جستجوی مقالات مرتبط با کلیدواژه « ضرایب اقتصادی » در نشریات گروه « کشاورزی »

The aims of interbreeding for the first level in planning interbreeding programs are generally maximize the improvement in the economical efficiency of the production system by means of increase the average of characteristics. The purpose of this research was to estimate the economic values for milk production traits, fat percentage, protein percentage, and lifetime of native cows of Ilam province and also consideration of their sensitivity to any change in productive and economical parameters in the production system.
Using a deterministic bio-economical model and economic and production parameters of Native cow, was estimated economic values of milk yield, fat percentage, protein percentage, herd life at the Ilam province in 2013. The economic values of each trait was estimated with increase of one unit of average traits used for the amount of annual profit change, so that were constant the other traits. Calculation of Revenues and Costs: Estimation of economical factors needs explanation of production system, revenue and costs sources and their relationship with existing characteristics for the aim of interbreeding. Costs are expressed as fixed and current. Current costs are depending on the level of cattle production. Fixed costs are independent of production level and including building and installations, machinery and so on.to calculate the nutritional costs for each age group of animals, four different levels according to the life style were defined by order. These levels include: from birth to weaning (bull calf and heifer before weaning),from weaning to selling age (bull calves in 8-months year old and heifers in 17 months of age, from selling age till the age of first delivery (for replaced heifers)and regenerator cows(over two years old). According to the definition, economical factor of each characteristic is described as a change in the net profit of factory for a unit of addition in the average considered characteristic in a way that the average of other characteristics in the population doesn’t change. In this research to calculate the economical factors of characteristics while other characteristics are in between in the population, the average for the considered characteristic was increased once by one unit and the difference of earned and profit or base mode was considered as the economical factor of that characteristic.
In the system of Native cows production, the economic values of milk yield, fat percentage, protein percentage, herd life were estimated 0.002079, 0.999782, 1 and - 0.000351 respectively. In the native cow's fostering system, revenue resources include annual sale of milk, bull calf, surplus heifer, annual, omitted regenerator cow and annual manure. Earned revenue out of annual milk sale equaled 43.54% of the total revenue which appropriated the greatest amount of revenue resources. Other revenue resources were including bull calf, surplus heifer and the sale of omitted cow that appropriated 11.23%, 32.37%, 10.04% and 2.81% of the revenues respectively. The costs were divided into two parts including annual fixed charge which contained the cost of building, installations, equipment and repairs. Annual current cost which contained nutritional costs, hygiene and reproduction, work force, cattle selling and transportation of manure from its place per each head of regenerator cow. Fixed annual cost per each head of regenerator cow equaled 4572556.56 Rial, which contained 14.44 percentage of the total costs .annual current cost per each head of regenerator cow equaled 27094514.46 Rials which appropriated85.56 percentage of the total cost. Among the current costs ,nutritional cost by 84.25% appropriated the most part .other current costs including workforce ,cattle sale and manure transportation from its place equaled 9.38% and costs of hygiene and reproduction appropriated 6.36% of the current costs.
Thus estimated the annual avenue of production system for Native cows -1801718.005 Rials. The results showed that positive amount of an economical factor to produce milk; selection of an average for an increase in the characteristic causes an increase in profiting in native cow's production system. According to the importance of interval in calving as a characteristic and specifically its influence in the situation of limitation in systems, it is suggested that interbreeding should be done to decrease it.

In this study a bio-economic model was used for a flock with 195 breeding ewes and 20 rams to determine economic values of important traits in Zel sheep of Golestan including litter size, pre-weaning survival, post-weaning survival, ewe survival, birth weight, weaning weight, yearling weight, ewe mature weight, dressing percentage, conception rate and wool weight. In this model, fixed environment was assumed and herd profit was estimated from difference between costs and revenues. Relative economic values of the traits were estimated based on wool weight. The highest economic value was found for litter size with relative economic value of 139.82. After litter size, the most important relative economic values were 3.81 and 3.66 for ewe survival and dressing percentage, respectively. Economic values of all traits were positive except for birth weight (-0.98). Sensitivity analysis of economic values were carried out for 20% increase and decrease in price levels of input (concentrate, forage) and output (meat, wool) system. Economic values​​ of all traits except for birth weight and wool weight were changed by changing the price of meat. The economic values of ewe mature weight, dressing percentage and wool weight did not change with change in price of concentrate and forage .Sheep farming system can increase in profits by increasing in the amount and value of product. As the highest economic values were found for amount and value of the products especially amount of products, in order to increase system profit it is better to select for these traits in a breeding program.

