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In this study, we aimed to evaluate the genetic diversity within and among chicken breeds from the northeast region of Brazil (states of Bahia and Piauí) using microsatellite markers. In addition, we assessed the identity and genetic relationships of chickens from Europe, Africa, and South America, as well as their influence on the formation of the Brazilian breeds. A total of 25 microsatellite markers and a panel containing 886 samples from 20 breeds (including the Brazilian chickens) were used in this study. Different statistical parameters were used to estimate the genetic diversity and relationship among the genetic groups studied. Our study indicates that the Brazilian Creole chickens have high genetic variability. The results show that chickens reared in the states of Bahia and Piauí could have originated from different ancestors. The Brazilian breeds studied have an evolutionary relationship with chickens from Portugal, Nigeria, Chile, and Spain. Our results will contribute directly to the conservation and recognition of Brazilian Creole chicken breeds and provide a solid basis for the demonstration of their genetic identity and genetic conservation of American Creole chicken populations.
RESUMO
Ahead of Print article withdrawn by publisher.
RESUMO
A research was conducted to evaluate the performance of broilers reared in conditions of heat stress, during 1-21 days of age, fed with diets containing different levels of selenium ( 0,5; 1,1; 1,7; 2,3; 2,9 and 3,5ppm of Se.Kg -1 of diet). The experimental diets were isonutritives except for selenium. Sixty chicken strains Ross, mixed, distributed in a randomized block design with six treatments and five replications with two birds per pen were used. The internal environment of the sheds was evaluated based on the Temperature Index Black Globe Humidity (BGT), the Temperature and Humidity Index (THI) and Effective Temperature (ET). The behavioral variables were: eating, drinking , open beak, wing open, stop, lie down, walk, scratching, stretching limbs, bunch of dust, clean feathers, fighting and prostrate. Levels of selenium in the diet interfered in the frequency of visits to the feeder of chickens, with the experimental treatments of 1.7 and 2.3mg Se.Kg -1, presenting lower values. However, the frequency of chickens with behaviors: drinking, with open wings standing, walking, carrying out cleaning of wings, fighting prostrate and were not influenced by the levels of selenium diets. Thus, it can be inferred from the contradictory behavioral results obtained in this study, several factors are involved in the behavior of birds, with emphasis on the environmental and nutritional variables.(AU)
A pesquisa foi desenvolvida para avaliar o comportamento de frangos de corte, criados em condições de estresse térmico, no período de 1 a 21 dias de idade, alimentados com dietas contendo diferentes níveis de selênio (0,5; 1,1; 1,7; 2,3; 2,9 e 3,5ppm de Se.Kg-1de ração). As dietas experimentais foram isonutritivas, exceto para o selênio. Foram utilizados sessenta pintos da linhagem Ross, mistos, distribuídas em delineamento em blocos casualizados, com seis tratamentos e cinco repetições com duas aves por parcela. O ambiente interno dos galpões foi avaliado com base no Índice de Temperatura de Globo Negro e Umidade (ITGU), no Índice de Temperatura e Umidade (ITU) e Temperatura Efetiva (TE). As variáveis comportamentais estudadas foram: comer, beber, abrir bico, asa aberta, parada, deitar, andar, ciscando, esticando membros, bando de poeira, limpar penas, brigar e prostrar. Os níveis de selênio na dieta interferiram na frequência de visita dos frangos ao comedouro, nos tratamentos experimentais com 1,7 e 2,3mg de Se.Kg-1, apresentando menores valores. Porem, as frequências dos frangos, com os comportamentos: bebendo, com asa aberta, parado, andando, realizando limpeza das asas, brigando e prostrado, não foram influenciadas pelos níveis de selênio das dietas. Assim, pode-se inferir a partir dos resultados comportamentais contraditórios obtidos neste estudo, que vários fatores estão envolvidos no comportamento das aves, com destaque para as variáveis ambientais e nutricionais.(AU)
Assuntos
Animais , Aves Domésticas/anormalidades , Aves Domésticas/crescimento & desenvolvimento , Comportamento Animal , Transtornos de Estresse por Calor , SelênioRESUMO
A research was conducted to evaluate the performance of broilers reared in conditions of heat stress, during 1-21 days of age, fed with diets containing different levels of selenium ( 0,5; 1,1; 1,7; 2,3; 2,9 and 3,5ppm of Se.Kg -1 of diet). The experimental diets were isonutritives except for selenium. Sixty chicken strains Ross, mixed, distributed in a randomized block design with six treatments and five replications with two birds per pen were used. The internal environment of the sheds was evaluated based on the Temperature Index Black Globe Humidity (BGT), the Temperature and Humidity Index (THI) and Effective Temperature (ET). The behavioral variables were: eating, drinking , open beak, wing open, stop, lie down, walk, scratching, stretching limbs, bunch of dust, clean feathers, fighting and prostrate. Levels of selenium in the diet interfered in the frequency of visits to the feeder of chickens, with the experimental treatments of 1.7 and 2.3mg Se.Kg -1, presenting lower values. However, the frequency of chickens with behaviors: drinking, with open wings standing, walking, carrying out cleaning of wings, fighting prostrate and were not influenced by the levels of selenium diets. Thus, it can be inferred from the contradictory behavioral results obtained in this study, several factors are involved in the behavior of birds, with emphasis on the environmental and nutritional variables.
A pesquisa foi desenvolvida para avaliar o comportamento de frangos de corte, criados em condições de estresse térmico, no período de 1 a 21 dias de idade, alimentados com dietas contendo diferentes níveis de selênio (0,5; 1,1; 1,7; 2,3; 2,9 e 3,5ppm de Se.Kg-1de ração). As dietas experimentais foram isonutritivas, exceto para o selênio. Foram utilizados sessenta pintos da linhagem Ross, mistos, distribuídas em delineamento em blocos casualizados, com seis tratamentos e cinco repetições com duas aves por parcela. O ambiente interno dos galpões foi avaliado com base no Índice de Temperatura de Globo Negro e Umidade (ITGU), no Índice de Temperatura e Umidade (ITU) e Temperatura Efetiva (TE). As variáveis comportamentais estudadas foram: comer, beber, abrir bico, asa aberta, parada, deitar, andar, ciscando, esticando membros, bando de poeira, limpar penas, brigar e prostrar. Os níveis de selênio na dieta interferiram na frequência de visita dos frangos ao comedouro, nos tratamentos experimentais com 1,7 e 2,3mg de Se.Kg-1, apresentando menores valores. Porem, as frequências dos frangos, com os comportamentos: bebendo, com asa aberta, parado, andando, realizando limpeza das asas, brigando e prostrado, não foram influenciadas pelos níveis de selênio das dietas. Assim, pode-se inferir a partir dos resultados comportamentais contraditórios obtidos neste estudo, que vários fatores estão envolvidos no comportamento das aves, com destaque para as variáveis ambientais e nutricionais.