الفهرس 
Non genetic factorsOnly 14 pages are availabe for public view
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Abstract
This investigation was designed to study non genetic factors affecting production traits 60 - day milk yield (60 MY) , 180-day milk yield (180 MY) , 305- day milk yield 1305 MY) , first 305 - day milk yield (MI) , later 305 - day milk yield (ML) , total lifetime milk yield (ITT’) and total lactation period (TLP) , and longevity traits ”culling age (cull. age) , productive life (p. life) and number of lactations completed (NLC)” . Estimates of genetic parameters of these trait were also studied . The lactation records were collected from Mehallet Mousa Farm , Ministry of Agriculture , during the period from 1962 to-1978 . The data used in this work comprised 3400 normal lactations records for 822 buffalo cows . Records classified by season of calving into four season , Winter , Spring . Sumner and Autumn. The results obtained from the analysis of is data this could be surnrnerized as flows : 1-Least squares means of 60 MY , 180 MY and 305 MY were 507 t 54.34 , 1169 + 55.86 and 1542 + 103.01 , resp. 2-Least squares means of M1 , M1 , MT , and TLF were 1132 + 16.11 kg , 1543 + 13.57 kg , 3521 t 81.96 kg and 995 2 23.35 day , resp.