Abstract :
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
