the aim of this study was to estimate the genetic trend and genetic parameters of survival traits in baluchi sheep using survival records from 27978 baluchi sheep, which were collected by the animal breeding center of iran during1979 to 2009. genetic parameters of lamb survival from 1 to 400 days of age and from 1 to the last recording date. traits were estimated using animal model (with or wit...

Selection for fertility in a fall lambing system was applied for 5 yr (1.45 generations) in a crossbred sheep population. Three flocks were involved: a fall-lambing selected (S) flock of 125 ewes and 10 rams, a fall-lambing environmental control (EC) flock of 55 ewes and five rams, and a spring-lambing genetic control flock of 45 ewes and five rams used to produce replacements for EC. Estimated...

the objectives of this study were to identify a suitable mathematical model for describing the growth curve of baluchi sheep based on monthly records of live weight from birth to yearling; and to evaluate the efficacies of nonlinear mixed effect model (nlmm) and the nonlinear fixed effect model (nlm) methodologies. growth models were fitted to a total of 16,650 weight–age data belonging to 2071...

Effects of environmental factors such as ewe age, season of exposure, and time from lambing to exposure on fertility were evaluated using records on 1,084 Dorset ewes in the STAR accelerated lambing system. The STAR program consisted of five 30-d concurrent breeding and lambing periods per year beginning on January 1, March 15, May 27, August 8, and October 20. Fertility in the flock changed in...

In this study, the potential association of PrP genotypes with ewe reproductive traits and lamb growth traits was investigated. Data were included on ewes and lambs of the INRA 401 breed from the Bourges-La Sapinière INRA experimental farm. This breed was chosen because of good breeding (prolificacy and maternal abilities) and carcass qualities, and the large number of available animals with pe...

Data of 3272 lambing records collected on 818 ewes born from 689 dams and sired by 371 rams were used in the evaluation of ewe lifetime productivity (total number born, number weaned and total weight weaned). These records were collected from ewes born from 1969 to 1994 and which gave birth during the period from 1971 to 1999. Year of birth of ewe and ewe two-tooth liveweight affected the ewe p...

The present study was performed to study the effect of inbreeding on the pre-weaning growth traits including the birth weight (BW), weaning weight (WW), average daily gain (ADG), Kleiber ratio (KR) and lamb survival from birth to weaning (SUR) in Baluchi, Iran-Black and Zandi sheep. Significant positive inbreeding trends were found only for Baluchi and Iran-Black breeds as 0.038 and 0.278, resp...

Myogenin gene (MYoG) affects the synthesis of muscle myofibrillar growth and increase of meat production. The myostatin (MSTN) gene is identified as a specific negative regulator of skeletal muscle growth. Reduction of the expression level of MSTN throughmutation in the sequence of this gene leads to an increase of myogenesis and regeneration of muscle cells during the postnatal growing period ...