كليدواژه :
net present value , دامپروري , گاوهاي نر , ارزش خالص فعلي , ده كشاورزي
چكيده لاتين :
A bio-economic model for calculating sire net present values (NPVs) was provided, by accounting for economic coefficients and transmitting abilities for milk yield and milk fat percentage. For this purpose data were used on costs and returns ofa dairy herd with 1200 cows, and also on results of genetic evaluation of a random sample of sires which have been used for artificial insemination. The sensitivity of NPVs to price change of concentrate, forage, milk and milk fat were investigated. By doubling these prices, the mean NPVs were increased by 0.99%. 0.64%, 96% and 8.1% respectively. The change of prices resulted in change of correlation coefficcints of new NPVs and base NPVs. The highst and the lowest correlations were related to feed price change, by 99.99%, and to milk price change, by 99.93%, respectively. The effect of feed price on the NPVs was not significant (p>0.05) and of milk and mill: fat prices were highly significant (p <0.001 ). Because of sensetivity of NPV to factors ofʹ production system, it is not possible to rank the sires for a specific situation and then generalize them to others. There was less than 100.5, correlation between NPVs and milk and milk fat transmitting abilities, thus they can not been used as an alternative to NPVs in sire selection.
