Records of 3691 growing Holstein Friesian calves, from birth up to weaning (born in a period from 2013 to 2019), belonging to commercial farm named El-Baiomy dairy farm located in Gamasa-Dakahlia Province- Egypt were used in this study. Data collected included management factors such as dam effect (dry period, parity, calving interval and previous milk production) and calves management (Housing system, suckling system, season and gender) and their effects on calves' performance (birth weight (kg), weaning weight (kg), weaning age (day) and daily gain (kg/day)). There were no significant effects in dry period length, parity, calving interval and previous milk production of dam on calf's performance. The lowest birth weight found to be in first parity cows (31.63 kg), while the heaviest one was found to be in third parity cows (33.00 kg). The lowest calves birth weight (30.40kg) was produced by high yielder cows (>11 ton). While it was been 31.71kg for calves belonging to cows with low (< 9 ton) milk production. There was significant effect (P ≤ 0.05) of housing system, suckling system and seasons of calving on weaning age and daily gain of calves. The lowest birth weight was been in winter (31.34 kg) however the heaviest one was been in winter (93.88 kg). The heaviest birth weight was been in male (32.93 kg) but female was 31.63 kg only. On the other hand weaning age found to be 81.31 and 79.14 days in female and male respectively.
In addition, a supplementary study has been made to explain management systems of calves raised in some Egyptian villages using field survey. Data of 267 questionnaires (3458 Animals) have been recorded and analyzed to study calf's management systems in different farms located in Nile delta.