifications. The use of one of them incombination with that of Eberhart and Russell or AMMI can add information to the stability analysis. Statistically significant differences in the genotype as well as in the genotype?environment interaction for minerals, proteins and grain yield were observed in all the assays. The lines presenting the highest protein contents showed the lowest grain yields, and it indicated the prominent ?phenotypic cost? of protein in overall cowpea seed production. The methods by Eberhart and Russell, Lin and Binns and AMMI showed similar results for selection of superior genotypes. For the protein content, the lines C3Q, C3M, C2S and C1J presented grain yields equal to or greater than the general mean of the experiments and average of 27% of protein. For iron and zinc contents, the line C4I and T16_2R presented grain yield equal to or greater than the general mean of the experiments, with mean values of Fe and Zn 15% higher than the values of the evaluated cultivars. For the potassium and calcium contents, the C4I and C3O strains showed grain yield equal to or greater than the general average, with K and Ca means higher than the values of the cultivars evaluated. All the lines mentioned above presented broad adaptability and good stability in the series of evaluated environments showing great potential to be released as new cultivars for the Brazilian semiarid. Cooking had a reduced effect on protein, potassium, calcium, iron and zinc contents in the cowpea beans. The CPCR3F6L17 obtained high grain yield and high levels of protein, potassium, iron and zinc, after cooking, being promising for the region studied / Os objetivos deste trabalho foram comparar e avaliar m?todos estat?sticos de an?lise de adaptabilidade e estabilidade para o teor de prote?nas totais, minerais e produ??o de gr?os em linhagens de feij?o-caupi, bem como a reten??o desses nutrientes ap?s a coc??o, para possibilitar a recomenda??o e registro de novos cultivares para o semi?rido brasileiro. Quarenta e quatro gen?tipos, distribu?dos em dois experimentos de diferentes densidades populacionais, foram avaliados em sete ambientes, nos estados da Bahia, Cear?, Pernambuco e Piau?. Inicialmente, foi realizado acompara??o de dez m?todos estat?sticos de adaptabilidade e estabilidade utilizando apenas dados de produ??o. Coeficientes de correla??o Spearman foram estimados entre os m?todos. Para as avalia??es de adaptabilidade e estabilidade dos gen?tipos aplicou-se os m?todos de Eberhart e Russell, Lin e Binns e o Modelo de efeitos aditivos principais e intera??o multiplicativa - AMMI. Para avaliar o efeito da coc??o, foram utilizados 24 gen?tipos, sendo dez linhagens, cinco cultivares comerciais e nove variedades mantidas por agricultores.A quantifica??o de prote?na total foi realizada pelo m?todo de Kjeldhal, e os minerais pelo procedimento padr?o da AOAC. As an?lises estat?sticas para os delineamentos experimentais foram efetuadas no SAS pelo procedimento GLM. O m?todo AMMI ? o mais indicado devido a disposi??o gr?fica e alta correla??o com os demais m?todos. A utiliza??o de m?todos que apresentam elevada correla??o, como os m?todos Plaisted e Peterson e Wricke, Annicchiarico e Lin e Binns, que mostram forte associa??o, e produzem classifica??es genot?picas similares, n?o ? recomendado. O uso de um deles em combina??o com o de Eberhart e Russell ou AMMI pode agregar informa??o ? an?lise de estabilidade. Foram observadas diferen?as estat?sticas significativas dos quadrados m?dios de tratamentos, dos ambientes e das intera??es ambientes x tratamentos para minerais, prote?nas e produ??o de gr?os. As linhagens que apresentaram os maiores teores de prote?na e minerais apresentaram produ??es de gr?os abaixo da m?dia geral, nos dois experimentos. Os m?todos de Eberhart e Russell, Lin e Binns e o AMMI apresentam resultados semelhantes quanto a sele??o de gen?tipos superiores. Para o teor de prote?na, As linhagens C3Q, C3M, C2S e C1J apresentaram produ??es de gr?os igual ou superior a m?dia geral dos experimentos e m?dia de 27% de prote?na. Para os teores de ferro e zinco, a linhagem C4I e T16_2R apresentou produ??o de gr?os igual ou superior a m?dia geral dos experimentos, com valores m?dios de Fe e Zn, 15% superiores aos valores dos cultivares avaliados. Para os teores de pot?ssio e c?lcio, as linhagens