Two experiments were carried out to investigate the effects of supplem
entation of 2-10% linseed cake (LC), type McGregor, in 700 chicken (ZE
H's White and Brown) from hatching to the 18th week of life. On the av
erage, the LC supplements diminished the feed intake and the life weig
ht gain in both, the chicken period (1st-8th week of life) and the pul
lets period (9th and 18th week of life) compared to the control group.
However, there was no effects of LC supplements on feed efficiency to
obtain 1 kg body weight. In pullers the thyroid mass, and thyroid's i
odine content as well as the concentration of thiocyanate in blood pla
sma were increased by the LC supplementation. A higher concentration o
f thyriod's hormons in plasma was observed but the differences remaine
d insignificant. There was not a significant influence of the LC conte
nt of the diet on the amount of blood cells and hemoglobin concentrati
on of blood. Furthermore, the content of LC in rearing diet did not in
fluence the egg production of laying hens. We can recommend an upper l
imit of supplementation of the diet with LC of 2% in chicken and 4% in
pullers.