The Black Shumen Chicken is an old breed originating in the north-eastern region of Bulgaria by crossing local hens with Black Minorca cockerels and with Rhode Island Red cockerels later. Its creation began in the late nineteenth and early twentieth century through native selection. The breed enjoys good vitality and stamina, non-exigent to nutrition and technology of farming, excelent fertility, but with sufficient laying capacity and low egg weight. The Black Shumen Chicken is a breed in risk and threatened by extinction now.
The purpose of this study was to investigate the egg productivity of a small population of hens of the Black Shumen breed (20 fimale and 2 male) reared in an organic farm system with natural day light.
The birds started nesting at 171 days of age. For the whole 23-week period (d 07.12.2008 – d 31.05.2009) the laying capacity was 45.40% at 7.6°C average ambient temperature for the period. The laying capacity was highest during the period from February to April (64-71%). The eggs weight increased with age. It was lowest in December (40.40±0.80 g) and highest in March (53.60±1.01 g). For the whole period of the investigation there were no significant changes in the egg components. The egg shell changed from 12.88% to 13.75%. The egg yolk varied from 28.73% to 30.65% and the egg albumen was between 56.61% and 57.95%.