Kropf- und Muskelmageninhalt von Öko-Masthühnern und Legehennen

Summary

The objective of this study was to evaluate the variation of feed intake from pasture in organic broilers and in laying hens. In the broiler experiment, in total 288 broilers of breeds Ross 708 (fast growth; FG), Isa 657 (medium growth; MG) and Isa 757 (slow growth, SG) were kept in mixed groups. Between week 7 and 12 of life birds were slaughtered, crops and gizzards were collected and investigated for contents of feed, grit and plant particles. FG broilers had higher feed proportions in crops than MG and SG broilers. Proportions of plant particles have been higher in SG broilers than in MG and FG broilers. SG broilers had higher proportions of plant particles and grit in the gizzard. It is estimated that the proportion of plant particles amounts to 5-10 % of daily feed intake in slow growing broilers kept under organic conditions. In the laying hen experiment 60 young and 60 old laying hens were used. The crop and the gizzard content were analyzed in the morning, at noon and in the afternoon in the same way as in broilers. Proportions of plant particles varied between 6 and 12 %and between 32 and 38 % in the crop and the gizzard, respectively. It is estimated that the intake of plant particles amounts to 20-25 % of daily feed intake in laying hens.