In this study, production, reproduction, management and economic parameters resulted from recording of 4 flocks with 1155 head of breeding ewes during annual cycle of production (August 2011 to August 2012) in extensive rearing system were used to determine the breeding objective and relative economic values for Dalagh sheep. To calculate the economic values for traits, the level of each trait for the flock was increased by 0.1 standard deviation, while all other traits were held at their mean value and changes in profit was as sum of the absolute economic value for all traits. To calculate the relative economic values, absolute economic value of each trait was divided by sum of the absolute economic value of all of traits. In the base situation, live weight or carcass weight was accounted as 87.45% of revenue and wool and milk accounted for the remaining 12.55%. Feeding and management costs (variable costs) represented about 75.50% and 22.30% of total cost respectively. Relative economic values were 15.49 for conception rate, 12.26 for ewe survival, 9.81 for lambing frequency,9.14 for litter size, -12.5 for weight of ewe, -2.61 for replacement weight, 2.97 for weight of wool, 5.73 for weight of milk and 18.86 for 6-month live weight.

In this study production, reproduction, management and economic parameters resulted from recording of 6 flocks with 1500 head of breeding ewes during annual cycle of production (August 2011 to August 2012) in extensive system were used to determine of the breeding objective and relative economic values of survival, production and reproduction traits for Zel breed of sheep. For deriving economic weights, change in profit by one percent increase in mean of a trait, while all other traits were fixed at their means, were calculated and then divided by amount increased in that trait. With analysis of cost and revenue for each of breeding ewe, the highest level of revenue and cost were for live weight and nutrition, respectively. The breeding goals of Zel sheep consist of relative economic values 15.47 for conception rate, 10.58 ewe survival, 10.79 for lamb survival from birth to 6 month, 8.04 for lambing frequency, 8.83 for litter size, -12.89 for weight of ewe, -4.32 for replacement weight, 6.11 for weight of wool, 1.68 for weight of milk and 21.25 for 6 month live lamb weight. The results showed that survival and reproduction traits are important for Zel sheep as well as body weight traits. So, precious registration of the data and implementation of these traits in breeding schemes of this breed is strongly recommended.

The Harki sheep is a fat-tailed breed which medium- sized body and dairy- meat sheep. In this study parameters of production, reproduction and economic management obtained from data recorded for Harki sheep breed was evaluated in five flocks with 500 ewe during annual cycle of production in village system in 2012. Traits included; fertility, pregnancy rate, weight lambs from birth to the end of period, survival rate of lambs, wool production weight, average daily gain and milk production. A bioeconomic model was written for rearing system and flock information, economic values using maximum profit orientation was calculated by partial derivative of the profit function for a production system with one lambing per year by the Ecoweight software. To calculate economic values, change in system profit per unit change in the trait while was kept the other characters in the average, and was considered the average change in profit as an economic value. First all costs, revenues, profits and flock structure determined then intered input files and run the software. The relative economic values for birth weight, daily gain from birth until weaning, daily gain from weaning until end of period, conception rates ewes, little size, lamb survival at weaning, lifetime, milk yield during the standardized milking period of 150 d, milk fat, milk protein and fleece weight were 6.12, 0.68, 0.515, 2.36, 2.12, 2.54, 16.72, 3.54, 0.047, 0.024 and 1 respectively. Breeding objective in Harki sheep breed were productive lifetime, birth weight, milk yield, lamb survival at weaning, conception rates ewes, little size, wool yield, daily gain from birth until weaning, daily gain from weaning until end of period, milk fat and milk protein.

