Abstract
Over a 10 years period, data were collected on 374 H.Friesian X Sahiwal/Cholistani crossbred cows maintained at the Livestock Production Research Institute, Bahadurnagar (Okara). Overall first lactation milk yield, total and average milk yield for first three lactations and milk yield da)'l of age at second and fourth calvings averaged 2384.62 ± 46.16, 7044.33 ± 163.59, 2348.11 ± 54.53, 1.67 ± 0.03 and 3.19 ± 0.07 Iitres, respectively. The genetic group had a significant (P
