EFFECTS OF THE HOUSING SYSTEM APPLIED IN LAYING HENS REARING, ON THE EXTERNAL QUALITY OF TABLE EGGS
Cristina Gabriela Radu-Rusu, I.M. Pop, R.M. Radu-Rusu, Aida Albu
In order to investigate the possibilities to adapt the alternative technological systems approved by the E.U. laws in table eggs production, at small scale farms, a more extended study was carried out. This paper is a comparative synthesis of the results related to external quality of the eggs (weight, shape index, shell traits) produced within three different rearing systems: conventional batteries (group CB-100 eggs), improved cages (group IC-100 eggs) and free range (group FR-100 eggs). Hens were fed a standard layer mixed feed, completed with green mass from a fenced pasture, in the FR system. Investigation methodology comprised modern, standard methods, usually applied worldwide in this research field. Statistics were used to process the acquired data, using ANOVA single factor method. Eggs weight varied between 57.49±0.73g (CB) and 60.99±0.78 g (FR) (no statistic significance), while shape index scored 74.36±0.27% (FR), 77.03±0.39% (CB) and 78.34±0.40% (CI) and significance was noticed. Shell area was calculated within the 64.22±0.52cm2 - 69.05±0.60cm2 interval (CB vs. FR groups). Shell gauge presented a reversed dynamics, thus the thickest shells were measured in CB and IC groups (0.38-0.39 mm) and the thinnest ones in FR group (0.33 mm). Of all analyzed eggs, 24% presented shell faults in FR group (mainly marbled shells), 14 % in IC group and 13 % in CB group (2% eggs without shell). These differences, including shell faults issues, suggest an influence of the housing system on eggs external quality. However, other influential factors (age and genotype differences between groups) should be removed before stating a final conclusion on the investigated topic.
Key words: conventional batteries, improved cages, free range, eggshell, quality