Identification of Polymorphism in the MC1R Gene and Its Association with the Melanin Content in Feathers of Chinese Yellow Quails

MC1R plays a crucial role in controlling the type of melanin synthesized in the melanocytes, which greatly affects plumage color in birds. One g.16796362G/T SNP was found in the MC1R gene coding region, which caused a Met120Ile mutation in the amino acid sequence. The Met120Ile mutation was located in the third transmembrane domain of the MC1R protein and decreased protein stability. The g.16796362G/T locus achieved medium polymorphism and had significant association with feather melanin content in Chinese yellow quails. The contents of total melanin and pheomelanin with AA genotype were significant lower than those with AB or BB genotypes in skin tissues, while the expression levels of MC1R mRNA had no significant difference in feathers with different genotypes. This experiment indicated that the Met120Ile mutation could affect the function of the MC1R protein and change the biosynthesis of melanin in Chinese yellow quails.(AU)

Different Selection Strategies for the Improvement of the Growth Performance and Carcass Traits of Japanese Quails

The present study evaluated different selection strategies to improve the growth performance and carcass traits of Japanese quails. To this end, 540 Japanese quails previously selected for high body weight at three ages (10, 12 and 14 weeks) from four close-bred flocks (Major, Kaleem, Saadat and Zahid) were subjected to three selection strategies: pedigree-based, mass selection or random-bred (controls). For pedigree-based selection, 108 birds (4 close-bred flocks × 3 age groups × 9 replicates × 1 bird each) with full pedigree and selected for high body weight were used, whereas in mass selection 324 birds (4 close-bred flocks × 3 age groups × 9 replicates × 3 birds each) with high body weight were selected to be the parents of next generation. Random-bred controls included 108 birds (4 close-bred flocks × 3 age groups × 9 replicates × 1bird each) which were not previously submitted to selection. The effects of selection strategies of Japanese quail parents from four close-bred flocks (CBF) at three ages on the performance growth and carcass traits of their progenies were measured. The parent flocks were selected at three ages (10, 12 and 14 weeks) and reared for 20 weeks, and their progenies were reared for four weeks. The progeny of pedigree-based selected parents presented better feed intake (g), body weight gain (g), feed conversion ratio, live and carcass weights (g), and carcass yield. The progeny of 10- and 14-week-old parents showed better growth performance and carcass traits, respectively. Moreover, there was no influence of CBF on growth and carcass traits. It was concluded that pedigree-based selection had pronounced effect on the growth performance and carcass traits of the progeny compared with mass selection and random breeding. It is suggested that parental ages of 10 and 14 weeks of age promote better progeny growth performance and carcass traits.(AU)

Different Selection Strategies for the Improvement of the Growth Performance and Carcass Traits of Japanese Quails

The present study evaluated different selection strategies to improve the growth performance and carcass traits of Japanese quails. To this end, 540 Japanese quails previously selected for high body weight at three ages (10, 12 and 14 weeks) from four close-bred flocks (Major, Kaleem, Saadat and Zahid) were subjected to three selection strategies: pedigree-based, mass selection or random-bred (controls). For pedigree-based selection, 108 birds (4 close-bred flocks × 3 age groups × 9 replicates × 1 bird each) with full pedigree and selected for high body weight were used, whereas in mass selection 324 birds (4 close-bred flocks × 3 age groups × 9 replicates × 3 birds each) with high body weight were selected to be the parents of next generation. Random-bred controls included 108 birds (4 close-bred flocks × 3 age groups × 9 replicates × 1bird each) which were not previously submitted to selection. The effects of selection strategies of Japanese quail parents from four close-bred flocks (CBF) at three ages on the performance growth and carcass traits of their progenies were measured. The parent flocks were selected at three ages (10, 12 and 14 weeks) and reared for 20 weeks, and their progenies were reared for four weeks. The progeny of pedigree-based selected parents presented better feed intake (g), body weight gain (g), feed conversion ratio, live and carcass weights (g), and carcass yield. The progeny of 10- and 14-week-old parents showed better growth performance and carcass traits, respectively. Moreover, there was no influence of CBF on growth and carcass traits. It was concluded that pedigree-based selection had pronounced effect on the growth performance and carcass traits of the progeny compared with mass selection and random breeding. It is suggested that parental ages of 10 and 14 weeks of age promote better progeny growth performance and carcass traits.

Sensitivity of breeding values of meat quail as a result of tryptophan: lysine ratios in the diet / Sensibilidade de valores genéticos de codornas de corte em função das relações triptofano: lisina da dieta

We aimed to evaluate the random regression models that promote the best fit of residual variance predicting the breeding values of quail body weights and the sensitivity of its breeding values to the variations of different tryptophan:lysine ratios in the diets via reaction norms. A total of 1112 meat quails from LF1 and LF2 lines with 35 days of age were evaluated. During the period of 1 to 21 days of age, birds were fed with different tryptophan:lysine ratios (0.17, 0.20, 0.23, 0.26 and 0.29%) containing 2900 kcal ME/kg and 26.10% crude protein, followed by basal diet provided up to 35 days. The best model fit for residual variance was evaluated comparing heterogeneity (2, 3 and 4 classes) and homogeneity (1 class), including sex as fixed effect and the additive genetic effect as random. The second order Legendre polynomial was used to analyze the genotype x environment interaction using reaction norms. The model considering two classes of residual variance was the one that promoted the best fit of the data, being adopted to predict the breeding values. Thus, we observed changes in the sensitivity of the breeding values, characterized by the rearrangement of the breeding values, according to the different ratios of amino acids, suggesting the genotype x environment interaction.(AU)

