| Sumario: | This study was undertaken to estimate the potential genetic gains in milk yield by using several
alternative selection criteria which included milk yield and reproductive traits of dairy cattle in
Malawi. Applying the selection index procedure, the expected genetic gain in each trait in the
different scenarios was calculated for bull performance. On average, there were six daughters
per sire. Including calving interval in the selection criteria increased expected genetic gain by
55.9% for milk yield and 94.4 % for calving interval from the currently applied selection
criteria after one round of selection. The correlation between the index and the aggregate
genotype (rHI), which indicates the accuracy of estimation, increased from 0.221 to 0.495.
Adding age at first calving in the selection criteria resulted in very minimal increases. The
optimal breeding strategy for the aggregate genotype which aims at improving milk yield and
calving interval, is one whose selection criteria is based on milk yield and calving interval
obtained from daughters performing in Malawi.
|
|---|