This study was designed to estimate the economic values for important economic traits of Lori goat in Lorestan. Finally the breeding objectives of this animal were determined. Phenotypic and production data for the study were collected from 6 flocks of goats raised under Lori goat breeding project. The questionnaire was designed and the goat rancher breeders were interviewed too. Statistics on revenues and costs were calculated based on the prices of years 2010-2011, according to mentioned questionnaires. Four traits including litter size, birth survival rates, replacement rates and the amount of milk in a lactation period were examined in this study. Also four growth traits including birth weight, weaning weight, daily growth from weaning to 6 months, and 6 months weight for kids were estimated in this research. A biological-economic model as an overall model and sub models for each of the above traits were designed. The corresponding coefficients for traits were estimated. Finally the production system was also analyzed. Based on this study the relative economic weights for litter size, survival rates, replacement rates and the amount of milk yield measured in two systems (one birth in year and 3 births in two years) were 361.89, 487.37, -1.38, 1, and 591.88, 799.75, -1.03 and 1 respectively. The relative economic weights for birth weight, weaning weight, daily growth from weaning to 6 months and 6 months weight in two mentioned systems were 4.96, 11.92, 92.28, 9.25 and 4.07, 18.97, 157.69 and 15.81 respectively. As a conclusion, the reproductive traits and growth rate have the highest economic coefficient, hence shoul be considered in Lori goat breeding programs under rural system.

To assess the economics of rural sheep production systems and estimation of economic values of important traits in Zandi breed, bio-economic approach was used. In order to estimate economical parameters for using in bio-economical equations and to calculate the EVs of traits, two farms with the flock sizes of 500 and 450 head of Zandi sheep breed in Varamin were studied since the beginning of September 2010 to September 2011. EVs (economic values) of six important traits including pregnancy rate (FE), litter size (LS), lamb weights at birth (BW0), 3 (weaning; BW3), 6 (BW6) months old and survival rate until the age of 6 months (SRL6) were estimated. To estimate the EV of each trait, the level of the trait was increased by both 1% of its mean value and 1 unit while all other traits were constant in their mean values and the amount of change in the profit of system was considered as the EV of the trait. The sensitivity of the EVs was investigated by changing prices of feed and live weight of animals by ±20%. The economic analysis results indicated that the average of feeding cost ratio to the overall costs; and also the average of management cost ratio to the overall costs of rural sheep production system were 64.5 and 33.2 percent respectively and the average annual profit of each breeding ewe in rural sheep production system was 1109594 Rials. The most important trait in this system was FE, followed by LS, BW6, SRL6, BW3 and BW0, respectively when used by 1% increase.

In this study, production, reproduction, management and economic parameters deduced from recordings of 5 flocks with 720 heads of native goats during an annual cycle of production in transhumance, village and farming systems were employed to determine the trait's economic values. The economic values of the traits were estimated, using maximizing profit, revenue per cost as well as minimizing cost situations. The relative economic values of traits for transhumance system resulted from maximizing profit situation were 15.29 for survival rate in goat, 5.60 for conception rate, 4.92 for kidding frequency, 2.37 for kidding rate, 3.34 for kid survival rate up to weaning, 2.74 for kid survival rate to yearling, 1.00 for kid live weight at sale, -5.45 for body weight of goat and 13.37 for milk yield. In village system, these values were 8.30, 4.52, 4.16, 1.21, 1.55, 1.38, 1.00, -6.42 and 4.96, respectively. In farming system, these values were estimated as 1.73, 1.13, 0.73, 0.37, 0.53, 0.50, 1.00, -0.77 and 1.16, respectively. The absolute economic values of traits increased with improving economic efficiency from transhumance to farming systems, but the relative economic values decreased. Although, the calculated economic values from all the three situations were different numerically, but from the rank point of view of traits they ended up with apporoximatly similar results.

