This study was conducted to collect comprehensive identification about Markhoz goat population and to simulate past dynamics of the population under its living conditions.Census data of the population size and the required parametersfor the simulation modelwere obtained frompublished data or were collected in its habitat in the last 3 years. In this study, past population dynamics and expected loss of genetic diversity in the population were simulated by population viability analysis (PVA) using Vortex modeling program version 10.0.Markhoz breeding goats and population size showed a downward trend on its own habitat. The last known number of breeding does, bucks and total population of the Markhoz goat breed on its habitat were 917, 55 and 1669 heads in 2012. Computed and simulated inbreeding rates (ΔF)were 2.4%and 3.9%, respectively. Simulated Ne for this population was 128 which are near to critical size of 100.Furthermore, the extinction probability (EP) of 0%, stochastic growth rate of -0.1624, losing genetic diversity of 5% and inbreeding of 0.0311 were simulated using the PVA for a past time horizon( from 1996 to 2012). Having considered different parameters and threats with the reliable values and probabilities, PVA model simulated correctly the past period of population dynamics. Based on our findings, 1) future viability and the expected loss of diversity should be estimated under obtained demographic and environmental parameters. 2) different management scenarios should be examined to provide a conservation program. تفاصيل المقالة

Random regression models (RRM) have become common for the analysis of longitudinal data or repeated records on individual over time. The goal of this paper was to explore the use of random regression models with orthogonal / Legendre polynomials (RRL) to analyze new repeated measures called clutch size (CS) as a meristic trait for Iranian native fowl. Legendre polynomial functions of increasing order 0 (no covariate) to 4 were fitted to the age at sexual maturity (ASM) and 1 to 10 to the additive genetic and permanent environmental effects. Days in production (clutch) were used as time variables. Homogeneity of residual variance through the time was assumed. Analyses were carried out within restricted maximum likelihood algorithm (REML) using WOMBAT software. Adequacy of models was checked by Bayesian information criterion (BIC). The resulted BICs suggested a model composed of the second order polynomial for ASM and 8th order polynomial for additive genetic and permanent environmental effect was the most suitable for adjusting the present records. The highest phenotypic and permanent environmental variance of CS was at the beginning of the production period. Additive genetic variance was fairly consistent during 210 and 265 days of age (d 210-d265). Estimates of heritability for CS ranged from 0.033 to 0.199 for d 161 and d 242 in the first cycle of egg production, respectively. The ratio of animal permanent environmental variance to phenotypic variance was in the range of 0.01 and 0.264. The estimated ranges for additive genetic and permanent environmental correlations were -0.18 to 0.99 and -0.5 to 0.99, respectively and were high between the adjacent ages and they tended to decrease at nonadjacent ages. تفاصيل المقالة