Ali Sadeghi-Sefidmazgi; Mohammad Moradi Shahrbabak; Ardeshir Nejati Javaremi; Seyed Reza Miraei Ashtiyani; P. R. Eymer
Volume 42, Issue 4 , March 2012, , Pages 345-353
Abstract
The financial losses, absolute and net economic values (EVs) for direct (DCD) and Maternal Calving Difficulty (MCD) were estimated using a bioeconomic model and taking into account the categorical nature of the trait. The effects of dystocia on other traits were estimated. But because of low reliability ...
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The financial losses, absolute and net economic values (EVs) for direct (DCD) and Maternal Calving Difficulty (MCD) were estimated using a bioeconomic model and taking into account the categorical nature of the trait. The effects of dystocia on other traits were estimated. But because of low reliability they were not considered for calculations in the base situation. In the base situation, the average costs of dystocia incidence were estimated to be Rls 518,700 per calving. Absolute EVs (per calving per cow) and net EVs (per cow per year) for DCD were Rls -27,800 and -14,200 respectively, and for MCD the two of them were stimated as Rls-2800. Most important economic consequences of calving difficulty were milk losses, probability of dead cow and stillbirth. Sensitivity analysis showed that frequency of dystocia incidence was the factor with the largest impact on the costs and economic values for difficult calving. According to population, production and economic parameters valid in 2009, total dystocia costs to Holstein dairy cattle industry were estimated to be Rls 49.1 billions. Results obtained in this study can be helpful to change the attitudes of farmers and their consultants to pay more attention to calving performance and use management and genetic strategies to reduce dystocia incidence.
Ali Sadeghi Sefidmazgi; Ardeshir Nejati-Javaremi; Mohammad Moradi-Shahrbabak; Seyed Reza Miraei Ashtiani; Peter R AYMER
Volume 42, Issue 3 , January 2011, , Pages 189-197
Abstract
The objective of this study was to assess the Discounted Genetic Expressions (DGEs) for different categories of animal traits as regards Holstein cattle of Iran. Using discounted gene-flow principles, DGEs per calf born were estimated for self replacing females and also for their sires. In the situation ...
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The objective of this study was to assess the Discounted Genetic Expressions (DGEs) for different categories of animal traits as regards Holstein cattle of Iran. Using discounted gene-flow principles, DGEs per calf born were estimated for self replacing females and also for their sires. In the situation for sires of self replacing females, relative GDEs per cow per year for annual cow traits, traits of the calf at birth and slaughter, traits of heifer and traits of cow at culling were estimated as 1, 0.96, 0.4, 0.44 and 0.43, respectively. The respective values for self replacing females were 1, 0.5, 0.21, 0.44 and 0.43, respectively. The effects of different factors on DGEs were quantified using sensitivity analysis. Results obtained in this study provide important information for properly weighting the traits in national selection indexes and as well in conducting cost- benefit analyses of breeding strategies.
MohammadAli Talebi; Seyed Reza Miraei Ashtiani; Mohammad Moradi Shahrbabak; Ardeshir Nejati Javaromi
Volume 41, Issue 3 , December 2010, , Pages 203-210
Abstract
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 ...
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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.
