Breeding goals and selection criteria for intensive and semi-intensive dairy goat system in Brazil

The aim of this study was to identify traits of socio-economic relevance for intensive and semi-intensive dairy goat production system, to derive economic weights for the breeding goals and to propose selection indices whose criteria are easily collected by dairy goat breeders. The economic value of each trait was calculated as the difference between the average profit before and after the improvement of criteria, after increasing each trait by 1%, keeping the average of other traits unchanged. Eight selection indices were proposed. Four indices (I–IV) were determined for the intensive system and four (V–VIII) for the semiintensive system. The traits included in each index were: milk production (MP) and lactation length (LL) (I and V); MP, LL, and age at first kidding (AFC) (II and VI); MP, LL, AFC and kidding interval (CI) (III and VII); and MP, LL, AFC, CI, somatic cell count (SCC) and total solids (TS) (IV and VIII). The average profit of the semi-intensive system was higher than the intensive system, R$ 0.18 and R$ 0.14, respectively. The use of indices III and VI promoted simultaneous improvement in both productive and reproductive traits. With differential payment for better quality milk, TS and SCC levels, use of indices IV and VIII are indicated. The choice and use of these indices depend on the definition of objectives and of the measurement ease of selection criteria