الفهرس 
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Abstract
Nanotechnology has different applications in the medical, veterinary, and agricultural fields. In
poultry, different nanomaterials have been used to improve egg and meat production such as
nanoselenium and nanosilver (Nano-Ag). Nano-Ag are small enough to penetrate the cell, enter the
nucleus and interact with DNA molecules or DNA-related proteins leading to alterations in gene
expression profiles. Colloidal Nano-Ag has been reported to affect the expression of myogenic
regulatory factors (MRFs) and myocyte enhancing factor 2a (MEF2A) genes crucial for muscle
development (myogenesis) in chicken. This study was conducted to investigate the effect of silver
nanoparticles on gene expression of MRFs and MEF2A during the pre-hatch and post-hatch muscle
development at both the transcriptional and translational levels, histological structure of breast
muscle tissues, productive performance parameters, and microbiological examination of intestinal
contents and pH in chicken. A total of 270 breeder broilers egg (Indian River) were randomly
divided into four groups; non-injected control, injected control with placebo, treatment I injected
with 20 ppm Nano-Ag, and treatment II injected with 40 ppm Nano-Ag. The eggs were incubated for
21 days under standard conditions of temperature and humidity and breast muscle samples were
collected at 5th, 8th, and 18th days of incubation. The hatched chicks completed the experiment and
were divided into ten groups: G1 (normal water), G2 (magnetic water), G3 (20 ppm/normal water),
G4 (20 ppm/magnetic water), G5 (40 ppm/normal water), G6 (40 ppm/magnetic water), G7 (20
ppm/20 ppm/normal water), G8 (20 ppm/20 ppm/magnetic water), G9 (40 ppm/40 ppm/normal
water), G10 (40 ppm/40 ppm/magnetic water). The chicks were reared for 35 days, fed commercial
diets, and had free access to water either normal or magnetic with (20 or 40 ppm) or without Nano-
Ag. The body weight and feed intake were recorded weekly. Breast muscle and intestinal samples
were collected at the end of the cycle for gene expression analyses, histological examination, and
intestinal content examination, respectively. Total RNA was extracted, reverse transcribed, and real-
time PCR was performed. For western blot, total protein was extracted, quantified, and blotted.
Histological slides were prepared, examined, and analyzed. TBC, TLC, TCC, and E. coli were
detected. The results indicated that in ovo injection of 20 ppm Nano-Ag induced the expression of
MYOD1 at the mRNA and protein levels. Also, during the production cycle the expression of
MYOD1 and MYF5 was induced. Furthermore, the 20-ppm treatment increased the number of
myogenic progenitor cells (myocytes). Moreover, Nano-Ag with 40 ppm proved to have an effective
antibacterial activity during the production cycle. The effect of magnetic water was reflected on the
general health status of birds but not affect muscle development. Nano-Ag can be used to improve
muscle development in chicken due to its effect on genes essential for myogenesis. Also, magnetic
water can be used to improve poultry production.