I. Zwolinska-bartczak et al., Length of productive life and lifetime production of cows-daughters of high yielding dams in Poland, CZEC J ANIM, 46(3), 2001, pp. 101-104
Records of 19 017 Black-and-White and 10 135 Red-and-White cows and their d
aughters used in 1978-1993 in the South-West region of Poland were analysed
. Cows-dams were classified to a group of cows with high performance if the
y exceeded the assumed production level ((x) over bar +1.96s or 1.28s, resp
ectively). The following traits of cows-daughters were examined: number of
lactations, number of calves, lifetime production of milk and fat, lifetime
, length of productive life and milk and fat yield per life day and per pro
duction day. Daughters of cows with high performance produced higher milk a
nd fat yields per production day than daughters of other dams. Lifetime and
length of productive life of those cows were shorter.