From 2810 animals of black-and-white breed of Novosibirsk region diagnosed, 31% fell ill. Young animals were found to be more resistant to brucellosis. It is evidently more probable that they can reach the reproductive age. Intrapopulation hereditary heterogeneity to brucellosis was found. The progeny of certain bulls has a higher resistance than others. There is no statistical reliability of differences in the frequency of the disease between animal lines. A normal distribution of fathers according to the frequency of daughters diseases can point to a polymeric type of the inheritance of resistance to brucellosis. The coefficient of inheritability of brucellosis is 0,194 +/- 0,03. The purebredness and mongrel of animals did not influence the frequency of the disease. The crossing of cows of black-and-white breed with bulls of Holland black-and-white breed did not influence the frequency of the disease of the hybrids of the first generation.
Aging Animals