Objetivou-se avaliar o modelo de regressão aleatória que promove o melhor ajuste da variância residual para a predição dos valores genéticos dos pesos corporais de codornas de corte e a sensibilidade dos seus valores genéticos às variações de diferentes relações triptofano:lisina. Foram avaliadas 1112 codornas de corte das linhagens LF1 e LF2, do nascimento aos 35 dias de idade. No período de 1 a 21 dias de idade as aves receberam alimentação com dietas de diferentes relações triptofano:lisina (0,17, 0,20, 0,23, 0,26 e 0,29%), contendo 2900 kcal EM/kg e 26,10% de proteína bruta, seguido pelo fornecimento de ração basal até os 35 dias. Foi avaliado o ajuste da variância residual comparando a homogeneidade (1 classe) e a heterogeneidade (2, 3 e 4 classes) incluindo o sexo como efeito fixo e o efeito genético aditivo como aleatório. O polinômio de Legendre de segunda ordem foi utilizado para a análise da interação genótipo x ambiente utilizando normas de reação. O modelo que considerou duas classes de variância residual foi o que promoveu o melhor ajuste dos dados e foi adotado para predição dos valores genéticos. Desta forma, foi observada alteração na sensibilidade dos valores genéticos, caracterizados pelo reordenamento dos valores genéticos, em função das diferentes relações estudadas, indicando a presença de interação genótipo x ambiente.(AU)

Sensitivity of breeding values of meat quail as a result of tryptophan: lysine ratios in the diet / Sensibilidade de valores genéticos de codornas de corte em função das relações triptofano: lisina da dieta

We aimed to evaluate the random regression models that promote the best fit of residual variance predicting the breeding values of quail body weights and the sensitivity of its breeding values to the variations of different tryptophan:lysine ratios in the diets via reaction norms. A total of 1112 meat quails from LF1 and LF2 lines with 35 days of age were evaluated. During the period of 1 to 21 days of age, birds were fed with different tryptophan:lysine ratios (0.17, 0.20, 0.23, 0.26 and 0.29%) containing 2900 kcal ME/kg and 26.10% crude protein, followed by basal diet provided up to 35 days. The best model fit for residual variance was evaluated comparing heterogeneity (2, 3 and 4 classes) and homogeneity (1 class), including sex as fixed effect and the additive genetic effect as random. The second order Legendre polynomial was used to analyze the genotype x environment interaction using reaction norms. The model considering two classes of residual variance was the one that promoted the best fit of the data, being adopted to predict the breeding values. Thus, we observed changes in the sensitivity of the breeding values, characterized by the rearrangement of the breeding values, according to the different ratios of amino acids, suggesting the genotype x environment interaction.

Objetivou-se avaliar o modelo de regressão aleatória que promove o melhor ajuste da variância residual para a predição dos valores genéticos dos pesos corporais de codornas de corte e a sensibilidade dos seus valores genéticos às variações de diferentes relações triptofano:lisina. Foram avaliadas 1112 codornas de corte das linhagens LF1 e LF2, do nascimento aos 35 dias de idade. No período de 1 a 21 dias de idade as aves receberam alimentação com dietas de diferentes relações triptofano:lisina (0,17, 0,20, 0,23, 0,26 e 0,29%), contendo 2900 kcal EM/kg e 26,10% de proteína bruta, seguido pelo fornecimento de ração basal até os 35 dias. Foi avaliado o ajuste da variância residual comparando a homogeneidade (1 classe) e a heterogeneidade (2, 3 e 4 classes) incluindo o sexo como efeito fixo e o efeito genético aditivo como aleatório. O polinômio de Legendre de segunda ordem foi utilizado para a análise da interação genótipo x ambiente utilizando normas de reação. O modelo que considerou duas classes de variância residual foi o que promoveu o melhor ajuste dos dados e foi adotado para predição dos valores genéticos. Desta forma, foi observada alteração na sensibilidade dos valores genéticos, caracterizados pelo reordenamento dos valores genéticos, em função das diferentes relações estudadas, indicando a presença de interação genótipo x ambiente.

