Defining breeding goal and strategy for Kermani sheep.
2014
Kargar, Najmehe | Abasi, Moktar Ali | Savarsofla, Sima | Vatankhah, Mahmood | Vali, Ali Asgar | Ghorbani, Golam Reza | Sadeghian barzaki
For estimate genetic parameters and genetic trends of growth traits and reproductive traits, Data collected from 1993 to 2010 by the Kermani Breeding Station were analyzed . Traits were included birth weight (BW), 3 months weight (3MW), 6 months weight (6MW), 9 months weight (9MW) ,12 months weight (12MW), Daily gain before weaning(ADGa) , Daily gain from weaning to 6 months weight (ADGb), Daily gain from 6 months weight to 12 months weight (ADGc), Klibr ratio before weaning (KRa ) , Klibr ratio for 6 months weight (KRb), Klibr ratio for 12 months weight (KRc), litter size at birth (NLB), litter size at weaning (NLW), total litter weight at birth (KGLB) and total litter weight at weaning (KGLW).The variances and genetic parameters were estimated with single or multiple trait animal models.Direct estimated heritability for growth traitwere 0.04 to 0.33. Direct estimated heritability for NLB, NLW, KGLB and KGLW were 0/01,0/04,0/06 and 0/22 respectively. Genetic correlation cofficient between growth traitswere 0/184 to 0.988 and Genetic correlation cofficient between reproductive traitswere 0/245 to 0.991.Genetic trend for growth traits were positive and Genetic trend for NLB and NLW were negative but for KGLB and KGLW were positive . In this study were used production, reproduction, management and economic parameters resulted from recording of 5 flocks during annual cycle of production in Kerman. The profit equation were evaluated . To calculate the economic value for traits, the level of trait included in profit equation was increased by 0.1 standard deviation, while all other traits were held at their mean value and change in profit was as the absolute economic value for trait. To calculate the relative economic values, the absolute economic value of each trait divided by the absolute economic value of weight of wool. In the current situation, live weight or carcass weight accounted for 87.44% of revenue , Feeding costsrepresented about 75.50% of total cost . For the current situation, relative economic values were 11.93 for ewe survival,8.38 for conception rate, 8.38 for Number of lambing, 10.52 for litter size,14.28 for lamb survival at weaning, 24.99 for weaning weight,4.30 for weight of wool,-8.41 for mature ewe live weight and 4.74 for weight of ewe survival and conception rate were the most important traits . in a breeding objective for ewe. Lamb survival at weaning and weaning weight were the most important traits in a breeding objective for lamb in system. To evaluate thecurrentbreeding program, breedingpopulationswere simulatedandreal dataand simulatedresultswere compared . with Usingthe estimatedeconomic values, the best selection indexandbreedingobjective for Kermanisheepwas introduced. Toachieve thispurpose, Changes ingenetic gain, selection indexand economic gain with different herd size and Ramratio, in four selection index were compared(I1,I2,I3 and I4). Estimated maximum of genetic gain and economic gain in 300 herd size and 0/02 ramratio with full selection index) I1(. Keywords: Breeding Objective; Economic Values; Kermani Sheep. : Abstract
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