The objective of the paper was to determine some figures of fattening
performance, carcass value and meat quality in hybrid pigs (n = 105) w
ith 50% blood share of the Pietrain breed. The mothers of the terminal
hybrid were crossbred dams of the Large White x White Pork or Large W
hite x Landrace breeds. Slaughter pigs received two commercial feed mi
xes lower and/or higher in crude protein content (11.4 and/or 14.1%) w
hile the mix type and structure did not change during the trial. The s
ex ration (young boars: gilts) was approximately equal in the sets. Wh
en the hybrids reached slaughter weight, they were slaughtered in the
slaughterhouses of Agrokombinat a. s., where stress-free conditions we
re actually maintained. A choice of animal for a fattening trial on th
e basis of halothane test in a set of 34 pigs demonstrated that approx
imately 30% of animals had positive reactions to narcotane inhalation.
Some carcass indicators were determined in vivo instrumentally (PIGLO
G 105 and ALOKA SSD 210 DX II) in all pigs a day before slaughter. The
se traits were determined (Tabs. I-IV): backfat thickness between the
3rd and 4th lumbar vertebrae 7 cm laterally from the central dorsal li
ne (ECHO 1, PIGLOG 1 measures) thickness of backfat and/or m.l.d. betw
een the 3rd and 4th last but one rib 7 cm laterally from the central d
orsal line (ECHO 2, PIGLOG 2 and/or ECHO mld, PIGLOG mld) muscle perce
ntage in the carcass instrumentally by PIGLOG 105. Besides usual indic
ators (pH1, electrical conductivity and color), meat quality was asses
sed by meat quality index (D e m o et al., 1994). Tabs. I-IV show the
values of the investigated indicators as depending upon feed mix type,
sex, sensitivity to halothane test and slaughter weight; Tab. V conta
ins chemical analysis of muscles in the hybrids. In comparison with th
e pigs receiving feed mix higher in crude protein content, the hybrids
receiving feed mix with the lower content of crude protein had the st
atistically significantly lower daily weight gain (602 vs. 621 g), low
er percentage of valuable lean cuts (47.9 vs. 50.28%), higher backfat
thickness (29.1 vs. 23.2 mm) and higher percentage of fatty parts (18.
1 vs 16.3%). No statistically significant differences were observed in
meat quality. As for the differences in the investigated indicators a
s depending upon the sex and/or sensitivity to halothane test, statist
ically significant differences were determined in most carcass indicat
ors in favor of the gilts and/or halothane-positive pigs. These were n
o significant differences between the males and females in flesh quali
ty while this indicator had undoubtedly worse values in the halothane-
positive pigs. The set of experimental pigs was divided into three gro
ups according to slaughter weight while significant differences in mos
t carcass traits were determined between the evaluated groups. Chemica
l analysis of the m.l.d. sample enabled to determine the basic compone
nts while the percentage of intramuscular fat was 3.05 and the percent
age of total water 73.31. It is possible to summarize on the basis of
the results of the indicators of fattening performance and carcass val
ue in the hybrid pigs in which a sire of the Pietrain breed was used a
s the father of terminal hybrid that the hybrid pigs had the average p
ercentage of valuable lean cuts below 48, which does not comply with t
he criteria established for slaughter pigs produced in the Slovak Repu
blic. The increased content of crude protein and energy (subgroup II)
administrated to the hybrid pigs resulted in their better values of fa
ttening performance and carcass value. PSE meat occurrence was found t
o be 35% in a trial conducted according to the established criteria (m
eat quality index).