RESUMO
This study investigated phenotypic differences of zebu females from four breeds using variables of growth, feed efficiency, and age at first calving. Weights throughout the life were recorded, and a growth curve was fitted using the Gompertz model. The growth was also evaluated at standardized ages (205, 365, and 550 days) using the body weight and the total and daily weight gains. The Kleiber index and age at first calving were used as measures of feed efficiency and sexual precocity, respectively, totaling 25 variables. New variables were created using the factor analysis and used in new multivariate analyzes. Only six factors explained 95.41% of the total variance and were used for the subsequent analyses. The factors were defined as maturity, precocity, feed efficiency postweaning, feed efficiency post 1 year of age, puberty, and birth weight. There were differences between breeds according to the multivariate analysis of variance. Each breed appeared in a quadrant on the Biplot graph, showing relationship with different factors, demonstrating the diversity of zebu females. There is a difference in growth, feed efficiency, and sexual precocity in Brazilian zebu females, allowing the identification of potentials of the animals and help breeders and decision-makers.
Assuntos
Maturidade Sexual , Aumento de Peso , Animais , Brasil , Bovinos , FemininoRESUMO
The intense selection process for economic traits conducted by the poultry breeding programs has been caused several changes in broiler meat quality. A database belonging to a selection program of a broiler male line was used to estimate heritability and genetic correlations for feed conversion ratio and meat quality traits, which were: initial and final pH, lightness, drip loss, thawing loss and shear force. Two-trait analyses were performed and the components of co(variance) and genetic parameters were determined using the Bayesian approach and the GIBBS3F90 software. The heritability estimate found for feed conversion ratio (0.52) showed high influence of direct additive genetic effects on the expression of this trait; therefore, this trait is able to respond to selection. The genetic correlation estimates obtained (-0.50 to 0.33) were indicative of important associations between feed conversion ratio and meat quality traits. The selection to improve feed conversion ratio may cause injury in greater or lesser degree for L*, drip loss (DL), thawing loss (TL) and shear force (SF) in broilers. It is recommended the monitoring of consequences of feed conversion ratio used as selection criteria or meat quality traits in broilers, due to its unfavorable indirect selection for these variables in this population. Breeding methods for efficiency improvements in broilers feed are suggested, which also benefit sensorial and functional properties of the meat.(AU)
Assuntos
Animais , Criação de Animais Domésticos/métodos , Carne/análise , Galinhas/genética , Teorema de BayesRESUMO
The intense selection process for economic traits conducted by the poultry breeding programs has been caused several changes in broiler meat quality. A database belonging to a selection program of a broiler male line was used to estimate heritability and genetic correlations for feed conversion ratio and meat quality traits, which were: initial and final pH, lightness, drip loss, thawing loss and shear force. Two-trait analyses were performed and the components of co(variance) and genetic parameters were determined using the Bayesian approach and the GIBBS3F90 software. The heritability estimate found for feed conversion ratio (0.52) showed high influence of direct additive genetic effects on the expression of this trait; therefore, this trait is able to respond to selection. The genetic correlation estimates obtained (-0.50 to 0.33) were indicative of important associations between feed conversion ratio and meat quality traits. The selection to improve feed conversion ratio may cause injury in greater or lesser degree for L*, drip loss (DL), thawing loss (TL) and shear force (SF) in broilers. It is recommended the monitoring of consequences of feed conversion ratio used as selection criteria or meat quality traits in broilers, due to its unfavorable indirect selection for these variables in this population. Breeding methods for efficiency improvements in broilers feed are suggested, which also benefit sensorial and functional properties of the meat.
Assuntos
Animais , Carne/análise , Criação de Animais Domésticos/métodos , Galinhas/genética , Teorema de BayesRESUMO
Genetic diversity is one of the most important issues in studies on conservation of cattle breeds and endangered species. The objective of this study was to estimate the levels of genetic differentiation between locally adapted taurine (Bos taurus taurus) and zebu (Bos taurus indicus) breeds in Brazil, which were genotyped for more than 777,000 SNPs. The fixation index (F ST), principal component analysis (PCA), and Bayesian clustering were estimated. The F ST highlighted genetic differentiation between taurine and zebu breeds. The taurine lines, Caracu and Caracu Caldeano, had significant genetic differentiation (F ST close to 5%) despite their recent selection for different uses (meat and milk). This genetic variability can be used for conservation of locally adapted animals, as well as for breeding programs on zebu breeds. Introgression of zebu in locally adapted breeds was identified, especially in Curraleiro Pé-Duro breed. The Gyr breed, however, had low breed purity at genomic level due to its very heterogeneous mixing pattern.
