الفهرس 
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Abstract
SUMMARY AND CONCLUSION
The present study was carried out at the Department of Poultry
Production, Faculty of Agriculture Ain Shams University during the
period from March to May, 2014 .
The main objective was to study the effect of in ovo
administration of either folic acid or vitamin D3 as well as the time of
injection on embryonic development, posthatch performance, some
physiological and histological traits of broiler chicks.
A total of 600 eggs with average weight of 60 g were obtained
from a commercial broiler breeder flock (Hubbard) at 55 weeks of age.
At day 7 of incubation period, eggs were randomly divided into six
groups of 100 eggs; each includes four replicates of 25 eggs. All eggs
were normally incubated at 37.8°C and 65% RH in an automatic
incubator. The first and the second groups were used as controls, where
the 1st group was used as a negative control and received no treatment
(C) and second group were injected at day 7 of incubation with 0.1 ml
of distilled water/egg as solvent (S) . Eggs of the 3rd and 4th groups
were injected into air cell at the 7th day of incubation with 0.1 ml of
( 500 IU) vit.D3 or folic acid 10% .The fifth and sixth groups were
injected at the 14th day of incubation with the same concentrations of
vit.D14 and folic acid . At the 18th day of incubation, all eggs were
transferred to the hatcher and kept till hatching at 37.2°C and 70% RH.
The hatched chicks from all groups were weighed and then reared under
similar management, environmental and nutritional conditions.
Hatchability and embryonic mortality, posthatching productive
performance, carcass and muscle traits, blood constituents and
histological sections in the tibiae and small intestine were investigated .
The results obtained can be summarized as follows:
1- in ovo injection of broiler eggs with vitamin D3 or folic acid specially
at the 7th day of incubation has no deleterious effect on hatchability
SUMMARY AND CONCLUSION
Sherin G. Abd El-Razik ,(2016), Ph. D., Fac. Agric., Ain Shams Univ.
69
(%) ,early and late embryonic mortality compared with the other
groups.
2- In ovo injection with vitamin D3 and folic acid specially at the 7th
day (D7 & F7) of embryogenesis decreased residual yolk sac weight
followed by those injected at day 14 of incubation (D14 &F14)
compared with the control groups.
3- Live body weight (LBW) of day old chicks and at 21 and DOA was
significantly improved by in ovo injection with folic acid or vitamin
D3 at the 7th day of embryogenesis (D7 &F7) , followed by those
injected at day 14 of incubation period ( F14 & D14 ) compared with
the control groups . A similar trend was also observed for body weight
gain ( BWG ) at the periods from 1 to 21 ,21 to 42 and for the whole
period ( 1 to 42 DOA ).
4- There is a positive effect on productive performance of broiler chicks
when in ovo injection was done at the 7th day of incubation compared
with in ovo injection at the 14th day .
5- In ovo injection with folic acid or vitamin D3 during embryogenesis,
either at day 7 or 14 of incubation period , had significantly increased
feed consumption of broilers chicks during the whole experimental
period
6- Feed conversion ratio treatments was significantly improved in chicks
that hatched from in ovo injected eggs at day 7 of incubation period
(F7 & D7) followed with those of F14 and D14 treatments compared
with the control groups during the whole experimental period.
7- Both in ovo injection with folic acid (F7 &F14) or vitamin D3 (D7
&D14) had significantly increased carcass yield of broiler chicks at
marketing age (42 DOA), where hot carcass weight ,liver ,heart ,
gizzard and edible parts weights were significantly increased ,but
abdominal fat weight was decreased , compared with control groups .
8- Breast muscles ( Pectoralis major , P. minor ) weight ,width and depth
were significantly increased in chicks from folic acid treatments
SUMMARY AND CONCLUSION
Sherin G. Abd El-Razik ,(2016), Ph. D., Fac. Agric., Ain Shams Univ.
70
(F7& D7) followed by vit.D3 (D14& D14) treatments compared
with the control groups , respectively.