Molecular authentication of meats from three terrestrial birds based on PCR-RFLP analysis of the mitochondrial 12S rRNA gene

In this study, a method utilizing PCR-restriction fragment length polymorphism (PCR-RFLP) of a mitochondrial gene was developed for the identification of chicken (Gallus gallus), quail (Coturnix coturnix), and common pigeon (Columba livia) meat. PCR products of ~440 bp were obtained from the 12S rRNA gene of these three birds using a pair of universal primers. The three terrestrial birds can be distinguished using one restriction endonuclease, Alu I, which was selected based on species-specific variations in the mt 12S rRNA gene sequence using 9 newly-obtained and 44 published chicken, quail and pigeon sequences. This method was also successfully used to identify commercial quail and pigeon meat products, which were found to be adulterated with chicken meat. Additionally, our method had relatively high sensitivity for detecting a meat mixture. Ten percent of chicken meat in the mixed quail and pigeon sample was detectable. This assay can be useful for the accurate identification of meats from terrestrial birds, avoiding mislabeling or fraudulent species substitution in meat products.(AU)

Molecular authentication of meats from three terrestrial birds based on PCR-RFLP analysis of the mitochondrial 12S rRNA gene

In this study, a method utilizing PCR-restriction fragment length polymorphism (PCR-RFLP) of a mitochondrial gene was developed for the identification of chicken (Gallus gallus), quail (Coturnix coturnix), and common pigeon (Columba livia) meat. PCR products of ~440 bp were obtained from the 12S rRNA gene of these three birds using a pair of universal primers. The three terrestrial birds can be distinguished using one restriction endonuclease, Alu I, which was selected based on species-specific variations in the mt 12S rRNA gene sequence using 9 newly-obtained and 44 published chicken, quail and pigeon sequences. This method was also successfully used to identify commercial quail and pigeon meat products, which were found to be adulterated with chicken meat. Additionally, our method had relatively high sensitivity for detecting a meat mixture. Ten percent of chicken meat in the mixed quail and pigeon sample was detectable. This assay can be useful for the accurate identification of meats from terrestrial birds, avoiding mislabeling or fraudulent species substitution in meat products.

Genetic parameters for egg production in meat quails through partial periods / Estimação de parâmetros genéticos para produção de ovos em codornas de corte através de períodos parciais

We estimated genetic and phenotypic parameters for egg production in meat-type quails aiming to propose an optimal age for selection through partial record egg production. Data of 3,503 female quails from two strains (namely, UFV1, with 1,811 and UFV2 with 1,692 females) were used. Egg production was assessed by the number of eggs recorded after 42 days of age and each partial period consisted on 35 days of egg production forward. Covariance components were estimated by using single and bivariate animal model, comprising each partial period of egg production and full egg production period (one year of egg laying). Regarding strain UFV1, heritability estimates ranges from 0.03 to 0.16, and for strain UFV2 0.20 to 0.25. The highest genetic correlation with full egg production was with second period (0.64) for strain UFV1 and with third period (0.47) for UFV2. Therefore, animal selection based on egg production until 112 days for the strain UFV1 and 147 days for the strain UFV2 provided increased genetic gain by reducing generation interval.

Este estudo teve como objetivo estimar os parâmetros genéticos e fenotípicos para a produção de ovos de codornas de corte e propor uma idade ideal para a seleção através da característica de produção de ovos. Os dados utilizados neste estudo vieram de 3.503 codornas de duas linhagens (1.811 fêmeas UFV1 e 1.692 fêmeas UFV2). A produção de ovos foi avaliada pelo número de ovos coletados a partir do 42o dia de vida em diante, usando modelo animal uni ou bicaracterístico, em períodos parciais de 35 dias cada e período total (um ano de postura). Para a linhagem UFV1, as estimativas de herdabilidade variaram de 0,03 a 0,16, e para a linhagem UFV2, de 0,20-0,25. A correlação genética maior foi entre o segundo período e total (0,64) para a linhagem UFV1 e 0,47 (terceiro período e total) para UFV2. Portanto, recomenda-se usar o período de produção de ovos até 112 dias para a linhagem UFV1 e o período de produção de ovos até 147 dias para a linhagem UFV2, permitindo, assim, uma redução no intervalo de geração.

Suplementação de prebiótico (mananoligossacarídeo) na dieta de dois genótipos de codornas em crescimento / Prebiotic supplementation (mannan oligosaccharides) on the diet of two quails genotypes during growth / Suplementación prebiótica (mananoligosacáridos) en dieta de dos genotipos de codorniz en crecimiento

O uso de antibióticos como aditivo melhorador de desempenho tem sido proibido pela possibilidade de favorecer o desenvolvimento de resistência bacteriana em humanos. Com isso, o objetivo da realização do trabalho foi avaliar o efeito da suplementação do prebiótico mananoligossacarídeo na alimentação de codornas japonesas e europeias em crescimento. Foram usadas 240 codornas de cada linhagem (Coturnix japonica e Coturnix coturnix) distribuídas em delineamento experimental inteiramente casualizado e arranjados em fatorial 2 x 4 (genótipos x níveis de suplementação de prebiótico) e seis repetições de dez aves. As codornas foram alimentadas com ração basal suplementadas com 0,0; 0,05; 0,10 e 0,15% de mananoligossacarídeo em substituição ao inerte. Não houve efeito de interação para nenhuma das variáveis avaliadas (P>0,05). Os níveis de suplementação do prebiótico não afetaram o desempenho e as características de carcaça (P>0,05) das codornas. O consumo de ração não foi alterado entre os genótipos (P>0,05), por outro lado, as codornas europeias apresentaram maior ganho de peso e melhor valor de conversão alimentar (P≤0,05) que as codornas japonesas. Os genótipos comerciais de codornas diferiram nas características de carcaça (P≤0,05). Recomenda-se formular rações sem suplementação do prebiótico mananoligossacarídeo para codornas japonesas e europeias de 21 a 42 dias de idade em ambiente considerando limpo.(AU)

