The main goals of layer breeding are a result of eeonomie eonditions. GOWE et al. (1993) reported that in egg stock seleetion programs the key traits are egg produetion rate, age at sexual maturity, viability at all ages, egg size, egg shell strength, feed effieieney as weil as fertility and hatehability. However, in praetiee, laying intensity is usually the main seleetion eriterion (WJ,;:ZYK, ...

an experiment was conducted to evaluate the effects of different levels of mineral and vitamin premix on performance and egg traits of laying hens from 37 to 49 weeks of age. two hundred and forty laying hens (hy-line w-36 strain) were randomly assigned to 5 dietary treatments of four replicates each with 12 hens per replicate). the levels of mineral and vitamin premixes in the experiment were ...

this experiment was conducted to evaluate the effects of different levels of dried lemon pulp in corn- soybean meal diets on egg production, egg traits and as well as blood metabolites of laying hens. throughout the experiment, 144 hi- line (w36) laying hens from 65 to 76 weeks of age were assigned to 4 treatments of 3 replicates each, with 12 hens per replicate. a completely randomized design ...

The avianuncoupling protein (avUCP) is a member of the mitochondrial transporter superfamily that uncouples proton entry in the mitochondrial matrix from ATP synthesis. The polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method was used to estimate the allele and genotype frequencies of the UCP/HhaI polymorphisms and to determine associations between these polymorp...

The present study was conducted to investigate the effects of four different levels of dietary probiotic (protexin) on productive traits and egg quality of broiler breeder hens. One hundred sixty female 64-week-old broiler breeders (Hubbard classic) were involved in this experiment. The birds were randomly assigned to control Group A (unsupplemented diet), Group B (0.25% protexin supplemented d...

Broad ecological shifts can render previously adaptive traits nonfunctional. It is an open question as to how and how quickly nonfunctional traits decay once the selective pressures that favored them are removed. The village weaverbird (Ploceus cucullatus) avoids brood parasitism by rejecting foreign eggs. African populations have evolved high levels of within-clutch uniformity as well as indiv...

the objective of present study was to determine the effects of β-mannanase-based enzyme (hemicell®) on productive performance and egg quality in diets containing graded levels of whole date waste (wdw) fed to laying hens. a total of 336 hy-line leghorn hens after production peak were randomly divided into 56 cages. eight iso-energetic and iso-nitrogenous experimental diets in a 4 × 2 factorial ...

Routine, upgrading, and intersecting cross-breeding strategies are three methods frequently used in poultry breeding. But, till now, comparative assessment of the effects on improvement geese economic traits with these is largely unknown. Here, using Carlos goose Zi goose, were employed compared. The main traits, including egg production capability, quality, growth performance, meat down feathe...