Objetivos E Critérios De Seleção Para Dois Sistemas De Criação De Caprinos Leiteiros No Brasil

• Autor(a) principal: LOPES, Fernando Brito
• Data de Publicação: 2011
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tde/1117
• topic: Índice de seleção; lucro; objetivo de seleção; peso econômico; Breeding objective; econômic weight; profit; selection indice; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::PRODUCAO ANIMAL

The objectives and selection criteria used for dairy goats in Brazil are determined empirically. Brazil has climate, soil and environmental diversity, as well as distinct socioeconomic and political realities, producing distinctions among the political administrative regions of the country. The aim of this study was to obtain spatial distribution of physical, climatic and socioeconomic aspects that best discriminate the Brazilian dairy goats production, identifying the characteristics of higher socio-economic relevance for intensive or semi-intensive rearing of dairy goats, derive economic weights for selection objectives and propose selection indices whose criteria are easy to be collected by breeders of dairy goats in Brazil. The spatial analysis was performed using local climatic variables, physical and socioeconomic. The selection objectives were defined by their relative economic importance to farming systems. The economic value of each characteristic was calculated as the difference between the average profit before and after the upgrade, after increasing by 1% each feature, keeping the average remaining unchanged. It was proposed eight selection indices. The traits included in each indice were: I and V indices, milk production (MP) and lactation length (LL); II and VI indices, MP, LL, and age at first calving (AFC); III and VII indices, MP , LL, AFC and calving interval (CI) and IV and VIII indices, MP, LL, AFC, CI, somatic cell count (SCC) and total solids (TS). To test the selection indices were simulated dairy goats herds using selection intensities of 10%, 25% and 50%. For each herd, were simulated MP, LL, AFC, CI, SCC and TS. To compare the means was used the Tukey test (p<0.01). Multivariate analysis revealed distinctions between the Brazilian Regions. Climatic factors were most important for discrimination between the regions of Brazil. Thus, animal breeding programs should be implemented according to the specificities of each region. The average profit of the semi-intensive system was higher than the intensive system, R $ 0.18 and $ 0.14, respectively. Productive and reproductive traits were improved by selecting animals for PL, DL, IPP and IDP simultaneously. Having differentiated payment for milk of better quality, for the levels of EST and SCC, we suggest the use of indices with these selection criteria. The choice and use of these indices depend on the definition of the objectives of selection and ease of measurement of selection criteria to be used.