9- Femur weight and length, and thigh weigh weight were significantly
increased in all in ovo injected groups (D7 , D14 , F7 and F14 )
compared with the control groups.
10- Tibiae bone weight, length ,and width were significantly increased in
chicks hatched from eggs injected with vit.D3 either at day 7 or 14 of
incubation period , followed by folic acid treatments ,and then the
control groups . A similar trend was also observed for shank length at
42 DOA.
11- In ovo injection with vitamin D3 (D7 & D14) or folic acid (F7 &
F14) had no significant effect on thyroid glands , thymus, Bursa of
Fabricius and spleen weights of broilers at 42 DOA .
12- Plasma total proteins, albumin and globulin of day old chicks were
significantly increased by in ovo injection with vit.D3 (D7 & D14),
or folic acid (F7 & F14) and this elevation continued until 42 DOA
compared with the control groups .
13- Vit.D3 (D7 & D14) and then folic acid (F7 &F14) , treatments had
significantly decreased plasma levels of cholesterol and triglycerides
of day old chicks and for 42 DOA chicks compared with the control
groups
14- Plasma triiodothyronine ( T3 ) levels were significantly increased
by in ovo injection of folic acid ( F7 and F14) followed by vitamin
D3 injection ( D7and D14 ) in day old chicks compared with the
controls ,however at 42 DOA , plasma T3 concentration was
significantly higher in chicks from F7 and D7 treatments than the
other chick groups.
15- Plasma parathyroid hormone ( PTH ) level , alkaline phosphatase
(ALK.P) and acid phosphatase ( ACP) activities ,plasma calcium and
phosphorus concentration of day old chicks were significantly
increased by in ovo injection of vit.D3 (D7 & D14), followed by
those hatched from eggs injected with folic acid and then the control
SUMMARY AND CONCLUSION
Sherin G. Abd El-Razik ,(2016), Ph. D., Fac. Agric., Ain Shams Univ.
71
groups . This elevation was also observed in a similar pattern for the
42 day old chicks
16- Plasma transaminases activity ( ALT & AST ) was significantly
higher in day old chicks from all injected groups compared with the
control ones , however , the differences among all groups were not
significant in 42 day old chicks.
17- The histological investigation of small intestine ( Jejunum ) sections
from day – old and 42 day old chicks showed that in ovo injection
with folic acid or vit.D3 improved the general appearance of
intestinal villi epithelial lining ,accompanied by an increase in the
size and number of crypts of Lieberkuhn . These changes were clearly
observed in folic acid treatment group of chicks followed by those
from vitamin D3- chick groups compared with the control chicks .
18- Tibiae bone sections from day – old chicks showed many
chondrocytes and osteoblasts , accompanied by an increase in the
proliferative zone , especially for sections from chicks of in ovo
vitamin D3 – injected eggs at the 7th day of embryonic development
,followed by D14 and then – to a lesser extent – F14 treatment group
,compared with the other treatment groups . A similar observation
were also detected in tibia sections from 42 day old chicks with a
rapid calcification of bones associated with an increase of compact
bone area and the presence of many osteoid in vitamin D3- in ovoinjected
treatments
from the results reported herein, it could be concluded that:
The in ovo injection with folic acid or vit.D3 during incubation
period, preferably at the 7th day, enhanced the productive performance
of post hatch broiler chicks and increased meat yield at the marketing
age. Vitamin D3 injection (in ovo) either at day 7 or 14 of embryogenesis
could improve bone resorption and remodeling in broilers which may
help reducing leg problems in fast – growing chicks. On the other hand
SUMMARY AND CONCLUSION
Sherin G. Abd El-Razik ,(2016), Ph. D., Fac. Agric., Ain Shams Univ.
72
,folic acid injection benefits in muscle building via its physiological effect
on myogenesis and haemopeiotic action.
It is concluded that, under the conditions of the present study, the best
time of in ovo injection of vitamin D3 and folic acid was the 7th day of
incubation period ,which improved most of the studied traits.