This study was conducted in the farm of Department Animal Production, college Agriculture –Tikrit University for duration 19/11/2021 to 23/12/2021. The aim this effect colour plumage and breeding system on traits reproductive Japanese quail Use experiment 180 A bird age 21 Days were divided into two groups according 90 brown Black birds, each group that raised systems (batteries floor). Contain...

Change in sex ratios for broiler chickens, has many economic benefits of the poultry industry. The gonads in chick embryo at an early stage have the potential to convert to both sexes (male and female). Sexual differentiation is due to aromatase expression in the left gonad in 5-6 days of the embryonic period and the production of estrogen from testosterone. Administration of aromatase inhibito...

Using an established experimental paradigm, feed restriction during the last week of lactation in primiparous sows reduces embryonic growth and development and produces female-specific embryonic mortality by Day 30 of gestation. Because this gender-specific loss of embryos at Day 30 was associated with changes in the variation of markers of epigenetic imprinting, the present study sought to est...

The aim of this study was to isolate mouse embryonic stem cells from late blastocyst stage embryos and to use them as a model system for the study of hematopoietic induction outside the embryo by coculturing of embryonic stem cells with bone marrow stromal cells. Blastocyst stage embryos from pregnant NMRI mice were obtained and cultured for 1-2 days in DMEM medium. The inner cell masses formed...

One hundred and two nonparous females, 18 to 24 mo old, and 55 parous or multiparous beef females, 3 to 12 yr old, were mated naturally (d 0) and slaughtered on d 2 to 5, 6 to 8 or 14 to 16 of gestation. Each reproductive tract was flushed with phosphate-buffered saline, and the flushings were searched for an oocyte or embryo. Parous females had a higher (P less than .05) fertilization rate tha...

Stress experienced by a reproducing female can substantially affect the morphology, behavior, and physiology (and hence fitness) of her offspring. In addition, recent studies demonstrate that stress hormones (corticosterone) influence sex determination of embryos. To explore these issues, we manipulated corticosterone levels in eggs of two Australian lizard species (Amphibolurus muricatus and B...

Reproductive technologies are widely used in cattle, although many are associated with high-embryonic mortality, especially during early gestation, when the yolk sac undergoes macroscopic changes in structure. We hypothesized that vasculogenesis and angiogenesis are affected, thereby affecting embryonic and placental differentiation. To test this, we studied yolk sac development and gene expres...

We conducted a transplant study in which embryonic southern toads (Bufo terrestris) were held in a site polluted with coal ash (site AB; containing As, Cd, Cr, Cu, Se, and other elements) and a reference site (site R) through hatching and early larval development. To examine the remainder of the larval period, surviving larvae in AB were then transplanted to R and back-transplanted to AB, where...

Fish ecotypes found in north temperate lakes are increasingly used as model organisms to explore patterns and processes of population divergence that may ultimately cause speciation. Processes involved in their reproductive isolation are, however, still poorly understood. Recent experimental studies on white®sh ecotypes from di€erent glacial races revealed that embryonic mortality of hybrids wa...

among the female sexual hormones, the estrogen and progesterone are of significant importance. these hormones are prescribed for the treatment of certain female genital system disorders as well as used in the synthesis of contraceptive drugs. it has been shown that administration of the above hor mones during early pregnancy may produce abortion in early gestational days. in the present investi...