The Growth Pattern of Brazilian Canela-Preta Chickens with Different Plumages Reared in Two Rearing Systems

Growth pattern is essential for economically efficient poultry production. In this study, we aimed to describe the growth curve of chickens of the Canela-Preta breed reared in two different rearing systems, considering their different plumage colors. Initially, 204 one-day-old male and female chicks were randomly distributed in confinement and semi-confinement (102 animals in each system) without separation by gender. The animals were individually identified by wing and foot plastic brands and were weighted every seven days. The body weight and age records were used to estimate the growth curves of the following factors using the Richards model: plumage color, gender, and rearing system. The likelihood ratio test was used to verify the equality of parameters and identify nonlinear models to compare the growth patterns of the evaluated groups. The growth pattern of Canela-Preta chickens changed as a function of gender, plumage color, and rearing system. Females with black plumage, black and gold hens, and males with black and white plumage showed greater sensitivity to changes in rearing systems. Within-breed selection strategies for specific colors can improve the use of growth pattern differences, improving production efficiency. Semi-confinement is suitable for rearing Canela-Preta chickens with any plumage color, as these animals meet the free-range poultry niche market requirements.(AU)

Growth Curve of Brazilian Creole Chickens (Canela-Preta Breed) Raised in Two Different Rearing Systems under Tropical Climate

The objective of this study was to describe the growth curve of Brazilian Creole chickens of the Canela-Preta breed raised in two different rearing systems using non-linear growth models. A total of 400 birds were divided into two groups of 200 animals (of both genders), which were kept in confined or semi-confined systems. The confined birds were housed in an experimental masonry shed and the semi-confined animals were housed in another shed with access to pasture from 29 days of age. Birds were individually weighed every seven days during six months for determination of the growth curves of body weight using 10 non-linear models. The parameters of the models were estimated using the Gauss Newton method. The performance of the models was assessed using mean squared error (MSE), coefficient of determination (R2), percentage of convergence, and residual mean absolute deviation (MAD). With the exception of the Inverse Polynomial, all the other models had R2 values close to one. Therefore, the best models were chosen based on the lowest MSE and MAD values, with the Richards model ranking first followed by the Von Bertalanffy model. Gender and rearing system effects significantly influenced (p<0.05) some parameters of the Richards model. In conclusion, the Richards model was the most adequate to describe the growth of Canela-Preta chickens. Gender and rearing system significantly influenced the growth of the birds. The growth rates observed indicated that management strategies can be performed to increase the production efficiency of Canela-Preta chickens.(AU)

Variabilidade genética de 12 loci de microssatélites em galinhas crioulas Canela-Preta / Genetic variability of twelve microsatellite loci in native Canela-Preta chickens

Esta pesquisa foi realizada com o objetivo de se conhecer a variabilidade genética de 12 loci de microssatélites em galinhas crioulas Canela-Preta. Foram coletadas amostras de sangue de 118 galinhas crioulas Canela-Preta, provenientes de três municípios do estado do Piauí (Oeiras, Queimada Nova e Teresina). Após extração do DNA, foram utilizados marcadores para 12 loci de microssatélites: LEI0192, LEI0209, LEI0212, LEI0217, LEI0221, LEI0234, LEI0237, LEI0248, LEI0258, MCW0081, MCW0183 e MCW0213, que foram amplificados pela técnica de reação em cadeia da polimerase (PCR). Foram obtidos 408 alelos (somando os alelos dos 12 loci), com os fragmentos variando entre 50 e 460 pares de bases. O número de alelos variou de 15 (MCW0081) a 52 (LEI0212), com média de 31,5 alelos por locus. A média de heterozigosidade esperada e o conteúdo de informações polimórficas foram, respectivamente, 0,887 e 0,909. Foram observados desvios no equilíbrio de Hardy-Weinberg e valores positivos do índice de fixação com excesso de homozigotos. Os microssatélites utilizados mostraram-se polimórficos e podem ser usados para investigações genéticas em galinhas Canela-Preta. As galinhas dos plantéis avaliados apresentam grande variabilidade gênica, o que as qualifica como importante fonte de recursos genéticos e, consequentemente, faculta a utilização delas em programas de melhoramento genético animal.(AU)

