The objective of the paper was to evaluate hybrid pig meatiness by usi
ng carcass detailed dissection as well as instrumentally (Fat-O-Meater
) in the conditions of packing plants. Hybrids (n = 92) SLOVHYB-1 and
SLOVHYB-2 were used to comply with the goals of the first part of expe
riments. The former cross combination has been most frequently used in
Slovakia until now; it consists of domestic breeds Large White and Wh
ite Meaty and of so called synthetic line in the terminal position (Be
lgian Landrace x Duroc cross). Newly produced cross combination SLOVHY
B-2 is based on a domestic and imported gene pool while the main breed
s contributing to its creation are White Meaty, Landrace, Duroc and Yo
rkshire. Hybrid pigs were fattened in identical conditions, receiving
feed mixture with the content of digestible substances 15.33%, energy
12.73 MJ ME, lysine 0.92% and fiber max. 5.0%. Their slaughter at aver
age live weight of 105 kg was followed by detailed dissection of dress
ed carcasses while the per cent of lean meat, fat, skin and bones in t
he parts of the side of pork were determined. Thirty-five pigs with li
ve weight of 100 kg were selected out of the evaluated set in order to
determine the observed indicators in this weight category (Tab. I). T
he analyzed set was also divided by the sex into gilts - barrows (Tab.
III) and by genotype constitution (Tab. IV). In the second part of st
udy (Tab. V) the lean meat in slaughter pigs (n = 14 011) with average
dead weight of 97.57 kg was estimated instrumentally in operating con
ditions of slaughterhouses using the instrument Fat-O-Meater (FOM). Th
e per cent of valuable lean cuts and/or lean meat content (LMC) made 5
0.35 and 54.38%, respectively, in the analyzed set while 46.7% of anim
als were included in classification grades S and E. The pigs under eva
luation were divided into final hybrids SLOVHYB 1 and 2 on the basis o
f cross combination (Tab. IV). SLOVHYB-1 has recently represented a ma
jor part of carcass pig production in Slovakia. The other cross combin
ation has beed bred for increased per cent of LMC in keeping with the
prepared grading of slaughter hybrids pursuant to EU regulations. Diff
erences in the observed indicators of the cross combinations concerned
are statistically significant for all analyzed carcass parts, with be
tter values for the newly produced hybrid combination, in which 71.9%
of animals against 5.7% were included in grades S and E. In the condit
ions of packing plants (Tab. V) the group of 14,011 carcass hybrids sh
owed the LMC at the value of 46.51 while about 22% of pigs were includ
ed in grades E and U. Increasing dead weight was accompanied by a decr
ease in the relative LMC in the specific weight categories. In the lar
gest subgroup (95.18 kg, n = 3 933) the LMC determined instrumentally
was 46.87% while grades E and U involved 22.2% of animals. The meatine
ss of slaughter pigs in operating conditions, estimated instrumentally
, did not reach such a level as in the EU countries with advanced bree
ding programs. It was also lower in the cross combination SLOVHYB-1. W
e believe that besides the worse factors of external environment (low-
quality nutrition, level of management and breeding work, lack of long
run breeding of produced types for an increased portion of LMC) an un
suitable regression equation of the instrument for our hybrids could b
e a cause of lower meatiness. One of the producers' tasks will be to d
ecrease variability of this trait substantially since the present slau
ghter weight ranges from 90 to 150 kg in many cases. It is expected to
examine both in theoretical and practical terms the problems of an al
l-in all-out system of filling and unloading the fattening facility wi
th respect to balanced live weights, separate fattening of gilts and b
arrows to various slaughter weights and possible substantial increase
in the LMC in dressed carcasses.