Material and methods
The experiment was carried out on 36 crossbred gilts (♀Polish Large White ×
♂Danish Landrace) of a body weight (BW) from 60 to 105 kg. Origin of piglets
minimised genetic variability as they were the offspring of one Danish Landrace boar
and five half-sibling Large White sows. One piglet from each litter was allocated to
each experimental group. Pigs were kept in individual pens (2.6 m2) on concrete floor,
without straw, with free access to drinking water, in thermo-neutral air temperature
of 18-20°C and humidity of 60-70%. Animals of control group (diet/group C)
were fed diet containing barley, wheat, maize, post-extractive soyabean and postextractive
rapeseed oil meal, supplemented with mineral-vitamin mixture enriched
with crystalline amino acids. In the experimental diets, approximately 13% of ME
energy of diet C was replaced with energy of linseed oil (diet/group L), rapeseed oil
(diet/group R), beef tallow (diet/group T) or fish oil (diet/group F). All diets were