The use of antibiotics as a feed additive promoting performance has been prohibited due to the possibility of favoring bacterial resistance in humans. Thus, the purpose of this paper was to assess the effect of mannan oligosaccharides supplementation in prebiotic feed provided to Japanese and European quails during the growth stage. A total of 240 quails for each strain (Coturnix japonica and Coturnix coturnix) were used, distributed in a completely randomized design and arranged in a 2 x 4 (genotypes x prebiotic supplementation levels) matrix, with six replications containing ten birds each. The quails were fed with basal feed supplemented with 0.0; 0.05; 0.10 and 0.15% mannan oligosaccharide prebiotic. There was no interaction effect for any of the assessed variables (P> 0.05). The prebiotic supplementation levels did not affect performance and carcass characteristics (P> 0.05) of the quails. Feed intake was not changed between genotypes (P> 0.05); on the other hand, European quails showed greater weight gain and better feed conversion rate (P≤ 0.05) than Japanese quails. Commercial genotypes differed inn carcass characteristics (P≤ 0.05). It is recommended that feeds are formulated without supplementation of mannan oligosaccharides prebiotic for Japanese and European quails aged 21 to 42-days' old in production environment that are considered clean.(AU)

El uso de antibióticos como aditivo de mejora de rendimiento ha sido prohibido por la posibilidad de promover el desarrollo de resistencia bacteriana en humanos. Por lo tanto, el propósito de llevar a cabo este estudio fue evaluar el efecto de la suplementación del prebiótico mananoligosacáridos en la alimentación de codornices japonesas y europeas en crecimiento. Se usaron 240 codornices de cada linaje (Coturnix japonica y Coturnix coturnix) distribuidas en un diseño completamente aleatorizado y dispuestos en factorial 2 x 4 (genotipos x niveles de suplementación prebiótica) y seis repeticiones de diez aves. Las codornices fueron alimentadas con la dieta basal suplementadas con 0,0; 0,05; 0,10 y 0,15% mananoligosacárido en sustitución al inerte. No hubo efecto de interacción para ninguna de las variables evaluadas (P >0,05). Los niveles de suplementación del prebiótico no afectaron el rendimiento y las características del caparazón (P >0,05) de las codornices. El consumo de alimento no se cambió entre los genotipos (P > 0,05), por otro lado, las codornices Europeas presentaron mayor ganancia de peso y mejor valor de conversión del alimento (p≤ 0.05) que las codornices japonesas. Los genotipos comerciales de codornices difirieron en las características del caparazón (p≤ 0.05). Se recomienda formular dietas sin suplementación del prebiótico mananoligosacáridos para codornices japonesas y europeas de 21 a 42 días de edad en ambiente considerado limpio.(AU)

Genetic parameters for egg production in meat quails through partial periods / Estimação de parâmetros genéticos para produção de ovos em codornas de corte através de períodos parciais

We estimated genetic and phenotypic parameters for egg production in meat-type quails aiming to propose an optimal age for selection through partial record egg production. Data of 3,503 female quails from two strains (namely, UFV1, with 1,811 and UFV2 with 1,692 females) were used. Egg production was assessed by the number of eggs recorded after 42 days of age and each partial period consisted on 35 days of egg production forward. Covariance components were estimated by using single and bivariate animal model, comprising each partial period of egg production and full egg production period (one year of egg laying). Regarding strain UFV1, heritability estimates ranges from 0.03 to 0.16, and for strain UFV2 0.20 to 0.25. The highest genetic correlation with full egg production was with second period (0.64) for strain UFV1 and with third period (0.47) for UFV2. Therefore, animal selection based on egg production until 112 days for the strain UFV1 and 147 days for the strain UFV2 provided increased genetic gain by reducing generation interval.(AU)

Este estudo teve como objetivo estimar os parâmetros genéticos e fenotípicos para a produção de ovos de codornas de corte e propor uma idade ideal para a seleção através da característica de produção de ovos. Os dados utilizados neste estudo vieram de 3.503 codornas de duas linhagens (1.811 fêmeas UFV1 e 1.692 fêmeas UFV2). A produção de ovos foi avaliada pelo número de ovos coletados a partir do 42o dia de vida em diante, usando modelo animal uni ou bicaracterístico, em períodos parciais de 35 dias cada e período total (um ano de postura). Para a linhagem UFV1, as estimativas de herdabilidade variaram de 0,03 a 0,16, e para a linhagem UFV2, de 0,20-0,25. A correlação genética maior foi entre o segundo período e total (0,64) para a linhagem UFV1 e 0,47 (terceiro período e total) para UFV2. Portanto, recomenda-se usar o período de produção de ovos até 112 dias para a linhagem UFV1 e o período de produção de ovos até 147 dias para a linhagem UFV2, permitindo, assim, uma redução no intervalo de geração.(AU)

Estimação de valores genéticos para codornas europeias em função dos níveis da relação treonina: lisina da dieta: do nascimento aos 21 dias de idade / Estimation of breeding values for European quails in function of threonine: lysine ratios of diet: from birth to 21 days of age

