Some aspects of environmental effects and genetic modifications in animal breeding
1998
Bogre, J. | Dohy, J. | Magyary, I. (Godolloi Agrartud. Egyet., Godollo (Hungary))
Previously the authors (Bogre and Dohy, 1991) showed that the currently applied highly intensive genetic methods (hybrid breeding), in connection with the industralized animal keeping technologies, considerably altered the genotype of the poultry (hen, turkey, duck) and that of the swine as well. In the past 25 years significant changes could be observed in the growing capacity of the broiler parent stock, and especially in the final product (Bogre, 1987). An increased effect of gene erosion can be detected (Bogre and Dohy, 1990), which can hardly be balanced by conscious immigration. The genome is becoming more and more deformed. The authors suppose (Bogre and Dohy, 1991) that the so called 'adequate mutation' (termed by the authors) plays an important role in this process. The common effect of the four factors described above and covered by this term could be highly significant through the effects of transposons, virus infections, and increasing stress sensitivy. These factors are as follows: 1. genetic 'overbreeding', 2. negative effects of industry-like keeping, 3. widespread diseases, 4. international mobility of broodstocks. The authors suppose that the above-listed factors predispose the more and more frequently appearing degradation of broodstocks as well as a strong decrease in fitness, resistance (incl. growing mortality), and in constitution. The emerging problems urge the revision of breeding politics, exportation, etc. The restoration of the economically and biologically balanced breeding, defined earlier by Horn (1955), should be emphasized. The authors think that the problems mentioned above cannot be eluded in the future
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