C4I e C3O mostraram rendimento de gr?os igual ou maior do que a m?dia geral, com m?dia de K e Ca mais elevadas do que os valores dos cultivares avaliados. Todas as linhagens citadas anteriormente apresentaram ampla adaptabilidade e boa estabilidade na s?rie de ambientes avaliados mostrando grande potencial para serem lan?ados como novos cultivares para o semi?rido brasileiro. A coc??o teve efeito reduzido nos teores de prote?na, pot?ssio, c?lcio, ferro e zinco, nos gr?os de feij?o-caupi. A linhagem CPCR3F6L17 obteve alta produtividade de gr?os e elevados teores de prote?na, pot?ssio, ferro e zinco, ap?s a coc??o, mostrando-se promissora para a regi?o estudada
2

Intera??o gen?tipo x triptofano: lisina em codornas de corte via normas de rea??o / Genotype interaction x triptofan: lysine in cutting quality via reaction norms

Alc?ntara, Diego Coimbra 31 October 2016 (has links)
Linha de pesquisa: Melhoramento animal. / Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2017-09-29T00:35:26Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) diego_coimbra_alcantara.pdf: 1887370 bytes, checksum: 3b18dc6adcb9630901b41a57c4a4a351 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2017-10-09T14:23:40Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) diego_coimbra_alcantara.pdf: 1887370 bytes, checksum: 3b18dc6adcb9630901b41a57c4a4a351 (MD5) / Made available in DSpace on 2017-10-09T14:23:40Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) diego_coimbra_alcantara.pdf: 1887370 bytes, checksum: 3b18dc6adcb9630901b41a57c4a4a351 (MD5) Previous issue date: 2016 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Funda??o de Amparo ? Pesquisa do estado de Minas Gerais (FAPEMIG) / Objetivou-se com este estudo, caracterizar a intera??o gen?tipo x ambiente em codornas de corte, alimentadas com dietas contendo diferentes rela??es de triptofano:lisina, via normas de rea??o. Para realizar o experimento foram utilizadas duas linhagens de codornas de corte, LF1 e LF2. A ra??o fornecida no per?odo de crescimento, nascimento aos 21 dias de idade, continha uma rela??o de 0,20% de triptofano:lisina, e no per?odo final do crescimento, 22 a 35 dias, as codornas foram separadas em 5 tratamentos com as rela??es: 0,15; 0,20; 0,25; 0,30; 0,35% de triptofano:lisina. As aves foram pesadas aos 28 e 35 dias e abatidas aos 35 dias de idade. As caracter?sticas avaliadas foram os pesos pr?-abate, peso 28, peso 35, peso e rendimentos da carca?a, peito, coxa+sobrecoxa e as caracter?sticas de qualidade da carne. As an?lises foram realizadas utilizando modelos de regress?o aleat?ria considerando efeito fixo de sexo e o efeito aleat?rio gen?tico aditivo direto como fun??es das rela??es triptofano:lisina da dieta, admitindo-se homogeneidade de vari?ncia residual. Os resultados para desempenho, caracter?sticas de carca?a e caracter?sticas de qualidade da carne indicam que o coeficiente de regress?o do intercepto (b0), foi maior que o coeficiente de regress?o aleat?rio (b1). A herdabilidade e a vari?ncia gen?tica aditiva foram influenciadas pelas diferentes rela??es triptofano:lisina da dieta. Houve intera??o gen?tipo x ambiente para as caracter?sticas rendimento de carca?a, rendimento de peito e rendimento de coxa+sobrecoxa. As caracter?sticas de qualidade da carne CRA, b*, c* e H* (LF1) e CRA, PPC, L* e H* (LF2) apresentaram intera??o gen?tipo x ambiente. A intera??o gen?tipo x ambiente observada para as caracteristicas de rendimento e qualidade da carne indicam que a sele??o seja feita na rela??o triptofano:lisina em que as codornas ser?o criadas. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Zootecnia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016. / We animed of this experiment was to characterize the genotype x environment interaction in the production of meat quails, fed diets containing different tryptophan:lysine ratios, via reaction standards. Two lines of cutting quails, LF1 and LF2, were used to perform the experiment. The feed provided in the growing period, from birth to 21 days, contained a 0.20% tryptophan:lysine ratio and in the final growth period, from 22 to 35 days of age, quails were separated into 5 treatments containing the Ratios of 0.15; 0.20; 0.25; 0.30; 0.35% tryptophan: lysine. The birds were weighed at 28 and 35 days of age and slaughtered at 35 days of age. The evaluated