O presente trabalho foi realizado com o objetivo de avaliar a sensibilidade dos valores genéticos dos pesos corporais e as características de carcaças de codornas europeias às mudanças do gradiente ambiental (níveis da relação treonina com a lisina das dietas), do nascimento aos 21 dias de idade, por meio de modelos de regressão aleatória com diferentes classes de variância residual. Os dados utilizados neste estudo são provenientes de 915 codornas de corte da linhagem LF1 e 839 da linhagem LF2, pertencentes ao Programa de Melhoramento Genético da Universidade Federal dos Vales do Jequitinhonha e Mucuri. Foram avaliados os pesos corporais e os rendimentos da carcaça das aves. As sensibilidades dos valores genéticos às mudanças nos níveis da relação treonina:lisina (interação genótipo x ambiente) foram obtidas por modelos de regressão aleatória (utilizando normas de reação) por meio do programa Wombat, que utiliza o princípio da máxima verossimilhança restrita (REML). O modelo de regressão aleatória que considerou duas classes de variância residual foi o mais indicado para a maioria das análises realizadas. Verificaram-se alterações na classificação dos valores genéticos para as duas linhagens de codornas de corte estudadas. Esse comportamento indica sensibilidade de valores genéticos aditivos às mudanças nutricionais, o que caracteriza a existência de interação genótipo x ambiente. A predição dos valores genéticos deve ser feita com o mesmo nível da relação treonina:lisina da dieta com a qual as codornas serão alimentadas no sistema de produção.(AU)

This research was carried out to evaluate the sensitivity of breeding values of body weight and carcass traits in two lines of European quails (LF1 and LF2) to changes in the environment gradient (levels of threonine: lysine ratio of diets) from hatch to 21 days of age in two lines LF1 and LF2 using Random Regression Models with different classes of residual variance. Records are from 915 quails of line LF1 and 839 of line LF2 belonging to the Breeding Improvement Program of Universidade Federal dos Vales do Jequitinhonha e Mucuri. Live body weight and weights and yields of carcass, breast, and thigh and drumstick were measured. The sensitivities of breeding values to changes in threonine: lysine ratios (genotype x environment interaction) of diets were obtained by random regression models (reaction model) using the WOMBAT program using the Restricted Maximum Likelihood principle. Model considering two classes of residual variance showed the best goodness of fit. The Reaction Norms analyses indicated changes in the ranking of breeding values for both lines suggesting quails selected in one level of threonine: lysine ratio will not express all their genetic potential if fed different threonine: lysine ratio diets. This behavior indicates sensitivity of breeding values to changes in the nutrition characterizing the genotype by environment interaction. The prediction of breeding values must be performed using the same level of threonine: lysine ratio in diet the quails will be fed in the production system.(AU)

Estimação de valores genéticos para codornas europeias em função dos níveis da relação treonina: lisina da dieta: do nascimento aos 21 dias de idade / Estimation of breeding values for European quails in function of threonine: lysine ratios of diet: from birth to 21 days of age

O presente trabalho foi realizado com o objetivo de avaliar a sensibilidade dos valores genéticos dos pesos corporais e as características de carcaças de codornas europeias às mudanças do gradiente ambiental (níveis da relação treonina com a lisina das dietas), do nascimento aos 21 dias de idade, por meio de modelos de regressão aleatória com diferentes classes de variância residual. Os dados utilizados neste estudo são provenientes de 915 codornas de corte da linhagem LF1 e 839 da linhagem LF2, pertencentes ao Programa de Melhoramento Genético da Universidade Federal dos Vales do Jequitinhonha e Mucuri. Foram avaliados os pesos corporais e os rendimentos da carcaça das aves. As sensibilidades dos valores genéticos às mudanças nos níveis da relação treonina:lisina (interação genótipo x ambiente) foram obtidas por modelos de regressão aleatória (utilizando normas de reação) por meio do programa Wombat, que utiliza o princípio da máxima verossimilhança restrita (REML). O modelo de regressão aleatória que considerou duas classes de variância residual foi o mais indicado para a maioria das análises realizadas. Verificaram-se alterações na classificação dos valores genéticos para as duas linhagens de codornas de corte estudadas. Esse comportamento indica sensibilidade de valores genéticos aditivos às mudanças nutricionais, o que caracteriza a existência de interação genótipo x ambiente. A predição dos valores genéticos deve ser feita com o mesmo nível da relação treonina:lisina da dieta com a qual as codornas serão alimentadas no sistema de produção.(AU)

This research was carried out to evaluate the sensitivity of breeding values of body weight and carcass traits in two lines of European quails (LF1 and LF2) to changes in the environment gradient (levels of threonine: lysine ratio of diets) from hatch to 21 days of age in two lines LF1 and LF2 using Random Regression Models with different classes of residual variance. Records are from 915 quails of line LF1 and 839 of line LF2 belonging to the Breeding Improvement Program of Universidade Federal dos Vales do Jequitinhonha e Mucuri. Live body weight and weights and yields of carcass, breast, and thigh and drumstick were measured. The sensitivities of breeding values to changes in threonine: lysine ratios (genotype x environment interaction) of diets were obtained by random regression models (reaction model) using the WOMBAT program using the Restricted Maximum Likelihood principle. Model considering two classes of residual variance showed the best goodness of fit. The Reaction Norms analyses indicated changes in the ranking of breeding values for both lines suggesting quails selected in one level of threonine: lysine ratio will not express all their genetic potential if fed different threonine: lysine ratio diets. This behavior indicates sensitivity of breeding values to changes in the nutrition characterizing the genotype by environment interaction. The prediction of breeding values must be performed using the same level of threonine: lysine ratio in diet the quails will be fed in the production system.(AU)

