Single Comb White Leghorn pullets were used to determine the effects of 6-methoxy-2-benzoxazolinone (6-MBOA) and photoperiod on sexual maturity and egg production. Pullets were maintained on a constant 11L:13D photoperiod until 18 weeks of age and then were divided into two light-controlled chambers. Half the pullets in each chamber received a standard layer mash and the other half received the...

Rainbow trout, oncorhynchus mykiss is one of the most important cold water fishes in Iran. For successful artificial propagation of rainbow trout, the quality and quantity of brooders and sexual materials are key factors. In the present study, we investigated the age-dependent changes of reproductive efficiency. For this purpose, the brooders were divided into age classes and then three age gro...

Polymorphisms in 5’-flanking region of prolactin (PRL), exon 2 and exon 5 of prolactin receptor (PRLR) genesand its association with growth and egg traits were examined in breeder hens of Mazandaran native fowlsbreeding station. A single nucleotide polymorphism at site C-2402T and a 24 bp nucleotide sequence insertionat situation -382 in 5’-flanking regions of PRL gene were id...

AIM The present study was conducted to investigate the important climatic variables affecting production and reproduction in a broiler breeder flock. MATERIALS AND METHODS The experiment was conducted for a period of 1 year on colored synthetic female line male and female poultry birds. 630 female progeny and 194 male progenies from 69 sires and 552 dams produced in four consecutive hatches a...

An experiment was carried out with SHAVER Starbro broiler parent stock from one day old to the point of peak production to investigate the growth, early laying performance and their adaptability during brooding, growing and early laying periods. The experimental period was divided into five phases, phase I (0 – 2 week), phase II (3 – 8 week), phase III (9 – 22 week), phase IV (23 – sexual matur...

In 15 consecutive patients with slipped capital femoral epiphysis we recorded height, weight and skeletal maturity. Sexual maturity was assessed clinically and biochemically, and Harris's hypothesis that there is an increased ratio of serum growth hormone to oestrogen was tested in comparison with 15 age and sex matched controls. We found no difference in skeletal or sexual maturity between the...

The aim of the study was to evaluate effect genotype on productivity and egg quality three hen strains included in genetic resource protection program Poland. encompassed populations laying hens, i.e., Rhode Island Red/RIR (R-11 K-22) White (A-33). analysis over five generations basic production traits, weight birds at 20 weeks (g), weights 33 53 weeks, sexual maturity, number eggs laid up 56 a...

Iranian native hens are a valuable genetic resource, due to their adaptability to harsh conditions of husbandry and environment in rural area. The genetic parameters for various traits of economic importance were studied in an Iranian Native chicken population under short term selection for egg production and body weight for over 2 years. The parameters studied were body weight at day old (BW1)...