Genetic improvement in a dairy cattle population can be brought about by selection on the basis of milk production of the cows. For evaluating the producing ability at least one lactation record is essential. Study of subsequent lactation yields provides valuable informations about lifetime production of cows. The economics of dairying is largely based on the life time production of cow. The present investigation was therefore undertaken to evaluate the effect of period, season and sex of calf on cumulative first two, first three and first four lactations milk yields.
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