Suplementação de prebiótico (mananoligossacarídeo) na dieta de dois genótipos de codornas em crescimento / Prebiotic supplementation (mannan oligosaccharides) on the diet of two quails genotypes during growth / Suplementación prebiótica (mananoligosacáridos) en dieta de dos genotipos de codorniz en crecimiento

O uso de antibióticos como aditivo melhorador de desempenho tem sido proibido pela possibilidade de favorecer o desenvolvimento de resistência bacteriana em humanos. Com isso, o objetivo da realização do trabalho foi avaliar o efeito da suplementação do prebiótico mananoligossacarídeo na alimentação de codornas japonesas e europeias em crescimento. Foram usadas 240 codornas de cada linhagem (Coturnix japonica e Coturnix coturnix) distribuídas em delineamento experimental inteiramente casualizado e arranjados em fatorial 2 x 4 (genótipos x níveis de suplementação de prebiótico) e seis repetições de dez aves. As codornas foram alimentadas com ração basal suplementadas com 0,0; 0,05; 0,10 e 0,15% de mananoligossacarídeo em substituição ao inerte. Não houve efeito de interação para nenhuma das variáveis avaliadas (P>0,05). Os níveis de suplementação do prebiótico não afetaram o desempenho e as características de carcaça (P>0,05) das codornas. O consumo de ração não foi alterado entre os genótipos (P>0,05), por outro lado, as codornas europeias apresentaram maior ganho de peso e melhor valor de conversão alimentar (P≤0,05) que as codornas japonesas. Os genótipos comerciais de codornas diferiram nas características de carcaça (P≤0,05). Recomenda-se formular rações sem suplementação do prebiótico mananoligossacarídeo para codornas japonesas e europeias de 21 a 42 dias de idade em ambiente considerando limpo.(AU)

The use of antibiotics as a feed additive promoting performance has been prohibited due to the possibility of favoring bacterial resistance in humans. Thus, the purpose of this paper was to assess the effect of mannan oligosaccharides supplementation in prebiotic feed provided to Japanese and European quails during the growth stage. A total of 240 quails for each strain (Coturnix japonica and Coturnix coturnix) were used, distributed in a completely randomized design and arranged in a 2 x 4 (genotypes x prebiotic supplementation levels) matrix, with six replications containing ten birds each. The quails were fed with basal feed supplemented with 0.0; 0.05; 0.10 and 0.15% mannan oligosaccharide prebiotic. There was no interaction effect for any of the assessed variables (P> 0.05). The prebiotic supplementation levels did not affect performance and carcass characteristics (P> 0.05) of the quails. Feed intake was not changed between genotypes (P> 0.05); on the other hand, European quails showed greater weight gain and better feed conversion rate (P≤ 0.05) than Japanese quails. Commercial genotypes differed inn carcass characteristics (P≤ 0.05). It is recommended that feeds are formulated without supplementation of mannan oligosaccharides prebiotic for Japanese and European quails aged 21 to 42-days' old in production environment that are considered clean.(AU)

El uso de antibióticos como aditivo de mejora de rendimiento ha sido prohibido por la posibilidad de promover el desarrollo de resistencia bacteriana en humanos. Por lo tanto, el propósito de llevar a cabo este estudio fue evaluar el efecto de la suplementación del prebiótico mananoligosacáridos en la alimentación de codornices japonesas y europeas en crecimiento. Se usaron 240 codornices de cada linaje (Coturnix japonica y Coturnix coturnix) distribuidas en un diseño completamente aleatorizado y dispuestos en factorial 2 x 4 (genotipos x niveles de suplementación prebiótica) y seis repeticiones de diez aves. Las codornices fueron alimentadas con la dieta basal suplementadas con 0,0; 0,05; 0,10 y 0,15% mananoligosacárido en sustitución al inerte. No hubo efecto de interacción para ninguna de las variables evaluadas (P >0,05). Los niveles de suplementación del prebiótico no afectaron el rendimiento y las características del caparazón (P >0,05) de las codornices. El consumo de alimento no se cambió entre los genotipos (P > 0,05), por otro lado, las codornices Europeas presentaron mayor ganancia de peso y mejor valor de conversión del alimento (p≤ 0.05) que las codornices japonesas. Los genotipos comerciales de codornices difirieron en las características del caparazón (p≤ 0.05). Se recomienda formular dietas sin suplementación del prebiótico mananoligosacáridos para codornices japonesas y europeas de 21 a 42 días de edad en ambiente considerado limpio.(AU)

Expressão gênica de IGF-I e GHR no fígado e no músculo do peito de codornas de corte suplementadas com diferentes níveis de metionina em duas gerações sucessivas / IGF-I and GHR gene expression in liver and breast muscle of meat quails supplemented with different levels of methionine in two successive generations