characteristics were the pre-slaughter weights, weight 28, weight 35, weight and yields of the carcass, breast, thigh + sobrecoxa and the quality traitsof the meat. The analyzes were performed using random regression models considering fixed sex effect and direct additive genetic random effect as functions of the tryptophan:lysine ratios of the diet, assuming homogeneity of residual variance. The results for performance, carcass traitsand meat quality traitsindicate that the regression coefficient of the intercept (b0) was higher than the random regression coefficient (b1). Heritability and additive genetic variance were influenced by the different tryptophan:lysine ratios of the diet. There was no genotype x environment interaction for the traitsof carcass yield, yield of breast and yield of thigh + overcoat. The quality traits of the meat CRA, b *, c * and H * (LF1) and CRA, PPC, L * and H * (LF2) presented genotype x environment interaction. It is possible to conclude that for yield traitsthe selection can be made in the lowest tryptophan: diet lysine ratios. For meat quality traitsthe sensitivity of the values indicates that the selection must be made in the tryptophan:lysine ratio in which the quails will be created.
3

Sensibilidade de valores gen?ticos de til?pias do Nilo, variedade tailandesa, aos n?veis de lisina digest?vel das dietas

Campideli, Thaiza da Silva 15 May 2017 (has links)
Incluir como ag?ncias financiadoras: Funda??o de Amparo ? Pesquisa do Estado de Minas Gerais (FAPEMIG), Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES), Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq). / Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2018-01-05T18:15:19Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) thaiza_silva_campideli.pdf: 3972827 bytes, checksum: d46dcbd4e39c922c90034d3992c8ad54 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2018-01-19T16:55:01Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) thaiza_silva_campideli.pdf: 3972827 bytes, checksum: d46dcbd4e39c922c90034d3992c8ad54 (MD5) / Made available in DSpace on 2018-01-19T16:55:01Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) thaiza_silva_campideli.pdf: 3972827 bytes, checksum: d46dcbd4e39c922c90034d3992c8ad54 (MD5) Previous issue date: 2017 / Esta pesquisa foi realizada com o objetivo de avaliar a sensibilidade dos valores gen?ticos aos n?veis diet?ticos de lisina digest?vel para caracter?sticas de desempenho e medidas morfom?tricas de til?pias do Nilo da linhagem tailandesa. Vinte e nove fam?lias de irm?os completos foram produzidas pelo acasalamento de 21 machos e 29 f?meas. A distribui??o entre os tanques foi feita aleatoriamente, por fam?lia, ap?s marca??o dos peixes, entre 94 a 109 dias de idade, at? formar um lote inicial de vinte alevinos por tanque, totalizando 700 peixes. ? idade aproximada de 150 dias os peixes foram aleatoriamente redistribu?dos no sistema, at? formar lotes com aproximadamente 138 peixes por n?vel de lisina digest?vel na dieta. Os peixes foram alimentados quatro vezes ao dia com dietas contendo diferentes n?veis de lisina digest?vel: 1,43; 1,53; 1,63; 1,73; e 1,83% nas idades entre 94 a 150 dias; e 1,28; 1,38; 1,48; 1,58 e 1,68% a partir da idade de 150 at? 255 dias. As informa??es individuais das til?pias (peso, comprimento total, comprimento padr?o, comprimento de cabe?a, altura e largura) foram padronizadas para 150, 185, 220 e 255 dias de idade. A partir de ent?o foram calculados o ganho de peso total, o ganho de peso di?rio, rela??o entre cabe?a e comprimento padr?o, rela??o entre largura e altura e a rela??o entre comprimento padr?o e comprimento total. Para as an?lises foi utilizado modelo de regress?o aleat?ria, sob modelo animal uni-caracter?stica. Foram testados modelos de ordens 2 e 3 do polin?mio de Legendre para o efeito fixo e ordem 2 para os efeitos gen?tico aditivo e de fam?lia e testados modelos com vari?ncia residual homog?nea (1classe) a heterog?nea (2, 3, e 4 classes). Os modelos que proporcionaram melhor ajuste na maioria das caracter?sticas foram os que consideraram vari?ncia residual homog?nea. De forma geral, os valores da correla??o de posto foram altas. As normas de rea??o de 25 til?pias tailandesas amostradas aleatoriamente indicaram altera??o na sensibilidade dos valores gen?ticos de algumas caracter?sticas ?s mudan?as no n?vel nutricional de lisina digest?vel. Observou-se, portanto, que as til?pias apresentam altera??o nos valores gen?ticos, sugerindo de maneira geral, a exist?ncia da intera??o gen?tipo x n?veis de lisina digest?vel para caracter?sticas, o que pode acarretar em sele??o de diferentes animais nos diferentes ambientes. