Document Type : Research Paper
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Abstract
In this study production, reproduction, management and economic parameters resulted from recording of 4 flocks with 600 head of breeding ewe during the annual cycle of production in village system were used to determine of the breeding objective, absolute economic values and relative emphasis for a Lori_Bakhtiari breed of sheep. To calculate the economic values of traits, the level of each trait for the flock was increased by 1 unit, while all other traits were held at their mean values and change in profit was as the absolute economic value (maximize profit, P), the ratio of revenue to costs (maximize efficiency, Q) and the ratio of costs to revenue (minimize costs,) calculated for considerable trait. To calculate the economic weight and relative emphasis, the absolute economic value of each trait multiplied to the genetic standard deviation of trait in three ways. The results showed that annual profit per ewe, the ratio of revenue to costs and the ratio of costs to revenue were 667023 rials, 1.16 and 0.86, respectively. The breeding objective for Lori-Bakhtiari sheep in village system in order of relative emphasis were reproductive traits (Litter size, conception rate, number of parturition in each year); durability traits (in lamb up to sale and ewe); growth traits (lamb weight at sale time, weight of replacement, weight of mature ewe) and greasy fleece weight. The economic values of corresponding traits resulted from various ways were different in values and the sign of economic values from P was the same as Q but different to. The sum of relative emphasis for reproductive traits, durability traits, growth traits and greasy fleece weight resulted from P were 57.09, 23.39, 19.32 and 0.19; from Q were 55.54, 22.98, 21.29 and 0.19 and from were 55.05, 23.06, 21.69 and 0.19, respectively. Thus, the relative emphasis resulted from different ways for various traits were equal relatively and if the relative emphasis is used instead of absolute economic values, the result of each different ways could apply
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