Este estudo foi desenvolvido com o objetivo de avaliar a expressão gênica do fator de crescimento semelhante à insulina I (IGF-I) e do receptor do hormônio do crescimento (GHR) no fígado e no músculo do peito de codornas de corte, alimentadas com dietas contendo diferentes níveis de suplementação de metionina, em duas gerações sucessivas. Foram utilizadas codornas dos 22 aos 42 dias de idade, distribuídas em três e cinco tratamentos na primeira e na segunda geração, respectivamente. Ao final, as aves foram abatidas por deslocamento cervical, sendo coletados fígado e músculo do peito para extração de RNA total. O cDNA foi amplificado usando primers específicos para os genes analisados. Os resultados mostraram que a expressão dos genes GHR e IGF-I sofreu influência da suplementação. No quinto tratamento, em que apenas a primeira geração recebeu uma suplementação acima do padrão das exigências para o período, houve uma expressão significativamente maior do GHR tanto no músculo do peito como no fígado e igualmente do IGF-I no músculo, levando a concluir que o excesso de metionina na dieta torna-se tóxica para as aves. Apesar de a expressão dos genes ter sofrido influência da adição de metionina nos níveis estudados, não foi observada diferença no consumo alimentar, na conversão alimentar e no peso das aves.(AU)

This study was conducted to evaluate the gene expression of the insulin-like I growth factor (IGF-I) and growth hormone receptor (GHR), in the liver and chest muscle of slaughter quails fed with diets containing different levels of methionine supplementation, in two successive generations. Twenty-two to 42 day-old quails were used, distributed in three and five treatments in the first and second generation, respectively. At the end, the birds were killed by cervical dislocation, and their liver and chest muscle were collected for total RNA extraction. The cDNA was amplified using specific primers for the genes analyzed. The results showed that the expression of GHR gene and IGF-I were influenced by the supplementation. In the fifth treatment, where only the first generation received supplementation above the standard requirements for the period, there was a significantly higher expression of GHR both in muscle chest and in the liver, and also IGF-I on muscle, leading to the conclusion that the excess dietary methionine becomes toxic to birds. Despite the gene´s expression seeming to be influenced by the addition of methionine levels in the study, there was no difference in feed intake, feed conversion and weight of the birds.(AU)

Expressão gênica de IGF-I e GHR no fígado e no músculo do peito de codornas de corte suplementadas com diferentes níveis de metionina em duas gerações sucessivas / IGF-I and GHR gene expression in liver and breast muscle of meat quails supplemented with different levels of methionine in two successive generations

Este estudo foi desenvolvido com o objetivo de avaliar a expressão gênica do fator de crescimento semelhante à insulina I (IGF-I) e do receptor do hormônio do crescimento (GHR) no fígado e no músculo do peito de codornas de corte, alimentadas com dietas contendo diferentes níveis de suplementação de metionina, em duas gerações sucessivas. Foram utilizadas codornas dos 22 aos 42 dias de idade, distribuídas em três e cinco tratamentos na primeira e na segunda geração, respectivamente. Ao final, as aves foram abatidas por deslocamento cervical, sendo coletados fígado e músculo do peito para extração de RNA total. O cDNA foi amplificado usando primers específicos para os genes analisados. Os resultados mostraram que a expressão dos genes GHR e IGF-I sofreu influência da suplementação. No quinto tratamento, em que apenas a primeira geração recebeu uma suplementação acima do padrão das exigências para o período, houve uma expressão significativamente maior do GHR tanto no músculo do peito como no fígado e igualmente do IGF-I no músculo, levando a concluir que o excesso de metionina na dieta torna-se tóxica para as aves. Apesar de a expressão dos genes ter sofrido influência da adição de metionina nos níveis estudados, não foi observada diferença no consumo alimentar, na conversão alimentar e no peso das aves.(AU)

This study was conducted to evaluate the gene expression of the insulin-like I growth factor (IGF-I) and growth hormone receptor (GHR), in the liver and chest muscle of slaughter quails fed with diets containing different levels of methionine supplementation, in two successive generations. Twenty-two to 42 day-old quails were used, distributed in three and five treatments in the first and second generation, respectively. At the end, the birds were killed by cervical dislocation, and their liver and chest muscle were collected for total RNA extraction. The cDNA was amplified using specific primers for the genes analyzed. The results showed that the expression of GHR gene and IGF-I were influenced by the supplementation. In the fifth treatment, where only the first generation received supplementation above the standard requirements for the period, there was a significantly higher expression of GHR both in muscle chest and in the liver, and also IGF-I on muscle, leading to the conclusion that the excess dietary methionine becomes toxic to birds. Despite the gene´s expression seeming to be influenced by the addition of methionine levels in the study, there was no difference in feed intake, feed conversion and weight of the birds.(AU)

Effects of Different Selection Methods Using Body Weight on Egg Yield Parameters in Japanese Quail