Assuntos
Adaptação Biológica , Bovinos/genética , Variação Genética , Polimorfismo de Nucleotídeo Único , Animais , Teorema de Bayes , Brasil , Cruzamento , Análise de Componente PrincipalRESUMO
Este trabalho foi realizado para avaliar os efeitos da adição de diferentes aditivos promotores de crescimento em dietas de frangos de corte de 1 a 10 dias de idade. O delineamento experimental foi o inteiramente casualizado, com seis tratamentos e quatro repetições, com 30 aves por unidade experimental. Os tratamentos foram: dieta sem aditivos, com antibióticos (avilamicina e colistina), com prebiótico (mananoligossacarídeos), com prebiótico mais ácidos fumárico e propiônico, com probiótico (Bacillus subtillis) e com mistura de probióticos (Lactobacillus plantarum, Lactobacillus bulgaricus, Lactobacillus acidophilus, Lactobacillus rhamnosus, Bifidobacterium bifidum, Streptococcus thermophilus e Enterococcus faecium). Os parâmetros analisados foram: ganho de peso, consumo de ração, conversão alimentar, rendimento de peito, rendimento de coxa, peso do fígado, do coração e do intestino. Os resultados mostraram que as dietas com inclusão de aditivos não diferiram entre si em nenhum dos parâmetros estudados. Concluiu-se que o uso dos antibióticos, do prebiótico com ácidos fumárico e propiônico e da mistura de probióticos melhorou o consumo de ração e a conversão alimentar em relação à dieta sem aditivos.
This trial was carried out in order to evaluate the effects of growth promoters on broiler chicken diets, from 1 to 10 days. The experiment was in a completely randomized design, with six treatments, four replications and 30 chicks as experimental unity. The treatments were: a basal diet of corn and soybeans meal without additives and basal diet with inclusion of antibiotics (avilamicin and colistin); or prebiotic (mannanoligosaccharides); or prebiotic plus fumaric and propionic acids; or probiotic (Bacillus subtillis); or a pool of probiotics (Lactobacillus plantarum, Lactobacillus bulgaricus, Lactobacillus acidophilus, Lactobacillus rhamnosus, Bifidobacterium bifidum, Streptococcus thermophilus and Enterococcus faecium). The parameters assessed were weight gain; feeding intake; feeding conversion; carcass yield; thigh yield; weight of liver, heart and intestine. The results showed that the diets with inclusion of additives were not significant in all parameters studied. It was concluded that the use of antibiotics, prebiotic plus fumaric and propionic acids and the pool of probiotics improved ration intake and the feeding conversion in relation to diet without additives.
Assuntos
Animais , Aves Domésticas/métodos , Probióticos/administração & dosagem , Probióticos/efeitos adversosRESUMO
Este trabalho foi realizado para avaliar os efeitos da adição de diferentes aditivos promotores de crescimento em dietas de frangos de corte de 1 a 10 dias de idade. O delineamento experimental foi o inteiramente casualizado, com seis tratamentos e quatro repetições, com 30 aves por unidade experimental. Os tratamentos foram: dieta sem aditivos, com antibióticos (avilamicina e colistina), com prebiótico (mananoligossacarídeos), com prebiótico mais ácidos fumárico e propiônico, com probiótico (Bacillus subtillis) e com mistura de probióticos (Lactobacillus plantarum, Lactobacillus bulgaricus, Lactobacillus acidophilus, Lactobacillus rhamnosus, Bifidobacterium bifidum, Streptococcus thermophilus e Enterococcus faecium). Os parâmetros analisados foram: ganho de peso, consumo de ração, conversão alimentar, rendimento de peito, rendimento de coxa, peso do fígado, do coração e do intestino. Os resultados mostraram que as dietas com inclusão de aditivos não diferiram entre si em nenhum dos parâmetros estudados. Concluiu-se que o uso dos antibióticos, do prebiótico com ácidos fumárico e propiônico e da mistura de probióticos melhorou o consumo de ração e a conversão alimentar em relação à dieta sem aditivos.(AU)
This trial was carried out in order to evaluate the effects of growth promoters on broiler chicken diets, from 1 to 10 days. The experiment was in a completely randomized design, with six treatments, four replications and 30 chicks as experimental unity. The treatments were: a basal diet of corn and soybeans meal without additives and basal diet with inclusion of antibiotics (avilamicin and colistin); or prebiotic (mannanoligosaccharides); or prebiotic plus fumaric and propionic acids; or probiotic (Bacillus subtillis); or a pool of probiotics (Lactobacillus plantarum, Lactobacillus bulgaricus, Lactobacillus acidophilus, Lactobacillus rhamnosus, Bifidobacterium bifidum, Streptococcus thermophilus and Enterococcus faecium). The parameters assessed were weight gain; feeding intake; feeding conversion; carcass yield; thigh yield; weight of liver, heart and intestine. The results showed that the diets with inclusion of additives were not significant in all parameters studied. It was concluded that the use of antibiotics, prebiotic plus fumaric and propionic acids and the pool of probiotics improved ration intake and the feeding conversion in relation to diet without additives.(AU)