Estimation of Genetic, Phenotypic and Environmental Trends in Hariana Cattle
نویسندگان
چکیده
The breeding data relating to Hariana herd spread over 18 years (1979-96) were analysed to estimate genetic, phenotypic and environmental changes in characters of economic importance which might have taken place during the several years of selective breeding practiced in the herd. The average genetic changes in a given character were estimated by four methods. The phenotypic trends observed for different economic traits were not significant. On changing the method of estimation, magnitude and direction of genetic trends changed. Comparison of estimates of genetic trends by different methods showed that adjustments for biases due to non-random allotment of dams with respect to their age and merit suggested by Powell and Freeman (1974) were useful for increasing the precision of the estimates. Hence, this method was found to be the best method for estimation of genetic trends. The estimate of genetic trends by this method were 4.03±6.21 days, 3.24±5.33 kg, 0.15±0.43 days, 0.09±0.59 days, 0.01±0.02 kg and 0.01±0.01 kg for age at first calving, first lactation milk yield, first lactation length, first calving interval, first lactation milk yield per day lactation length and first lactation milk yield per day of calving interval, respectively. (Asian-Aust. J. Anim. Sci. 2002. Vol 15, No. 1 : 7-10)
منابع مشابه
Estimation of Genetic Trends for Test-Day Milk Yield by the Logarithmic Form of Wood Function Using a Random Regression Model
Estimation of genetic trends is necessary to monitor and evaluate selection programs. The objective of this study was to estimate the genetic trends for milk yield in Iranian Holsteins cows using random regression test day model. Data set was consisted of 743205 test-day records from 1991 to 2008, which were collected by the Animal Breeding Centre of Iran. Breeding, environmental and phenotypic...
متن کاملEstimation of genetic and phenotypic trends for body weight traits of sheep in Guilan province of Iran
The main objective of the present study was to estimate genetic and phenotypic trends for body weight traits in Guilan province sheep. Traits included were birth weight (BW, n=14,549), 3-month weight (3MW, n=13,109) and 6-month weight (6MW, n=10,141). Data and pedigree information used in this study were collected during 1994 to 2011 by the Agricultural Organization of Guilan province in Iran. ...
متن کاملبررسی روند ژنتیکی، فنوتیپی و محیطی صفات بیومتریک در گوسفند نژاد ماکویی
In this research, investigation of genetic, phenotypic and environmental trends of biometric traits in Makuie sheep was performed using collected data from 1989 to 2012 at Makouei sheep breeding station. Estimation of trends was performed by multivariate animal model using the DFREML software. Genetic, phenotypic and environmental trends were estimated by regression of breeding values average, ...
متن کاملEstimation of Genetic Parameters for Kleiber Ratio and Trends for Weight at Birth and Weaning in Arabi Sheep
Objective: Estimation of genetic parameters for Kleiber ratio (KR) and genetic trends for pre-weaning weights of Arabi sheep has not been previously conducted.Methods: Data and pedigree information were collected at the Khuzestan Ramin Agricultural and Natural Resources University, Animal Science Research Station, located in southwest Iran, from 2001 to 2008. (Co)variance components and corresp...
متن کاملEstimation of Genetic Parameters for Kleiber Ratio and Trends for Weight at Birth and Weaning in Arabi Sheep
Objective: Estimation of genetic parameters for Kleiber ratio (KR) and genetic trends for pre-weaning weights of Arabi sheep has not been previously conducted.Methods: Data and pedigree information were collected at the Khuzestan Ramin Agricultural and Natural Resources University, Animal Science Research Station, located in southwest Iran, from 2001 to 2008. (Co)variance components and corresp...
متن کامل