This experiment was conducted to investigate the effects of different selection methods of parent lines on the body weight of Japanese quails. For this purpose, line M55 was subjected to individual selection for body weight at 5 weeks of age, while a reciprocal recurrent selection method was applied to lines R33 and S55. Selection lasted two generations. Body weight changes, age and weight at sexual maturity, egg weight, and egg production were investigated in the parent generations as well as in the selection lines. Body weight at 5 weeks of age of the parents of the M55, R33 and S55 lines were 299.0, 285.3, and 280.4 g in the first generation, and 314.8, 316.6, and 306.8±3.11 g in the second generation, respectively. The first generation of the M55, R33, and S55 lines presented egg production rates of 73.4, 77.6, and 75.8%, respectively, and egg weights of 12.7, 11.9, and 12.1g, respectively. The second generation of the M55, R33, and S55 lines presented egg production rates of 74.6, 77.8, and 78.3%, and egg weights of 12.72, 12.59, and 12.56 g, respectively. Both egg production and egg weights were significantly different between the first and the second generations (p>0.05). As a result, despite significant increase in body weight of the selection lines, no significant differences in egg production or egg weight were determined among generations. However, reciprocal selection lines of both generations presented higher egg yield than the individual selected line.(AU)

Effects of Different Selection Methods Using Body Weight on Egg Yield Parameters in Japanese Quail

This experiment was conducted to investigate the effects of different selection methods of parent lines on the body weight of Japanese quails. For this purpose, line M55 was subjected to individual selection for body weight at 5 weeks of age, while a reciprocal recurrent selection method was applied to lines R33 and S55. Selection lasted two generations. Body weight changes, age and weight at sexual maturity, egg weight, and egg production were investigated in the parent generations as well as in the selection lines. Body weight at 5 weeks of age of the parents of the M55, R33 and S55 lines were 299.0, 285.3, and 280.4 g in the first generation, and 314.8, 316.6, and 306.8±3.11 g in the second generation, respectively. The first generation of the M55, R33, and S55 lines presented egg production rates of 73.4, 77.6, and 75.8%, respectively, and egg weights of 12.7, 11.9, and 12.1g, respectively. The second generation of the M55, R33, and S55 lines presented egg production rates of 74.6, 77.8, and 78.3%, and egg weights of 12.72, 12.59, and 12.56 g, respectively. Both egg production and egg weights were significantly different between the first and the second generations (p>0.05). As a result, despite significant increase in body weight of the selection lines, no significant differences in egg production or egg weight were determined among generations. However, reciprocal selection lines of both generations presented higher egg yield than the individual selected line.

Microsatellite analysis of genetic diversity in quail populations from China

Polymorphism of three quail communities was analyzed by using 12 microsatellite markers in this paper, aiming to provide scientific references for the evaluation, protection and utilization of quail genetic resources in China. Results demonstrated that the number of observed alleles by 12 microsatellite markers ranges between 4~7. The average polymorphism information contents (PIC) of the Chinese yellow quail, the Chinese black quail and the Korean quail, as detected by 12 microsatellite markers, are 0.6853, 0.6401 and 0.6565,respectively, and average heterozygosity values are 0.7333, 0.6957 and 0.7111, respectively. This indicates that the Chinese yellow quail has the richest genetic polymorphism. According to cluster analysis, the Chinese black quail and the Korean quail have the smallest genetic distance (0.0628), which reflects that they have the closest genetic relationship. The genetic distance between the Chinese yellow quail and the Korean quail is 0.0951. Therefore, the Chinese black quail and the Korean quail are clustered together firstly, and then the Chinese yellow quail.

Microsatellite analysis of genetic diversity in quail populations from China

Polymorphism of three quail communities was analyzed by using 12 microsatellite markers in this paper, aiming to provide scientific references for the evaluation, protection and utilization of quail genetic resources in China. Results demonstrated that the number of observed alleles by 12 microsatellite markers ranges between 4~7. The average polymorphism information contents (PIC) of the Chinese yellow quail, the Chinese black quail and the Korean quail, as detected by 12 microsatellite markers, are 0.6853, 0.6401 and 0.6565,respectively, and average heterozygosity values are 0.7333, 0.6957 and 0.7111, respectively. This indicates that the Chinese yellow quail has the richest genetic polymorphism. According to cluster analysis, the Chinese black quail and the Korean quail have the smallest genetic distance (0.0628), which reflects that they have the closest genetic relationship. The genetic distance between the Chinese yellow quail and the Korean quail is 0.0951. Therefore, the Chinese black quail and the Korean quail are clustered together firstly, and then the Chinese yellow quail.(AU)

Development and application of Est-Ssr markers in quails

Aiming at accelerating the application of molecular markers in the genetic improvement of quails, six EST-SSR markers were successfully developed using a bioinformatics method. Polymorphisms of three quail populations (Chinese yellow quail, China black quail and Korean quail) were detected. The results showed that there were 2-6 alleles in six EST-SSR markers. Mean polymorphism information contents of Chinese yellow quails, Chinese black quails and Korean quails were determined as 0.5451, 0.4962 and 0.4937, respectively. Average heterozygosity valuesof 0.6134, 0.5759 and 0.5613 were calculated. Among the six EST-SSR markers, three were highly polymorphic, and the other three were moderately polymorphic. The newly-developed six EST-SSR markers may be used to determine the genetic diversity of quails. The six EST-SSR markers identified were related to carbohydrate metabolism and melanin synthesis, but their specific mechanisms need to be further analyzed.