برآورد ارزش های اقتصادی صفات تولیدی و تولید مثلی گاوهای شیری کشت و صنعت مغان با استفاده از شبیه سازی و مدل زیست اقتصادی

Abstract

Introduction: Dairy cattle industry based milk production and reproduction.The best way to maximize profitability through genetic improvement is to use economic weights of the trait involved.The objective of this study was to estimate the economic value of productive and reproductive traits in Holstein dairy cattle in the Moghan Agro Industrial and animal husbandandry CO, based on data collected from 13000 head dairy cattle, based on market conditions in 2014, were estimated using a bio-economic model. Materials and Methods:Annual revenues and costs based on different age groups were calculated and profit per cow and year was estimated to be equal 15966572.69 Rials.The proportion of revenues from sale of milk, cows culled for age per year, male calves, surplus heifers and dung sale were as 71%, 10%, 11%, 6% and 2%, respectively.Among variable costs, feed, labor and marketing , hygiene and reproduction costs were 68%, 17% and 10% of total costs, respectively.Economic values were calculated for 11 traits, classifying into four categories of production, reproduction, growth and survival.Economic value of each trait was estimated as the amount of change in the annual profit of production system by one unit increase in mean of the considered trait while the means of other traits were hold unchanged. Results and Discussion:In this study, the economic values, for some production and reproductive traits includingmilk yield, fat yield, age at first calving, calving interval, pre-weaning daily gain, post-weaning daily gain, birth weight, mature live weight, pre-weaning survival rate and post-weaning survival rate were, respectively 4718.59, 144757.8, -30756.52, -86789.17, 1284.45, 34.57, 9894.16, -1900.13, 5805, 107521.9 and 14859.14. Highest relative importance of production traits (54.37 percent) and then to the reproductive (21.98%) and durability (20.56 percent) and the lowest growth (3.07 per cent) respectively. Conclusion:Economic values are representative of the diversity of production systems in the dairy herd coefficients may vary and can not be used in other herds. Change the price of inputs and outputs of the system, in determining the economic value balance each other traits, but a large increase in the price of inputs and outputs to the contrary, many changes in the economic value of traits creates.