Specific activity of Sr-90 and Cs-137 in rabbits of various genotypes
Abstract
O.V. Bojko, L.M. Darmohray, I.S. Luchyn, O.F. Honchar and B.V. Gutyj*
Numerous researches conducted by scientists in many countries in the world still do not give a complete picture of the specific activity and aftereffect of Sr-90 and Cs-137 on the animal organisms. The specific activity of radionuclides in meat products, muscles, and bones of rabbits is also of great importance when creating new genotypes. We conducted research in individual muscle groups and rabbit bones to study the relationship between growth rate, origin and specific activity of Sr-90 and Cs-137 radionuclides in dynamics over three stages of control cultivation (2-, 3- and 4th month). During the whole period of young rabbits growing, we determined the intensity of growth, fattening productivity by post-weighing on electronic weight and developed indices. These indicators were higher in the crossbreeds of rabbits of the new type of chinchilla being created (NTSH) compared to the peers of the local chinchilla (LS). Thus, during the growing period the weight gain of one head of this genotype (NTSH) was greater by 170 g than the peers (LS). We registered that the specific activity of Sr-90 and Cs-137 in the muscles and bones of young rabbits of the investigated genotypes, providing intensive cultivation, changes with age with success. The specific activity of Sr-90 decreases in the muscles of young rabbits during the fattening period (60-120 days) from 0.032 to 0.018 Bq/kg, and in the bones increases from 0.348 to 0.584 Bq/kg. We proved that the specific activity of Cs-137 on the contrary in muscles with age increases from 0.63 to 0.732 Bq/kg, and in bones decreases from 7.13 to 5.936 Bq/kg. We also found out that the specific activity of Sr-90 in the muscles is lower by 0.011–0.02 Bq/kg (37.9–45.5%), and in the bones by 0.44 Bq/kg (55.9%) in young rabbits of newly formed chinchilla (NTSH) under intensive cultivation compared to young rabbits of local chinchilla (LS). The specific activity of Cs-137 in the muscles of the newly formed three-breed chinchilla was also lower by 0.18–0.21 Bq/kg (22.3–22.4%), and in the bones by 1.08 –1.22 Bq/kg (13.2–18.8%). We suggested that the specific activity of Sr-90 and Cs-137 radionuclides in carcasses of young rabbits under the conditions of natural radioactive background of the Carpathian region is insignificant and depends on the genetic characteristics of the animals and to a greater extent on the complete feeding.