The present investigation was conducted on 1138 HF × Gir and 301 Jersey × Gir halfbreds to study the effect of genetic group and stage of lactation oh milk yield, fat, SNF and T.S. content in milk. The results obtained revealed that 90 days milk yield declined with the advancement of stage of lactation in both the groups. However, fat, SNF and T.S. content in milk increased linearly with increase in stage of lactation.