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Zootecnia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017. / This research was carried out with the aim of evaluating the sensitivity of breeding values to dietary digestible lysine level for performance traits and morphometric measurements of Nile tilapia of Thai lineage. Twenty-nine full sib families were produced by mating 21 males and 29 females. The distribution among the tanks was randomized by family, after marking the fish, between 94 and 109 days of age, until forming an initial batch of twenty fingerlings per tank, totaling 700 fish. At the approximate age of 150 days the fish were randomly redistributed into the system until they formed lots with approximately 138 fish per level of digestible lysine in the diet. Four times a day the fishes were fed diets containing different levels of lysine: 1.43; 1.53; 1.63; 1.73 and 1.83% in the growing phase; and 1.28; 1.38; 1.48; 1.58 and 1.68% in the finishing phase. The individual tilapia information (weight, total length, standard length, head length, height and width) were standardized for 150, 185, 220 and 255 days of age. From then on the weight gain, daily weight gain, head to standard length ratio, width to height ratio and the relationship between standard length and total length were calculated. . For the analyses, a random regression model was used under a single animal model. Legendre polynomial models of 2 and 3 orders were tested for the fixed effect, and of order 2 for the additive and family genetic effects. In addition, models were also tested using homogeneous residual variance (1 class) and heterogeneous variance (2, 3, and 4 classes). The models that provide better fit in most of the characteristics were those that considered homogeneous residual variance. In general, the rank correlations of breeding values of pairs of dietary digestible lysine levels were high. The reaction norms of 25 randomly sampled Thai tilapia showed change in the sensitivity of breeding values of some traits to changes in dietary digestible lysine level. Therefore, it was observed that breeding values of tilapia traits generally changed along the environment gradient, suggesting the existence of genotype x dietary digestible lysine level interaction which can lead to the selection of different fishes in different environments.
4

Sensibilidade dos valores gen?ticos de til?pias do Nilo, variedade GIFT, aos n?veis de lisina digest?vel das dietas

Leite, Nam?bia Rizzari 16 May 2017 (has links)
Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2018-03-20T18:00:43Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) namibia_rizzari_leite.pdf: 3000386 bytes, checksum: 4ad82a1678a4c363522c1631a2cdead0 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2018-03-29T14:18:22Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) namibia_rizzari_leite.pdf: 3000386 bytes, checksum: 4ad82a1678a4c363522c1631a2cdead0 (MD5) / Made available in DSpace on 2018-03-29T14:18:22Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) namibia_rizzari_leite.pdf: 3000386 bytes, checksum: 4ad82a1678a4c363522c1631a2cdead0 (MD5) Previous issue date: 2017 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (Capes) / Funda??o de Amparo ? Pesquisa do Estado de Minas Gerais (FAPEMIG) / Esta pesquisa foi realizada com o objetivo de avaliar o efeito da intera??o gen?tipo x n?veis de lisina digest?vel das dietas sobre caracter?sticas morfom?tricas e de desempenho de til?pias do Nilo, variedade GIFT, em fase de crescimento. O experimento foi constitu?do de duas fases, sendo que na primeira as til?pias foram alimentadas dos 90 aos 150 dias de idade com dietas contendo percentuais de lisina iguais a 1,43, 1,53, 1,63, 1,73 e 1,83 e na segunda fase, dos 151 aos 255 dias, os percentuais de lisina das dietas foram iguais a 1,28, 1,38, 1,48, 1,58 e 1,68. As til?pias foram pesadas dos 90 aos 255 dias de idade com intervalos de aproximadamente 30 dias, foram calculados o ganho de peso total e o