INVESTIGATIONS OF THE INFLUENCES ON THE C ONDITION OF THE PLUMAGE OF LAYERS IN DIFFERENT AGES

By means of 960 groups of 20 layers each the different conditions of t he plumage was judged in different ages during the laying period. The hens were of different white and brown hybrid proveniances. Brown laye rs are superior in the condition of plumage up to the 32nd week of the laying period; later on they were surpassed by the white layers. The feed's content of energy and crude protein seems to be without any imp ortance for the condition of the plumage. In dependency on the phase o f the laying period its coefficients of heritability vary between 0.25 and 0.43. Regardless of the worsening of the plumage in course of the laying period there are high correlations between the condition of th e plumage in all the phases of the laying period. An intact plumage is related to a fewer mortality, a higher egg production, a lower feed c onsumption and fewer cracked eggs.