leptin (lep), the expression product of the obese gene produced primarily in the adipose tissue, is related to feed intake, growth and lipid metabolism. the aim of this study was to study the possible association between polymorphism of the lep gene with growth and carcass traits among three iranian sheep breeds of the shal, zandi and zel varieties. a total of 180 purebred animals of the shal, ...

This research investigated the effect of stress mid-pregnancy shorn Zandi ewes on live birth weight and body sizes twin lambs. A total 96 ewes, confirmed pregnant with twins, were randomly allocated day 80 pregnancy into 4 groups, each group containing 6 replicates (each replicate sheep). The experimental groups included: 1. Control, 2. Crutched, 3. Sham-Shorn, 4. Shorn. Blood cortisol concentr...

The aim of this study was to model the variances and covariances of body weight in Zandi sheep from 60 to 365 days of age using random regression models (RRM). Legendre polynomials of different orders were used to model the direct and maternal covariances. Mean trends were also modeled through a quadratic regression on orthogonal polynomials of age. Homogeneity and heterogeneity of the residual...

Myostatin (MSTN) is an inhibitor of skeletal muscle growth, and a mutation in the gene coding region leads to increased muscling. Calpastatin (CAST) is a specific inhibitor of the ubiquitous calcium-dependent proteases, µ-calpain and m-calpain, found in mammalian tissues. In this study, genomic DNA was extracted from Zandi sheep blood samples. Gel monitoring and spectrophotometer methods were u...

Melatonin regulates some major physiological processes such as maturation and function of reproductive system, pubertal development, seasonal reproduction and adaptation. The activation of melatonin hormone is mediated by melatonin receptor. Previous studies showed melatonin receptor 1A gene (MTNR1A) is highly polymorphic in seasonally breeding species. The aim of the present study was detectio...

Early growth traits in sheep are economically important. Breeding for these traits has been shown to be problematic using quantitative genetic methods, particularly in native sheep herds. Molecular genetics is useful for sheep breeding. The gene for insulin-like growth factor 1 (IGF1) is one of the important candidate genes known for ovine early growth traits. The aim of this study was to inves...

in this research, 6517 records, collected by khojir sheep breeding station (tehran, iran), during 1991 to 2011 were used to estimate genetic parameters of lamb survival in zandi sheep. genetic parameters were estimated using 16 different models of animal model, sire and threshold models using reml procedures. the aic criterion was used to evaluate the models. the effects in the most suitable an...