The objective of the study was to determine the effect of breed (A) and free-range production
system (B) on quality of meat from hens of two breeds, Greenleg Partridge (Z-11) and Rhode
Island Red (R-11), which are under the biodiversity conservation programme in Poland. Subjects
were 120 hens of each breed, which were assigned to two treatment groups differing in the housing
system: 60 layers were kept on litter without outdoor access (C) and 60 layers were raised on
litter with access to free range (FR). At 56 weeks of age, 8 hens were randomly chosen from each
group, slaughtered, and subjected to slaughter analysis. It was found from the study that carcasses
from 56-week-old multi-purpose hens are characterized by poor muscle development and considerable
fat content. After the first year of egg production, the meat of hens was characterized by
low tenderness, high water holding capacity, and a fatty acid profile that was desirable from the
viewpoint of human nutrition. In the meat of hens that completed their first year of egg production,
the profile of fatty acids was beneficial from the standpoint of human nutrition. The free-range
production system reduced carcass fatness, enhanced carcass and meat yellowness, and increased
the proportion of polyunsaturated fatty acids (both n-6 and n-3) in breast and leg muscles while
causing no significant changes in the content of saturated fatty acids. The meat of the native Z-11
breed was found to contain less saturated and more unsaturated fatty acids compared to the meat
of R-11 hens. There was no statistically significant effect of the production system on the sensory
evaluation of cooked meat and broth.