A recombinant attenuated vaccine against infectious bursal disease virus (IBDV) was administered in ovo to 18-day-old embryos. The vaccine was genetically tailored to protect from challenges in the field against classic and variant strains of IBDV. The vaccine virus contains neutralizing epitopes from both classic (D78) and variant strain (GLS), and abrogates expression of the nonstructural pro...

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...

Chick embryos were treated in ovo and in vitro with L-phenylalanine from the intermediate streak stage (Hamburger & Hamilton stage 3, 12-13 h of incubation) to the 7-somite stage (H & H stage 9, 29-33 h of incubation). Treatment in ovo resulted in a large number of embryos developing somite blocks, i.e. imperfectly segmented somites. In embryos treated at an early developmental stage (12-21 h o...

Early embryonic avian tissue is resistant to transformation by Rous sarcoma virus. To determine the nature of this resistance, we examined the expression and properties of the Rous sarcoma virus transforming protein pp60v-src, in infected embryonic chicken limbs in ovo. Lysates from Rous sarcoma virus-infected limbs contained the viral structural protein p19gag, as detected by immunoblot analys...

These trials examined whether the demonstrated effects of embryonic and dietary carotenoid exposure on the inflammatory immune response in fast growing chickens also occur in slow growing chickens. The systemic and local inflammatory responses of chicks were examined in two experiments with two in ovo lutein levels (C+, carotenoid replete; or C-, carotenoid-deplete), two dietary lutein levels (...

The aim of this study was to examine the efficacy of in ovo prime-boost vaccination against infectious bursal disease virus (IBDV) using a DNA vaccine to prime in ovo followed by a killed-vaccine boost post hatching. In addition, the adjuvant effects of plasmid-encoded chicken interleukin-2 and chicken interferon-gamma were tested in conjunction with the vaccine. A plasmid DNA vaccine (pcDNA-VP...

The effect of in ovo administration of chicken growth hormone (cGH) on growth rate and efficiency of gain, organ, and long bone growth of 42-d-old broiler chickens was investigated. Eggs were injected once with 100 microL vehicle (0.03 M NaHCO3, 0.15 M NaCl, pH 8.3) per embryo or vehicle containing 100 ng cGH/100 microL per embryo (n = 630 eggs total) on one of the following Days: 1, 4, or 7 th...

The use of rodent models to evaluate efficacy during testing is accompanied by significant economic and regulatory hurdles which compound the costs of screening for promising drug candidates. Vasopermeation Enhancement Agents (VEAs) are a new class of biologics that are designed to increase the uptake of cancer therapeutics at the tumor site by modifying vascular permeability in the tumor to in...

Objective: In recent years, amino acids are used in veterinary medicine for many purposes. They injected into hatching eggs to increase chick body weight and performance at hatch, but the adverse effects of amino acids have always been a major concern. There is scant information available about the pathological alterations of amino acids in the chicken embryonated eggs. The objective of this st...