جستجوی مقالات مرتبط با کلیدواژه "phenotype trend" در نشریات گروه "علوم دام"

The objective of this study was estimate of the genetic and phenotypic trends of growth traits in Moghani sheep. In this study, a total of 21,423 records of growth traits belong to Moghani lambs that collected by raising and breeding of Moghani sheep station between 2003 and 2010, was used. The SAS 9.1 statistical software was used to evaluate the effect of environmental factors. Variance components and genetic parameters were estimated using restricted maximum procedure and univariate animal model and with wombat software. Animal breeding value of were estimated using the best univariate animal model. Environmental factors, like birth year, sex, herd, type of birth, and the age of mother are the significant factors as fixed effects. Estimation of direct genetic trend for birth weight, weaning weight, 6 month weight, 9 month weight and 12 month weight were as 6±1, 8±1.5, 8±6, 11±5 and 86±5 gr per year, respectively. The phenotypic trend for mentioned traits was estimated 30±1, 116±1, 37±6, -342±5 and -43±5 gr per year, respectively. The results showed that before designing any breeding program, optimum environmental condition must be prepared for appearance of maximum genetic potential, so phenotypic and genetic trends will be desirable in the herd.

In the present research some reproductive traits in Holstein cows of Khoramdareh agro-industry were studied. The data set comprised of 10،891 records collected from 23 years (1988 to 2010) by animal breeding centre، Iran. The total number of animals in the pedigree file was 16/087. Genetic and phenotypic parameters using soft WOMBAT software and restricted maximum likelihood method under animal models and a multivariate trait was estimated. Genetic trend for each trait was estimated using SPSS programmer based upon regression of mean breeding value on year of calving. Phenotypic trend was also estimated based upon regression of phenotypic mean of the trait on year of calving. Levels of heritability from linear model for the traits age at first insemination (AFS)، age at first calving (AFC)، number of insemination resulted in conception (NSPC)، open days (OD)، pregnancy rate (PR)، calving interval (CI)، Non return rate to 90 days (NRR90) respectively 0. 037، 0. 016، 0. 01، 0. 032، 0. 021، 0. 051 and 0. 034، respectively. Maximum genetic correlation between traits and open days and pregnancy rates between insemination number of days open and pregnancy، respectively، leading to -0. 99 and 0/84 and the lowest genetic correlation between PR with NRR90 (0. 001) respectively. Open days and pregnancy rate with the open days and NRR9 respectively Olsen -0. 99 and 0. 00 the highest and lowest phenotypic correlation showed. Genetic trend for the reproduction traits was between -0/009 for NRR90 and -0/04 for CI respectively. Phenotype trend for the about traits has lower trend for (0/002) NRR90 and (-0/74) for AFS respectively. Lower among environmental trend (-0/007) for NSPC and upper among environmental trend for AFS (-6/52) respectively.