Conception of new bioeconomic indexes to evaluate caprine genotypes of meat productivity

Abstract

The comparison of different caprine genotypes' productivity remains limited by the technical and zootechnical parameters used to evaluate the individual animal performances such as kid's growth, goat lactation or herd reproduction. Data issued from 16 years of periodical animal survey of a herd compound from local goats, pure breeds and crosses was used to elaborate new bio-economic indexes allowing an accurate evaluation of the productive potentialities per genotype. The bio-economic indices have been developed to correct dairy performance and growth by the genotype reproductive parameters and kids' mortality rates. These indexes of overall productivity of genetic groups were subsequently adjusted by the metabolic weight of each group to take into account the production charges per animal which vary with the adult body size. The application of bio-economic indexes led to a genotypes classification quite different from this based on the comparison of individual performances. Some breeds, having high lactating performances or heavy kids weights at weaning, seem severely penalized by infertility or kid's mortality rates. Hence, the integration of the components of profitability, such as fertility, mortality and metabolic weight, in the evaluation criteria is essential for the reasonable herd management and genetic improvement. However, the development of bio-economic indexes must take into account all the components and production factors affecting the final animal phenotype and the farmer incomes.