Three metabolism trials were conducted to evaluate differences in mass
digestibility of nutrients between eight breeding boars of the Large
White x Holland Yorkshire (paternal line) breeds at the average live w
eight of 48 kg, 73 kg and 98 kg. The young boars received the feed mix
OPO (rearing of breeding pigs) containing soybean meal (12%) and grai
ns (78.7%) and the feed mix OPO/H containing pea (10%) and rapeseed 00
meal (2.5%), and grains (69.2%). The animals of control groups receiv
ed the feed mix OPO, the experimental animals were fed the mix OPO/H.
Crude protein content in the feed mix OPO was higher by 13.5 g, which
equals 7.7% in comparison with the feed mix containing pea. The latter
mix had the fiber content higher by 16.7 g, which makes 29.2% against
the mixture with soybean meal. The coefficients of apparent mass dige
stibility of nutrients in the 1st metabolic trial at the average live
weight of 48 kg (80.03 and 79.08% for dry matter, 80.98 and 80.22% for
crude protein, 63.91 and 72.40% for fat, 23.31 and 26.20% for fiber,
87.91 and 87.46% for nitrogen-free extract, 43.81 and 4133% for ash, 8
2.49 and 81.63% for organic matter) were insignificantly different in
the particular groups (P > 0.05). Tabs. III and IV show the determined
coefficients of nutrient digestibility in the 2nd and 3rd trial at th
e average live weight of young boars 73 and 98 kg. There were insignif
icant differences in nutrient digestibility between the groups when ev
aluated by t-test (P > 0.05). Comparison of the metabolism trials cond
ucted at the given live weight showed the best efficiency of the feed
mix with soybean meal in the boars at the average live weight of 73 kg
(highest digestibility of dry matter, crude protein, nitrogen-free ex
tract, ash). The highest digestibility of fiber and fat was determined
in the highest weight category. Nutrient digestibility in the feed mi
x with pea was variable in the particular balance periods (fiber, fat)
. There were small differences in the digestibility of dry matter, nit
rogen-free extract, ash and organic matter between the metabolism tria
ls. Crude protein digestibility tended to increase with growing live w
eight of young boars. Overall evaluation of nutrient digestibility (Fi
g. 1) in the particular groups for the feed mix containing soybean mea
l (control group) indicated the higher digestibility of dry matter (81
.19% and/or 79.64%), crude protein (83.55% and/or 82.35%) and nitrogen
-free extract (88.59% and/or 87.67%). Higher digestibility of fiber (3
0.44% and/or 26.19%) and fat (69.14% and/or 62.21%) was determined whe
n the animals received the feed mix containing pea (experimental group
). The difference in the digestibility of organic matter (83.33% and/o
r 83.88%) and ash (43.85% and/or 43.36%) was however minimum between t
he groups. There were insignificant differences in the coefficients of
nutrient digestibility (P > 0.05) for all the basic nutrients. Overal
l evaluation of the indicators of nitrogen utilization, i.e. nitrogen
uptake and its retention, indicates increases in their values with the
growing five weight of young boars. Nitrogen retention from its uptak
e and biological value of proteins tended to decrease their values wit
h the growing live weight of young boars. There were no statistically
significant differences in the indicators of fattening performance and
carcass value, even though certain trends in favor of the feed mix wi
th soybean meal were observed. A significant difference was determined
only in the spare rib weight (P < 0.05) in favor of the control group
. The above results demonstrate that both tested mixtures are usable (
alternatively) for the rearing of breeding young boars, both in indivi
dual test and in usual rearing system.