average age distribution and generation interval were investigated in four different selection pathways. i.e., sire of future sires (ss), sire of future dams (sd), dam of future sires (ds) and dam of future dams (dd). young bulls pathway (yb) is also considered as a path that affects the generation interval in sd pathway when using progeny testing program. data were collected from animal breedi...

A deterministic model based on the gene flow method, considering the features of Iranian Holstein cattle population, was implemented in this study to evaluate the effect of altering the number of age-classes in the dams of future sire (DS) path and the number of dams required for breeding a young bull (YB), to be evaluated as future sire, on genetic gain and resultant economic efficiency of a g...

An experiment was designed to evaluate the effects of five sire breeds (Dorset, Finnsheep, Romanov, Texel, and Montadale), two dam breeds (Composite III [CIII] and northwestern whiteface [WF]), and three shearing seasons (December, February, and April, corresponding to August, October, and December breeding seasons) and their interactions on wool and other characteristics of F1 ewes. Fleeces we...

Several sheep fetuses were thymectomized, and their tails were removed at 58 to 65 days of gestation for tissue culture. Bovine leukemia virus (BLV) antigens were detected in serial culture of tissues from fetuses whose dams and sires were both BLV positive. However, no BLV antigens were detected in serial cultures of tissues from fetuses whose dams were negative but whose sire was positive. Pr...

The heritability response for growth of rainbow trout during early developmental stages was detected on the basis of full-sib and half-sib cross between the selected lines. The experiment was done in Shahid Bahonar Salmon Propagation Center, Kelardasht, Iran. Breeders were taken from the stocks maintained in this station. A bifactorial cross was done between two line using four randomly sire an...

Calving difficulty, survival from birth to weaning, birth weight, and weaning weight of 167 calves and carcass traits of 88 cattle (63 for adjusted fat thickness) were compared for progeny of Red Poll and Longhorn bulls mated to crossbred cows that calved at 2 or 3 yr of age. Results indicated that Longhornsired calves required 28% less assistance at calving than Red Poll-sired calves when dams...

Gestation length, birth weight calving difficulty, calf mortality rate at birth, calf mortality rate from birth to weaning, preweaning calf growth rate and calf 200-d weight were evaluated in a biological type study in which four sire breeds were bred by AI to Hereford dams. Angus and Red Poll sires represented breeds of medium size, and Pinzgauer and Simmental sires represented large breeds. A...

  Wild common carp of the Caspian Sea is one of the important fish in the north of Iran, which has been introduced to inland aquaculture. Its genetic characteristics are investigated to set up for breeding programs that are still unknown. Using wild common carp in aquaculture is limited for uncontrolled variation in performance of fish derived from undomesticated breeders. A 7×7 factorial matin...

Abstract We hypothesized that late gestational nutrient restriction (NR) would decrease organ mass in neonatal calves. Fall-calving crossbred beef heifers (BW: 466 ± 30 [SD] kg; BCS: 5.4 0.5) bred to a single sire were individually fed 100% (control; n = 10) or 70% (nutrient restricted; NR; 12) of NASEM metabolizable energy and protein requirements for maintenance, pregnancy, growth from d 160 ...

  Wild common carp of the Caspian Sea is one of the important fish in the north of Iran, which has been introduced to inland aquaculture. Its genetic characteristics are investigated to set up for breeding programs that are still unknown. Using wild common carp in aquaculture is limited for uncontrolled variation in performance of fish derived from undomesticated breeders. A 7×7 factorial matin...