Original scientific paper
Offspring - parent regression's non-linearity in cows' milk production
Ivan Jurić
; Agronomski fakultet, Svetošimunska 25, 10000 Zagreb
Marija Đikić
Abstract
Offspring-parent regression's non-linearity hypothesized A. Robertson in 1977. We calculated the regressive relation daughter-mother for milk yield during 305 days of the first lactation. All mothers (n = 224) were daughters of the same bull, theirs daughters were offspring of another same one bull, consequently they were half sisters as well. So mothers had the same father and daughters the same grandfather and father. Among these related animals we ascertained linear regression daughter-mother Y= -23.43 + 0.0462 X, and the curvilinear regression Y = - 25.93 + 0.348767 X - 0.0002572 x^2. Testing the curvilinearity we obtained F = 4.908, its tendency was significant at the 11.4 per cent level. According to own data it is possible to form a hypothesis relative to different relation between additive variance and variance resulting from the interaction of genes in subpopulations differently distant from the mean value of population.
Keywords
regression; non-linearity; daughters-mothers; milk yield
Hrčak ID:
95050
URI
Publication date:
4.9.1995.
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