جستجوی مقالات مرتبط با کلیدواژه « همبستگی ژنتیکی » در نشریات گروه « محیط زیست »

The aim of this study was to estimate genetic parameters of humoral immune responses (antibody titers against sheep red blood cells (SRBC) and Newcastle Disease Virus (NDV)) and residual feed intake from 20 to 45 days of age in Japanese quail. For this purpose, a total of 2492 records of residual feed intake traits and 5238 records of immune traits were used. The analyses of Genetic parameters of traits were estimated through single and bivariate animal models via Gibbs sampling method. Heritability estimates of total antibody titer (AbT), titer of immunoglobulin Y (IgY), titer of immunoglobulin M (IgM) and titer of immunoglobulin F (IgF) against SRBC were 0.08, 0.14, 0.02 and 0.24, respectively, however, heritability of antibody titer against NDV was lower than estimated of SRBC antigen (h2= 0.05). heritability of RFI in different ages were in ranges of 0.04 to 0.07. genetic correlations estimate between total antibody and IgY were positive and high and was 0.92. The negative genetic correlations were related to IgM with RFI and genetic correlations estimates between RFI and other immunoglobulins (IgY, AbT, IgF) and NDV were positive. As a conclusion, selection for IgF due to its heritability (0.24) and negative genetic correlation (-0.23) with RFI, cause improve in RFI and reduce costs, related mainly to feeding and selecting of animals with phenotyping. On the other hand, due to moderate to high positive genetic correlations (0.34-0.80) were found between IgF and other immunoglobulins, selection of it didn’t lead to decline of humoral immune responses in quail.

In this study, performance and pedigree records of the native fowls of Fars province collected by Breeding Center during 1990-2004 were analyzed. A pedigree file collected on 30855 female and male birds was used to calculate the inbreeding coefficients. Heritability and Genetic and phenotypic correlations between recorded traits including body weight at 12 weeks (BW12), egg number (EN), egg weight (EW) and age sexual maturity (ASM) were estimated by multivariate animal model procedure by restricted maximum likelihood using ASREML software. On the other hand, The Inbreeding coefficient has been considered as a covariate to estimate its effects on traits. Results showed that inbreeding has not significant effects on recorded traits. The average of inbreeding coefficient for all birds were 0.002%, ranged from 0 to 14.8%. In this population, 14% of the birds were inbred, and average inbreeding coefficient for inbred birds was 0.019%. Estimated heritabilities were 0.53, 0.47, 0.57 and 0.22 for body weight at 12 weeks (BW12), age of sexual maturity (ASM), egg weight (EW) and egg number (EN), respectively. Due to relatively high heritability and low inbreeding coefficient of productive and reproductive traits, it is possible to achieve more progress in these traits using appropriate genetic selection.

In this study, total number of 4817, 1913, 1515, 6249, 1871, 1532, 1208 records of birth weight, weight of 3 and 12 month age, cashmere weight, total number of lambs born, total number of lambs weaned and lambing interval in Raienian cashmere goat were used. These records were collected in Baft station from 1989 to 2006. The animal model was used for genetic evaluation and estimation of genetic and phenotypic correlations for these traits. Heritability above was estimated 0.24, 0.07, 0.20, 0.17, 0.06, 0.08 and 0.03, respectively on the basis of the best model for each trait. Genetic correlation between birth weight and12 month weight, birth weight and cashmere weight, 3month weight and total number of lambs weaned, 3month weight and total number of lambs born, 12 month weight and cashmere weight, 12month weight and total number of lambs born, 12 month weight and total number of lams weaned, 12month weight and lambing interval, lambing interval and total number of lambs born, lambing interval and total number of lambs weaned, was estimated 0.27, 0.072, 0.02, -0.16, 0.28, 0.10, -0.27, -0.12, 0.30 and 0.42, respectively and phenotypic correlation was estimated 0.23, 0.056, 0.066, 0.07, 0.20, 0.01, -0.54, -0.43, 0.02 and 0.04 respectively, using Bivariate analaysis.