The design of selection schemes relies on certain genetic parameters, the estimation of which is an essential step for the development of selection tools. This book presents the results of research on the identification of the main genetic parameters of growth at young age of local kids. The work analyzed data from 16 years of follow-up performance. The results concluded the importance of the effects of the arid environment and the modes of management on the observed phenotypes. Data collected at an early age, when kids are fed milk, are necessary to assess maternal effects. Later recordings may not provide sufficient information on maternal ability and thus less effective selection for this component would be expected. The results suggest that selection to alter the growth pattern is feasible, the estimated genetic trends indicated that there was no effective selection in the population evaluated.