In this study, production, reproduction, managerial, and economic parameters obtained from data recorded for Lori-Bakhtiari flock of sheep (500 heads of breeding ewe) stationed at the sheep's Breeding Station, were employed to determine the relative economic values of and breeding objectives for an annual cycle of production, in village system in this breed of sheep. Economic value for a trait was estimated as the level of change in the profit of system as its mean increased by one unit, while the means of other traits being kept constant. The economic values were investigated in three approaches including a included to maximization profit to maximize economic efficiency and to minimize cost. The results show, live weight of (carcass weight) accounted for 94.51% while wool and manure for the remaining 5.49% of the revenue, respectivly. Feeding and management costs represented about 72.28 and 25.94% of total costs, respectively. Relative economic values for conception rate, litter size, mature ewe live weight, weight of wool, lamb survival at 6 months of age, 6-month live weight, carcass lean weight and carcass fat weight at 6 months of age were 60.52, 48.00, -0.05, 1, 56.55, 1.01, 4.61 and -0.92, respectivly for maximization of profit approach. Relative economic values from the three approaches were approximately the same. Litter size, conception rate and ewe live weight were the most important traits in the breeding objectives for ewe in the village system. Lamb survival at 6 months of age, carcass lean and fat weights were the most important traits in the breeding objectives for the lamb in the village system. Estimates of sensitivity analysis of relative economic values to changes in prices of input and output by? 20% indicated that the relative economic values of traits, relative to change in cost of input (feed and management), were of low sensitivity, while relative to change in output (carcass and carcass lean weight) indicated a relatively higher sensitivity.

In this study, the economic coefficient of 10 traits including birth weight, 3-month weight, 6-month weight, 12-month weight, survival before 3-month, survival before 6-month, ewe survival, cumulative survival, twining percentage and fertility percentage were investigated in four different production systems with mean number 250 ewe of karakul by bio-economic model in Fars province. The obtained results showed that 6-month weight had the highest importance among the above traits. 3-month weight, cumulative survival, twining and fertility rate, ewe survival, birth weight, survival before 3-month, survival before 12- month, survival before 6-month, had positive coefficients and 12-month weight, had negative coefficients in the following ranking.

In this research, the statistical data related to karakul (fars grey) sheep that were collected during years 1986 to 2001 by national animal breeding center, were used to estimate the economic coefficient for 15 traits including: birth weight (bw), weaning weight (ww), weight on six month (wsm), weight on nine month (wnm), weight on one year (woy), colour of skin (cs), skin flower type (cft), rate of skin flower type (rsft), concession of skin flower type (csft), extent of skin flower (esf), diameter of skin flower (dsf), radiation and luminosity of skin (rls), scheme and harmony of skin flowers (shsf), skin size (ss) and skin thickness (st) for 7 distinct animal group in 3 herds of this breed in Abadeh, Marvdasht and Fasa townships in fars province. The economic indices of traits were estimated through applying system analysis method,via partial derivation of profit function in relation to the considered trait. Then, sensitivity of the model to changes in each parameter in the model was calculated. Among Skin and weight traits, the highest economic coefficient was related to weaning weight trait and skin thickness trait. Also, it was observed that the increase in costs and the decrease in productions price (by ±20% from base condition) lead to reduction of relative economic indices with regard to base condition and the decrease in costs and the increase in productions price lead to increase of relative economic indices with regard to base condition. Finally, According to the results obtained in this study, a selection index was determined based on market condition in this breed of sheep. hisbreed of sheep this breed of sheep this breed of sheep is breed of heep.

Using a deterministic model for dairy herd according to milk pricing system in Iran, the economic weights of milk production, fat percentage, protein percentage and herd life with minimized cost were identified, while restricted total input and total costs were variable in animal unit. By data simulation and the data obtained from 3 different dairy herds in Iran, the sensitivity of economic values with the assumption of 20% change in forage and concentrate price, forage to concentrate ratio, feed-cost, non-feed cost, base price of milk, free-market price of milk, average milk production, fat percentage, protein percentage and herd life were estimated. In the base condition, the economic weights of milk production, fat and protein percentage and herd life in three herds were -0.55, -0.24, -0.54 -34, -20, -11 -34, -37, -33 -0.37, 0.67, -0.39, respectively. The effect of change in different factors of production system on economic weights of three farms was variable. The economic weights of milk production, fat percentage, protein percentage and herd life had the most sensitivity to change in the average milk productoin, base price of milk and herd life, respectively.