BackgroundAmong various feed additives currently used in poultry nutrition, an important role is played by bioactive substances, including prebiotics. The beneficial effect of these bioactive substances on the gastrointestinal tract and immune system give rise to improvements in broiler health and performance nutrition, thus increasing the productivity of these birds. An innovative method for introducing bioactive substances into chickens is the in ovo injection into eggs intended for hatching. The aim of the study was to evaluate the development of histomorphological parameters of the duodenum and productivity in chickens injected in ovo with the prebiotic DiNovo® (extract of Laminaria species of seaweed, BioAtlantis Ltd., Ireland) on d 12 of incubation, under large - scale, high density poultry production conditions.ResultsThere was no significant impact of the injection of DiNovo® prebiotic on the production parameters of broiler chickens (body weight, FCR, EBI and mortality) obtained on d 42 of rearing. No significant impact of the DiNovo® injection on the duodenum weight and length was observed, as well as on the CSA, diameter and muscular layer thickness of the duodenum. The in ovo injection of DiNovo® significantly increased the width of the duodenal villi (P < 0.05) and crypt depth (P < 0.01) of chickens on d 21 of rearing. Other histomorphological parameters of duodenal villi at d 42 of chickens rearing such as: the height, width, and cross section area of villi were significantly greater in chickens from the control group compared to those from the DiNovo® group (P < 0.05 and P < 0.01).ConclusionsIn conclusion, this study demonstrates that injection of DiNovo® prebiotic into the air chamber of egg significantly influences the histomorphological parameters on d 21 of rearing without negatively affecting productivity in chickens at the end of rearing.

Effects of prebiotics and synbiotics delivered in ovo on broiler small intestine histomorphology during the first days after hatching. Folia Biologica (Kraków) 64: 131-143. The objective of the study was to determine the effect of prebiotics and synbiotics administered in ovo on the 12 th day of incubation, on the development of the intestinal villi and the number of goblet cells in the small intestine of broiler chickens on the 1 st and the 4 th days of life of chicks. Two prebiotics: inulin (PI) or Bi 2 tos (PB) and two synbiotics: inulin + L. lactis subsp. lactis (SI) or Bi 2 tos + L. lactis subsp. cremoris (SB) were injected in ovo on the 12 th day of embryonic development. The control group of the embryos was injected with physiological saline (C). On the 1 st day of life, an increase in the height of the villi in the jejunum was reported as a result of the injection of pre-and synbiotics, moreover an increase in the surface area of the villi in the jejunum and the duodenum in chicks from the SB group was also observed. A stimulatory effect of synbiotics on the morphology of the duodenum and the jejunum was also observed on the 4 th day after hatching. Conversely, in the ileum, in the SB group, a reduction in the height of villi was found both on the 1 st and the 4 th days of life. In contrast, injection of inulin and synbiotic with the addition of inulin resulted in an increase in the number of goblet cells in the duodenum and the jejunum on the 1 st day of life, and caused a significant decrease on the 4 th day after hatching.

Transgenic chickens have, in general, been produced by two different procedures. The first procedure is based on viral transfection systems. The second procedure, the non-viral method, is based on genetically modified embryonic cells transferred directly into the recipient embryo. In this review, we analyzed the effectiveness of important elements of the non-viral, cell-based strategy of transgenic chicken production. The main elements of this strategy are: isolation and cultivation of donor embryonic cells; transgene construction; cell transfection in vitro; and chimera production: injection of cells into recipient embryos, raising and identification of germline chimeras, mating germline chimeras, transgene inheritance, and transgene expression. In this overview, recent progress and important limitations in the development of transgenic chickens are presented.