The aim of this study was to analyze the genetic variability of twelve microsatellite loci in native Canela-Preta chickens. Blood samples were collected from 118 chickens of the breed from five properties in three cities (Oeiras, Queimada Nova and Teresina) of Piauí state. After the DNA extraction, markers were used for twelve microsatellite loci: LEI0192, LEI0209, LEI0212, LEI0217, LEI0221, LEI0234, LEI0237, LEI0248, LEI0258, MCW0081, MCW0183, and MCW0213 that were amplified by polymerase chain reaction technique (PCR). The results showed a total of 408 alleles (adding alleles from the 12 loci) with the fragments ranging between 50 and 460 base pairs, the number of alleles ranged from 15 (MCW0081) to 52 (LEI0212) with an average of 31,5 alleles per locus. The average expected heterozygosity and PIC were, respectively, 0.887 and 0.909. Deviations were observed in the Hardy-Weinberg equilibrium and positive values of the fixation index with excess of homozygotes. It is concluded that the used microsatellites are polymorphic and can, therefore, be used for genetic research in Canela-Preta chickens. The birds of the analyzed cores present great genetic variability, which qualifies them as an important source of genetic resources, which could be used for future animal breeding programs.(AU)

Variabilidade genética de 12 loci de microssatélites em galinhas crioulas Canela-Preta / Genetic variability of twelve microsatellite loci in native Canela-Preta chickens

Esta pesquisa foi realizada com o objetivo de se conhecer a variabilidade genética de 12 loci de microssatélites em galinhas crioulas Canela-Preta. Foram coletadas amostras de sangue de 118 galinhas crioulas Canela-Preta, provenientes de três municípios do estado do Piauí (Oeiras, Queimada Nova e Teresina). Após extração do DNA, foram utilizados marcadores para 12 loci de microssatélites: LEI0192, LEI0209, LEI0212, LEI0217, LEI0221, LEI0234, LEI0237, LEI0248, LEI0258, MCW0081, MCW0183 e MCW0213, que foram amplificados pela técnica de reação em cadeia da polimerase (PCR). Foram obtidos 408 alelos (somando os alelos dos 12 loci), com os fragmentos variando entre 50 e 460 pares de bases. O número de alelos variou de 15 (MCW0081) a 52 (LEI0212), com média de 31,5 alelos por locus. A média de heterozigosidade esperada e o conteúdo de informações polimórficas foram, respectivamente, 0,887 e 0,909. Foram observados desvios no equilíbrio de Hardy-Weinberg e valores positivos do índice de fixação com excesso de homozigotos. Os microssatélites utilizados mostraram-se polimórficos e podem ser usados para investigações genéticas em galinhas Canela-Preta. As galinhas dos plantéis avaliados apresentam grande variabilidade gênica, o que as qualifica como importante fonte de recursos genéticos e, consequentemente, faculta a utilização delas em programas de melhoramento genético animal.(AU)

The aim of this study was to analyze the genetic variability of twelve microsatellite loci in native Canela-Preta chickens. Blood samples were collected from 118 chickens of the breed from five properties in three cities (Oeiras, Queimada Nova and Teresina) of Piauí state. After the DNA extraction, markers were used for twelve microsatellite loci: LEI0192, LEI0209, LEI0212, LEI0217, LEI0221, LEI0234, LEI0237, LEI0248, LEI0258, MCW0081, MCW0183, and MCW0213 that were amplified by polymerase chain reaction technique (PCR). The results showed a total of 408 alleles (adding alleles from the 12 loci) with the fragments ranging between 50 and 460 base pairs, the number of alleles ranged from 15 (MCW0081) to 52 (LEI0212) with an average of 31,5 alleles per locus. The average expected heterozygosity and PIC were, respectively, 0.887 and 0.909. Deviations were observed in the Hardy-Weinberg equilibrium and positive values of the fixation index with excess of homozygotes. It is concluded that the used microsatellites are polymorphic and can, therefore, be used for genetic research in Canela-Preta chickens. The birds of the analyzed cores present great genetic variability, which qualifies them as an important source of genetic resources, which could be used for future animal breeding programs.(AU)

Antibacterial activity of plant extracts from Brazil against fish pathogenic bacteria

The aim of this work was to evaluate the antibacterial activity of Brazilian plants extracts against fish pathogenic bacteria. Forty six methanolic extracts were screened to identify their antibacterial properties against Streptococcus agalactiae, Flavobacterium columnare and Aeromonas hydrophila. Thirty one extracts showed antibacterial activity.

O objetivo deste trabalho foi avaliar a atividade antibacteriana de extratos de plantas brasileiras contra bactérias patogênicas para peixes. A atividade antibacteriana de quarenta e seis extratos metanólicos de plantas foi avaliada contra os agentes Streptococcus agalactiae, Flavobacterium columnare e Aeromonas hydrophila. Trinta e um extratos apresentaram atividade antibacteriana.