ArticleOriginal scientific text
Title
Rearing system, utility type and age of hens as factors modifying the hydrolytic activity of lysozyme
Authors 1, 2, 2, 3, 4
Affiliations
- Institute of Biological Basis of Animal Production, University of LIfe Sciences in Lublin, 13 Akademicka St., 20-950 Lublin, Poland
- Students' Research Group of Poultry Biology, Breeding and Management, University of Life Sciences in Lublin, 13 Akademicka St., 20-950 Lublin, Poland
- Institute of Biological Basis of Animal Production, University of Life Sciences in Lublin, 13 Akademicka St., 20-950 Lublin, Poland
- University of Life Sciences in Lublin, 13 Akademicka St., 20-950 Lublin, Poland
Abstract
The aim of study was to analyse the impact of the utility type, age and rearing system of
hens on egg quality traits and the enzymatic activity of egg albumen lysozyme (LA). The
research material consisted of eggs from two genotypes of hens: Hy-Line Brown laying hens
and Ross 308 parental stock (meat-type). Laying-type hens were reared in two systems (60
eggs/system): intensive (litter, balanced feed) and extensive (open runs, on-farm fodder). The
second variable was the age of hens from the parent stock (29, 33, 41, 53 and 70 wks; 60
eggs/age). Selected quality traits of eggs (egg weight, albumen weight and its proportion in the
egg, albumen height, and Haugh unit) were measured, as well as albumen lysozyme activity.
The rearing system significantly modified egg weight, albumen weight, and thick albumen
height, but did not affect LA. LA also did not depend on the utility type of birds; however, it
decreased after 33 weeks of age. The enzymatic activity of lysozyme was highly negatively
correlated with the age of hens, and positively with albumen height and Haugh unit.
Keywords
meat-type layers, hen, extensive system, muramidase, egg quality, albumen