ganho de peso di?rio e, posteriormente, as idades foram ajustadas para 90 e 150 dias na primeira fase, e 185, 220 e 255 dias na segunda fase. As medidas de altura, largura, comprimento de cabe?a, comprimento padr?o e comprimento total das til?pias foram coletadas aos 150 dias de idade. A partir desses dados, foram calculadas as rela??es cabe?a/comprimento padr?o, comprimento padr?o/comprimento total e largura/altura. Modelos de regress?o aleat?ria, por meio do modelo animal uni caracter?stica, foram utilizados para avaliar a sensibilidades dos valores gen?ticos aos n?veis de lisina digest?vel das dietas, plotando-se as normas de rea??o de 25 peixes amostrados aleatoriamente para as diferentes caracter?sticas para demonstrar o padr?o de comportamento dos valores gen?ticos das caracter?sticas ao longo do gradiente ambiental. Foram testados modelos com homogeneidade (1 classe) e heterogeneidade de vari?ncia residual (2, 3 e 4 classes). Modelos com heterogeneidade de vari?ncia residual foram mais adequados para avalia??o gen?tica da maioria das caracter?sticas das til?pias na primeira fase e modelos com homogeneidade de vari?ncia residual para a maioria das caracter?sticas de desempenho das til?pias avaliadas na segunda fase. Os valores gen?ticos das til?pias, em ambas as fases, variaram entre os n?veis de lisina estudados para a maioria das caracter?sticas, indicando a presen?a de intera??o gen?tipo x ambiente. No geral, as herdabilidades e vari?ncias gen?ticas aditivas variaram de baixas a altas magnitudes. As correla??es de Spearman, assim como as normas de rea??o, indicaram reordenamento dos valores gen?ticos ao longo do gradiente ambiental, sugerindo a presen?a de intera??o gen?tipo x ambiente. A sele??o para desempenho e medidas morfom?tricas de til?pias GIFT deve ser realizada no n?vel de lisina da dieta com a qual as til?pias ser?o alimentadas. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Zootecnia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017. / This research was carried out with the objective of evaluating the effect of genotype x levels of digestible lysine of the diets on morphometric and performance characteristics of Nile tilapia, GIFT variety, in the growing phase. The experiment consisted of two phases, and in the first the tilapia were fed from 90 to 150 days of age diets containing lysine percentages equal to 1.43, 1.53, 1.63, 1.73 and 1.83. In the second phase, from 151 to 255 days, the lysine percentages of the diets were 1.28, 1.38, 1.48, 1.58 and 1.68. Tilapia were weighed from 90 to 255 days of age at intervals of approximately 30 days. Total weight gain and daily weight gain were calculated and, subsequently, were adjusted for 90 and 150 days in the first phase, and 185 , 220 and 255 days in the second phase. The measurements of height, width, head length, standard length and total length of tilapias were collected at 150 days of age. From these data, the head / standard length ratios, standard length / total length and width / height ratios were calculated. Single trait random regression modes were used in the analyses and the reaction norm plots of 25 randomly sampled fishes were used to demonstrate the sensitivity of breeding values to dietary digestible lysine level. Models with homogeneity (1 class) and heterogeneity of residual variance (2, 3 and 4 classes) were tested. Models considering heterogeneity of residual variance were more adequate for genetic evaluation of most of the characteristics of tilapia in the first phase and models considering homogeneity of residual variance for most of the performance characteristics of tilapia evaluated in the second phase. The breeding values of tilapia, in both phases, varied among the lysine levels studied for most of the traits, indicating the presence of genotype x environment interaction. In general, heritabilities and additive genetic variances varied from low to high magnitude. Spearman correlations, as well as the reaction norms, suggested rearrangement of breeding values along the environmental gradient, again indicating the presence of genotype x environment interaction. The selection for performance and morphometric traits of tilapia GIFT strain should be performed at the lysine level of the diet with which the tilapia will be fed.

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