Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 5

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
The transgenic chicken has great potential as a bioreactor for the production of valuable pharmaceutical proteins, notably in the oviduct/egg. Whereas conventional transgenic approaches have significant limitations in this species, an alternative approach employing primordial germ cells (PGCs), the progenitor cells to ova and spermatozoa, has now been successfully applied to the insertion of exogenous genes into birds. Recent developments in manipulating avian embryos make it possible to produce germline chimeras derived from transferred PGCs. In this review we describe the migration pathway of chicken PGCs during early development. We then summarize different methods for the isolation of PGCs and the diversity of techniques used to introduce genes into these cells. Finally, we describe an in vitro assay for testing tissue-specific vectors designed to express heterologous proteins in transgenic chickens.
Two trials were conducted. The aim of the first trial, performed under field conditions, was the comparison of the rearing performance between the chickens injected in ovo with 1.9 mg of raffinose family oligosaccharides (RFOs) (experimental group E), and chickens administered with the antibiotics (control group C). Environmental and feed conditions were similar for both groups. The mortality, feed intake, and slaughter body weight were recorded from farm documentation. Feed conversion ratio (FCR) and European production efficiency factor (EPEF) were calculated. The aim of the second trial, performed under laboratory condition, was to determine the prebiotic effect of different doses of RFOs (0.5%, 1.0%, 3.0%, or 5.0%) on the growth of Bifidobacterium bifidum and Lactobacillus acidophilus in vitro. Prebiotic effect of RFOs administered with a single in ovo injection had a similar effect on broiler performance (survivability, growing period, and EPEF), to antibiotics given as growth promoters. Body weight and FCR was significantly higher in the group E in comparison to the group C. The prebiotic in vitro effect of RFOs was evident. The obtained data suggest that at least in the case of Bifidobacterium bifidum, RFOs could show the dose-dependent effects on the bacteria number. This work opens the opportunity of using, in technical scale, in ovo technology to deliver other bioactives to stimulate the prebiotic effect.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.