breeding programs strategies depends on genetical mechanism of selection traits. in the present research, generation mean analysis with joint scaling test was performed to determine the gene action. f1, f2 and f3 generations, derived from roushan and kavir cross along with their parents were sown in a partial lattice design with two replications under stress condition at the research field of s...

Although a number of recent studies have focused on the existence of a non-negligible sire contemporary group interaction effect (s) affecting the estimation of genetic parameters for maternally influenced traits in beef cattle, the assessment and interpretation of this effect using field data remains poorly understood. In this study 27,639 records of both birth weight (BW) and weaning weight (...

Maintenance energy requirements of cattle can be predicted from published equations utilizing metabolic BW and milk production potential. Metabolic BW is a function of BW at a constant fat percentage or BCS. Pedigree and performance records can be used in random regression models to predict genetic merit for metabolic BW and milk production potentials. The purpose of this study was to present a...

Data from the slaughter of 24,001 chickens that were part of a selection program for the production of commercial broilers were used to estimate genetic trend for absolute carcass (CW), breast meat (BRW), and leg (LW) weights, and relative carcass (CY), breast meat (BRY), and leg (LY) weights. The components of (co)variance and breeding values of individuals were obtained by the restricted maxi...

in order to estimate heritability, heterosis, general and specific combining ability and relationships between them in traits of fruit number per plant, days to the first fruit harvest, yield per plant, average fruit weight and rind thickness, seven local populations of iranian melon (‘tashkandi’, ‘khatouni’, ‘garmak’, ‘aran1’, ‘mirpanji’, ‘suski-e-sabz’ and ‘golpaygan’) were crossed using a co...

Beef outputs from dairy farms make an important contribution to overall profitability in Irish dairy herds and are the sole source of revenue in many beef herds. The aim of this study was to estimate genetic parameters for animal BW and price across different stages of maturity. Data originated from 2 main sources: price and BW from livestock auctions and BW from on-farm weighings between 2000 ...

Restricted maximum likelihood (REML) was used to determine the choice of statistical model, additive genetic maternal and common litter effects and consequences of ignoring these effects on estimates of variance–covariance components under random and phenotypic selection in swine using computer simulation. Two closed herds of different size and two traits, (i) pre-weaning average daily gain and...