On gene interaction in Indian dairy cattle

Abstract

Considering thirty two Holstein Friesian-Shaiwal grade (generation) means obtained from the adjusted data of seven Military Farms (pertaining to the period 1945-79) as dependent variable (y) and the coefficients of the parameters of components of mean in the corresponding expected means as independent variable (x), the digenic, trigenic and quadrigenic interaction models were fitted by the weighted least square method for characters lactation yield, dry period and calving interval. Although digenic interactiion model is inadequate for all the three traits, the trigenic interaction model is adequate for dry period and quadrigenic interaction model for lactation yield and calving interval. Thus non-allelic interaction of one kind or other is present in all the traits considered. As such these characters having mainly non-additive gene action can be imporved throgh crossbreeding.