Homological variation of embryonic abnormalities in poultry

Aggravation of a number of poultry lines and strains due to hereditary pathology controlled by some autosomal loci was evaluated for the purpose of obtaining data on occurrence frequencies of genetic developmental defects in commercial poultry stocks. The objects for the research were nine selected lines of chickens, five selected lines of turkeys, one strain of geese, four strains of common ducks and two of muscovies. All the perished embryos and day-old chicks were observed and their inherited pathology was diagnosed. The following amounts of day-old poults and dead embryos were phenotyped: 36606 in chickens, 7305 in turkeys, 5023 in geese, 13066 in domestic ducks and 3305 in muscovies. Among dead embryos and day-old chicks, the widest spectrum of genetic abnormalities was revealed in chickens (nine variants) and the narrowest one in domestic ducks (four variants). About 95% mutant embryos perished at the late stages of incubation and those hatched survived not more than three to five days. With decreasing occurrence frequencies of morphological defects, the order of the species observed is as follows : domestic ducks, 0.56±0.09% ; geese, 0.55±0.10%; muscovy ducks, 0.54±0.13% ; chickens, 0.25±0.04% ; turkeys, 0.23±0.12%. A considerable similarity of genetic abnormalities occurrence and spectrum corresponded well to Vavilov (1968) law of homological rows in hereditary variation, the differences being stated between domestic Galliformes (0.23 to 0.25) and Anseriformes (0.54 to 0.56).